chore(firehose-client): add stream ethereum blocks example

crates/firehose-client/examples/stream_ethereum.rs

@@ -0,0 +1,30 @@
+//! # Example: Stream Ethereum Blocks
+//!
+//! This example demonstrates how to stream Ethereum blocks using the Firehose client.
+use firehose_client::{Chain, FirehoseClient};
+use futures::StreamExt;
+use sf_protos::ethereum::r#type::v2::Block as FirehoseEthBlock;
+
+#[tokio::main]
+async fn main() {
+    // Testing this so far without proper benchmarking, the time taken to fetch the blocks
+    // grows linearly with the number of TOTAL_BLOCKS requested, to around 20 minutes for 8192 blocks!
+    const TOTAL_BLOCKS: u64 = 100;
+    const START_BLOCK: u64 = 19581798;
+
+    let mut client = FirehoseClient::new(Chain::Ethereum);
+    let stream = client
+        .stream_ethereum_with_retry(START_BLOCK, TOTAL_BLOCKS)
+        .await;
+
+    tokio::pin!(stream);
+
+    let mut blocks: Vec<FirehoseEthBlock> = Vec::with_capacity(TOTAL_BLOCKS as usize);
+
+    while let Some(block) = stream.next().await {
+        blocks.push(block);
+    }
+
+    // For now, just using this to signal that the test has completed
+    assert_eq!(blocks.len(), TOTAL_BLOCKS as usize);
+}

crates/firehose-client/src/lib.rs

@@ -376,4 +376,3 @@ mod tests {
         assert_eq!(blocks.len(), TOTAL_SLOTS as usize);
     }
 }
-