load test from #77 added

examples/load_test.py

@@ -0,0 +1,58 @@
+################################################################################
+# Load test
+# e.g. test for lock contention: https://github.com/sysid/sse-starlette/issues/77
+#
+# to run it:
+# PYTHONPATH=. uvicorn examples.load_test:app
+# curl http://localhost:8000/stream | pv --line-mode --average-rate > /dev/null
+################################################################################
+
+import uvicorn
+import json
+from fastapi import FastAPI, Request
+from sse_starlette.sse import EventSourceResponse
+
+position = (
+    json.dumps(
+        {
+            "position_timestamp": "2023-09-19T11:25:35.286Z",
+            "x": 0,
+            "y": 0,
+            "z": 0,
+            "a": 0,
+            "b": 0,
+            "c": 0,
+            # some more fields
+        }
+    )
+    + "\n"
+)
+positions = [position] * 500
+
+sse_clients = 0
+
+app = FastAPI()
+
+
+@app.get("/stream")
+async def message_stream(request: Request):
+    async def event_generator():
+        global sse_clients
+        sse_clients += 1
+        print(f"{sse_clients} sse clients connected", flush=True)
+        while True:
+            # If client closes connection, stop sending events
+            if await request.is_disconnected():
+                break
+
+            for p in positions:
+                # fixes socket.send() raised exception, but makes it very slow!!
+                if await request.is_disconnected():
+                    break
+                yield p
+
+    return EventSourceResponse(event_generator())
+
+
+if __name__ == "__main__":
+    uvicorn.run(app, host="0.0.0.0", port=8000, log_level="error", log_config=None)  # type: ignore