Messages truncated at 2032 characters

[kentkr]

I'm using the sseclient library on py 3.7.11 and the sse messages are truncated at 2032 characters. This is not the case when accessing the data from other methods. Is there an argument to extend the character length?

I haven't found much in the source code other than chunk_size but that does not seem to be the issue. Could it be something about line endings?

[eino]

Hi, are you sure it isn't related to chunks? It looks like #28. At least for me, merging @mutantmonkey 's PR #35 fixed a similar issue.

[kentkr]

It may be but specifying chunk_size = xxx in SSEClient() changed nothing about its behavior.

Are there other solutions to try out?

[yangyang-zhang]

I encountered a similar problem. Have you found the reason

[apapsch]

I haven't found the reason, but have fared better with this SSE client: https://github.com/mpetazzoni/sseclient

[TheSandDoctor]

Tested by dockerizing a scenario and issue doesn't appear to currently be present in Python 3.7.11 or Python 3.13 as of 0.0.27 (the last version available in PyPi) or current in-repo when tested with a message > 2100 characters. Is this still being experienced @kentkr? If you have a test case that can trigger it that would be helpful. Including my test setup below for easy replication/transparency.

server.py:

from http.server import BaseHTTPRequestHandler, HTTPServer
import time

class SSEHandler(BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path != "/stream":
            self.send_error(404)
            return

        self.send_response(200)
        self.send_header("Content-Type", "text/event-stream")
        self.send_header("Cache-Control", "no-cache")
        self.end_headers()

        payload = '{"comment":"Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque eget consequat nulla. Suspendisse potenti. Duis fermentum, lorem ac dictum blandit, justo risus commodo nibh, non lacinia diam magna eu erat. Etiam condimentum turpis eget velit fringilla, a luctus arcu pretium. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia curae; Suspendisse nec dignissim nunc. Curabitur sed lacus non justo sodales rutrum in sed nisi. Proin nec justo dictum, accumsan est vel, volutpat nunc. Curabitur fermentum a magna vel ornare. Donec rutrum, elit nec aliquam fermentum, velit est convallis libero, vitae placerat justo quam sed nunc. Suspendisse potenti. Vivamus sagittis felis sem, nec sodales ipsum tristique nec. Sed rhoncus lectus et ante tincidunt, ac malesuada ipsum tincidunt. Aenean lobortis rhoncus mi non fringilla. Pellentesque rutrum diam felis, at tincidunt libero tristique ac. Vestibulum et sapien vel odio malesuada porta nec at orci. Sed laoreet ipsum non justo dapibus bibendum. Vivamus vel luctus lacus. Suspendisse dapibus, mi id congue faucibus, nisi justo laoreet nulla, ut posuere eros metus in purus. Morbi ullamcorper a lacus a gravida. Sed vel felis bibendum, viverra eros vel, finibus orci. Curabitur nec faucibus sapien. Phasellus suscipit tellus eget erat posuere accumsan. Nulla a augue in sem dapibus suscipit. Quisque imperdiet nisl non magna pharetra luctus. Integer pharetra est vel orci consectetur, non porta nulla facilisis. Cras euismod dapibus massa sed vestibulum. Fusce in nisl non tortor malesuada ultricies. Morbi eu sodales nulla. Sed efficitur blandit justo, nec convallis mauris porttitor vitae. Nullam in magna luctus, luctus libero nec, cursus libero. Aliquam convallis odio id sapien lobortis finibus. Vivamus rhoncus tincidunt odio, et commodo massa accumsan at. Curabitur porttitor ac leo eget porttitor. Curabitur vehicula tortor at elit accumsan fermentum. Nunc ut sapien et est lacinia vulputate. Morbi ultrices eget nisi vitae lacinia. In laoreet, eros vel finibus vulputate, nisl ante egestas risus, id congue nisi elit vel eros."}'
        self.wfile.write(f"data: {payload}\n\n".encode("utf-8"))
        self.wfile.flush()
        time.sleep(1)

if __name__ == "__main__":
    server = HTTPServer(("localhost", 5050), SSEHandler)
    print("Listening at http://localhost:5050/stream  (CTRL+C to stop)")
    server.serve_forever()

client.py:

from sseclient import SSEClient

messages = SSEClient('http://host.docker.internal:5050/stream')
for msg in messages:
    print(msg)

Dockerfile:

FROM python:3.7.11-slim

RUN apt-get update && apt-get install -y git && rm -rf /var/lib/apt/lists/*

# Replace with your actual Git repo URL
#RUN pip install git+https://github.com/TheSandDoctor/sseclient.git@fix/iss28
RUN pip install sseclient

WORKDIR /app
COPY . /app

CMD ["python"]

docker-compose.yml:

services:
  python_app:
    build: .
    volumes:
      - .:/app
    stdin_open: true
    tty: true
    extra_hosts:
      - "host.docker.internal:host-gateway"