https://github.com/alexvanzyl/shoutout
Realtime messaging with Redis PUB/SUB.
https://github.com/alexvanzyl/shoutout
Last synced: 2 months ago
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Realtime messaging with Redis PUB/SUB.
- Host: GitHub
- URL: https://github.com/alexvanzyl/shoutout
- Owner: alexvanzyl
- License: mit
- Created: 2020-11-08T20:11:34.000Z (over 4 years ago)
- Default Branch: master
- Last Pushed: 2020-11-08T20:36:59.000Z (over 4 years ago)
- Last Synced: 2025-02-03T06:39:46.475Z (4 months ago)
- Language: Python
- Size: 14.6 KB
- Stars: 1
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Shoutout
## Realtime messaging with Redis PUB/SUB.
Shout-out is designed to work with [FastAPI websocket](https://fastapi.tiangolo.com/advanced/websockets/), while running behind [Gunicorn](https://gunicorn.org/) with multiple [Uvicorn workers](https://www.uvicorn.org/deployment/#gunicorn). Where a centralized caching layer (Redis) is required to maintain state (messages) across workers.
You can also use Shoutout as a standalone asynchronous application.
## Installation
```shell
pip install shoutout-py
```
## Usage
### Standalone
```python
import asyncio
from shoutout.broadcast import Broadcast
broadcast = Broadcast("redis://localhost:6379")
async def main():
await broadcast.connect()
async with broadcast.subscribe("hello") as subscriber:
if subscriber:
await broadcast.publish("hello", message={
"channel": "hello", "message": "Hello World!"})
async for _, msg in subscriber:
print(msg)
break
if __name__ == "__main__":
asyncio.run(main())
```
_The example above is complete and should run as is._
### FastAPI
```python
from fastapi import FastAPI, WebSocket
from fastapi.responses import HTMLResponse
from shoutout.broadcast import Broadcast
from starlette.concurrency import run_until_first_complete
broadcast = Broadcast("redis://localhost:6379")
app = FastAPI(on_startup=[broadcast.connect], on_shutdown=[broadcast.disconnect])
async def ws_receiver(websocket):
async for message in websocket.iter_text():
await broadcast.publish(channel="shout", message={"msg": message})
async def ws_sender(websocket):
async with broadcast.subscribe(channel="shout") as subscriber:
if subscriber:
async for _, msg in subscriber:
await websocket.send_json(msg)
@app.websocket("/ws")
async def websocket_endpoint(websocket: WebSocket):
await websocket.accept()
await run_until_first_complete(
(ws_receiver, {"websocket": websocket}),
(ws_sender, {"websocket": websocket}),
)
html = """
Chat
WebSocket Chat
Send
var ws = new WebSocket("ws://localhost:8000/ws");
ws.onmessage = function(event) {
var messages = document.getElementById('messages')
var message = document.createElement('li')
var content = document.createTextNode(event.data)
message.appendChild(content)
messages.appendChild(message)
};
function sendMessage(event) {
var input = document.getElementById("messageText")
ws.send(input.value)
input.value = ''
event.preventDefault()
}
"""
@app.get("/")
async def get():
return HTMLResponse(html)
```
_The example above is complete and should run as is._
Run it:
```shell
uvicorn main:app --reload
```