added debugStreaming config parameter

Author: pkaeding

src/main/java/com/launchdarkly/client/LDClient.java

@@ -190,10 +190,10 @@ public boolean toggle(String featureKey, LDUser user, boolean defaultValue) {
       if (this.config.stream && this.streamProcessor != null && this.streamProcessor.initialized()) {
         logger.debug("Using feature flag stored from streaming API");
         result = (FeatureRep<Boolean>) this.streamProcessor.getFeature(featureKey);
-        if (logger.isDebugEnabled()) {
+        if (config.debugStreaming) {
           FeatureRep<Boolean> pollingResult = fetchFeature(featureKey);
           if (!result.equals(pollingResult)) {
-            logger.debug("Mismatch between streaming and polling feature! Streaming: {} Polling: {}", result, pollingResult);
+            logger.warn("Mismatch between streaming and polling feature! Streaming: {} Polling: {}", result, pollingResult);
           }
         }
       } else {

src/main/java/com/launchdarkly/client/LDConfig.java

@@ -32,6 +32,7 @@ public final class LDConfig {
   final int flushInterval;
   final HttpHost proxyHost;
   final boolean stream;
+  final boolean debugStreaming;
 
   protected LDConfig(Builder builder) {
     this.baseURI = builder.baseURI;
@@ -42,6 +43,7 @@ protected LDConfig(Builder builder) {
     this.proxyHost = builder.proxyHost();
     this.streamURI = builder.streamURI;
     this.stream = builder.stream;
+    this.debugStreaming = builder.debugStreaming;
   }
 
   /**
@@ -67,6 +69,7 @@ public static class Builder{
     private int proxyPort = -1;
     private String proxyScheme;
     private boolean stream = false;
+    private boolean debugStreaming = false;
 
     /**
      * Creates a builder with all configuration parameters set to the default
@@ -94,6 +97,18 @@ public Builder streamURI(URI streamURI) {
       return this;
     }
 
+    /**
+     * Set whether we should debug streaming mode. If set, the client will fetch features via polling and compare the
+     * retrieved feature with the value in the feature store. There is a performance cost to this, so it is not
+     * recommended for production use.
+     * @param debugStreaming whether streaming mode should be debugged
+     * @return
+     */
+    public Builder debugStreaming(boolean debugStreaming) {
+      this.debugStreaming = debugStreaming;
+      return this;
+    }
+
     /**
      * Set whether streaming mode should be enabled
      * @param stream whether streaming mode should be enabled