[Python] output_buffer_limit is not fully respected #567

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claunia · 2026-01-29T20:45:54Z

claunia commented

2026-01-29 20:45:54 +00:00

Originally created by @illia-v on GitHub (Nov 23, 2025).

Version 1.2.0 added output_buffer_limit – "If set, the output buffer will not grow once its size equal or exceeding that value."
While it does usually prevent decompressing the whole data at once, the output size is not limited by it.

import brotli

compressed = brotli.compress(b"x" * (10 * 2**20))  # 10 MiB

decompressor = brotli.Decompressor()
print(len(decompressor.process(compressed, output_buffer_limit=2**20)))  # Output 2_064_288, expected 1_048_576
print(len(decompressor.process(b"", output_buffer_limit=1024)))  # Output 32_752, expected 1024
print(len(decompressor.process(b"", output_buffer_limit=32_753)))  # Output 98_272, expected 32_753

Originally created by @illia-v on GitHub (Nov 23, 2025). Version 1.2.0 added `output_buffer_limit` – "If set, the output buffer will not grow once its size equal or exceeding that value." While it does usually prevent decompressing the whole data at once, the output size is not limited by it. ```python import brotli compressed = brotli.compress(b"x" * (10 * 2**20)) # 10 MiB decompressor = brotli.Decompressor() print(len(decompressor.process(compressed, output_buffer_limit=2**20))) # Output 2_064_288, expected 1_048_576 print(len(decompressor.process(b"", output_buffer_limit=1024))) # Output 32_752, expected 1024 print(len(decompressor.process(b"", output_buffer_limit=32_753))) # Output 98_272, expected 32_753 ```

claunia commented

2026-01-29 20:45:55 +00:00

@illia-v commented on GitHub (Nov 23, 2025):

FYI, brotlicffi v1.2.0.0 built on top of this library outputs the exact requested amount of bytes
https://github.com/python-hyper/brotlicffi/pull/207

@illia-v commented on GitHub (Nov 23, 2025): FYI, brotlicffi v1.2.0.0 built on top of this library outputs the exact requested amount of bytes https://github.com/python-hyper/brotlicffi/pull/207

claunia referenced this issue

2026-01-29 20:53:02 +00:00

[PR #567] [MERGED] Added windows platform support to premake #1217

claunia referenced this issue

2026-01-29 20:53:03 +00:00

[PR #567] Added windows platform support to premake #1222

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