Do multiple reads for WSGI even with content length #37
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stefanvanburen
approved these changes
Oct 21, 2025
src/connectrpc/_server_sync.py
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| environ: WSGIEnvironment, content_length: int | ||
| ) -> bytes: | ||
| bytes_read = 0 | ||
| chunks = [] |
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nit: could we pre-allocate a bytearray to be size content_length and then use readinto?
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WSGI doesn't actually define readinto.
https://peps.python.org/pep-3333/#input-and-error-streams
Since most servers will prebuffer anyways, I added a small optimization for that case instead
spenczar
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Oct 21, 2025
Signed-off-by: Anuraag Agrawal <[email protected]>
Signed-off-by: Anuraag Agrawal <[email protected]>
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spenczar
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i2y
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For
.read()methodshttps://docs.python.org/3/library/io.html#io.RawIOBase.read
In practice, all WSGI servers seem to buffer the request to content-length before calling the app...except for pyvoy ;) Incidentally that means pyvoy is able to pass bidi streaming tests with WSGI too. I'm currently debugging an occasional macOS crash which seems envoy-related, but am feeling pretty good about the project.
I also took care to follow the WSGI spec "The application should not attempt to read more data than is specified by the CONTENT_LENGTH variable.". If this text wasn't there, it would be easiest to just call
.read()with no parameter.https://peps.python.org/pep-3333/#input-and-error-streams
I'm interested in adding pyvoy to conformance tests after some more debugging, but without it it's quite challenging to add a regression test for this change. I wanted to separate out the logic change from any testing changes but let me know if I should hold off until having that regression test.