ADD: block_stream

Signed-off-by: Stukalov-A-M <stukalov07@gmail.com>

Author: Stukalov-A-M

Rust/examples/block_stream.rs

@@ -0,0 +1,70 @@
+use iroha_client::client::Client;
+use std::num::NonZeroU64;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let config = get_config(get_config_path()?);
+    let iroha_client: Client = Client::new(&config)?;
+
+    initiate_block_listener(&iroha_client, 1)?;
+
+    Ok(())
+}
+/// Auxiliary method for a block listener
+/// You shall implement it first
+fn non_zero_handler(number: u64) -> NonZeroU64 {
+    NonZeroU64::new(number).map_or_else(
+        || {
+            println!("The number must be > 0, using default value 1");
+            NonZeroU64::new(1).unwrap()
+        },
+        |non_zero| non_zero,
+    )
+}
+/// A block listener configuration
+/// iroha_client - Your iroha client implementation
+/// initial_block_number - The number of a block listener should start from.
+/// To get total quantity of blocks, you may use method iroha_client.get_status().
+fn initiate_block_listener(
+    iroha_client: &Client,
+    initial_block_number: u64,
+) -> Result<(), Box<dyn Error>> {
+    // Processing the non zero value from the u64
+    let block_number = non_zero_handler(initial_block_number);
+    // Initiating the block listener object
+    let block_iter = iroha_client.listen_for_blocks(block_number)?;
+    // Initiating iteration by blocks. The iterator is infinite
+    for block in block_iter {
+        match &block {
+            Ok(block) => println!("Received block: {block:?}"),
+            Err(e) => println!("Error happened: {}", e),
+        }
+    }
+    Ok(())
+}
+use iroha_config::client::Configuration;
+use std::env;
+use std::error::Error;
+use std::fs::File;
+use std::path::{Path, PathBuf};
+
+pub fn get_config_path() -> Result<PathBuf, Box<dyn Error>> {
+    let exe_path = env::current_exe();
+    let binding = exe_path?;
+    let ancestors = binding.ancestors();
+    for ancestor in ancestors {
+        if ancestor.file_name() == Some("target".as_ref()) {
+            let source_path = Path::new(ancestor);
+            let mut config_path = PathBuf::from(source_path.parent().unwrap());
+            config_path.push("src");
+            config_path.push("resources");
+            config_path.push("config.json");
+            return Ok(config_path);
+        }
+    }
+    Err("The source directory was not found in the ancestor path.".into())
+}
+pub fn get_config(path_buf: PathBuf) -> Configuration {
+    let file =
+        File::open(&path_buf).unwrap_or_else(|_| panic!("Failed to read file at: {path_buf:?}"));
+    serde_json::from_reader(file).unwrap_or_else(|_| panic!("Failed to read config at ?????"))
+}