improve: pooling httpx clients for requests to code sandbox and ssrf (#26052)

api/core/helper/http_client_pooling.py

@@ -0,0 +1,59 @@
+"""HTTP client pooling utilities."""
+
+from __future__ import annotations
+
+import atexit
+import threading
+from collections.abc import Callable
+
+import httpx
+
+ClientBuilder = Callable[[], httpx.Client]
+
+
+class HttpClientPoolFactory:
+    """Thread-safe factory that maintains reusable HTTP client instances."""
+
+    def __init__(self) -> None:
+        self._clients: dict[str, httpx.Client] = {}
+        self._lock = threading.Lock()
+
+    def get_or_create(self, key: str, builder: ClientBuilder) -> httpx.Client:
+        """Return a pooled client associated with ``key`` creating it on demand."""
+        client = self._clients.get(key)
+        if client is not None:
+            return client
+
+        with self._lock:
+            client = self._clients.get(key)
+            if client is None:
+                client = builder()
+                self._clients[key] = client
+        return client
+
+    def close_all(self) -> None:
+        """Close all pooled clients and clear the pool."""
+        with self._lock:
+            for client in self._clients.values():
+                client.close()
+            self._clients.clear()
+
+
+_factory = HttpClientPoolFactory()
+
+
+def get_pooled_http_client(key: str, builder: ClientBuilder) -> httpx.Client:
+    """Return a pooled client for the given ``key`` using ``builder`` when missing."""
+    return _factory.get_or_create(key, builder)
+
+
+def close_all_pooled_clients() -> None:
+    """Close every client created through the pooling factory."""
+    _factory.close_all()
+
+
+def _register_shutdown_hook() -> None:
+    atexit.register(close_all_pooled_clients)
+
+
+_register_shutdown_hook()