源码快照 @ 2026-09-01 (source-only, 剔除非源码素材)

plugins/bundle/cloudpaw/modules/a2a/call_stream.py

@@ -0,0 +1,89 @@
+# -*- coding: utf-8 -*-
+"""In-process SSE stream for a2a_call tool progress.
+
+a2a_call pushes incremental events into start_stream() queue while it
+runs.  The /a2a/call/stream REST endpoint reads from read_stream_sse()
+and forwards them to the frontend as Server-Sent Events, enabling
+real-time display without relying on QwenPaw to forward intermediate
+ToolResponse yields.
+
+Only one a2a_call runs at a time (the LLM is blocked until it returns),
+so a single module-level queue is safe.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import json
+import logging
+from collections.abc import AsyncIterator
+
+logger = logging.getLogger("qwenpaw").getChild(
+    __name__.replace("plugin_cloudpaw.", ""),
+)
+
+_queue: asyncio.Queue | None = None
+
+
+def start_stream() -> asyncio.Queue:
+    """Create a fresh queue for a new call.  Called by a2a_call at startup."""
+    global _queue
+    _queue = asyncio.Queue(maxsize=1000)
+    return _queue
+
+
+def get_stream() -> asyncio.Queue | None:
+    """Return the current stream queue (if any)."""
+    return _queue
+
+
+def finish_stream() -> None:
+    """Signal the end of the stream by putting a None sentinel."""
+    global _queue
+    if _queue is not None:
+        try:
+            _queue.put_nowait(None)
+        except asyncio.QueueFull:
+            pass
+        _queue = None
+
+
+def push(data: dict) -> None:
+    """Push an event dict into the current stream queue."""
+    global _queue
+    if _queue is not None:
+        try:
+            _queue.put_nowait(data)
+        except asyncio.QueueFull:
+            logger.warning("A2A stream queue full, dropping event")
+
+
+async def read_stream_sse() -> AsyncIterator[str]:
+    """Yield SSE-formatted strings until the call finishes.
+
+    Waits up to 3 s for the call to start (handles the race where the
+    frontend connects before a2a_call has initialised the queue).
+    """
+    for _ in range(30):
+        if _queue is not None:
+            break
+        await asyncio.sleep(0.1)
+
+    queue = _queue
+    if queue is None:
+        msg = json.dumps({"done": True, "error": "no active call"})
+        yield f"data: {msg}\n\n"
+        return
+
+    while True:
+        try:
+            item = await asyncio.wait_for(queue.get(), timeout=60.0)
+        except asyncio.TimeoutError:
+            yield ": keepalive\n\n"
+            continue
+
+        if item is None:
+            yield f"data: {json.dumps({'done': True})}\n\n"
+            break
+
+        yield f"data: {json.dumps(item, ensure_ascii=False)}\n\n"