From f560f2c742b3ca72b18f31defbab49f6e709188a Mon Sep 17 00:00:00 2001
From: Mateusz Cholewka <mateusz@cholewka.com.pl>
Date: Wed, 30 Apr 2025 00:13:43 +0200
Subject: [PATCH 01/14] feature: add predis to dev deps

Signed-off-by: Mateusz Cholewka <mateusz@cholewka.com.pl>
---
 composer.json | 1 +
 1 file changed, 1 insertion(+)

diff --git a/composer.json b/composer.json
index dec37f8..15efa9e 100644
--- a/composer.json
+++ b/composer.json
@@ -25,6 +25,7 @@
         "phpstan/phpstan-phpunit": "^1.1.0",
         "phpstan/phpstan-strict-rules": "^1.1.0",
         "phpunit/phpunit": "^9.4",
+        "predis/predis": "^2.3",
         "squizlabs/php_codesniffer": "^3.6",
         "symfony/polyfill-apcu": "^1.6"
     },

From 92f4beb0530934515c281d785feb4bb486668196 Mon Sep 17 00:00:00 2001
From: Mateusz Cholewka <mateusz@cholewka.com.pl>
Date: Wed, 30 Apr 2025 00:14:19 +0200
Subject: [PATCH 02/14] feature: implement redis client interface

Signed-off-by: Mateusz Cholewka <mateusz@cholewka.com.pl>
---
 src/Prometheus/Storage/Redis.php              | 282 +++++++-----------
 .../Storage/RedisClients/RedisClient.php      |  36 +++
 .../RedisClients/RedisClientException.php     |   7 +
 3 files changed, 152 insertions(+), 173 deletions(-)
 create mode 100644 src/Prometheus/Storage/RedisClients/RedisClient.php
 create mode 100644 src/Prometheus/Storage/RedisClients/RedisClientException.php

diff --git a/src/Prometheus/Storage/Redis.php b/src/Prometheus/Storage/Redis.php
index 730fac8..2b11436 100644
--- a/src/Prometheus/Storage/Redis.php
+++ b/src/Prometheus/Storage/Redis.php
@@ -5,6 +5,7 @@
 namespace Prometheus\Storage;
 
 use InvalidArgumentException;
+use Predis\Client;
 use Prometheus\Counter;
 use Prometheus\Exception\MetricJsonException;
 use Prometheus\Exception\StorageException;
@@ -12,6 +13,10 @@
 use Prometheus\Histogram;
 use Prometheus\Math;
 use Prometheus\MetricFamilySamples;
+use Prometheus\Storage\RedisClients\PHPRedis;
+use Prometheus\Storage\RedisClients\Predis;
+use Prometheus\Storage\RedisClients\RedisClient;
+use Prometheus\Storage\RedisClients\RedisClientException;
 use Prometheus\Summary;
 use RuntimeException;
 
@@ -43,54 +48,51 @@ class Redis implements Adapter
     private $options = [];
 
     /**
-     * @var \Redis
+     * @var RedisClient
      */
     private $redis;
 
-    /**
-     * @var boolean
-     */
-    private $connectionInitialized = false;
-
     /**
      * Redis constructor.
-     * @param mixed[] $options
+     *
+     * @param  mixed[]  $options
      */
     public function __construct(array $options = [])
     {
         $this->options = array_merge(self::$defaultOptions, $options);
-        $this->redis = new \Redis();
+        $this->redis = PHPRedis::create($this->options);
     }
 
     /**
-     * @param \Redis $redis
-     * @return self
      * @throws StorageException
      */
-    public static function fromExistingConnection(\Redis $redis): self
+    public static function fromExistingConnection(\Redis|Client $redis): self
     {
+        $self = new self;
+
+        if ($redis instanceof Client) {
+            $self->redis = new Predis($redis);
+
+            return $self;
+        }
+
         if ($redis->isConnected() === false) {
             throw new StorageException('Connection to Redis server not established');
         }
 
-        $self = new self();
-        $self->connectionInitialized = true;
-        $self->redis = $redis;
+        $self->redis = new PHPRedis($redis, self::$defaultOptions);
 
         return $self;
     }
 
     /**
-     * @param mixed[] $options
+     * @param  mixed[]  $options
      */
     public static function setDefaultOptions(array $options): void
     {
         self::$defaultOptions = array_merge(self::$defaultOptions, $options);
     }
 
-    /**
-     * @param string $prefix
-     */
     public static function setPrefix(string $prefix): void
     {
         self::$prefix = $prefix;
@@ -98,6 +100,7 @@ public static function setPrefix(string $prefix): void
 
     /**
      * @throws StorageException
+     *
      * @deprecated use replacement method wipeStorage from Adapter interface
      */
     public function flushRedis(): void
@@ -106,15 +109,15 @@ public function flushRedis(): void
     }
 
     /**
-     * @inheritDoc
+     * {@inheritDoc}
      */
     public function wipeStorage(): void
     {
-        $this->ensureOpenConnection();
+        $this->redis->ensureOpenConnection();
 
-        $searchPattern = "";
+        $searchPattern = '';
 
-        $globalPrefix = $this->redis->getOption(\Redis::OPT_PREFIX);
+        $globalPrefix = $this->redis->getOption(RedisClient::OPT_PREFIX);
         // @phpstan-ignore-next-line false positive, phpstan thinks getOptions returns int
         if (is_string($globalPrefix)) {
             $searchPattern .= $globalPrefix;
@@ -124,7 +127,7 @@ public function wipeStorage(): void
         $searchPattern .= '*';
 
         $this->redis->eval(
-            <<<LUA
+            <<<'LUA'
 redis.replicate_commands()
 local cursor = "0"
 repeat 
@@ -142,43 +145,41 @@ public function wipeStorage(): void
     }
 
     /**
-     * @param mixed[] $data
-     *
-     * @return string
+     * @param  mixed[]  $data
      */
     private function metaKey(array $data): string
     {
         return implode(':', [
             $data['name'],
-            'meta'
+            'meta',
         ]);
     }
 
     /**
-     * @param mixed[] $data
-     *
-     * @return string
+     * @param  mixed[]  $data
      */
     private function valueKey(array $data): string
     {
         return implode(':', [
             $data['name'],
             $this->encodeLabelValues($data['labelValues']),
-            'value'
+            'value',
         ]);
     }
 
     /**
      * @return MetricFamilySamples[]
+     *
      * @throws StorageException
      */
     public function collect(bool $sortMetrics = true): array
     {
-        $this->ensureOpenConnection();
+        $this->redis->ensureOpenConnection();
         $metrics = $this->collectHistograms();
         $metrics = array_merge($metrics, $this->collectGauges($sortMetrics));
         $metrics = array_merge($metrics, $this->collectCounters($sortMetrics));
         $metrics = array_merge($metrics, $this->collectSummaries());
+
         return array_map(
             function (array $metric): MetricFamilySamples {
                 return new MetricFamilySamples($metric);
@@ -188,76 +189,13 @@ function (array $metric): MetricFamilySamples {
     }
 
     /**
-     * @throws StorageException
-     */
-    private function ensureOpenConnection(): void
-    {
-        if ($this->connectionInitialized === true) {
-            return;
-        }
-
-        $this->connectToServer();
-        $authParams = [];
-
-        if (isset($this->options['user']) && $this->options['user'] !== '') {
-            $authParams[] = $this->options['user'];
-        }
-
-        if (isset($this->options['password'])) {
-            $authParams[] = $this->options['password'];
-        }
-
-        if ($authParams !== []) {
-            $this->redis->auth($authParams);
-        }
-
-        if (isset($this->options['database'])) {
-            $this->redis->select($this->options['database']);
-        }
-
-        $this->redis->setOption(\Redis::OPT_READ_TIMEOUT, $this->options['read_timeout']);
-
-        $this->connectionInitialized = true;
-    }
-
-    /**
-     * @throws StorageException
-     */
-    private function connectToServer(): void
-    {
-        try {
-            $connection_successful = false;
-            if ($this->options['persistent_connections'] !== false) {
-                $connection_successful = $this->redis->pconnect(
-                    $this->options['host'],
-                    (int)$this->options['port'],
-                    (float)$this->options['timeout']
-                );
-            } else {
-                $connection_successful = $this->redis->connect($this->options['host'], (int)$this->options['port'], (float)$this->options['timeout']);
-            }
-            if (!$connection_successful) {
-                throw new StorageException(
-                    sprintf("Can't connect to Redis server. %s", $this->redis->getLastError()),
-                    0
-                );
-            }
-        } catch (\RedisException $e) {
-            throw new StorageException(
-                sprintf("Can't connect to Redis server. %s", $e->getMessage()),
-                $e->getCode(),
-                $e
-            );
-        }
-    }
-
-    /**
-     * @param mixed[] $data
+     * @param  mixed[]  $data
+     *
      * @throws StorageException
      */
     public function updateHistogram(array $data): void
     {
-        $this->ensureOpenConnection();
+        $this->redis->ensureOpenConnection();
         $bucketToIncrease = '+Inf';
         foreach ($data['buckets'] as $bucket) {
             if ($data['value'] <= $bucket) {
@@ -269,7 +207,7 @@ public function updateHistogram(array $data): void
         unset($metaData['value'], $metaData['labelValues']);
 
         $this->redis->eval(
-            <<<LUA
+            <<<'LUA'
 local result = redis.call('hIncrByFloat', KEYS[1], ARGV[1], ARGV[3])
 redis.call('hIncrBy', KEYS[1], ARGV[2], 1)
 if tonumber(result) >= tonumber(ARGV[3]) then
@@ -281,7 +219,7 @@ public function updateHistogram(array $data): void
             ,
             [
                 $this->toMetricKey($data),
-                self::$prefix . Histogram::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX,
+                self::$prefix.Histogram::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX,
                 json_encode(['b' => 'sum', 'labelValues' => $data['labelValues']]),
                 json_encode(['b' => $bucketToIncrease, 'labelValues' => $data['labelValues']]),
                 $data['value'],
@@ -292,50 +230,51 @@ public function updateHistogram(array $data): void
     }
 
     /**
-     * @param mixed[] $data
+     * @param  mixed[]  $data
+     *
      * @throws StorageException
      */
     public function updateSummary(array $data): void
     {
-        $this->ensureOpenConnection();
+        $this->redis->ensureOpenConnection();
 
         // store meta
-        $summaryKey = self::$prefix . Summary::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX;
-        $metaKey = $summaryKey . ':' . $this->metaKey($data);
+        $summaryKey = self::$prefix.Summary::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX;
+        $metaKey = $summaryKey.':'.$this->metaKey($data);
         $json = json_encode($this->metaData($data));
-        if (false === $json) {
+        if ($json === false) {
             throw new RuntimeException(json_last_error_msg());
         }
-        $this->redis->setNx($metaKey, $json);/** @phpstan-ignore-line */
-
+        $this->redis->setNx($metaKey, $json); /** @phpstan-ignore-line */
 
         // store value key
-        $valueKey = $summaryKey . ':' . $this->valueKey($data);
+        $valueKey = $summaryKey.':'.$this->valueKey($data);
         $json = json_encode($this->encodeLabelValues($data['labelValues']));
-        if (false === $json) {
+        if ($json === false) {
             throw new RuntimeException(json_last_error_msg());
         }
-        $this->redis->setNx($valueKey, $json);/** @phpstan-ignore-line */
+        $this->redis->setNx($valueKey, $json); /** @phpstan-ignore-line */
 
         // trick to handle uniqid collision
         $done = false;
-        while (!$done) {
-            $sampleKey = $valueKey . ':' . uniqid('', true);
+        while (! $done) {
+            $sampleKey = $valueKey.':'.uniqid('', true);
             $done = $this->redis->set($sampleKey, $data['value'], ['NX', 'EX' => $data['maxAgeSeconds']]);
         }
     }
 
     /**
-     * @param mixed[] $data
+     * @param  mixed[]  $data
+     *
      * @throws StorageException
      */
     public function updateGauge(array $data): void
     {
-        $this->ensureOpenConnection();
+        $this->redis->ensureOpenConnection();
         $metaData = $data;
         unset($metaData['value'], $metaData['labelValues'], $metaData['command']);
         $this->redis->eval(
-            <<<LUA
+            <<<'LUA'
 local result = redis.call(ARGV[1], KEYS[1], ARGV[2], ARGV[3])
 
 if ARGV[1] == 'hSet' then
@@ -353,7 +292,7 @@ public function updateGauge(array $data): void
             ,
             [
                 $this->toMetricKey($data),
-                self::$prefix . Gauge::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX,
+                self::$prefix.Gauge::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX,
                 $this->getRedisCommand($data['command']),
                 json_encode($data['labelValues']),
                 $data['value'],
@@ -364,16 +303,17 @@ public function updateGauge(array $data): void
     }
 
     /**
-     * @param mixed[] $data
+     * @param  mixed[]  $data
+     *
      * @throws StorageException
      */
     public function updateCounter(array $data): void
     {
-        $this->ensureOpenConnection();
+        $this->redis->ensureOpenConnection();
         $metaData = $data;
         unset($metaData['value'], $metaData['labelValues'], $metaData['command']);
         $this->redis->eval(
-            <<<LUA
+            <<<'LUA'
 local result = redis.call(ARGV[1], KEYS[1], ARGV[3], ARGV[2])
 local added = redis.call('sAdd', KEYS[2], KEYS[1])
 if added == 1 then
@@ -384,7 +324,7 @@ public function updateCounter(array $data): void
             ,
             [
                 $this->toMetricKey($data),
-                self::$prefix . Counter::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX,
+                self::$prefix.Counter::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX,
                 $this->getRedisCommand($data['command']),
                 $data['value'],
                 json_encode($data['labelValues']),
@@ -394,15 +334,15 @@ public function updateCounter(array $data): void
         );
     }
 
-
     /**
-     * @param mixed[] $data
+     * @param  mixed[]  $data
      * @return mixed[]
      */
     private function metaData(array $data): array
     {
         $metricsMetaData = $data;
         unset($metricsMetaData['value'], $metricsMetaData['command'], $metricsMetaData['labelValues']);
+
         return $metricsMetaData;
     }
 
@@ -411,12 +351,12 @@ private function metaData(array $data): array
      */
     private function collectHistograms(): array
     {
-        $keys = $this->redis->sMembers(self::$prefix . Histogram::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX);
+        $keys = $this->redis->sMembers(self::$prefix.Histogram::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX);
         sort($keys);
         $histograms = [];
         foreach ($keys as $key) {
-            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->_prefix('')));
-            if (!isset($raw['__meta'])) {
+            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getPrefix()));
+            if (! isset($raw['__meta'])) {
                 continue;
             }
             $histogram = json_decode($raw['__meta'], true);
@@ -440,7 +380,7 @@ private function collectHistograms(): array
 
             // We need set semantics.
             // This is the equivalent of array_unique but for arrays of arrays.
-            $allLabelValues = array_map("unserialize", array_unique(array_map("serialize", $allLabelValues)));
+            $allLabelValues = array_map('unserialize', array_unique(array_map('serialize', $allLabelValues)));
             sort($allLabelValues);
 
             foreach ($allLabelValues as $labelValues) {
@@ -450,9 +390,9 @@ private function collectHistograms(): array
                 $acc = 0;
                 foreach ($histogram['buckets'] as $bucket) {
                     $bucketKey = json_encode(['b' => $bucket, 'labelValues' => $labelValues]);
-                    if (!isset($raw[$bucketKey])) {
+                    if (! isset($raw[$bucketKey])) {
                         $histogram['samples'][] = [
-                            'name' => $histogram['name'] . '_bucket',
+                            'name' => $histogram['name'].'_bucket',
                             'labelNames' => ['le'],
                             'labelValues' => array_merge($labelValues, [$bucket]),
                             'value' => $acc,
@@ -460,7 +400,7 @@ private function collectHistograms(): array
                     } else {
                         $acc += $raw[$bucketKey];
                         $histogram['samples'][] = [
-                            'name' => $histogram['name'] . '_bucket',
+                            'name' => $histogram['name'].'_bucket',
                             'labelNames' => ['le'],
                             'labelValues' => array_merge($labelValues, [$bucket]),
                             'value' => $acc,
@@ -470,7 +410,7 @@ private function collectHistograms(): array
 
                 // Add the count
                 $histogram['samples'][] = [
-                    'name' => $histogram['name'] . '_count',
+                    'name' => $histogram['name'].'_count',
                     'labelNames' => [],
                     'labelValues' => $labelValues,
                     'value' => $acc,
@@ -478,7 +418,7 @@ private function collectHistograms(): array
 
                 // Add the sum
                 $histogram['samples'][] = [
-                    'name' => $histogram['name'] . '_sum',
+                    'name' => $histogram['name'].'_sum',
                     'labelNames' => [],
                     'labelValues' => $labelValues,
                     'value' => $raw[json_encode(['b' => 'sum', 'labelValues' => $labelValues])],
@@ -486,22 +426,19 @@ private function collectHistograms(): array
             }
             $histograms[] = $histogram;
         }
+
         return $histograms;
     }
 
-    /**
-     * @param string $key
-     *
-     * @return string
-     */
     private function removePrefixFromKey(string $key): string
     {
         // @phpstan-ignore-next-line false positive, phpstan thinks getOptions returns int
-        if ($this->redis->getOption(\Redis::OPT_PREFIX) === null) {
+        if ($this->redis->getOption(RedisClient::OPT_PREFIX) === null) {
             return $key;
         }
+
         // @phpstan-ignore-next-line false positive, phpstan thinks getOptions returns int
-        return substr($key, strlen($this->redis->getOption(\Redis::OPT_PREFIX)));
+        return substr($key, strlen($this->redis->getOption(RedisClient::OPT_PREFIX)));
     }
 
     /**
@@ -509,9 +446,9 @@ private function removePrefixFromKey(string $key): string
      */
     private function collectSummaries(): array
     {
-        $math = new Math();
-        $summaryKey = self::$prefix . Summary::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX;
-        $keys = $this->redis->keys($summaryKey . ':*:meta');
+        $math = new Math;
+        $summaryKey = self::$prefix.Summary::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX;
+        $keys = $this->redis->keys($summaryKey.':*:meta');
 
         $summaries = [];
         foreach ($keys as $metaKeyWithPrefix) {
@@ -532,7 +469,7 @@ private function collectSummaries(): array
                 'samples' => [],
             ];
 
-            $values = $this->redis->keys($summaryKey . ':' . $metaData['name'] . ':*:value');
+            $values = $this->redis->keys($summaryKey.':'.$metaData['name'].':*:value');
             foreach ($values as $valueKeyWithPrefix) {
                 $valueKey = $this->removePrefixFromKey($valueKeyWithPrefix);
                 $rawValue = $this->redis->get($valueKey);
@@ -544,18 +481,19 @@ private function collectSummaries(): array
                 $decodedLabelValues = $this->decodeLabelValues($encodedLabelValues);
 
                 $samples = [];
-                $sampleValues = $this->redis->keys($summaryKey . ':' . $metaData['name'] . ':' . $encodedLabelValues . ':value:*');
+                $sampleValues = $this->redis->keys($summaryKey.':'.$metaData['name'].':'.$encodedLabelValues.':value:*');
                 foreach ($sampleValues as $sampleValueWithPrefix) {
                     $sampleValue = $this->removePrefixFromKey($sampleValueWithPrefix);
-                    $samples[] = (float)$this->redis->get($sampleValue);
+                    $samples[] = (float) $this->redis->get($sampleValue);
                 }
 
                 if (count($samples) === 0) {
                     try {
                         $this->redis->del($valueKey);
-                    } catch (\RedisException $e) {
+                    } catch (RedisClientException $e) {
                         // ignore if we can't delete the key
                     }
+
                     continue;
                 }
 
@@ -572,7 +510,7 @@ private function collectSummaries(): array
 
                 // Add the count
                 $data['samples'][] = [
-                    'name' => $metaData['name'] . '_count',
+                    'name' => $metaData['name'].'_count',
                     'labelNames' => [],
                     'labelValues' => $decodedLabelValues,
                     'value' => count($samples),
@@ -580,7 +518,7 @@ private function collectSummaries(): array
 
                 // Add the sum
                 $data['samples'][] = [
-                    'name' => $metaData['name'] . '_sum',
+                    'name' => $metaData['name'].'_sum',
                     'labelNames' => [],
                     'labelValues' => $decodedLabelValues,
                     'value' => array_sum($samples),
@@ -592,11 +530,12 @@ private function collectSummaries(): array
             } else {
                 try {
                     $this->redis->del($metaKey);
-                } catch (\RedisException $e) {
+                } catch (RedisClientException $e) {
                     // ignore if we can't delete the key
                 }
             }
         }
+
         return $summaries;
     }
 
@@ -605,12 +544,12 @@ private function collectSummaries(): array
      */
     private function collectGauges(bool $sortMetrics = true): array
     {
-        $keys = $this->redis->sMembers(self::$prefix . Gauge::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX);
+        $keys = $this->redis->sMembers(self::$prefix.Gauge::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX);
         sort($keys);
         $gauges = [];
         foreach ($keys as $key) {
-            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->_prefix('')));
-            if (!isset($raw['__meta'])) {
+            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getPrefix()));
+            if (! isset($raw['__meta'])) {
                 continue;
             }
             $gauge = json_decode($raw['__meta'], true);
@@ -630,27 +569,29 @@ private function collectGauges(bool $sortMetrics = true): array
 
             if ($sortMetrics) {
                 usort($gauge['samples'], function ($a, $b): int {
-                    return strcmp(implode("", $a['labelValues']), implode("", $b['labelValues']));
+                    return strcmp(implode('', $a['labelValues']), implode('', $b['labelValues']));
                 });
             }
 
             $gauges[] = $gauge;
         }
+
         return $gauges;
     }
 
     /**
      * @return mixed[]
+     *
      * @throws MetricJsonException
      */
     private function collectCounters(bool $sortMetrics = true): array
     {
-        $keys = $this->redis->sMembers(self::$prefix . Counter::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX);
+        $keys = $this->redis->sMembers(self::$prefix.Counter::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX);
         sort($keys);
         $counters = [];
         foreach ($keys as $key) {
-            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->_prefix('')));
-            if (!isset($raw['__meta'])) {
+            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getPrefix()));
+            if (! isset($raw['__meta'])) {
                 continue;
             }
             $counter = json_decode($raw['__meta'], true);
@@ -672,19 +613,16 @@ private function collectCounters(bool $sortMetrics = true): array
 
             if ($sortMetrics) {
                 usort($counter['samples'], function ($a, $b): int {
-                    return strcmp(implode("", $a['labelValues']), implode("", $b['labelValues']));
+                    return strcmp(implode('', $a['labelValues']), implode('', $b['labelValues']));
                 });
             }
 
             $counters[] = $counter;
         }
+
         return $counters;
     }
 
-    /**
-     * @param int $cmd
-     * @return string
-     */
     private function getRedisCommand(int $cmd): string
     {
         switch ($cmd) {
@@ -695,13 +633,12 @@ private function getRedisCommand(int $cmd): string
             case Adapter::COMMAND_SET:
                 return 'hSet';
             default:
-                throw new InvalidArgumentException("Unknown command");
+                throw new InvalidArgumentException('Unknown command');
         }
     }
 
     /**
-     * @param mixed[] $data
-     * @return string
+     * @param  mixed[]  $data
      */
     private function toMetricKey(array $data): string
     {
@@ -709,47 +646,46 @@ private function toMetricKey(array $data): string
     }
 
     /**
-     * @param mixed[] $values
-     * @return string
+     * @param  mixed[]  $values
+     *
      * @throws RuntimeException
      */
     private function encodeLabelValues(array $values): string
     {
         $json = json_encode($values);
-        if (false === $json) {
+        if ($json === false) {
             throw new RuntimeException(json_last_error_msg());
         }
+
         return base64_encode($json);
     }
 
     /**
-     * @param string $values
      * @return mixed[]
+     *
      * @throws RuntimeException
      */
     private function decodeLabelValues(string $values): array
     {
         $json = base64_decode($values, true);
-        if (false === $json) {
+        if ($json === false) {
             throw new RuntimeException('Cannot base64 decode label values');
         }
         $decodedValues = json_decode($json, true);
-        if (false === $decodedValues) {
+        if ($decodedValues === false) {
             throw new RuntimeException(json_last_error_msg());
         }
+
         return $decodedValues;
     }
 
     /**
-     * @param string $redisKey
-     * @param string|null $metricName
-     * @return void
      * @throws MetricJsonException
      */
     private function throwMetricJsonException(string $redisKey, ?string $metricName = null): void
     {
         $metricName = $metricName ?? 'unknown';
-        $message = 'Json error: ' . json_last_error_msg() . ' redis key : ' . $redisKey . ' metric name: ' . $metricName;
+        $message = 'Json error: '.json_last_error_msg().' redis key : '.$redisKey.' metric name: '.$metricName;
         throw new MetricJsonException($message, 0, null, $metricName);
     }
 }
diff --git a/src/Prometheus/Storage/RedisClients/RedisClient.php b/src/Prometheus/Storage/RedisClients/RedisClient.php
new file mode 100644
index 0000000..5d53294
--- /dev/null
+++ b/src/Prometheus/Storage/RedisClients/RedisClient.php
@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Prometheus\Storage\RedisClients;
+
+interface RedisClient
+{
+    const OPT_PREFIX = 2;
+
+    const OPT_READ_TIMEOUT = 3;
+
+    public function getOption(int $option): mixed;
+
+    public function eval(string $script, array $args = [], int $num_keys = 0): mixed;
+
+    public function set(string $key, mixed $value, mixed $options = null): string|bool;
+
+    public function setNx(string $key, mixed $value): bool;
+
+    public function hSetNx(string $key, string $field, mixed $value): bool;
+
+    public function sMembers(string $key): array|false;
+
+    public function hGetAll(string $key): array|false;
+
+    public function keys(string $pattern);
+
+    public function get(string $key): mixed;
+
+    public function del(array|string $key, string ...$other_keys): int|false;
+
+    public function getPrefix(): string;
+
+    public function ensureOpenConnection(): void;
+}
diff --git a/src/Prometheus/Storage/RedisClients/RedisClientException.php b/src/Prometheus/Storage/RedisClients/RedisClientException.php
new file mode 100644
index 0000000..36d8cf3
--- /dev/null
+++ b/src/Prometheus/Storage/RedisClients/RedisClientException.php
@@ -0,0 +1,7 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Prometheus\Storage\RedisClients;
+
+class RedisClientException extends \Exception {}

From e5d6196d1d9dafdfccd65d203b0d7312f003487d Mon Sep 17 00:00:00 2001
From: Mateusz Cholewka <mateusz@cholewka.com.pl>
Date: Wed, 30 Apr 2025 00:14:33 +0200
Subject: [PATCH 03/14] feature: implement predis and phpredis clients

Signed-off-by: Mateusz Cholewka <mateusz@cholewka.com.pl>
---
 .../Storage/RedisClients/PHPRedis.php         | 157 ++++++++++++++++++
 .../Storage/RedisClients/Predis.php           | 117 +++++++++++++
 2 files changed, 274 insertions(+)
 create mode 100644 src/Prometheus/Storage/RedisClients/PHPRedis.php
 create mode 100644 src/Prometheus/Storage/RedisClients/Predis.php

diff --git a/src/Prometheus/Storage/RedisClients/PHPRedis.php b/src/Prometheus/Storage/RedisClients/PHPRedis.php
new file mode 100644
index 0000000..a650f01
--- /dev/null
+++ b/src/Prometheus/Storage/RedisClients/PHPRedis.php
@@ -0,0 +1,157 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Prometheus\Storage\RedisClients;
+
+use Prometheus\Exception\StorageException;
+
+class PHPRedis implements RedisClient
+{
+    /**
+     * @var \Redis
+     */
+    private $redis;
+
+    private $options = [];
+
+    /**
+     * @var bool
+     */
+    private $connectionInitialized = false;
+
+    public function __construct(\Redis $redis, array $options)
+    {
+        $this->redis = $redis;
+        $this->options = $options;
+    }
+
+    public static function create(array $options): self
+    {
+        $redis = new \Redis;
+
+        return new self($redis, $options);
+    }
+
+    public function getOption(int $option): mixed
+    {
+        return $this->redis->getOption($option);
+    }
+
+    public function eval(string $script, array $args = [], int $num_keys = 0): mixed
+    {
+        return $this->redis->eval($script, $args, $num_keys);
+    }
+
+    public function set(string $key, mixed $value, mixed $options = null): string|bool
+    {
+        return $this->redis->set($key, $value, $options);
+    }
+
+    public function setNx(string $key, mixed $value): bool
+    {
+        return $this->redis->setNx($key, $value);
+    }
+
+    public function hSetNx(string $key, string $field, mixed $value): bool
+    {
+        return $this->redis->hSetNx($key, $field, $value);
+    }
+
+    public function sMembers(string $key): array|false
+    {
+        return $this->redis->sMembers($key);
+    }
+
+    public function hGetAll(string $key): array|false
+    {
+        return $this->redis->hGetAll($key);
+    }
+
+    public function keys(string $pattern)
+    {
+        return $this->redis->keys($pattern);
+    }
+
+    public function get(string $key): mixed
+    {
+        return $this->redis->get($key);
+    }
+
+    public function del(array|string $key, string ...$other_keys): int|false
+    {
+        try {
+            return $this->redis->del($key, ...$other_keys);
+        } catch (\RedisException $e) {
+            throw new RedisClientException($e->getMessage());
+        }
+    }
+
+    public function getPrefix(): string
+    {
+        return $this->redis->_prefix('');
+    }
+
+    /**
+     * @throws StorageException
+     */
+    public function ensureOpenConnection(): void
+    {
+        if ($this->connectionInitialized === true) {
+            return;
+        }
+
+        $this->connectToServer();
+        $authParams = [];
+
+        if (isset($this->options['user']) && $this->options['user'] !== '') {
+            $authParams[] = $this->options['user'];
+        }
+
+        if (isset($this->options['password'])) {
+            $authParams[] = $this->options['password'];
+        }
+
+        if ($authParams !== []) {
+            $this->redis->auth($authParams);
+        }
+
+        if (isset($this->options['database'])) {
+            $this->redis->select($this->options['database']);
+        }
+
+        $this->redis->setOption(RedisClient::OPT_READ_TIMEOUT, $this->options['read_timeout']);
+
+        $this->connectionInitialized = true;
+    }
+
+    /**
+     * @throws StorageException
+     */
+    private function connectToServer(): void
+    {
+        try {
+            $connection_successful = false;
+            if ($this->options['persistent_connections'] !== false) {
+                $connection_successful = $this->redis->pconnect(
+                    $this->options['host'],
+                    (int) $this->options['port'],
+                    (float) $this->options['timeout']
+                );
+            } else {
+                $connection_successful = $this->redis->connect($this->options['host'], (int) $this->options['port'], (float) $this->options['timeout']);
+            }
+            if (! $connection_successful) {
+                throw new StorageException(
+                    sprintf("Can't connect to Redis server. %s", $this->redis->getLastError()),
+                    0
+                );
+            }
+        } catch (\RedisException $e) {
+            throw new StorageException(
+                sprintf("Can't connect to Redis server. %s", $e->getMessage()),
+                $e->getCode(),
+            );
+        }
+    }
+}
diff --git a/src/Prometheus/Storage/RedisClients/Predis.php b/src/Prometheus/Storage/RedisClients/Predis.php
new file mode 100644
index 0000000..d359640
--- /dev/null
+++ b/src/Prometheus/Storage/RedisClients/Predis.php
@@ -0,0 +1,117 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Prometheus\Storage\RedisClients;
+
+use Predis\Client;
+use Predis\Configuration\Option\Prefix;
+
+class Predis implements RedisClient
+{
+    private const OPTIONS_MAP = [
+        RedisClient::OPT_PREFIX => Prefix::class,
+    ];
+
+    private $client;
+
+    private $prefix = '';
+
+    public function __construct(Client $redis)
+    {
+        $this->client = $redis;
+    }
+
+    public static function create(array $options): self
+    {
+        $this->prefix = $options['prefix'] ?? '';
+        $redisClient = new Client($options, ['prefix' => $options['prefix'] ?? '']);
+
+        return new self($redisClient);
+    }
+
+    public function getOption(int $option): mixed
+    {
+        if (! isset(self::OPTIONS_MAP[$option])) {
+            return null;
+        }
+
+        $mappedOption = self::OPTIONS_MAP[$option];
+
+        return $this->client->getOptions()->$mappedOption;
+    }
+
+    public function eval(string $script, array $args = [], int $num_keys = 0): mixed
+    {
+        return $this->client->eval($script, $num_keys, ...$args);
+    }
+
+    public function set(string $key, mixed $value, mixed $options = null): string|bool
+    {
+        $result = $this->client->set($key, $value, ...$this->flattenFlags($options));
+
+        return (string) $result;
+    }
+
+    private function flattenFlags(array $flags): array
+    {
+        $result = [];
+        foreach ($flags as $key => $value) {
+            if (is_int($key)) {
+                $result[] = $value;
+            } else {
+                $result[] = $key;
+                $result[] = $value;
+            }
+        }
+
+        return $result;
+    }
+
+    public function setNx(string $key, mixed $value): bool
+    {
+        return $this->client->setnx($key, $value) === 1;
+    }
+
+    public function hSetNx(string $key, string $field, mixed $value): bool
+    {
+        return $this->hsetnx($key, $field, $value);
+    }
+
+    public function sMembers(string $key): array|false
+    {
+        return $this->client->smembers($key);
+    }
+
+    public function hGetAll(string $key): array|false
+    {
+        return $this->client->hgetall($key);
+    }
+
+    public function keys(string $pattern)
+    {
+        return $this->client->keys($pattern);
+    }
+
+    public function get(string $key): mixed
+    {
+        return $this->client->get($key);
+    }
+
+    public function del(array|string $key, string ...$other_keys): int|false
+    {
+        return $this->client->del($key, ...$other_keys);
+    }
+
+    public function getPrefix(): string
+    {
+        $key = RedisClient::OPT_PREFIX;
+
+        return $this->prefix;
+    }
+
+    public function ensureOpenConnection(): void
+    {
+        // Predis doesn't require to trigger connection
+    }
+}

From fb4ab038775c39c493353d6b91586357f42be1de Mon Sep 17 00:00:00 2001
From: Mateusz Cholewka <mateusz@cholewka.com.pl>
Date: Wed, 30 Apr 2025 00:14:44 +0200
Subject: [PATCH 04/14] feature: add predis test

Signed-off-by: Mateusz Cholewka <mateusz@cholewka.com.pl>
---
 .../Predis/CollectorRegistryTest.php          | 23 ++++++++++++++
 tests/Test/Prometheus/Predis/CounterTest.php  | 25 +++++++++++++++
 .../Predis/CounterWithPrefixTest.php          | 25 +++++++++++++++
 tests/Test/Prometheus/Predis/GaugeTest.php    | 25 +++++++++++++++
 .../Prometheus/Predis/GaugeWithPrefixTest.php | 25 +++++++++++++++
 .../Test/Prometheus/Predis/HistogramTest.php  | 25 +++++++++++++++
 .../Predis/HistogramWithPrefixTest.php        | 25 +++++++++++++++
 tests/Test/Prometheus/Predis/SummaryTest.php  | 31 +++++++++++++++++++
 .../Predis/SummaryWithPrefixTest.php          | 25 +++++++++++++++
 9 files changed, 229 insertions(+)
 create mode 100644 tests/Test/Prometheus/Predis/CollectorRegistryTest.php
 create mode 100644 tests/Test/Prometheus/Predis/CounterTest.php
 create mode 100644 tests/Test/Prometheus/Predis/CounterWithPrefixTest.php
 create mode 100644 tests/Test/Prometheus/Predis/GaugeTest.php
 create mode 100644 tests/Test/Prometheus/Predis/GaugeWithPrefixTest.php
 create mode 100644 tests/Test/Prometheus/Predis/HistogramTest.php
 create mode 100644 tests/Test/Prometheus/Predis/HistogramWithPrefixTest.php
 create mode 100644 tests/Test/Prometheus/Predis/SummaryTest.php
 create mode 100644 tests/Test/Prometheus/Predis/SummaryWithPrefixTest.php

diff --git a/tests/Test/Prometheus/Predis/CollectorRegistryTest.php b/tests/Test/Prometheus/Predis/CollectorRegistryTest.php
new file mode 100644
index 0000000..2add921
--- /dev/null
+++ b/tests/Test/Prometheus/Predis/CollectorRegistryTest.php
@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Test\Prometheus\Predis;
+
+use Predis\Client;
+use Prometheus\Storage\Redis;
+use Test\Prometheus\AbstractCollectorRegistryTest;
+
+/**
+ * @requires extension redis
+ */
+class CollectorRegistryTest extends AbstractCollectorRegistryTest
+{
+    public function configureAdapter(): void
+    {
+        $connection = new Client(['host' => REDIS_HOST]);
+
+        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter->wipeStorage();
+    }
+}
diff --git a/tests/Test/Prometheus/Predis/CounterTest.php b/tests/Test/Prometheus/Predis/CounterTest.php
new file mode 100644
index 0000000..a35b51c
--- /dev/null
+++ b/tests/Test/Prometheus/Predis/CounterTest.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Test\Prometheus\Predis;
+
+use Predis\Client;
+use Prometheus\Storage\Redis;
+use Test\Prometheus\AbstractCounterTest;
+
+/**
+ * See https://prometheus.io/docs/instrumenting/exposition_formats/
+ *
+ * @requires extension redis
+ */
+class CounterTest extends AbstractCounterTest
+{
+    public function configureAdapter(): void
+    {
+        $connection = new Client(['host' => REDIS_HOST]);
+
+        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter->wipeStorage();
+    }
+}
diff --git a/tests/Test/Prometheus/Predis/CounterWithPrefixTest.php b/tests/Test/Prometheus/Predis/CounterWithPrefixTest.php
new file mode 100644
index 0000000..c4636b0
--- /dev/null
+++ b/tests/Test/Prometheus/Predis/CounterWithPrefixTest.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Test\Prometheus\Predis;
+
+use Predis\Client;
+use Prometheus\Storage\Redis;
+use Test\Prometheus\AbstractCounterTest;
+
+/**
+ * See https://prometheus.io/docs/instrumenting/exposition_formats/
+ *
+ * @requires extension redis
+ */
+class CounterWithPrefixTest extends AbstractCounterTest
+{
+    public function configureAdapter(): void
+    {
+        $connection = new Client(['host' => REDIS_HOST, 'prefix' => 'prefix:']);
+
+        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter->wipeStorage();
+    }
+}
diff --git a/tests/Test/Prometheus/Predis/GaugeTest.php b/tests/Test/Prometheus/Predis/GaugeTest.php
new file mode 100644
index 0000000..f141861
--- /dev/null
+++ b/tests/Test/Prometheus/Predis/GaugeTest.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Test\Prometheus\Predis;
+
+use Predis\Client;
+use Prometheus\Storage\Redis;
+use Test\Prometheus\AbstractGaugeTest;
+
+/**
+ * See https://prometheus.io/docs/instrumenting/exposition_formats/
+ *
+ * @requires extension redis
+ */
+class GaugeTest extends AbstractGaugeTest
+{
+    public function configureAdapter(): void
+    {
+        $connection = new Client(['host' => REDIS_HOST]);
+
+        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter->wipeStorage();
+    }
+}
diff --git a/tests/Test/Prometheus/Predis/GaugeWithPrefixTest.php b/tests/Test/Prometheus/Predis/GaugeWithPrefixTest.php
new file mode 100644
index 0000000..dcc5748
--- /dev/null
+++ b/tests/Test/Prometheus/Predis/GaugeWithPrefixTest.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Test\Prometheus\Predis;
+
+use Predis\Client;
+use Prometheus\Storage\Redis;
+use Test\Prometheus\AbstractGaugeTest;
+
+/**
+ * See https://prometheus.io/docs/instrumenting/exposition_formats/
+ *
+ * @requires extension redis
+ */
+class GaugeWithPrefixTest extends AbstractGaugeTest
+{
+    public function configureAdapter(): void
+    {
+        $connection = new Client(['host' => REDIS_HOST, 'prefix' => 'prefix:']);
+
+        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter->wipeStorage();
+    }
+}
diff --git a/tests/Test/Prometheus/Predis/HistogramTest.php b/tests/Test/Prometheus/Predis/HistogramTest.php
new file mode 100644
index 0000000..2d2b670
--- /dev/null
+++ b/tests/Test/Prometheus/Predis/HistogramTest.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Test\Prometheus\Predis;
+
+use Predis\Client;
+use Prometheus\Storage\Redis;
+use Test\Prometheus\AbstractHistogramTest;
+
+/**
+ * See https://prometheus.io/docs/instrumenting/exposition_formats/
+ *
+ * @requires extension redis
+ */
+class HistogramTest extends AbstractHistogramTest
+{
+    public function configureAdapter(): void
+    {
+        $connection = new Client(['host' => REDIS_HOST]);
+
+        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter->wipeStorage();
+    }
+}
diff --git a/tests/Test/Prometheus/Predis/HistogramWithPrefixTest.php b/tests/Test/Prometheus/Predis/HistogramWithPrefixTest.php
new file mode 100644
index 0000000..bf5f8ea
--- /dev/null
+++ b/tests/Test/Prometheus/Predis/HistogramWithPrefixTest.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Test\Prometheus\Predis;
+
+use Predis\Client;
+use Prometheus\Storage\Redis;
+use Test\Prometheus\AbstractHistogramTest;
+
+/**
+ * See https://prometheus.io/docs/instrumenting/exposition_formats/
+ *
+ * @requires extension redis
+ */
+class HistogramWithPrefixTest extends AbstractHistogramTest
+{
+    public function configureAdapter(): void
+    {
+        $connection = new Client(['host' => REDIS_HOST, 'prefix' => 'prefix:']);
+
+        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter->wipeStorage();
+    }
+}
diff --git a/tests/Test/Prometheus/Predis/SummaryTest.php b/tests/Test/Prometheus/Predis/SummaryTest.php
new file mode 100644
index 0000000..430bf6b
--- /dev/null
+++ b/tests/Test/Prometheus/Predis/SummaryTest.php
@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Test\Prometheus\Predis;
+
+use Predis\Client;
+use Prometheus\Storage\Redis;
+use Test\Prometheus\AbstractSummaryTest;
+
+/**
+ * See https://prometheus.io/docs/instrumenting/exposition_formats/
+ *
+ * @requires extension redis
+ */
+class SummaryTest extends AbstractSummaryTest
+{
+    public function configureAdapter(): void
+    {
+        $connection = new Client(['host' => REDIS_HOST]);
+
+        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter->wipeStorage();
+    }
+
+    /** @test  */
+    public function it_should_observe_with_labels(): void
+    {
+        parent::itShouldObserveWithLabels(); // TODO: Change the autogenerated stub
+    }
+}
diff --git a/tests/Test/Prometheus/Predis/SummaryWithPrefixTest.php b/tests/Test/Prometheus/Predis/SummaryWithPrefixTest.php
new file mode 100644
index 0000000..d6bd40a
--- /dev/null
+++ b/tests/Test/Prometheus/Predis/SummaryWithPrefixTest.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Test\Prometheus\Predis;
+
+use Predis\Client;
+use Prometheus\Storage\Redis;
+use Test\Prometheus\AbstractSummaryTest;
+
+/**
+ * See https://prometheus.io/docs/instrumenting/exposition_formats/
+ *
+ * @requires extension redis
+ */
+class SummaryWithPrefixTest extends AbstractSummaryTest
+{
+    public function configureAdapter(): void
+    {
+        $connection = new Client(['host' => REDIS_HOST, 'prefix' => 'prefix:']);
+
+        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter->wipeStorage();
+    }
+}

From fb7913e0b0b0ac4280fc344767d670f5d1486bce Mon Sep 17 00:00:00 2001
From: Mateusz Cholewka <mateusz@cholewka.com.pl>
Date: Wed, 30 Apr 2025 14:30:39 +0200
Subject: [PATCH 05/14] refactor: yagni for interface

Signed-off-by: Mateusz Cholewka <mateusz@cholewka.com.pl>
---
 .../Storage/RedisClients/PHPRedis.php         | 21 ++++-----
 .../Storage/RedisClients/Predis.php           | 43 ++++++++-----------
 .../Storage/RedisClients/RedisClient.php      | 10 ++---
 3 files changed, 29 insertions(+), 45 deletions(-)

diff --git a/src/Prometheus/Storage/RedisClients/PHPRedis.php b/src/Prometheus/Storage/RedisClients/PHPRedis.php
index a650f01..9dcfbbf 100644
--- a/src/Prometheus/Storage/RedisClients/PHPRedis.php
+++ b/src/Prometheus/Storage/RedisClients/PHPRedis.php
@@ -38,19 +38,19 @@ public function getOption(int $option): mixed
         return $this->redis->getOption($option);
     }
 
-    public function eval(string $script, array $args = [], int $num_keys = 0): mixed
+    public function eval(string $script, array $args = [], int $num_keys = 0): void
     {
-        return $this->redis->eval($script, $args, $num_keys);
+        $this->redis->eval($script, $args, $num_keys);
     }
 
-    public function set(string $key, mixed $value, mixed $options = null): string|bool
+    public function set(string $key, mixed $value, mixed $options = null): void
     {
-        return $this->redis->set($key, $value, $options);
+        $this->redis->set($key, $value, $options);
     }
 
-    public function setNx(string $key, mixed $value): bool
+    public function setNx(string $key, mixed $value): void
     {
-        return $this->redis->setNx($key, $value);
+        $this->redis->setNx($key, $value);
     }
 
     public function hSetNx(string $key, string $field, mixed $value): bool
@@ -78,20 +78,15 @@ public function get(string $key): mixed
         return $this->redis->get($key);
     }
 
-    public function del(array|string $key, string ...$other_keys): int|false
+    public function del(array|string $key, string ...$other_keys): void
     {
         try {
-            return $this->redis->del($key, ...$other_keys);
+            $this->redis->del($key, ...$other_keys);
         } catch (\RedisException $e) {
             throw new RedisClientException($e->getMessage());
         }
     }
 
-    public function getPrefix(): string
-    {
-        return $this->redis->_prefix('');
-    }
-
     /**
      * @throws StorageException
      */
diff --git a/src/Prometheus/Storage/RedisClients/Predis.php b/src/Prometheus/Storage/RedisClients/Predis.php
index d359640..c2d0c65 100644
--- a/src/Prometheus/Storage/RedisClients/Predis.php
+++ b/src/Prometheus/Storage/RedisClients/Predis.php
@@ -5,29 +5,29 @@
 namespace Prometheus\Storage\RedisClients;
 
 use Predis\Client;
-use Predis\Configuration\Option\Prefix;
 
 class Predis implements RedisClient
 {
     private const OPTIONS_MAP = [
-        RedisClient::OPT_PREFIX => Prefix::class,
+        RedisClient::OPT_PREFIX => 'prefix',
     ];
 
     private $client;
 
-    private $prefix = '';
+    private $options = [];
 
-    public function __construct(Client $redis)
+    public function __construct(Client $redis, array $options)
     {
         $this->client = $redis;
+
+        $this->options = $options;
     }
 
-    public static function create(array $options): self
+    public static function create(array $parameters, array $options): self
     {
-        $this->prefix = $options['prefix'] ?? '';
-        $redisClient = new Client($options, ['prefix' => $options['prefix'] ?? '']);
+        $redisClient = new Client($parameters, $options);
 
-        return new self($redisClient);
+        return new self($redisClient, $options);
     }
 
     public function getOption(int $option): mixed
@@ -38,19 +38,17 @@ public function getOption(int $option): mixed
 
         $mappedOption = self::OPTIONS_MAP[$option];
 
-        return $this->client->getOptions()->$mappedOption;
+        return $this->options[$mappedOption] ?? null;
     }
 
-    public function eval(string $script, array $args = [], int $num_keys = 0): mixed
+    public function eval(string $script, array $args = [], int $num_keys = 0): void
     {
-        return $this->client->eval($script, $num_keys, ...$args);
+        $this->client->eval($script, $num_keys, ...$args);
     }
 
-    public function set(string $key, mixed $value, mixed $options = null): string|bool
+    public function set(string $key, mixed $value, mixed $options = null): void
     {
-        $result = $this->client->set($key, $value, ...$this->flattenFlags($options));
-
-        return (string) $result;
+        $this->client->set($key, $value, ...$this->flattenFlags($options));
     }
 
     private function flattenFlags(array $flags): array
@@ -68,9 +66,9 @@ private function flattenFlags(array $flags): array
         return $result;
     }
 
-    public function setNx(string $key, mixed $value): bool
+    public function setNx(string $key, mixed $value): void
     {
-        return $this->client->setnx($key, $value) === 1;
+        $this->client->setnx($key, $value) === 1;
     }
 
     public function hSetNx(string $key, string $field, mixed $value): bool
@@ -98,16 +96,9 @@ public function get(string $key): mixed
         return $this->client->get($key);
     }
 
-    public function del(array|string $key, string ...$other_keys): int|false
-    {
-        return $this->client->del($key, ...$other_keys);
-    }
-
-    public function getPrefix(): string
+    public function del(array|string $key, string ...$other_keys): void
     {
-        $key = RedisClient::OPT_PREFIX;
-
-        return $this->prefix;
+        $this->client->del($key, ...$other_keys);
     }
 
     public function ensureOpenConnection(): void
diff --git a/src/Prometheus/Storage/RedisClients/RedisClient.php b/src/Prometheus/Storage/RedisClients/RedisClient.php
index 5d53294..89eadcb 100644
--- a/src/Prometheus/Storage/RedisClients/RedisClient.php
+++ b/src/Prometheus/Storage/RedisClients/RedisClient.php
@@ -12,11 +12,11 @@ interface RedisClient
 
     public function getOption(int $option): mixed;
 
-    public function eval(string $script, array $args = [], int $num_keys = 0): mixed;
+    public function eval(string $script, array $args = [], int $num_keys = 0): void;
 
-    public function set(string $key, mixed $value, mixed $options = null): string|bool;
+    public function set(string $key, mixed $value, mixed $options = null): void;
 
-    public function setNx(string $key, mixed $value): bool;
+    public function setNx(string $key, mixed $value): void;
 
     public function hSetNx(string $key, string $field, mixed $value): bool;
 
@@ -28,9 +28,7 @@ public function keys(string $pattern);
 
     public function get(string $key): mixed;
 
-    public function del(array|string $key, string ...$other_keys): int|false;
-
-    public function getPrefix(): string;
+    public function del(array|string $key, string ...$other_keys): void;
 
     public function ensureOpenConnection(): void;
 }

From 4f2c22c264559b9ed58cd4bab888204d1397baf2 Mon Sep 17 00:00:00 2001
From: Mateusz Cholewka <mateusz@cholewka.com.pl>
Date: Wed, 30 Apr 2025 14:31:05 +0200
Subject: [PATCH 06/14] refactor: use abstract redis and keep full backward
 compatibility

Signed-off-by: Mateusz Cholewka <mateusz@cholewka.com.pl>
---
 src/Prometheus/Storage/AbstractRedis.php      | 629 +++++++++++++++++
 src/Prometheus/Storage/Predis.php             |  94 +++
 src/Prometheus/Storage/Redis.php              | 634 +-----------------
 .../Predis/CollectorRegistryTest.php          |   7 +-
 tests/Test/Prometheus/Predis/CounterTest.php  |   7 +-
 .../Predis/CounterWithPrefixTest.php          |   7 +-
 tests/Test/Prometheus/Predis/GaugeTest.php    |   7 +-
 .../Prometheus/Predis/GaugeWithPrefixTest.php |   7 +-
 .../Test/Prometheus/Predis/HistogramTest.php  |   7 +-
 .../Predis/HistogramWithPrefixTest.php        |   7 +-
 tests/Test/Prometheus/Predis/SummaryTest.php  |   7 +-
 .../Predis/SummaryWithPrefixTest.php          |   7 +-
 12 files changed, 744 insertions(+), 676 deletions(-)
 create mode 100644 src/Prometheus/Storage/AbstractRedis.php
 create mode 100644 src/Prometheus/Storage/Predis.php

diff --git a/src/Prometheus/Storage/AbstractRedis.php b/src/Prometheus/Storage/AbstractRedis.php
new file mode 100644
index 0000000..4cab84d
--- /dev/null
+++ b/src/Prometheus/Storage/AbstractRedis.php
@@ -0,0 +1,629 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Prometheus\Storage;
+
+use InvalidArgumentException;
+use Prometheus\Counter;
+use Prometheus\Exception\MetricJsonException;
+use Prometheus\Exception\StorageException;
+use Prometheus\Gauge;
+use Prometheus\Histogram;
+use Prometheus\Math;
+use Prometheus\MetricFamilySamples;
+use Prometheus\Storage\RedisClients\RedisClient;
+use Prometheus\Storage\RedisClients\RedisClientException;
+use Prometheus\Summary;
+use RuntimeException;
+
+abstract class AbstractRedis implements Adapter
+{
+    const PROMETHEUS_METRIC_KEYS_SUFFIX = '_METRIC_KEYS';
+
+    /**
+     * @var string
+     */
+    protected static $prefix = 'PROMETHEUS_';
+
+    /**
+     * @var RedisClient
+     */
+    protected $redis;
+
+    public static function setPrefix(string $prefix): void
+    {
+        self::$prefix = $prefix;
+    }
+
+    /**
+     * @throws StorageException
+     *
+     * @deprecated use replacement method wipeStorage from Adapter interface
+     */
+    public function flushRedis(): void
+    {
+        $this->wipeStorage();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function wipeStorage(): void
+    {
+        $this->redis->ensureOpenConnection();
+
+        $searchPattern = '';
+
+        $globalPrefix = $this->redis->getOption(RedisClient::OPT_PREFIX);
+        // @phpstan-ignore-next-line false positive, phpstan thinks getOptions returns int
+        if (is_string($globalPrefix)) {
+            $searchPattern .= $globalPrefix;
+        }
+
+        $searchPattern .= self::$prefix;
+        $searchPattern .= '*';
+
+        $this->redis->eval(
+            <<<'LUA'
+redis.replicate_commands()
+local cursor = "0"
+repeat 
+    local results = redis.call('SCAN', cursor, 'MATCH', ARGV[1])
+    cursor = results[1]
+    for _, key in ipairs(results[2]) do
+        redis.call('DEL', key)
+    end
+until cursor == "0"
+LUA
+            ,
+            [$searchPattern],
+            0
+        );
+    }
+
+    /**
+     * @param  mixed[]  $data
+     */
+    protected function metaKey(array $data): string
+    {
+        return implode(':', [
+            $data['name'],
+            'meta',
+        ]);
+    }
+
+    /**
+     * @param  mixed[]  $data
+     */
+    protected function valueKey(array $data): string
+    {
+        return implode(':', [
+            $data['name'],
+            $this->encodeLabelValues($data['labelValues']),
+            'value',
+        ]);
+    }
+
+    /**
+     * @return MetricFamilySamples[]
+     *
+     * @throws StorageException
+     */
+    public function collect(bool $sortMetrics = true): array
+    {
+        $this->redis->ensureOpenConnection();
+        $metrics = $this->collectHistograms();
+        $metrics = array_merge($metrics, $this->collectGauges($sortMetrics));
+        $metrics = array_merge($metrics, $this->collectCounters($sortMetrics));
+        $metrics = array_merge($metrics, $this->collectSummaries());
+
+        return array_map(
+            function (array $metric): MetricFamilySamples {
+                return new MetricFamilySamples($metric);
+            },
+            $metrics
+        );
+    }
+
+    /**
+     * @param  mixed[]  $data
+     *
+     * @throws StorageException
+     */
+    public function updateHistogram(array $data): void
+    {
+        $this->redis->ensureOpenConnection();
+        $bucketToIncrease = '+Inf';
+        foreach ($data['buckets'] as $bucket) {
+            if ($data['value'] <= $bucket) {
+                $bucketToIncrease = $bucket;
+                break;
+            }
+        }
+        $metaData = $data;
+        unset($metaData['value'], $metaData['labelValues']);
+
+        $this->redis->eval(
+            <<<'LUA'
+local result = redis.call('hIncrByFloat', KEYS[1], ARGV[1], ARGV[3])
+redis.call('hIncrBy', KEYS[1], ARGV[2], 1)
+if tonumber(result) >= tonumber(ARGV[3]) then
+    redis.call('hSet', KEYS[1], '__meta', ARGV[4])
+    redis.call('sAdd', KEYS[2], KEYS[1])
+end
+return result
+LUA
+            ,
+            [
+                $this->toMetricKey($data),
+                self::$prefix.Histogram::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX,
+                json_encode(['b' => 'sum', 'labelValues' => $data['labelValues']]),
+                json_encode(['b' => $bucketToIncrease, 'labelValues' => $data['labelValues']]),
+                $data['value'],
+                json_encode($metaData),
+            ],
+            2
+        );
+    }
+
+    /**
+     * @param  mixed[]  $data
+     *
+     * @throws StorageException
+     */
+    public function updateSummary(array $data): void
+    {
+        $this->redis->ensureOpenConnection();
+
+        // store meta
+        $summaryKey = self::$prefix.Summary::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX;
+        $metaKey = $summaryKey.':'.$this->metaKey($data);
+        $json = json_encode($this->metaData($data));
+        if ($json === false) {
+            throw new RuntimeException(json_last_error_msg());
+        }
+        $this->redis->setNx($metaKey, $json); /** @phpstan-ignore-line */
+
+        // store value key
+        $valueKey = $summaryKey.':'.$this->valueKey($data);
+        $json = json_encode($this->encodeLabelValues($data['labelValues']));
+        if ($json === false) {
+            throw new RuntimeException(json_last_error_msg());
+        }
+        $this->redis->setNx($valueKey, $json); /** @phpstan-ignore-line */
+
+        // trick to handle uniqid collision
+        $done = false;
+        while (! $done) {
+            $sampleKey = $valueKey.':'.uniqid('', true);
+            $done = $this->redis->set($sampleKey, $data['value'], ['NX', 'EX' => $data['maxAgeSeconds']]);
+        }
+    }
+
+    /**
+     * @param  mixed[]  $data
+     *
+     * @throws StorageException
+     */
+    public function updateGauge(array $data): void
+    {
+        $this->redis->ensureOpenConnection();
+        $metaData = $data;
+        unset($metaData['value'], $metaData['labelValues'], $metaData['command']);
+        $this->redis->eval(
+            <<<'LUA'
+local result = redis.call(ARGV[1], KEYS[1], ARGV[2], ARGV[3])
+
+if ARGV[1] == 'hSet' then
+    if result == 1 then
+        redis.call('hSet', KEYS[1], '__meta', ARGV[4])
+        redis.call('sAdd', KEYS[2], KEYS[1])
+    end
+else
+    if result == ARGV[3] then
+        redis.call('hSet', KEYS[1], '__meta', ARGV[4])
+        redis.call('sAdd', KEYS[2], KEYS[1])
+    end
+end
+LUA
+            ,
+            [
+                $this->toMetricKey($data),
+                self::$prefix.Gauge::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX,
+                $this->getRedisCommand($data['command']),
+                json_encode($data['labelValues']),
+                $data['value'],
+                json_encode($metaData),
+            ],
+            2
+        );
+    }
+
+    /**
+     * @param  mixed[]  $data
+     *
+     * @throws StorageException
+     */
+    public function updateCounter(array $data): void
+    {
+        $this->redis->ensureOpenConnection();
+        $metaData = $data;
+        unset($metaData['value'], $metaData['labelValues'], $metaData['command']);
+        $this->redis->eval(
+            <<<'LUA'
+local result = redis.call(ARGV[1], KEYS[1], ARGV[3], ARGV[2])
+local added = redis.call('sAdd', KEYS[2], KEYS[1])
+if added == 1 then
+    redis.call('hMSet', KEYS[1], '__meta', ARGV[4])
+end
+return result
+LUA
+            ,
+            [
+                $this->toMetricKey($data),
+                self::$prefix.Counter::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX,
+                $this->getRedisCommand($data['command']),
+                $data['value'],
+                json_encode($data['labelValues']),
+                json_encode($metaData),
+            ],
+            2
+        );
+    }
+
+    /**
+     * @param  mixed[]  $data
+     * @return mixed[]
+     */
+    protected function metaData(array $data): array
+    {
+        $metricsMetaData = $data;
+        unset($metricsMetaData['value'], $metricsMetaData['command'], $metricsMetaData['labelValues']);
+
+        return $metricsMetaData;
+    }
+
+    /**
+     * @return mixed[]
+     */
+    protected function collectHistograms(): array
+    {
+        $keys = $this->redis->sMembers(self::$prefix.Histogram::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX);
+        sort($keys);
+        $histograms = [];
+        foreach ($keys as $key) {
+            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getOption(RedisClient::OPT_PREFIX)));
+            if (! isset($raw['__meta'])) {
+                continue;
+            }
+            $histogram = json_decode($raw['__meta'], true);
+            unset($raw['__meta']);
+            $histogram['samples'] = [];
+
+            // Add the Inf bucket so we can compute it later on
+            $histogram['buckets'][] = '+Inf';
+
+            $allLabelValues = [];
+            foreach (array_keys($raw) as $k) {
+                $d = json_decode($k, true);
+                if ($d['b'] == 'sum') {
+                    continue;
+                }
+                $allLabelValues[] = $d['labelValues'];
+            }
+            if (json_last_error() !== JSON_ERROR_NONE) {
+                $this->throwMetricJsonException($key);
+            }
+
+            // We need set semantics.
+            // This is the equivalent of array_unique but for arrays of arrays.
+            $allLabelValues = array_map('unserialize', array_unique(array_map('serialize', $allLabelValues)));
+            sort($allLabelValues);
+
+            foreach ($allLabelValues as $labelValues) {
+                // Fill up all buckets.
+                // If the bucket doesn't exist fill in values from
+                // the previous one.
+                $acc = 0;
+                foreach ($histogram['buckets'] as $bucket) {
+                    $bucketKey = json_encode(['b' => $bucket, 'labelValues' => $labelValues]);
+                    if (! isset($raw[$bucketKey])) {
+                        $histogram['samples'][] = [
+                            'name' => $histogram['name'].'_bucket',
+                            'labelNames' => ['le'],
+                            'labelValues' => array_merge($labelValues, [$bucket]),
+                            'value' => $acc,
+                        ];
+                    } else {
+                        $acc += $raw[$bucketKey];
+                        $histogram['samples'][] = [
+                            'name' => $histogram['name'].'_bucket',
+                            'labelNames' => ['le'],
+                            'labelValues' => array_merge($labelValues, [$bucket]),
+                            'value' => $acc,
+                        ];
+                    }
+                }
+
+                // Add the count
+                $histogram['samples'][] = [
+                    'name' => $histogram['name'].'_count',
+                    'labelNames' => [],
+                    'labelValues' => $labelValues,
+                    'value' => $acc,
+                ];
+
+                // Add the sum
+                $histogram['samples'][] = [
+                    'name' => $histogram['name'].'_sum',
+                    'labelNames' => [],
+                    'labelValues' => $labelValues,
+                    'value' => $raw[json_encode(['b' => 'sum', 'labelValues' => $labelValues])],
+                ];
+            }
+            $histograms[] = $histogram;
+        }
+
+        return $histograms;
+    }
+
+    protected function removePrefixFromKey(string $key): string
+    {
+        // @phpstan-ignore-next-line false positive, phpstan thinks getOptions returns int
+        if ($this->redis->getOption(RedisClient::OPT_PREFIX) === null) {
+            return $key;
+        }
+
+        // @phpstan-ignore-next-line false positive, phpstan thinks getOptions returns int
+        return substr($key, strlen($this->redis->getOption(RedisClient::OPT_PREFIX)));
+    }
+
+    /**
+     * @return mixed[]
+     */
+    protected function collectSummaries(): array
+    {
+        $math = new Math;
+        $summaryKey = self::$prefix.Summary::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX;
+        $keys = $this->redis->keys($summaryKey.':*:meta');
+
+        $summaries = [];
+        foreach ($keys as $metaKeyWithPrefix) {
+            $metaKey = $this->removePrefixFromKey($metaKeyWithPrefix);
+            $rawSummary = $this->redis->get($metaKey);
+            if ($rawSummary === false) {
+                continue;
+            }
+            $summary = json_decode($rawSummary, true);
+            $metaData = $summary;
+            $data = [
+                'name' => $metaData['name'],
+                'help' => $metaData['help'],
+                'type' => $metaData['type'],
+                'labelNames' => $metaData['labelNames'],
+                'maxAgeSeconds' => $metaData['maxAgeSeconds'],
+                'quantiles' => $metaData['quantiles'],
+                'samples' => [],
+            ];
+
+            $values = $this->redis->keys($summaryKey.':'.$metaData['name'].':*:value');
+            foreach ($values as $valueKeyWithPrefix) {
+                $valueKey = $this->removePrefixFromKey($valueKeyWithPrefix);
+                $rawValue = $this->redis->get($valueKey);
+                if ($rawValue === false) {
+                    continue;
+                }
+                $value = json_decode($rawValue, true);
+                $encodedLabelValues = $value;
+                $decodedLabelValues = $this->decodeLabelValues($encodedLabelValues);
+
+                $samples = [];
+                $sampleValues = $this->redis->keys($summaryKey.':'.$metaData['name'].':'.$encodedLabelValues.':value:*');
+                foreach ($sampleValues as $sampleValueWithPrefix) {
+                    $sampleValue = $this->removePrefixFromKey($sampleValueWithPrefix);
+                    $samples[] = (float) $this->redis->get($sampleValue);
+                }
+
+                if (count($samples) === 0) {
+                    try {
+                        $this->redis->del($valueKey);
+                    } catch (RedisClientException $e) {
+                        // ignore if we can't delete the key
+                    }
+
+                    continue;
+                }
+
+                // Compute quantiles
+                sort($samples);
+                foreach ($data['quantiles'] as $quantile) {
+                    $data['samples'][] = [
+                        'name' => $metaData['name'],
+                        'labelNames' => ['quantile'],
+                        'labelValues' => array_merge($decodedLabelValues, [$quantile]),
+                        'value' => $math->quantile($samples, $quantile),
+                    ];
+                }
+
+                // Add the count
+                $data['samples'][] = [
+                    'name' => $metaData['name'].'_count',
+                    'labelNames' => [],
+                    'labelValues' => $decodedLabelValues,
+                    'value' => count($samples),
+                ];
+
+                // Add the sum
+                $data['samples'][] = [
+                    'name' => $metaData['name'].'_sum',
+                    'labelNames' => [],
+                    'labelValues' => $decodedLabelValues,
+                    'value' => array_sum($samples),
+                ];
+            }
+
+            if (count($data['samples']) > 0) {
+                $summaries[] = $data;
+            } else {
+                try {
+                    $this->redis->del($metaKey);
+                } catch (RedisClientException $e) {
+                    // ignore if we can't delete the key
+                }
+            }
+        }
+
+        return $summaries;
+    }
+
+    /**
+     * @return mixed[]
+     */
+    protected function collectGauges(bool $sortMetrics = true): array
+    {
+        $keys = $this->redis->sMembers(self::$prefix.Gauge::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX);
+        sort($keys);
+        $gauges = [];
+        foreach ($keys as $key) {
+            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getOption(RedisClient::OPT_PREFIX)));
+            if (! isset($raw['__meta'])) {
+                continue;
+            }
+            $gauge = json_decode($raw['__meta'], true);
+            unset($raw['__meta']);
+            $gauge['samples'] = [];
+            foreach ($raw as $k => $value) {
+                $gauge['samples'][] = [
+                    'name' => $gauge['name'],
+                    'labelNames' => [],
+                    'labelValues' => json_decode($k, true),
+                    'value' => $value,
+                ];
+                if (json_last_error() !== JSON_ERROR_NONE) {
+                    $this->throwMetricJsonException($key, $gauge['name']);
+                }
+            }
+
+            if ($sortMetrics) {
+                usort($gauge['samples'], function ($a, $b): int {
+                    return strcmp(implode('', $a['labelValues']), implode('', $b['labelValues']));
+                });
+            }
+
+            $gauges[] = $gauge;
+        }
+
+        return $gauges;
+    }
+
+    /**
+     * @return mixed[]
+     *
+     * @throws MetricJsonException
+     */
+    protected function collectCounters(bool $sortMetrics = true): array
+    {
+        $keys = $this->redis->sMembers(self::$prefix.Counter::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX);
+        sort($keys);
+        $counters = [];
+        foreach ($keys as $key) {
+            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getOption(RedisClient::OPT_PREFIX)));
+            if (! isset($raw['__meta'])) {
+                continue;
+            }
+            $counter = json_decode($raw['__meta'], true);
+
+            unset($raw['__meta']);
+            $counter['samples'] = [];
+            foreach ($raw as $k => $value) {
+                $counter['samples'][] = [
+                    'name' => $counter['name'],
+                    'labelNames' => [],
+                    'labelValues' => json_decode($k, true),
+                    'value' => $value,
+                ];
+
+                if (json_last_error() !== JSON_ERROR_NONE) {
+                    $this->throwMetricJsonException($key, $counter['name']);
+                }
+            }
+
+            if ($sortMetrics) {
+                usort($counter['samples'], function ($a, $b): int {
+                    return strcmp(implode('', $a['labelValues']), implode('', $b['labelValues']));
+                });
+            }
+
+            $counters[] = $counter;
+        }
+
+        return $counters;
+    }
+
+    protected function getRedisCommand(int $cmd): string
+    {
+        switch ($cmd) {
+            case Adapter::COMMAND_INCREMENT_INTEGER:
+                return 'hIncrBy';
+            case Adapter::COMMAND_INCREMENT_FLOAT:
+                return 'hIncrByFloat';
+            case Adapter::COMMAND_SET:
+                return 'hSet';
+            default:
+                throw new InvalidArgumentException('Unknown command');
+        }
+    }
+
+    /**
+     * @param  mixed[]  $data
+     */
+    protected function toMetricKey(array $data): string
+    {
+        return implode(':', [self::$prefix, $data['type'], $data['name']]);
+    }
+
+    /**
+     * @param  mixed[]  $values
+     *
+     * @throws RuntimeException
+     */
+    protected function encodeLabelValues(array $values): string
+    {
+        $json = json_encode($values);
+        if ($json === false) {
+            throw new RuntimeException(json_last_error_msg());
+        }
+
+        return base64_encode($json);
+    }
+
+    /**
+     * @return mixed[]
+     *
+     * @throws RuntimeException
+     */
+    protected function decodeLabelValues(string $values): array
+    {
+        $json = base64_decode($values, true);
+        if ($json === false) {
+            throw new RuntimeException('Cannot base64 decode label values');
+        }
+        $decodedValues = json_decode($json, true);
+        if ($decodedValues === false) {
+            throw new RuntimeException(json_last_error_msg());
+        }
+
+        return $decodedValues;
+    }
+
+    /**
+     * @throws MetricJsonException
+     */
+    protected function throwMetricJsonException(string $redisKey, ?string $metricName = null): void
+    {
+        $metricName = $metricName ?? 'unknown';
+        $message = 'Json error: '.json_last_error_msg().' redis key : '.$redisKey.' metric name: '.$metricName;
+        throw new MetricJsonException($message, 0, null, $metricName);
+    }
+}
diff --git a/src/Prometheus/Storage/Predis.php b/src/Prometheus/Storage/Predis.php
new file mode 100644
index 0000000..758ec79
--- /dev/null
+++ b/src/Prometheus/Storage/Predis.php
@@ -0,0 +1,94 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Prometheus\Storage;
+
+use Predis\Client;
+use Prometheus\Exception\StorageException;
+use Prometheus\Storage\RedisClients\Predis as PredisClient;
+
+class Predis extends AbstractRedis
+{
+    /**
+     * @var mixed[]
+     */
+    private static $defaultParameters = [
+        'scheme' => 'tcp',
+        'host' => '127.0.0.1',
+        'port' => 6379,
+        'timeout' => 0.1,
+        'read_write_timeout' => 10,
+        'persistent' => false,
+        'password' => null,
+        'username' => null,
+    ];
+
+    /**
+     * @var mixed[]
+     */
+    private static $defaultOptions = [
+        'prefix' => '',
+        'throw_errors' => true,
+    ];
+
+    /**
+     * @var mixed[]
+     */
+    private $parameters = [];
+
+    /**
+     * @var mixed[]
+     */
+    private $options = [];
+
+    /**
+     * Redis constructor.
+     *
+     * @param  mixed[]  $options
+     */
+    public function __construct(array $parameters = [], array $options = [])
+    {
+        $this->parameters = array_merge(self::$defaultParameters, $parameters);
+        $this->options = array_merge(self::$defaultOptions, $options);
+        $this->redis = PredisClient::create($this->parameters, $this->options);
+    }
+
+    /**
+     * @throws StorageException
+     */
+    public static function fromExistingConnection(Client $client): self
+    {
+        $options = $client->getOptions();
+        $allOptions = [
+            'aggregate' => $options->aggregate,
+            'cluster' => $options->cluster,
+            'connections' => $options->connections,
+            'exceptions' => $options->exceptions,
+            'prefix' => $options->prefix,
+            'commands' => $options->commands,
+            'replication' => $options->replication,
+        ];
+
+        $self = new self;
+        $self->redis = new PredisClient($client, self::$defaultParameters, $allOptions);
+
+        return $self;
+    }
+
+    /**
+     * @param  mixed[]  $parameters
+     */
+    public static function setDefaultParameters(array $parameters): void
+    {
+        self::$defaultParameters = array_merge(self::$defaultParameters, $parameters);
+    }
+
+    /**
+     * @param  mixed[]  $options
+     */
+    public static function setDefaultOptions(array $options): void
+    {
+        self::$defaultOptions = array_merge(self::$defaultOptions, $options);
+    }
+}
diff --git a/src/Prometheus/Storage/Redis.php b/src/Prometheus/Storage/Redis.php
index 2b11436..f13352a 100644
--- a/src/Prometheus/Storage/Redis.php
+++ b/src/Prometheus/Storage/Redis.php
@@ -4,26 +4,11 @@
 
 namespace Prometheus\Storage;
 
-use InvalidArgumentException;
-use Predis\Client;
-use Prometheus\Counter;
-use Prometheus\Exception\MetricJsonException;
 use Prometheus\Exception\StorageException;
-use Prometheus\Gauge;
-use Prometheus\Histogram;
-use Prometheus\Math;
-use Prometheus\MetricFamilySamples;
 use Prometheus\Storage\RedisClients\PHPRedis;
-use Prometheus\Storage\RedisClients\Predis;
-use Prometheus\Storage\RedisClients\RedisClient;
-use Prometheus\Storage\RedisClients\RedisClientException;
-use Prometheus\Summary;
-use RuntimeException;
 
-class Redis implements Adapter
+class Redis extends AbstractRedis
 {
-    const PROMETHEUS_METRIC_KEYS_SUFFIX = '_METRIC_KEYS';
-
     /**
      * @var mixed[]
      */
@@ -37,21 +22,11 @@ class Redis implements Adapter
         'user' => null,
     ];
 
-    /**
-     * @var string
-     */
-    private static $prefix = 'PROMETHEUS_';
-
     /**
      * @var mixed[]
      */
     private $options = [];
 
-    /**
-     * @var RedisClient
-     */
-    private $redis;
-
     /**
      * Redis constructor.
      *
@@ -66,20 +41,13 @@ public function __construct(array $options = [])
     /**
      * @throws StorageException
      */
-    public static function fromExistingConnection(\Redis|Client $redis): self
+    public static function fromExistingConnection(\Redis $redis): self
     {
-        $self = new self;
-
-        if ($redis instanceof Client) {
-            $self->redis = new Predis($redis);
-
-            return $self;
-        }
-
         if ($redis->isConnected() === false) {
             throw new StorageException('Connection to Redis server not established');
         }
 
+        $self = new self;
         $self->redis = new PHPRedis($redis, self::$defaultOptions);
 
         return $self;
@@ -92,600 +60,4 @@ public static function setDefaultOptions(array $options): void
     {
         self::$defaultOptions = array_merge(self::$defaultOptions, $options);
     }
-
-    public static function setPrefix(string $prefix): void
-    {
-        self::$prefix = $prefix;
-    }
-
-    /**
-     * @throws StorageException
-     *
-     * @deprecated use replacement method wipeStorage from Adapter interface
-     */
-    public function flushRedis(): void
-    {
-        $this->wipeStorage();
-    }
-
-    /**
-     * {@inheritDoc}
-     */
-    public function wipeStorage(): void
-    {
-        $this->redis->ensureOpenConnection();
-
-        $searchPattern = '';
-
-        $globalPrefix = $this->redis->getOption(RedisClient::OPT_PREFIX);
-        // @phpstan-ignore-next-line false positive, phpstan thinks getOptions returns int
-        if (is_string($globalPrefix)) {
-            $searchPattern .= $globalPrefix;
-        }
-
-        $searchPattern .= self::$prefix;
-        $searchPattern .= '*';
-
-        $this->redis->eval(
-            <<<'LUA'
-redis.replicate_commands()
-local cursor = "0"
-repeat 
-    local results = redis.call('SCAN', cursor, 'MATCH', ARGV[1])
-    cursor = results[1]
-    for _, key in ipairs(results[2]) do
-        redis.call('DEL', key)
-    end
-until cursor == "0"
-LUA
-            ,
-            [$searchPattern],
-            0
-        );
-    }
-
-    /**
-     * @param  mixed[]  $data
-     */
-    private function metaKey(array $data): string
-    {
-        return implode(':', [
-            $data['name'],
-            'meta',
-        ]);
-    }
-
-    /**
-     * @param  mixed[]  $data
-     */
-    private function valueKey(array $data): string
-    {
-        return implode(':', [
-            $data['name'],
-            $this->encodeLabelValues($data['labelValues']),
-            'value',
-        ]);
-    }
-
-    /**
-     * @return MetricFamilySamples[]
-     *
-     * @throws StorageException
-     */
-    public function collect(bool $sortMetrics = true): array
-    {
-        $this->redis->ensureOpenConnection();
-        $metrics = $this->collectHistograms();
-        $metrics = array_merge($metrics, $this->collectGauges($sortMetrics));
-        $metrics = array_merge($metrics, $this->collectCounters($sortMetrics));
-        $metrics = array_merge($metrics, $this->collectSummaries());
-
-        return array_map(
-            function (array $metric): MetricFamilySamples {
-                return new MetricFamilySamples($metric);
-            },
-            $metrics
-        );
-    }
-
-    /**
-     * @param  mixed[]  $data
-     *
-     * @throws StorageException
-     */
-    public function updateHistogram(array $data): void
-    {
-        $this->redis->ensureOpenConnection();
-        $bucketToIncrease = '+Inf';
-        foreach ($data['buckets'] as $bucket) {
-            if ($data['value'] <= $bucket) {
-                $bucketToIncrease = $bucket;
-                break;
-            }
-        }
-        $metaData = $data;
-        unset($metaData['value'], $metaData['labelValues']);
-
-        $this->redis->eval(
-            <<<'LUA'
-local result = redis.call('hIncrByFloat', KEYS[1], ARGV[1], ARGV[3])
-redis.call('hIncrBy', KEYS[1], ARGV[2], 1)
-if tonumber(result) >= tonumber(ARGV[3]) then
-    redis.call('hSet', KEYS[1], '__meta', ARGV[4])
-    redis.call('sAdd', KEYS[2], KEYS[1])
-end
-return result
-LUA
-            ,
-            [
-                $this->toMetricKey($data),
-                self::$prefix.Histogram::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX,
-                json_encode(['b' => 'sum', 'labelValues' => $data['labelValues']]),
-                json_encode(['b' => $bucketToIncrease, 'labelValues' => $data['labelValues']]),
-                $data['value'],
-                json_encode($metaData),
-            ],
-            2
-        );
-    }
-
-    /**
-     * @param  mixed[]  $data
-     *
-     * @throws StorageException
-     */
-    public function updateSummary(array $data): void
-    {
-        $this->redis->ensureOpenConnection();
-
-        // store meta
-        $summaryKey = self::$prefix.Summary::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX;
-        $metaKey = $summaryKey.':'.$this->metaKey($data);
-        $json = json_encode($this->metaData($data));
-        if ($json === false) {
-            throw new RuntimeException(json_last_error_msg());
-        }
-        $this->redis->setNx($metaKey, $json); /** @phpstan-ignore-line */
-
-        // store value key
-        $valueKey = $summaryKey.':'.$this->valueKey($data);
-        $json = json_encode($this->encodeLabelValues($data['labelValues']));
-        if ($json === false) {
-            throw new RuntimeException(json_last_error_msg());
-        }
-        $this->redis->setNx($valueKey, $json); /** @phpstan-ignore-line */
-
-        // trick to handle uniqid collision
-        $done = false;
-        while (! $done) {
-            $sampleKey = $valueKey.':'.uniqid('', true);
-            $done = $this->redis->set($sampleKey, $data['value'], ['NX', 'EX' => $data['maxAgeSeconds']]);
-        }
-    }
-
-    /**
-     * @param  mixed[]  $data
-     *
-     * @throws StorageException
-     */
-    public function updateGauge(array $data): void
-    {
-        $this->redis->ensureOpenConnection();
-        $metaData = $data;
-        unset($metaData['value'], $metaData['labelValues'], $metaData['command']);
-        $this->redis->eval(
-            <<<'LUA'
-local result = redis.call(ARGV[1], KEYS[1], ARGV[2], ARGV[3])
-
-if ARGV[1] == 'hSet' then
-    if result == 1 then
-        redis.call('hSet', KEYS[1], '__meta', ARGV[4])
-        redis.call('sAdd', KEYS[2], KEYS[1])
-    end
-else
-    if result == ARGV[3] then
-        redis.call('hSet', KEYS[1], '__meta', ARGV[4])
-        redis.call('sAdd', KEYS[2], KEYS[1])
-    end
-end
-LUA
-            ,
-            [
-                $this->toMetricKey($data),
-                self::$prefix.Gauge::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX,
-                $this->getRedisCommand($data['command']),
-                json_encode($data['labelValues']),
-                $data['value'],
-                json_encode($metaData),
-            ],
-            2
-        );
-    }
-
-    /**
-     * @param  mixed[]  $data
-     *
-     * @throws StorageException
-     */
-    public function updateCounter(array $data): void
-    {
-        $this->redis->ensureOpenConnection();
-        $metaData = $data;
-        unset($metaData['value'], $metaData['labelValues'], $metaData['command']);
-        $this->redis->eval(
-            <<<'LUA'
-local result = redis.call(ARGV[1], KEYS[1], ARGV[3], ARGV[2])
-local added = redis.call('sAdd', KEYS[2], KEYS[1])
-if added == 1 then
-    redis.call('hMSet', KEYS[1], '__meta', ARGV[4])
-end
-return result
-LUA
-            ,
-            [
-                $this->toMetricKey($data),
-                self::$prefix.Counter::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX,
-                $this->getRedisCommand($data['command']),
-                $data['value'],
-                json_encode($data['labelValues']),
-                json_encode($metaData),
-            ],
-            2
-        );
-    }
-
-    /**
-     * @param  mixed[]  $data
-     * @return mixed[]
-     */
-    private function metaData(array $data): array
-    {
-        $metricsMetaData = $data;
-        unset($metricsMetaData['value'], $metricsMetaData['command'], $metricsMetaData['labelValues']);
-
-        return $metricsMetaData;
-    }
-
-    /**
-     * @return mixed[]
-     */
-    private function collectHistograms(): array
-    {
-        $keys = $this->redis->sMembers(self::$prefix.Histogram::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX);
-        sort($keys);
-        $histograms = [];
-        foreach ($keys as $key) {
-            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getPrefix()));
-            if (! isset($raw['__meta'])) {
-                continue;
-            }
-            $histogram = json_decode($raw['__meta'], true);
-            unset($raw['__meta']);
-            $histogram['samples'] = [];
-
-            // Add the Inf bucket so we can compute it later on
-            $histogram['buckets'][] = '+Inf';
-
-            $allLabelValues = [];
-            foreach (array_keys($raw) as $k) {
-                $d = json_decode($k, true);
-                if ($d['b'] == 'sum') {
-                    continue;
-                }
-                $allLabelValues[] = $d['labelValues'];
-            }
-            if (json_last_error() !== JSON_ERROR_NONE) {
-                $this->throwMetricJsonException($key);
-            }
-
-            // We need set semantics.
-            // This is the equivalent of array_unique but for arrays of arrays.
-            $allLabelValues = array_map('unserialize', array_unique(array_map('serialize', $allLabelValues)));
-            sort($allLabelValues);
-
-            foreach ($allLabelValues as $labelValues) {
-                // Fill up all buckets.
-                // If the bucket doesn't exist fill in values from
-                // the previous one.
-                $acc = 0;
-                foreach ($histogram['buckets'] as $bucket) {
-                    $bucketKey = json_encode(['b' => $bucket, 'labelValues' => $labelValues]);
-                    if (! isset($raw[$bucketKey])) {
-                        $histogram['samples'][] = [
-                            'name' => $histogram['name'].'_bucket',
-                            'labelNames' => ['le'],
-                            'labelValues' => array_merge($labelValues, [$bucket]),
-                            'value' => $acc,
-                        ];
-                    } else {
-                        $acc += $raw[$bucketKey];
-                        $histogram['samples'][] = [
-                            'name' => $histogram['name'].'_bucket',
-                            'labelNames' => ['le'],
-                            'labelValues' => array_merge($labelValues, [$bucket]),
-                            'value' => $acc,
-                        ];
-                    }
-                }
-
-                // Add the count
-                $histogram['samples'][] = [
-                    'name' => $histogram['name'].'_count',
-                    'labelNames' => [],
-                    'labelValues' => $labelValues,
-                    'value' => $acc,
-                ];
-
-                // Add the sum
-                $histogram['samples'][] = [
-                    'name' => $histogram['name'].'_sum',
-                    'labelNames' => [],
-                    'labelValues' => $labelValues,
-                    'value' => $raw[json_encode(['b' => 'sum', 'labelValues' => $labelValues])],
-                ];
-            }
-            $histograms[] = $histogram;
-        }
-
-        return $histograms;
-    }
-
-    private function removePrefixFromKey(string $key): string
-    {
-        // @phpstan-ignore-next-line false positive, phpstan thinks getOptions returns int
-        if ($this->redis->getOption(RedisClient::OPT_PREFIX) === null) {
-            return $key;
-        }
-
-        // @phpstan-ignore-next-line false positive, phpstan thinks getOptions returns int
-        return substr($key, strlen($this->redis->getOption(RedisClient::OPT_PREFIX)));
-    }
-
-    /**
-     * @return mixed[]
-     */
-    private function collectSummaries(): array
-    {
-        $math = new Math;
-        $summaryKey = self::$prefix.Summary::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX;
-        $keys = $this->redis->keys($summaryKey.':*:meta');
-
-        $summaries = [];
-        foreach ($keys as $metaKeyWithPrefix) {
-            $metaKey = $this->removePrefixFromKey($metaKeyWithPrefix);
-            $rawSummary = $this->redis->get($metaKey);
-            if ($rawSummary === false) {
-                continue;
-            }
-            $summary = json_decode($rawSummary, true);
-            $metaData = $summary;
-            $data = [
-                'name' => $metaData['name'],
-                'help' => $metaData['help'],
-                'type' => $metaData['type'],
-                'labelNames' => $metaData['labelNames'],
-                'maxAgeSeconds' => $metaData['maxAgeSeconds'],
-                'quantiles' => $metaData['quantiles'],
-                'samples' => [],
-            ];
-
-            $values = $this->redis->keys($summaryKey.':'.$metaData['name'].':*:value');
-            foreach ($values as $valueKeyWithPrefix) {
-                $valueKey = $this->removePrefixFromKey($valueKeyWithPrefix);
-                $rawValue = $this->redis->get($valueKey);
-                if ($rawValue === false) {
-                    continue;
-                }
-                $value = json_decode($rawValue, true);
-                $encodedLabelValues = $value;
-                $decodedLabelValues = $this->decodeLabelValues($encodedLabelValues);
-
-                $samples = [];
-                $sampleValues = $this->redis->keys($summaryKey.':'.$metaData['name'].':'.$encodedLabelValues.':value:*');
-                foreach ($sampleValues as $sampleValueWithPrefix) {
-                    $sampleValue = $this->removePrefixFromKey($sampleValueWithPrefix);
-                    $samples[] = (float) $this->redis->get($sampleValue);
-                }
-
-                if (count($samples) === 0) {
-                    try {
-                        $this->redis->del($valueKey);
-                    } catch (RedisClientException $e) {
-                        // ignore if we can't delete the key
-                    }
-
-                    continue;
-                }
-
-                // Compute quantiles
-                sort($samples);
-                foreach ($data['quantiles'] as $quantile) {
-                    $data['samples'][] = [
-                        'name' => $metaData['name'],
-                        'labelNames' => ['quantile'],
-                        'labelValues' => array_merge($decodedLabelValues, [$quantile]),
-                        'value' => $math->quantile($samples, $quantile),
-                    ];
-                }
-
-                // Add the count
-                $data['samples'][] = [
-                    'name' => $metaData['name'].'_count',
-                    'labelNames' => [],
-                    'labelValues' => $decodedLabelValues,
-                    'value' => count($samples),
-                ];
-
-                // Add the sum
-                $data['samples'][] = [
-                    'name' => $metaData['name'].'_sum',
-                    'labelNames' => [],
-                    'labelValues' => $decodedLabelValues,
-                    'value' => array_sum($samples),
-                ];
-            }
-
-            if (count($data['samples']) > 0) {
-                $summaries[] = $data;
-            } else {
-                try {
-                    $this->redis->del($metaKey);
-                } catch (RedisClientException $e) {
-                    // ignore if we can't delete the key
-                }
-            }
-        }
-
-        return $summaries;
-    }
-
-    /**
-     * @return mixed[]
-     */
-    private function collectGauges(bool $sortMetrics = true): array
-    {
-        $keys = $this->redis->sMembers(self::$prefix.Gauge::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX);
-        sort($keys);
-        $gauges = [];
-        foreach ($keys as $key) {
-            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getPrefix()));
-            if (! isset($raw['__meta'])) {
-                continue;
-            }
-            $gauge = json_decode($raw['__meta'], true);
-            unset($raw['__meta']);
-            $gauge['samples'] = [];
-            foreach ($raw as $k => $value) {
-                $gauge['samples'][] = [
-                    'name' => $gauge['name'],
-                    'labelNames' => [],
-                    'labelValues' => json_decode($k, true),
-                    'value' => $value,
-                ];
-                if (json_last_error() !== JSON_ERROR_NONE) {
-                    $this->throwMetricJsonException($key, $gauge['name']);
-                }
-            }
-
-            if ($sortMetrics) {
-                usort($gauge['samples'], function ($a, $b): int {
-                    return strcmp(implode('', $a['labelValues']), implode('', $b['labelValues']));
-                });
-            }
-
-            $gauges[] = $gauge;
-        }
-
-        return $gauges;
-    }
-
-    /**
-     * @return mixed[]
-     *
-     * @throws MetricJsonException
-     */
-    private function collectCounters(bool $sortMetrics = true): array
-    {
-        $keys = $this->redis->sMembers(self::$prefix.Counter::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX);
-        sort($keys);
-        $counters = [];
-        foreach ($keys as $key) {
-            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getPrefix()));
-            if (! isset($raw['__meta'])) {
-                continue;
-            }
-            $counter = json_decode($raw['__meta'], true);
-
-            unset($raw['__meta']);
-            $counter['samples'] = [];
-            foreach ($raw as $k => $value) {
-                $counter['samples'][] = [
-                    'name' => $counter['name'],
-                    'labelNames' => [],
-                    'labelValues' => json_decode($k, true),
-                    'value' => $value,
-                ];
-
-                if (json_last_error() !== JSON_ERROR_NONE) {
-                    $this->throwMetricJsonException($key, $counter['name']);
-                }
-            }
-
-            if ($sortMetrics) {
-                usort($counter['samples'], function ($a, $b): int {
-                    return strcmp(implode('', $a['labelValues']), implode('', $b['labelValues']));
-                });
-            }
-
-            $counters[] = $counter;
-        }
-
-        return $counters;
-    }
-
-    private function getRedisCommand(int $cmd): string
-    {
-        switch ($cmd) {
-            case Adapter::COMMAND_INCREMENT_INTEGER:
-                return 'hIncrBy';
-            case Adapter::COMMAND_INCREMENT_FLOAT:
-                return 'hIncrByFloat';
-            case Adapter::COMMAND_SET:
-                return 'hSet';
-            default:
-                throw new InvalidArgumentException('Unknown command');
-        }
-    }
-
-    /**
-     * @param  mixed[]  $data
-     */
-    private function toMetricKey(array $data): string
-    {
-        return implode(':', [self::$prefix, $data['type'], $data['name']]);
-    }
-
-    /**
-     * @param  mixed[]  $values
-     *
-     * @throws RuntimeException
-     */
-    private function encodeLabelValues(array $values): string
-    {
-        $json = json_encode($values);
-        if ($json === false) {
-            throw new RuntimeException(json_last_error_msg());
-        }
-
-        return base64_encode($json);
-    }
-
-    /**
-     * @return mixed[]
-     *
-     * @throws RuntimeException
-     */
-    private function decodeLabelValues(string $values): array
-    {
-        $json = base64_decode($values, true);
-        if ($json === false) {
-            throw new RuntimeException('Cannot base64 decode label values');
-        }
-        $decodedValues = json_decode($json, true);
-        if ($decodedValues === false) {
-            throw new RuntimeException(json_last_error_msg());
-        }
-
-        return $decodedValues;
-    }
-
-    /**
-     * @throws MetricJsonException
-     */
-    private function throwMetricJsonException(string $redisKey, ?string $metricName = null): void
-    {
-        $metricName = $metricName ?? 'unknown';
-        $message = 'Json error: '.json_last_error_msg().' redis key : '.$redisKey.' metric name: '.$metricName;
-        throw new MetricJsonException($message, 0, null, $metricName);
-    }
 }
diff --git a/tests/Test/Prometheus/Predis/CollectorRegistryTest.php b/tests/Test/Prometheus/Predis/CollectorRegistryTest.php
index 2add921..8a79852 100644
--- a/tests/Test/Prometheus/Predis/CollectorRegistryTest.php
+++ b/tests/Test/Prometheus/Predis/CollectorRegistryTest.php
@@ -4,8 +4,7 @@
 
 namespace Test\Prometheus\Predis;
 
-use Predis\Client;
-use Prometheus\Storage\Redis;
+use Prometheus\Storage\Predis;
 use Test\Prometheus\AbstractCollectorRegistryTest;
 
 /**
@@ -15,9 +14,7 @@ class CollectorRegistryTest extends AbstractCollectorRegistryTest
 {
     public function configureAdapter(): void
     {
-        $connection = new Client(['host' => REDIS_HOST]);
-
-        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter = new Predis(['host' => REDIS_HOST]);
         $this->adapter->wipeStorage();
     }
 }
diff --git a/tests/Test/Prometheus/Predis/CounterTest.php b/tests/Test/Prometheus/Predis/CounterTest.php
index a35b51c..fa610e1 100644
--- a/tests/Test/Prometheus/Predis/CounterTest.php
+++ b/tests/Test/Prometheus/Predis/CounterTest.php
@@ -4,8 +4,7 @@
 
 namespace Test\Prometheus\Predis;
 
-use Predis\Client;
-use Prometheus\Storage\Redis;
+use Prometheus\Storage\Predis;
 use Test\Prometheus\AbstractCounterTest;
 
 /**
@@ -17,9 +16,7 @@ class CounterTest extends AbstractCounterTest
 {
     public function configureAdapter(): void
     {
-        $connection = new Client(['host' => REDIS_HOST]);
-
-        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter = new Predis(['host' => REDIS_HOST]);
         $this->adapter->wipeStorage();
     }
 }
diff --git a/tests/Test/Prometheus/Predis/CounterWithPrefixTest.php b/tests/Test/Prometheus/Predis/CounterWithPrefixTest.php
index c4636b0..7283572 100644
--- a/tests/Test/Prometheus/Predis/CounterWithPrefixTest.php
+++ b/tests/Test/Prometheus/Predis/CounterWithPrefixTest.php
@@ -4,8 +4,7 @@
 
 namespace Test\Prometheus\Predis;
 
-use Predis\Client;
-use Prometheus\Storage\Redis;
+use Prometheus\Storage\Predis;
 use Test\Prometheus\AbstractCounterTest;
 
 /**
@@ -17,9 +16,7 @@ class CounterWithPrefixTest extends AbstractCounterTest
 {
     public function configureAdapter(): void
     {
-        $connection = new Client(['host' => REDIS_HOST, 'prefix' => 'prefix:']);
-
-        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter = new Predis(['host' => REDIS_HOST], ['prefix' => 'prefix:']);
         $this->adapter->wipeStorage();
     }
 }
diff --git a/tests/Test/Prometheus/Predis/GaugeTest.php b/tests/Test/Prometheus/Predis/GaugeTest.php
index f141861..9d48ec1 100644
--- a/tests/Test/Prometheus/Predis/GaugeTest.php
+++ b/tests/Test/Prometheus/Predis/GaugeTest.php
@@ -4,8 +4,7 @@
 
 namespace Test\Prometheus\Predis;
 
-use Predis\Client;
-use Prometheus\Storage\Redis;
+use Prometheus\Storage\Predis;
 use Test\Prometheus\AbstractGaugeTest;
 
 /**
@@ -17,9 +16,7 @@ class GaugeTest extends AbstractGaugeTest
 {
     public function configureAdapter(): void
     {
-        $connection = new Client(['host' => REDIS_HOST]);
-
-        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter = new Predis(['host' => REDIS_HOST]);
         $this->adapter->wipeStorage();
     }
 }
diff --git a/tests/Test/Prometheus/Predis/GaugeWithPrefixTest.php b/tests/Test/Prometheus/Predis/GaugeWithPrefixTest.php
index dcc5748..4f3dc21 100644
--- a/tests/Test/Prometheus/Predis/GaugeWithPrefixTest.php
+++ b/tests/Test/Prometheus/Predis/GaugeWithPrefixTest.php
@@ -4,8 +4,7 @@
 
 namespace Test\Prometheus\Predis;
 
-use Predis\Client;
-use Prometheus\Storage\Redis;
+use Prometheus\Storage\Predis;
 use Test\Prometheus\AbstractGaugeTest;
 
 /**
@@ -17,9 +16,7 @@ class GaugeWithPrefixTest extends AbstractGaugeTest
 {
     public function configureAdapter(): void
     {
-        $connection = new Client(['host' => REDIS_HOST, 'prefix' => 'prefix:']);
-
-        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter = new Predis(['host' => REDIS_HOST], ['prefix' => 'prefix:']);
         $this->adapter->wipeStorage();
     }
 }
diff --git a/tests/Test/Prometheus/Predis/HistogramTest.php b/tests/Test/Prometheus/Predis/HistogramTest.php
index 2d2b670..f4148b9 100644
--- a/tests/Test/Prometheus/Predis/HistogramTest.php
+++ b/tests/Test/Prometheus/Predis/HistogramTest.php
@@ -4,8 +4,7 @@
 
 namespace Test\Prometheus\Predis;
 
-use Predis\Client;
-use Prometheus\Storage\Redis;
+use Prometheus\Storage\Predis;
 use Test\Prometheus\AbstractHistogramTest;
 
 /**
@@ -17,9 +16,7 @@ class HistogramTest extends AbstractHistogramTest
 {
     public function configureAdapter(): void
     {
-        $connection = new Client(['host' => REDIS_HOST]);
-
-        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter = new Predis(['host' => REDIS_HOST]);
         $this->adapter->wipeStorage();
     }
 }
diff --git a/tests/Test/Prometheus/Predis/HistogramWithPrefixTest.php b/tests/Test/Prometheus/Predis/HistogramWithPrefixTest.php
index bf5f8ea..751a44a 100644
--- a/tests/Test/Prometheus/Predis/HistogramWithPrefixTest.php
+++ b/tests/Test/Prometheus/Predis/HistogramWithPrefixTest.php
@@ -4,8 +4,7 @@
 
 namespace Test\Prometheus\Predis;
 
-use Predis\Client;
-use Prometheus\Storage\Redis;
+use Prometheus\Storage\Predis;
 use Test\Prometheus\AbstractHistogramTest;
 
 /**
@@ -17,9 +16,7 @@ class HistogramWithPrefixTest extends AbstractHistogramTest
 {
     public function configureAdapter(): void
     {
-        $connection = new Client(['host' => REDIS_HOST, 'prefix' => 'prefix:']);
-
-        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter = new Predis(['host' => REDIS_HOST], ['prefix' => 'prefix:']);
         $this->adapter->wipeStorage();
     }
 }
diff --git a/tests/Test/Prometheus/Predis/SummaryTest.php b/tests/Test/Prometheus/Predis/SummaryTest.php
index 430bf6b..3566769 100644
--- a/tests/Test/Prometheus/Predis/SummaryTest.php
+++ b/tests/Test/Prometheus/Predis/SummaryTest.php
@@ -4,8 +4,7 @@
 
 namespace Test\Prometheus\Predis;
 
-use Predis\Client;
-use Prometheus\Storage\Redis;
+use Prometheus\Storage\Predis;
 use Test\Prometheus\AbstractSummaryTest;
 
 /**
@@ -17,9 +16,7 @@ class SummaryTest extends AbstractSummaryTest
 {
     public function configureAdapter(): void
     {
-        $connection = new Client(['host' => REDIS_HOST]);
-
-        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter = new Predis(['host' => REDIS_HOST]);
         $this->adapter->wipeStorage();
     }
 
diff --git a/tests/Test/Prometheus/Predis/SummaryWithPrefixTest.php b/tests/Test/Prometheus/Predis/SummaryWithPrefixTest.php
index d6bd40a..1c1d164 100644
--- a/tests/Test/Prometheus/Predis/SummaryWithPrefixTest.php
+++ b/tests/Test/Prometheus/Predis/SummaryWithPrefixTest.php
@@ -4,8 +4,7 @@
 
 namespace Test\Prometheus\Predis;
 
-use Predis\Client;
-use Prometheus\Storage\Redis;
+use Prometheus\Storage\Predis;
 use Test\Prometheus\AbstractSummaryTest;
 
 /**
@@ -17,9 +16,7 @@ class SummaryWithPrefixTest extends AbstractSummaryTest
 {
     public function configureAdapter(): void
     {
-        $connection = new Client(['host' => REDIS_HOST, 'prefix' => 'prefix:']);
-
-        $this->adapter = Redis::fromExistingConnection($connection);
+        $this->adapter = new Predis(['host' => REDIS_HOST], ['prefix' => 'prefix:']);
         $this->adapter->wipeStorage();
     }
 }

From 30387342d3b70c6d7ac45b9bdc533d26c1d9c118 Mon Sep 17 00:00:00 2001
From: Mateusz Cholewka <mateusz@cholewka.com.pl>
Date: Wed, 30 Apr 2025 15:05:18 +0200
Subject: [PATCH 07/14] fix: add phpdocs

Signed-off-by: Mateusz Cholewka <mateusz@cholewka.com.pl>
---
 src/Prometheus/Storage/AbstractRedis.php      |  7 ++---
 src/Prometheus/Storage/Predis.php             |  3 ++-
 .../Storage/RedisClients/PHPRedis.php         | 17 +++++++++---
 .../Storage/RedisClients/Predis.php           | 27 ++++++++++++++++---
 .../Storage/RedisClients/RedisClient.php      | 19 +++++++++++--
 5 files changed, 57 insertions(+), 16 deletions(-)

diff --git a/src/Prometheus/Storage/AbstractRedis.php b/src/Prometheus/Storage/AbstractRedis.php
index 4cab84d..820d7d8 100644
--- a/src/Prometheus/Storage/AbstractRedis.php
+++ b/src/Prometheus/Storage/AbstractRedis.php
@@ -56,7 +56,6 @@ public function wipeStorage(): void
         $searchPattern = '';
 
         $globalPrefix = $this->redis->getOption(RedisClient::OPT_PREFIX);
-        // @phpstan-ignore-next-line false positive, phpstan thinks getOptions returns int
         if (is_string($globalPrefix)) {
             $searchPattern .= $globalPrefix;
         }
@@ -183,7 +182,7 @@ public function updateSummary(array $data): void
         if ($json === false) {
             throw new RuntimeException(json_last_error_msg());
         }
-        $this->redis->setNx($metaKey, $json); /** @phpstan-ignore-line */
+        $this->redis->setNx($metaKey, $json);
 
         // store value key
         $valueKey = $summaryKey.':'.$this->valueKey($data);
@@ -191,7 +190,7 @@ public function updateSummary(array $data): void
         if ($json === false) {
             throw new RuntimeException(json_last_error_msg());
         }
-        $this->redis->setNx($valueKey, $json); /** @phpstan-ignore-line */
+        $this->redis->setNx($valueKey, $json);
 
         // trick to handle uniqid collision
         $done = false;
@@ -370,12 +369,10 @@ protected function collectHistograms(): array
 
     protected function removePrefixFromKey(string $key): string
     {
-        // @phpstan-ignore-next-line false positive, phpstan thinks getOptions returns int
         if ($this->redis->getOption(RedisClient::OPT_PREFIX) === null) {
             return $key;
         }
 
-        // @phpstan-ignore-next-line false positive, phpstan thinks getOptions returns int
         return substr($key, strlen($this->redis->getOption(RedisClient::OPT_PREFIX)));
     }
 
diff --git a/src/Prometheus/Storage/Predis.php b/src/Prometheus/Storage/Predis.php
index 758ec79..a12e58b 100644
--- a/src/Prometheus/Storage/Predis.php
+++ b/src/Prometheus/Storage/Predis.php
@@ -45,6 +45,7 @@ class Predis extends AbstractRedis
     /**
      * Redis constructor.
      *
+     * @param  mixed[]  $parameters
      * @param  mixed[]  $options
      */
     public function __construct(array $parameters = [], array $options = [])
@@ -71,7 +72,7 @@ public static function fromExistingConnection(Client $client): self
         ];
 
         $self = new self;
-        $self->redis = new PredisClient($client, self::$defaultParameters, $allOptions);
+        $self->redis = new PredisClient($client, $allOptions);
 
         return $self;
     }
diff --git a/src/Prometheus/Storage/RedisClients/PHPRedis.php b/src/Prometheus/Storage/RedisClients/PHPRedis.php
index 9dcfbbf..59c1da0 100644
--- a/src/Prometheus/Storage/RedisClients/PHPRedis.php
+++ b/src/Prometheus/Storage/RedisClients/PHPRedis.php
@@ -13,6 +13,9 @@ class PHPRedis implements RedisClient
      */
     private $redis;
 
+    /**
+     * @var mixed[]
+     */
     private $options = [];
 
     /**
@@ -20,12 +23,18 @@ class PHPRedis implements RedisClient
      */
     private $connectionInitialized = false;
 
+    /**
+     * @param  mixed[]  $options
+     */
     public function __construct(\Redis $redis, array $options)
     {
         $this->redis = $redis;
         $this->options = $options;
     }
 
+    /**
+     * @param  mixed[]  $options
+     */
     public static function create(array $options): self
     {
         $redis = new \Redis;
@@ -43,14 +52,14 @@ public function eval(string $script, array $args = [], int $num_keys = 0): void
         $this->redis->eval($script, $args, $num_keys);
     }
 
-    public function set(string $key, mixed $value, mixed $options = null): void
+    public function set(string $key, mixed $value, mixed $options = null): bool
     {
-        $this->redis->set($key, $value, $options);
+        return $this->redis->set($key, $value, $options);
     }
 
     public function setNx(string $key, mixed $value): void
     {
-        $this->redis->setNx($key, $value);
+        $this->redis->setNx($key, $value); /** @phpstan-ignore-line */
     }
 
     public function hSetNx(string $key, string $field, mixed $value): bool
@@ -58,7 +67,7 @@ public function hSetNx(string $key, string $field, mixed $value): bool
         return $this->redis->hSetNx($key, $field, $value);
     }
 
-    public function sMembers(string $key): array|false
+    public function sMembers(string $key): array
     {
         return $this->redis->sMembers($key);
     }
diff --git a/src/Prometheus/Storage/RedisClients/Predis.php b/src/Prometheus/Storage/RedisClients/Predis.php
index c2d0c65..562df6d 100644
--- a/src/Prometheus/Storage/RedisClients/Predis.php
+++ b/src/Prometheus/Storage/RedisClients/Predis.php
@@ -12,10 +12,19 @@ class Predis implements RedisClient
         RedisClient::OPT_PREFIX => 'prefix',
     ];
 
+    /**
+     * @var Client
+     */
     private $client;
 
+    /**
+     * @var mixed[]
+     */
     private $options = [];
 
+    /**
+     * @param  mixed[]  $options
+     */
     public function __construct(Client $redis, array $options)
     {
         $this->client = $redis;
@@ -23,6 +32,10 @@ public function __construct(Client $redis, array $options)
         $this->options = $options;
     }
 
+    /**
+     * @param  mixed[]  $parameters
+     * @param  mixed[]  $options
+     */
     public static function create(array $parameters, array $options): self
     {
         $redisClient = new Client($parameters, $options);
@@ -46,11 +59,17 @@ public function eval(string $script, array $args = [], int $num_keys = 0): void
         $this->client->eval($script, $num_keys, ...$args);
     }
 
-    public function set(string $key, mixed $value, mixed $options = null): void
+    public function set(string $key, mixed $value, mixed $options = null): bool
     {
-        $this->client->set($key, $value, ...$this->flattenFlags($options));
+        $result = $this->client->set($key, $value, ...$this->flattenFlags($options));
+
+        return (string) $result === 'OK';
     }
 
+    /**
+     * @param  array<int|string, mixed>  $flags
+     * @return mixed[]
+     */
     private function flattenFlags(array $flags): array
     {
         $result = [];
@@ -73,10 +92,10 @@ public function setNx(string $key, mixed $value): void
 
     public function hSetNx(string $key, string $field, mixed $value): bool
     {
-        return $this->hsetnx($key, $field, $value);
+        return $this->hSetNx($key, $field, $value);
     }
 
-    public function sMembers(string $key): array|false
+    public function sMembers(string $key): array
     {
         return $this->client->smembers($key);
     }
diff --git a/src/Prometheus/Storage/RedisClients/RedisClient.php b/src/Prometheus/Storage/RedisClients/RedisClient.php
index 89eadcb..e9149e4 100644
--- a/src/Prometheus/Storage/RedisClients/RedisClient.php
+++ b/src/Prometheus/Storage/RedisClients/RedisClient.php
@@ -12,22 +12,37 @@ interface RedisClient
 
     public function getOption(int $option): mixed;
 
+    /**
+     * @param  mixed[]  $args
+     */
     public function eval(string $script, array $args = [], int $num_keys = 0): void;
 
-    public function set(string $key, mixed $value, mixed $options = null): void;
+    public function set(string $key, mixed $value, mixed $options = null): bool;
 
     public function setNx(string $key, mixed $value): void;
 
     public function hSetNx(string $key, string $field, mixed $value): bool;
 
-    public function sMembers(string $key): array|false;
+    /**
+     * @return string[]
+     */
+    public function sMembers(string $key): array;
 
+    /**
+     * @return array<string, string>|false
+     */
     public function hGetAll(string $key): array|false;
 
+    /**
+     * @return string[]
+     */
     public function keys(string $pattern);
 
     public function get(string $key): mixed;
 
+    /**
+     * @param  string|string[]  $key
+     */
     public function del(array|string $key, string ...$other_keys): void;
 
     public function ensureOpenConnection(): void;

From d3b122251ca88070b3c6c20b4ed12f82e5273085 Mon Sep 17 00:00:00 2001
From: Mateusz Cholewka <mateusz@cholewka.com.pl>
Date: Wed, 30 Apr 2025 15:11:51 +0200
Subject: [PATCH 08/14] fix: bring _prefix() back

Signed-off-by: Mateusz Cholewka <mateusz@cholewka.com.pl>
---
 src/Prometheus/Storage/AbstractRedis.php            | 8 ++++----
 src/Prometheus/Storage/RedisClients/PHPRedis.php    | 5 +++++
 src/Prometheus/Storage/RedisClients/Predis.php      | 5 +++++
 src/Prometheus/Storage/RedisClients/RedisClient.php | 2 ++
 4 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/Prometheus/Storage/AbstractRedis.php b/src/Prometheus/Storage/AbstractRedis.php
index 820d7d8..dedd2c7 100644
--- a/src/Prometheus/Storage/AbstractRedis.php
+++ b/src/Prometheus/Storage/AbstractRedis.php
@@ -292,7 +292,7 @@ protected function collectHistograms(): array
         sort($keys);
         $histograms = [];
         foreach ($keys as $key) {
-            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getOption(RedisClient::OPT_PREFIX)));
+            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->prefix('')));
             if (! isset($raw['__meta'])) {
                 continue;
             }
@@ -373,7 +373,7 @@ protected function removePrefixFromKey(string $key): string
             return $key;
         }
 
-        return substr($key, strlen($this->redis->getOption(RedisClient::OPT_PREFIX)));
+        return substr($key, strlen($this->redis->prefix('')));
     }
 
     /**
@@ -483,7 +483,7 @@ protected function collectGauges(bool $sortMetrics = true): array
         sort($keys);
         $gauges = [];
         foreach ($keys as $key) {
-            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getOption(RedisClient::OPT_PREFIX)));
+            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->prefix('')));
             if (! isset($raw['__meta'])) {
                 continue;
             }
@@ -525,7 +525,7 @@ protected function collectCounters(bool $sortMetrics = true): array
         sort($keys);
         $counters = [];
         foreach ($keys as $key) {
-            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getOption(RedisClient::OPT_PREFIX)));
+            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->prefix('')));
             if (! isset($raw['__meta'])) {
                 continue;
             }
diff --git a/src/Prometheus/Storage/RedisClients/PHPRedis.php b/src/Prometheus/Storage/RedisClients/PHPRedis.php
index 59c1da0..f224806 100644
--- a/src/Prometheus/Storage/RedisClients/PHPRedis.php
+++ b/src/Prometheus/Storage/RedisClients/PHPRedis.php
@@ -96,6 +96,11 @@ public function del(array|string $key, string ...$other_keys): void
         }
     }
 
+    public function prefix(string $key): string
+    {
+        return $this->redis->_prefix($key);
+    }
+
     /**
      * @throws StorageException
      */
diff --git a/src/Prometheus/Storage/RedisClients/Predis.php b/src/Prometheus/Storage/RedisClients/Predis.php
index 562df6d..9cfe7ee 100644
--- a/src/Prometheus/Storage/RedisClients/Predis.php
+++ b/src/Prometheus/Storage/RedisClients/Predis.php
@@ -120,6 +120,11 @@ public function del(array|string $key, string ...$other_keys): void
         $this->client->del($key, ...$other_keys);
     }
 
+    public function prefix(string $key): string
+    {
+        return $this->getOption(RedisClient::OPT_PREFIX).$key;
+    }
+
     public function ensureOpenConnection(): void
     {
         // Predis doesn't require to trigger connection
diff --git a/src/Prometheus/Storage/RedisClients/RedisClient.php b/src/Prometheus/Storage/RedisClients/RedisClient.php
index e9149e4..cfc8b83 100644
--- a/src/Prometheus/Storage/RedisClients/RedisClient.php
+++ b/src/Prometheus/Storage/RedisClients/RedisClient.php
@@ -45,5 +45,7 @@ public function get(string $key): mixed;
      */
     public function del(array|string $key, string ...$other_keys): void;
 
+    public function prefix(string $key): string;
+
     public function ensureOpenConnection(): void;
 }

From 004381bf5a29a6217a2062ded77ce043af8a9310 Mon Sep 17 00:00:00 2001
From: Mateusz Cholewka <mateusz@cholewka.com.pl>
Date: Wed, 30 Apr 2025 15:30:37 +0200
Subject: [PATCH 09/14] fix: fix prefix for PHPRedis

Signed-off-by: Mateusz Cholewka <mateusz@cholewka.com.pl>
---
 src/Prometheus/Storage/AbstractRedis.php         |  8 ++++----
 src/Prometheus/Storage/Redis.php                 |  2 +-
 src/Prometheus/Storage/RedisClients/PHPRedis.php | 16 +++++++++++-----
 src/Prometheus/Storage/RedisClients/Predis.php   |  5 -----
 .../Storage/RedisClients/RedisClient.php         |  2 --
 5 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/src/Prometheus/Storage/AbstractRedis.php b/src/Prometheus/Storage/AbstractRedis.php
index dedd2c7..fac0e96 100644
--- a/src/Prometheus/Storage/AbstractRedis.php
+++ b/src/Prometheus/Storage/AbstractRedis.php
@@ -292,7 +292,7 @@ protected function collectHistograms(): array
         sort($keys);
         $histograms = [];
         foreach ($keys as $key) {
-            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->prefix('')));
+            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getOption(RedisClient::OPT_PREFIX) ?? ''));
             if (! isset($raw['__meta'])) {
                 continue;
             }
@@ -373,7 +373,7 @@ protected function removePrefixFromKey(string $key): string
             return $key;
         }
 
-        return substr($key, strlen($this->redis->prefix('')));
+        return substr($key, strlen($this->redis->getOption(RedisClient::OPT_PREFIX)));
     }
 
     /**
@@ -483,7 +483,7 @@ protected function collectGauges(bool $sortMetrics = true): array
         sort($keys);
         $gauges = [];
         foreach ($keys as $key) {
-            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->prefix('')));
+            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getOption(RedisClient::OPT_PREFIX) ?? ''));
             if (! isset($raw['__meta'])) {
                 continue;
             }
@@ -525,7 +525,7 @@ protected function collectCounters(bool $sortMetrics = true): array
         sort($keys);
         $counters = [];
         foreach ($keys as $key) {
-            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->prefix('')));
+            $raw = $this->redis->hGetAll(ltrim($key, $this->redis->getOption(RedisClient::OPT_PREFIX) ?? ''));
             if (! isset($raw['__meta'])) {
                 continue;
             }
diff --git a/src/Prometheus/Storage/Redis.php b/src/Prometheus/Storage/Redis.php
index f13352a..64422b7 100644
--- a/src/Prometheus/Storage/Redis.php
+++ b/src/Prometheus/Storage/Redis.php
@@ -48,7 +48,7 @@ public static function fromExistingConnection(\Redis $redis): self
         }
 
         $self = new self;
-        $self->redis = new PHPRedis($redis, self::$defaultOptions);
+        $self->redis = PHPRedis::fromExistingConnection($redis, self::$defaultOptions);
 
         return $self;
     }
diff --git a/src/Prometheus/Storage/RedisClients/PHPRedis.php b/src/Prometheus/Storage/RedisClients/PHPRedis.php
index f224806..b3edabf 100644
--- a/src/Prometheus/Storage/RedisClients/PHPRedis.php
+++ b/src/Prometheus/Storage/RedisClients/PHPRedis.php
@@ -42,6 +42,17 @@ public static function create(array $options): self
         return new self($redis, $options);
     }
 
+    /**
+     * @param  mixed[]  $options
+     */
+    public static function fromExistingConnection(\Redis $redis, array $options): self
+    {
+        $self = new self($redis, $options);
+        $self->connectionInitialized = true;
+
+        return $self;
+    }
+
     public function getOption(int $option): mixed
     {
         return $this->redis->getOption($option);
@@ -96,11 +107,6 @@ public function del(array|string $key, string ...$other_keys): void
         }
     }
 
-    public function prefix(string $key): string
-    {
-        return $this->redis->_prefix($key);
-    }
-
     /**
      * @throws StorageException
      */
diff --git a/src/Prometheus/Storage/RedisClients/Predis.php b/src/Prometheus/Storage/RedisClients/Predis.php
index 9cfe7ee..562df6d 100644
--- a/src/Prometheus/Storage/RedisClients/Predis.php
+++ b/src/Prometheus/Storage/RedisClients/Predis.php
@@ -120,11 +120,6 @@ public function del(array|string $key, string ...$other_keys): void
         $this->client->del($key, ...$other_keys);
     }
 
-    public function prefix(string $key): string
-    {
-        return $this->getOption(RedisClient::OPT_PREFIX).$key;
-    }
-
     public function ensureOpenConnection(): void
     {
         // Predis doesn't require to trigger connection
diff --git a/src/Prometheus/Storage/RedisClients/RedisClient.php b/src/Prometheus/Storage/RedisClients/RedisClient.php
index cfc8b83..e9149e4 100644
--- a/src/Prometheus/Storage/RedisClients/RedisClient.php
+++ b/src/Prometheus/Storage/RedisClients/RedisClient.php
@@ -45,7 +45,5 @@ public function get(string $key): mixed;
      */
     public function del(array|string $key, string ...$other_keys): void;
 
-    public function prefix(string $key): string;
-
     public function ensureOpenConnection(): void;
 }

From f0dbbb9c805693ec0b9ffefab5307e284873f5c2 Mon Sep 17 00:00:00 2001
From: Mateusz Cholewka <mateusz@cholewka.com.pl>
Date: Wed, 30 Apr 2025 16:03:37 +0200
Subject: [PATCH 10/14] fix: run phpcs

Signed-off-by: Mateusz Cholewka <mateusz@cholewka.com.pl>
---
 src/Prometheus/Storage/AbstractRedis.php      | 44 +++++++++----------
 src/Prometheus/Storage/Predis.php             |  2 +-
 src/Prometheus/Storage/Redis.php              |  2 +-
 .../Storage/RedisClients/PHPRedis.php         |  2 +-
 .../RedisClients/RedisClientException.php     |  4 +-
 tests/Test/Prometheus/Predis/SummaryTest.php  |  2 +-
 6 files changed, 29 insertions(+), 27 deletions(-)

diff --git a/src/Prometheus/Storage/AbstractRedis.php b/src/Prometheus/Storage/AbstractRedis.php
index fac0e96..8336c0c 100644
--- a/src/Prometheus/Storage/AbstractRedis.php
+++ b/src/Prometheus/Storage/AbstractRedis.php
@@ -156,7 +156,7 @@ public function updateHistogram(array $data): void
             ,
             [
                 $this->toMetricKey($data),
-                self::$prefix.Histogram::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX,
+                self::$prefix . Histogram::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX,
                 json_encode(['b' => 'sum', 'labelValues' => $data['labelValues']]),
                 json_encode(['b' => $bucketToIncrease, 'labelValues' => $data['labelValues']]),
                 $data['value'],
@@ -176,8 +176,8 @@ public function updateSummary(array $data): void
         $this->redis->ensureOpenConnection();
 
         // store meta
-        $summaryKey = self::$prefix.Summary::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX;
-        $metaKey = $summaryKey.':'.$this->metaKey($data);
+        $summaryKey = self::$prefix . Summary::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX;
+        $metaKey = $summaryKey . ':' . $this->metaKey($data);
         $json = json_encode($this->metaData($data));
         if ($json === false) {
             throw new RuntimeException(json_last_error_msg());
@@ -185,7 +185,7 @@ public function updateSummary(array $data): void
         $this->redis->setNx($metaKey, $json);
 
         // store value key
-        $valueKey = $summaryKey.':'.$this->valueKey($data);
+        $valueKey = $summaryKey . ':' . $this->valueKey($data);
         $json = json_encode($this->encodeLabelValues($data['labelValues']));
         if ($json === false) {
             throw new RuntimeException(json_last_error_msg());
@@ -195,7 +195,7 @@ public function updateSummary(array $data): void
         // trick to handle uniqid collision
         $done = false;
         while (! $done) {
-            $sampleKey = $valueKey.':'.uniqid('', true);
+            $sampleKey = $valueKey . ':' . uniqid('', true);
             $done = $this->redis->set($sampleKey, $data['value'], ['NX', 'EX' => $data['maxAgeSeconds']]);
         }
     }
@@ -229,7 +229,7 @@ public function updateGauge(array $data): void
             ,
             [
                 $this->toMetricKey($data),
-                self::$prefix.Gauge::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX,
+                self::$prefix . Gauge::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX,
                 $this->getRedisCommand($data['command']),
                 json_encode($data['labelValues']),
                 $data['value'],
@@ -261,7 +261,7 @@ public function updateCounter(array $data): void
             ,
             [
                 $this->toMetricKey($data),
-                self::$prefix.Counter::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX,
+                self::$prefix . Counter::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX,
                 $this->getRedisCommand($data['command']),
                 $data['value'],
                 json_encode($data['labelValues']),
@@ -288,7 +288,7 @@ protected function metaData(array $data): array
      */
     protected function collectHistograms(): array
     {
-        $keys = $this->redis->sMembers(self::$prefix.Histogram::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX);
+        $keys = $this->redis->sMembers(self::$prefix . Histogram::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX);
         sort($keys);
         $histograms = [];
         foreach ($keys as $key) {
@@ -329,7 +329,7 @@ protected function collectHistograms(): array
                     $bucketKey = json_encode(['b' => $bucket, 'labelValues' => $labelValues]);
                     if (! isset($raw[$bucketKey])) {
                         $histogram['samples'][] = [
-                            'name' => $histogram['name'].'_bucket',
+                            'name' => $histogram['name'] . '_bucket',
                             'labelNames' => ['le'],
                             'labelValues' => array_merge($labelValues, [$bucket]),
                             'value' => $acc,
@@ -337,7 +337,7 @@ protected function collectHistograms(): array
                     } else {
                         $acc += $raw[$bucketKey];
                         $histogram['samples'][] = [
-                            'name' => $histogram['name'].'_bucket',
+                            'name' => $histogram['name'] . '_bucket',
                             'labelNames' => ['le'],
                             'labelValues' => array_merge($labelValues, [$bucket]),
                             'value' => $acc,
@@ -347,7 +347,7 @@ protected function collectHistograms(): array
 
                 // Add the count
                 $histogram['samples'][] = [
-                    'name' => $histogram['name'].'_count',
+                    'name' => $histogram['name'] . '_count',
                     'labelNames' => [],
                     'labelValues' => $labelValues,
                     'value' => $acc,
@@ -355,7 +355,7 @@ protected function collectHistograms(): array
 
                 // Add the sum
                 $histogram['samples'][] = [
-                    'name' => $histogram['name'].'_sum',
+                    'name' => $histogram['name'] . '_sum',
                     'labelNames' => [],
                     'labelValues' => $labelValues,
                     'value' => $raw[json_encode(['b' => 'sum', 'labelValues' => $labelValues])],
@@ -381,9 +381,9 @@ protected function removePrefixFromKey(string $key): string
      */
     protected function collectSummaries(): array
     {
-        $math = new Math;
-        $summaryKey = self::$prefix.Summary::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX;
-        $keys = $this->redis->keys($summaryKey.':*:meta');
+        $math = new Math();
+        $summaryKey = self::$prefix . Summary::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX;
+        $keys = $this->redis->keys($summaryKey . ':*:meta');
 
         $summaries = [];
         foreach ($keys as $metaKeyWithPrefix) {
@@ -404,7 +404,7 @@ protected function collectSummaries(): array
                 'samples' => [],
             ];
 
-            $values = $this->redis->keys($summaryKey.':'.$metaData['name'].':*:value');
+            $values = $this->redis->keys($summaryKey . ':' . $metaData['name'] . ':*:value');
             foreach ($values as $valueKeyWithPrefix) {
                 $valueKey = $this->removePrefixFromKey($valueKeyWithPrefix);
                 $rawValue = $this->redis->get($valueKey);
@@ -416,7 +416,7 @@ protected function collectSummaries(): array
                 $decodedLabelValues = $this->decodeLabelValues($encodedLabelValues);
 
                 $samples = [];
-                $sampleValues = $this->redis->keys($summaryKey.':'.$metaData['name'].':'.$encodedLabelValues.':value:*');
+                $sampleValues = $this->redis->keys($summaryKey . ':' . $metaData['name'] . ':' . $encodedLabelValues . ':value:*');
                 foreach ($sampleValues as $sampleValueWithPrefix) {
                     $sampleValue = $this->removePrefixFromKey($sampleValueWithPrefix);
                     $samples[] = (float) $this->redis->get($sampleValue);
@@ -445,7 +445,7 @@ protected function collectSummaries(): array
 
                 // Add the count
                 $data['samples'][] = [
-                    'name' => $metaData['name'].'_count',
+                    'name' => $metaData['name'] . '_count',
                     'labelNames' => [],
                     'labelValues' => $decodedLabelValues,
                     'value' => count($samples),
@@ -453,7 +453,7 @@ protected function collectSummaries(): array
 
                 // Add the sum
                 $data['samples'][] = [
-                    'name' => $metaData['name'].'_sum',
+                    'name' => $metaData['name'] . '_sum',
                     'labelNames' => [],
                     'labelValues' => $decodedLabelValues,
                     'value' => array_sum($samples),
@@ -479,7 +479,7 @@ protected function collectSummaries(): array
      */
     protected function collectGauges(bool $sortMetrics = true): array
     {
-        $keys = $this->redis->sMembers(self::$prefix.Gauge::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX);
+        $keys = $this->redis->sMembers(self::$prefix . Gauge::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX);
         sort($keys);
         $gauges = [];
         foreach ($keys as $key) {
@@ -521,7 +521,7 @@ protected function collectGauges(bool $sortMetrics = true): array
      */
     protected function collectCounters(bool $sortMetrics = true): array
     {
-        $keys = $this->redis->sMembers(self::$prefix.Counter::TYPE.self::PROMETHEUS_METRIC_KEYS_SUFFIX);
+        $keys = $this->redis->sMembers(self::$prefix . Counter::TYPE . self::PROMETHEUS_METRIC_KEYS_SUFFIX);
         sort($keys);
         $counters = [];
         foreach ($keys as $key) {
@@ -620,7 +620,7 @@ protected function decodeLabelValues(string $values): array
     protected function throwMetricJsonException(string $redisKey, ?string $metricName = null): void
     {
         $metricName = $metricName ?? 'unknown';
-        $message = 'Json error: '.json_last_error_msg().' redis key : '.$redisKey.' metric name: '.$metricName;
+        $message = 'Json error: ' . json_last_error_msg() . ' redis key : ' . $redisKey . ' metric name: ' . $metricName;
         throw new MetricJsonException($message, 0, null, $metricName);
     }
 }
diff --git a/src/Prometheus/Storage/Predis.php b/src/Prometheus/Storage/Predis.php
index a12e58b..504b322 100644
--- a/src/Prometheus/Storage/Predis.php
+++ b/src/Prometheus/Storage/Predis.php
@@ -71,7 +71,7 @@ public static function fromExistingConnection(Client $client): self
             'replication' => $options->replication,
         ];
 
-        $self = new self;
+        $self = new self();
         $self->redis = new PredisClient($client, $allOptions);
 
         return $self;
diff --git a/src/Prometheus/Storage/Redis.php b/src/Prometheus/Storage/Redis.php
index 64422b7..78b0e37 100644
--- a/src/Prometheus/Storage/Redis.php
+++ b/src/Prometheus/Storage/Redis.php
@@ -47,7 +47,7 @@ public static function fromExistingConnection(\Redis $redis): self
             throw new StorageException('Connection to Redis server not established');
         }
 
-        $self = new self;
+        $self = new self();
         $self->redis = PHPRedis::fromExistingConnection($redis, self::$defaultOptions);
 
         return $self;
diff --git a/src/Prometheus/Storage/RedisClients/PHPRedis.php b/src/Prometheus/Storage/RedisClients/PHPRedis.php
index b3edabf..17f1912 100644
--- a/src/Prometheus/Storage/RedisClients/PHPRedis.php
+++ b/src/Prometheus/Storage/RedisClients/PHPRedis.php
@@ -37,7 +37,7 @@ public function __construct(\Redis $redis, array $options)
      */
     public static function create(array $options): self
     {
-        $redis = new \Redis;
+        $redis = new \Redis();
 
         return new self($redis, $options);
     }
diff --git a/src/Prometheus/Storage/RedisClients/RedisClientException.php b/src/Prometheus/Storage/RedisClients/RedisClientException.php
index 36d8cf3..1a81128 100644
--- a/src/Prometheus/Storage/RedisClients/RedisClientException.php
+++ b/src/Prometheus/Storage/RedisClients/RedisClientException.php
@@ -4,4 +4,6 @@
 
 namespace Prometheus\Storage\RedisClients;
 
-class RedisClientException extends \Exception {}
+class RedisClientException extends \Exception
+{
+}
diff --git a/tests/Test/Prometheus/Predis/SummaryTest.php b/tests/Test/Prometheus/Predis/SummaryTest.php
index 3566769..b3cc3b4 100644
--- a/tests/Test/Prometheus/Predis/SummaryTest.php
+++ b/tests/Test/Prometheus/Predis/SummaryTest.php
@@ -21,7 +21,7 @@ public function configureAdapter(): void
     }
 
     /** @test  */
-    public function it_should_observe_with_labels(): void
+    public function itShouldObserveWithLabels(): void
     {
         parent::itShouldObserveWithLabels(); // TODO: Change the autogenerated stub
     }

From a3c7a3e0963cc839ee44d9b68168ceea2ccb4973 Mon Sep 17 00:00:00 2001
From: Mateusz Cholewka <mateusz@cholewka.com.pl>
Date: Thu, 1 May 2025 00:12:40 +0200
Subject: [PATCH 11/14] tests: add config for blackbox test

Signed-off-by: Mateusz Cholewka <mateusz@cholewka.com.pl>
---
 composer.json                            | 1 +
 examples/flush_adapter.php               | 4 ++++
 examples/metrics.php                     | 2 ++
 examples/some_counter.php                | 2 ++
 examples/some_gauge.php                  | 3 ++-
 examples/some_histogram.php              | 2 ++
 examples/some_summary.php                | 2 ++
 src/Prometheus/Storage/AbstractRedis.php | 2 +-
 8 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/composer.json b/composer.json
index 15efa9e..b0f35bf 100644
--- a/composer.json
+++ b/composer.json
@@ -31,6 +31,7 @@
     },
     "suggest": {
         "ext-redis": "Required if using Redis.",
+        "predis/predis": "Required if using Predis.",
         "ext-apc": "Required if using APCu.",
         "ext-pdo": "Required if using PDO.",
         "promphp/prometheus_push_gateway_php": "An easy client for using Prometheus PushGateway.",
diff --git a/examples/flush_adapter.php b/examples/flush_adapter.php
index 1c00eab..82b73ae 100644
--- a/examples/flush_adapter.php
+++ b/examples/flush_adapter.php
@@ -10,6 +10,8 @@
     define('REDIS_HOST', $_SERVER['REDIS_HOST'] ?? '127.0.0.1');
 
     $adapter = new Prometheus\Storage\Redis(['host' => REDIS_HOST]);
+} elseif ($adapterName === 'predis') {
+    $adapter = new Prometheus\Storage\Predis(['host' => $_SERVER['REDIS_HOST'] ?? '127.0.0.1']);
 } elseif ($adapterName === 'apc') {
     $adapter = new Prometheus\Storage\APC();
 } elseif ($adapterName === 'apcng') {
@@ -18,4 +20,6 @@
     $adapter = new Prometheus\Storage\InMemory();
 }
 
+
+
 $adapter->wipeStorage();
diff --git a/examples/metrics.php b/examples/metrics.php
index 9c0fdb8..844c2b2 100644
--- a/examples/metrics.php
+++ b/examples/metrics.php
@@ -11,6 +11,8 @@
 if ($adapter === 'redis') {
     Redis::setDefaultOptions(['host' => $_SERVER['REDIS_HOST'] ?? '127.0.0.1']);
     $adapter = new Prometheus\Storage\Redis();
+} elseif ($adapter === 'predis') {
+    $adapter = new Prometheus\Storage\Predis(['host' => $_SERVER['REDIS_HOST'] ?? '127.0.0.1']);
 } elseif ($adapter === 'apc') {
     $adapter = new Prometheus\Storage\APC();
 } elseif ($adapter === 'apcng') {
diff --git a/examples/some_counter.php b/examples/some_counter.php
index c7426ce..b861a18 100644
--- a/examples/some_counter.php
+++ b/examples/some_counter.php
@@ -10,6 +10,8 @@
 if ($adapter === 'redis') {
     Redis::setDefaultOptions(['host' => $_SERVER['REDIS_HOST'] ?? '127.0.0.1']);
     $adapter = new Prometheus\Storage\Redis();
+} elseif ($adapter === 'predis') {
+    $adapter = new Prometheus\Storage\Predis(['host' => $_SERVER['REDIS_HOST'] ?? '127.0.0.1']);
 } elseif ($adapter === 'apc') {
     $adapter = new Prometheus\Storage\APC();
 } elseif ($adapter === 'apcng') {
diff --git a/examples/some_gauge.php b/examples/some_gauge.php
index 9e8b3da..a0a5894 100644
--- a/examples/some_gauge.php
+++ b/examples/some_gauge.php
@@ -5,7 +5,6 @@
 use Prometheus\CollectorRegistry;
 use Prometheus\Storage\Redis;
 
-
 error_log('c=' . $_GET['c']);
 
 $adapter = $_GET['adapter'];
@@ -13,6 +12,8 @@
 if ($adapter === 'redis') {
     Redis::setDefaultOptions(['host' => $_SERVER['REDIS_HOST'] ?? '127.0.0.1']);
     $adapter = new Prometheus\Storage\Redis();
+} elseif ($adapter === 'predis') {
+    $adapter = new Prometheus\Storage\Predis(['host' => $_SERVER['REDIS_HOST'] ?? '127.0.0.1']);
 } elseif ($adapter === 'apc') {
     $adapter = new Prometheus\Storage\APC();
 } elseif ($adapter === 'apcng') {
diff --git a/examples/some_histogram.php b/examples/some_histogram.php
index 2f1a5f9..b2d9135 100644
--- a/examples/some_histogram.php
+++ b/examples/some_histogram.php
@@ -12,6 +12,8 @@
 if ($adapter === 'redis') {
     Redis::setDefaultOptions(['host' => $_SERVER['REDIS_HOST'] ?? '127.0.0.1']);
     $adapter = new Prometheus\Storage\Redis();
+} elseif ($adapter === 'predis') {
+    $adapter = new Prometheus\Storage\Predis(['host' => $_SERVER['REDIS_HOST'] ?? '127.0.0.1']);
 } elseif ($adapter === 'apc') {
     $adapter = new Prometheus\Storage\APC();
 } elseif ($adapter === 'apcng') {
diff --git a/examples/some_summary.php b/examples/some_summary.php
index 363f919..34b30ce 100644
--- a/examples/some_summary.php
+++ b/examples/some_summary.php
@@ -12,6 +12,8 @@
 if ($adapter === 'redis') {
     Redis::setDefaultOptions(['host' => $_SERVER['REDIS_HOST'] ?? '127.0.0.1']);
     $adapter = new Prometheus\Storage\Redis();
+} elseif ($adapter === 'predis') {
+    $adapter = new Prometheus\Storage\Predis(['host' => $_SERVER['REDIS_HOST'] ?? '127.0.0.1']);
 } elseif ($adapter === 'apc') {
     $adapter = new Prometheus\Storage\APC();
 } elseif ($adapter === 'apcng') {
diff --git a/src/Prometheus/Storage/AbstractRedis.php b/src/Prometheus/Storage/AbstractRedis.php
index 8336c0c..ce46400 100644
--- a/src/Prometheus/Storage/AbstractRedis.php
+++ b/src/Prometheus/Storage/AbstractRedis.php
@@ -67,7 +67,7 @@ public function wipeStorage(): void
             <<<'LUA'
 redis.replicate_commands()
 local cursor = "0"
-repeat 
+repeat
     local results = redis.call('SCAN', cursor, 'MATCH', ARGV[1])
     cursor = results[1]
     for _, key in ipairs(results[2]) do

From fb527ba8032ffcb5e670d5174406f83d13c44c5c Mon Sep 17 00:00:00 2001
From: Mateusz Cholewka <mateusz@cholewka.com.pl>
Date: Thu, 1 May 2025 13:17:38 +0200
Subject: [PATCH 12/14] fix: remove all redis notes from predis

Signed-off-by: Mateusz Cholewka <mateusz@cholewka.com.pl>
---
 examples/flush_adapter.php                             | 10 ++++------
 tests/Test/Prometheus/Predis/CollectorRegistryTest.php |  3 ---
 tests/Test/Prometheus/Predis/CounterTest.php           |  2 --
 tests/Test/Prometheus/Predis/CounterWithPrefixTest.php |  2 --
 tests/Test/Prometheus/Predis/GaugeTest.php             |  2 --
 tests/Test/Prometheus/Predis/GaugeWithPrefixTest.php   |  2 --
 tests/Test/Prometheus/Predis/HistogramTest.php         |  2 --
 .../Test/Prometheus/Predis/HistogramWithPrefixTest.php |  2 --
 tests/Test/Prometheus/Predis/SummaryTest.php           |  4 +---
 tests/Test/Prometheus/Predis/SummaryWithPrefixTest.php |  2 --
 10 files changed, 5 insertions(+), 26 deletions(-)

diff --git a/examples/flush_adapter.php b/examples/flush_adapter.php
index 82b73ae..858e9b0 100644
--- a/examples/flush_adapter.php
+++ b/examples/flush_adapter.php
@@ -1,6 +1,6 @@
 <?php
 
-require __DIR__ . '/../vendor/autoload.php';
+require __DIR__.'/../vendor/autoload.php';
 
 $adapterName = $_GET['adapter'];
 
@@ -13,13 +13,11 @@
 } elseif ($adapterName === 'predis') {
     $adapter = new Prometheus\Storage\Predis(['host' => $_SERVER['REDIS_HOST'] ?? '127.0.0.1']);
 } elseif ($adapterName === 'apc') {
-    $adapter = new Prometheus\Storage\APC();
+    $adapter = new Prometheus\Storage\APC;
 } elseif ($adapterName === 'apcng') {
-    $adapter = new Prometheus\Storage\APCng();
+    $adapter = new Prometheus\Storage\APCng;
 } elseif ($adapterName === 'in-memory') {
-    $adapter = new Prometheus\Storage\InMemory();
+    $adapter = new Prometheus\Storage\InMemory;
 }
 
-
-
 $adapter->wipeStorage();
diff --git a/tests/Test/Prometheus/Predis/CollectorRegistryTest.php b/tests/Test/Prometheus/Predis/CollectorRegistryTest.php
index 8a79852..e1c54fb 100644
--- a/tests/Test/Prometheus/Predis/CollectorRegistryTest.php
+++ b/tests/Test/Prometheus/Predis/CollectorRegistryTest.php
@@ -7,9 +7,6 @@
 use Prometheus\Storage\Predis;
 use Test\Prometheus\AbstractCollectorRegistryTest;
 
-/**
- * @requires extension redis
- */
 class CollectorRegistryTest extends AbstractCollectorRegistryTest
 {
     public function configureAdapter(): void
diff --git a/tests/Test/Prometheus/Predis/CounterTest.php b/tests/Test/Prometheus/Predis/CounterTest.php
index fa610e1..f8508dc 100644
--- a/tests/Test/Prometheus/Predis/CounterTest.php
+++ b/tests/Test/Prometheus/Predis/CounterTest.php
@@ -9,8 +9,6 @@
 
 /**
  * See https://prometheus.io/docs/instrumenting/exposition_formats/
- *
- * @requires extension redis
  */
 class CounterTest extends AbstractCounterTest
 {
diff --git a/tests/Test/Prometheus/Predis/CounterWithPrefixTest.php b/tests/Test/Prometheus/Predis/CounterWithPrefixTest.php
index 7283572..25e2d01 100644
--- a/tests/Test/Prometheus/Predis/CounterWithPrefixTest.php
+++ b/tests/Test/Prometheus/Predis/CounterWithPrefixTest.php
@@ -9,8 +9,6 @@
 
 /**
  * See https://prometheus.io/docs/instrumenting/exposition_formats/
- *
- * @requires extension redis
  */
 class CounterWithPrefixTest extends AbstractCounterTest
 {
diff --git a/tests/Test/Prometheus/Predis/GaugeTest.php b/tests/Test/Prometheus/Predis/GaugeTest.php
index 9d48ec1..e84e814 100644
--- a/tests/Test/Prometheus/Predis/GaugeTest.php
+++ b/tests/Test/Prometheus/Predis/GaugeTest.php
@@ -9,8 +9,6 @@
 
 /**
  * See https://prometheus.io/docs/instrumenting/exposition_formats/
- *
- * @requires extension redis
  */
 class GaugeTest extends AbstractGaugeTest
 {
diff --git a/tests/Test/Prometheus/Predis/GaugeWithPrefixTest.php b/tests/Test/Prometheus/Predis/GaugeWithPrefixTest.php
index 4f3dc21..d5a895e 100644
--- a/tests/Test/Prometheus/Predis/GaugeWithPrefixTest.php
+++ b/tests/Test/Prometheus/Predis/GaugeWithPrefixTest.php
@@ -9,8 +9,6 @@
 
 /**
  * See https://prometheus.io/docs/instrumenting/exposition_formats/
- *
- * @requires extension redis
  */
 class GaugeWithPrefixTest extends AbstractGaugeTest
 {
diff --git a/tests/Test/Prometheus/Predis/HistogramTest.php b/tests/Test/Prometheus/Predis/HistogramTest.php
index f4148b9..381ed19 100644
--- a/tests/Test/Prometheus/Predis/HistogramTest.php
+++ b/tests/Test/Prometheus/Predis/HistogramTest.php
@@ -9,8 +9,6 @@
 
 /**
  * See https://prometheus.io/docs/instrumenting/exposition_formats/
- *
- * @requires extension redis
  */
 class HistogramTest extends AbstractHistogramTest
 {
diff --git a/tests/Test/Prometheus/Predis/HistogramWithPrefixTest.php b/tests/Test/Prometheus/Predis/HistogramWithPrefixTest.php
index 751a44a..d4029a0 100644
--- a/tests/Test/Prometheus/Predis/HistogramWithPrefixTest.php
+++ b/tests/Test/Prometheus/Predis/HistogramWithPrefixTest.php
@@ -9,8 +9,6 @@
 
 /**
  * See https://prometheus.io/docs/instrumenting/exposition_formats/
- *
- * @requires extension redis
  */
 class HistogramWithPrefixTest extends AbstractHistogramTest
 {
diff --git a/tests/Test/Prometheus/Predis/SummaryTest.php b/tests/Test/Prometheus/Predis/SummaryTest.php
index b3cc3b4..3d5a981 100644
--- a/tests/Test/Prometheus/Predis/SummaryTest.php
+++ b/tests/Test/Prometheus/Predis/SummaryTest.php
@@ -9,8 +9,6 @@
 
 /**
  * See https://prometheus.io/docs/instrumenting/exposition_formats/
- *
- * @requires extension redis
  */
 class SummaryTest extends AbstractSummaryTest
 {
@@ -21,7 +19,7 @@ public function configureAdapter(): void
     }
 
     /** @test  */
-    public function itShouldObserveWithLabels(): void
+    public function it_should_observe_with_labels(): void
     {
         parent::itShouldObserveWithLabels(); // TODO: Change the autogenerated stub
     }
diff --git a/tests/Test/Prometheus/Predis/SummaryWithPrefixTest.php b/tests/Test/Prometheus/Predis/SummaryWithPrefixTest.php
index 1c1d164..54ffd31 100644
--- a/tests/Test/Prometheus/Predis/SummaryWithPrefixTest.php
+++ b/tests/Test/Prometheus/Predis/SummaryWithPrefixTest.php
@@ -9,8 +9,6 @@
 
 /**
  * See https://prometheus.io/docs/instrumenting/exposition_formats/
- *
- * @requires extension redis
  */
 class SummaryWithPrefixTest extends AbstractSummaryTest
 {

From 8d1c694f6e445935b7b5fc621f92859968cf98c4 Mon Sep 17 00:00:00 2001
From: Mateusz Cholewka <mateusz@cholewka.com.pl>
Date: Thu, 1 May 2025 13:18:19 +0200
Subject: [PATCH 13/14] fix: estabish connection after first call in predis

Signed-off-by: Mateusz Cholewka <mateusz@cholewka.com.pl>
---
 examples/flush_adapter.php                    |  8 +++---
 src/Prometheus/Storage/Predis.php             | 26 +++++++++----------
 .../Storage/RedisClients/Predis.php           | 19 +++++++++-----
 3 files changed, 30 insertions(+), 23 deletions(-)

diff --git a/examples/flush_adapter.php b/examples/flush_adapter.php
index 858e9b0..712e2be 100644
--- a/examples/flush_adapter.php
+++ b/examples/flush_adapter.php
@@ -1,6 +1,6 @@
 <?php
 
-require __DIR__.'/../vendor/autoload.php';
+require __DIR__ . '/../vendor/autoload.php';
 
 $adapterName = $_GET['adapter'];
 
@@ -13,11 +13,11 @@
 } elseif ($adapterName === 'predis') {
     $adapter = new Prometheus\Storage\Predis(['host' => $_SERVER['REDIS_HOST'] ?? '127.0.0.1']);
 } elseif ($adapterName === 'apc') {
-    $adapter = new Prometheus\Storage\APC;
+    $adapter = new Prometheus\Storage\APC();
 } elseif ($adapterName === 'apcng') {
-    $adapter = new Prometheus\Storage\APCng;
+    $adapter = new Prometheus\Storage\APCng();
 } elseif ($adapterName === 'in-memory') {
-    $adapter = new Prometheus\Storage\InMemory;
+    $adapter = new Prometheus\Storage\InMemory();
 }
 
 $adapter->wipeStorage();
diff --git a/src/Prometheus/Storage/Predis.php b/src/Prometheus/Storage/Predis.php
index 504b322..c2d6b5b 100644
--- a/src/Prometheus/Storage/Predis.php
+++ b/src/Prometheus/Storage/Predis.php
@@ -4,8 +4,8 @@
 
 namespace Prometheus\Storage;
 
+use InvalidArgumentException;
 use Predis\Client;
-use Prometheus\Exception\StorageException;
 use Prometheus\Storage\RedisClients\Predis as PredisClient;
 
 class Predis extends AbstractRedis
@@ -43,7 +43,7 @@ class Predis extends AbstractRedis
     private $options = [];
 
     /**
-     * Redis constructor.
+     * Predis constructor.
      *
      * @param  mixed[]  $parameters
      * @param  mixed[]  $options
@@ -56,23 +56,23 @@ public function __construct(array $parameters = [], array $options = [])
     }
 
     /**
-     * @throws StorageException
+     * @throws InvalidArgumentException
      */
     public static function fromExistingConnection(Client $client): self
     {
-        $options = $client->getOptions();
-        $allOptions = [
-            'aggregate' => $options->aggregate,
-            'cluster' => $options->cluster,
-            'connections' => $options->connections,
-            'exceptions' => $options->exceptions,
-            'prefix' => $options->prefix,
-            'commands' => $options->commands,
-            'replication' => $options->replication,
+        $clientOptions = $client->getOptions();
+        $options = [
+            'aggregate' => $clientOptions->aggregate,
+            'cluster' => $clientOptions->cluster,
+            'connections' => $clientOptions->connections,
+            'exceptions' => $clientOptions->exceptions,
+            'prefix' => $clientOptions->prefix,
+            'commands' => $clientOptions->commands,
+            'replication' => $clientOptions->replication,
         ];
 
         $self = new self();
-        $self->redis = new PredisClient($client, $allOptions);
+        $self->redis = new PredisClient(self::$defaultParameters, $options, $client);
 
         return $self;
     }
diff --git a/src/Prometheus/Storage/RedisClients/Predis.php b/src/Prometheus/Storage/RedisClients/Predis.php
index 562df6d..e8164b1 100644
--- a/src/Prometheus/Storage/RedisClients/Predis.php
+++ b/src/Prometheus/Storage/RedisClients/Predis.php
@@ -13,22 +13,29 @@ class Predis implements RedisClient
     ];
 
     /**
-     * @var Client
+     * @var ?Client
      */
     private $client;
 
+    /**
+     * @var mixed[]
+     */
+    private $parameters = [];
+
     /**
      * @var mixed[]
      */
     private $options = [];
 
     /**
+     * @param  mixed[]  $parameters
      * @param  mixed[]  $options
      */
-    public function __construct(Client $redis, array $options)
+    public function __construct(array $parameters, array $options, ?Client $redis = null)
     {
         $this->client = $redis;
 
+        $this->parameters = $parameters;
         $this->options = $options;
     }
 
@@ -38,9 +45,7 @@ public function __construct(Client $redis, array $options)
      */
     public static function create(array $parameters, array $options): self
     {
-        $redisClient = new Client($parameters, $options);
-
-        return new self($redisClient, $options);
+        return new self($parameters, $options);
     }
 
     public function getOption(int $option): mixed
@@ -122,6 +127,8 @@ public function del(array|string $key, string ...$other_keys): void
 
     public function ensureOpenConnection(): void
     {
-        // Predis doesn't require to trigger connection
+        if ($this->client === null) {
+            $this->client = new Client($this->parameters, $this->options);
+        }
     }
 }

From b984afa034d93bf6c9bd4faaf2d3fc54e9a1f8ad Mon Sep 17 00:00:00 2001
From: Mateusz Cholewka <mateusz@cholewka.com.pl>
Date: Thu, 1 May 2025 13:24:58 +0200
Subject: [PATCH 14/14] fix: add exception handling for predis connection

Signed-off-by: Mateusz Cholewka <mateusz@cholewka.com.pl>
---
 src/Prometheus/Storage/RedisClients/Predis.php | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/Prometheus/Storage/RedisClients/Predis.php b/src/Prometheus/Storage/RedisClients/Predis.php
index e8164b1..1146a06 100644
--- a/src/Prometheus/Storage/RedisClients/Predis.php
+++ b/src/Prometheus/Storage/RedisClients/Predis.php
@@ -4,7 +4,9 @@
 
 namespace Prometheus\Storage\RedisClients;
 
+use InvalidArgumentException;
 use Predis\Client;
+use Prometheus\Exception\StorageException;
 
 class Predis implements RedisClient
 {
@@ -125,10 +127,17 @@ public function del(array|string $key, string ...$other_keys): void
         $this->client->del($key, ...$other_keys);
     }
 
+    /**
+     * @throws StorageException
+     */
     public function ensureOpenConnection(): void
     {
         if ($this->client === null) {
-            $this->client = new Client($this->parameters, $this->options);
+            try {
+                $this->client = new Client($this->parameters, $this->options);
+            } catch (InvalidArgumentException $e) {
+                throw new StorageException('Cannot establish Redis Connection:' . $e->getMessage());
+            }
         }
     }
 }