use .merge and pin the future

src/experimental/grpcmultiplex_fastestwins_channels.rs

@@ -3,7 +3,6 @@
 
 use std::collections::{HashMap};
 use std::ops::{Add};
-use std::pin::pin;
 use anyhow::{Context};
 use async_stream::stream;
 use futures::{pin_mut, Stream, StreamExt};
@@ -12,13 +11,14 @@ use log::{debug, info, warn};
 use solana_sdk::clock::Slot;
 use solana_sdk::commitment_config::CommitmentConfig;
 use solana_sdk::commitment_config::CommitmentLevel;
-use tokio::{select};
+use tokio::{pin, select};
 use tokio::sync::broadcast::{Sender};
 use tokio::time::{Duration, Instant, sleep_until};
 use yellowstone_grpc_client::GeyserGrpcClient;
 use yellowstone_grpc_proto::geyser::{SubscribeRequestFilterBlocks, SubscribeUpdate, SubscribeUpdateBlock};
 use yellowstone_grpc_proto::geyser::subscribe_update::UpdateOneof;
 use yellowstone_grpc_proto::tonic::transport::ClientTlsConfig;
+use merge_streams::MergeStreams;
 
 // use solana_lite_rpc_cluster_endpoints::grpc_subscription::{create_block_processing_task, map_produced_block};
 // use solana_lite_rpc_core::AnyhowJoinHandle;
@@ -45,22 +45,28 @@ pub async fn create_multiplex(
             grpc_sources.len(),
             grpc_sources.iter().map(|source| source.label.clone()).join(", "));
 
-        let mut futures = futures::stream::SelectAll::new();
+
+        let mut streams = vec![];
         for grpc_source in grpc_sources {
             // note: stream never terminates
-            let stream = create_geyser_reconnecting_stream(grpc_source.clone(), commitment_config).await;
-            futures.push(Box::pin(stream));
+            let stream = create_geyser_reconnecting_stream(grpc_source.clone(), commitment_config).await
+            .map(|update| {
+                // TODO wrap in new struct and add the source label
+                update
+            });
+            streams.push(stream);
         }
 
-        pin_mut!(futures);
-        let mut futures = pin!(futures.next());
+        let merged_streams = streams.merge();
+        pin_mut!(merged_streams);
+        let mut merged_futures = std::pin::pin!(merged_streams.next());
 
         let mut current_slot: Slot = 0;
 
         'main_loop: loop {
 
             let block_cmd = select! {
-                message = &mut futures => {
+                message = &mut merged_futures => {
                     match message {
                         Some(message) => {
                             map_filter_block_message(current_slot, message, commitment_config)