rust-async-pattern

name	rust-async-pattern
description	Advanced async patterns expert covering Stream implementation, zero-copy buffers, tokio::spawn lifetimes, plugin system scheduling, tonic streaming, and async lifetime management.
metadata	{"triggers":["async pattern","Stream","tokio::spawn","zero-copy","plugin system","tonic","streaming","BorrowedMessage","async scheduling","lifetime async"]}

Solution Patterns

Pattern 1: Stream with Internal Buffer (Worker + Channel)

use tokio::sync::mpsc::{channel, Sender, Receiver};
use bytes::Bytes;
use futures::Stream;
use std::pin::Pin;
use std::task::{Context, Poll};

// ❌ Problem: Stream returning borrowed data from internal buffer
// Can't work because Stream::Item may outlive self

// ✅ Solution: Worker holds buffer, Stream receives owned data

pub struct SessionWorker {
    rx_events: Receiver<Bytes>,
    tx_snapshots: Sender<SnapshotResponse>,
    buf: Vec<u8>,  // Internal buffer
}

impl SessionWorker {
    pub async fn run(& ) {
          (event) = .rx_events.(). {
              = .(event);
              = .tx_snapshots.(snapshot).;
        }
    }

     (& , event: Bytes)  SnapshotResponse {
        
          = .buf.();
        .buf.(&event);

        
        SnapshotResponse {
            id: .(),
            payload: Bytes::(&.buf[start..]),
        }
    }
}


   {
    rx_snapshots: Receiver<SnapshotResponse>,
}

    {
      = <SnapshotResponse, Status>;

     ( : Pin<& >, cx: & Context<>)  Poll<<::Item>> {
         .rx_snapshots.(cx) {
            Poll::((snapshot)) => Poll::(((snapshot))),
            Poll::() => Poll::(),
            Poll::Pending => Poll::Pending,
        }
    }
}


   {
     id: ,
     payload: Bytes,  
}