42 lines
1.6 KiB
Python
42 lines
1.6 KiB
Python
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import requests
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class EventSourceFollower:
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def __init__(self, url, timeout):
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self.resp = requests.get(url,
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headers={"accept": "text/event-stream"},
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stream=True,
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timeout=timeout)
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self.resp.raise_for_status()
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def close(self):
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self.resp.close()
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def _get_fields(self, lines):
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while True:
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first_line = lines.next() # raises StopIteration when closed
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fieldname, data = first_line.split(": ", 1)
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data_lines = [data]
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while True:
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next_line = lines.next()
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if not next_line: # empty string, original was "\n"
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yield (fieldname, "\n".join(data_lines))
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break
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data_lines.append(next_line)
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def iter_events(self):
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# I think Request.iter_lines and .iter_content use chunk_size= in a
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# funny way, and nothing happens until at least that much data has
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# arrived. So unless we set chunk_size=1, we won't hear about lines
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# for a long time. I'd prefer that chunk_size behaved like
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# read(size), and gave you 1<=x<=size bytes in response.
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eventtype = "message"
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lines_iter = self.resp.iter_lines(chunk_size=1)
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for (fieldname, data) in self._get_fields(lines_iter):
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if fieldname == "data":
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yield (eventtype, data)
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eventtype = "message"
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elif fieldname == "event":
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eventtype = data
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else:
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print("weird fieldname", fieldname, data)
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