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x/compress/brotli lacks decompress_with_callback #32306
Description
The pure-V x/compress/brotli module only exposes compress/decompress, while the native compress.brotli module also exposes decompress_with_callback (used by net/http response decoding for memory-bounded streaming with early-stop).
Switching the import to the pure-V module (e.g. for static builds without system libbrotli) therefore breaks any caller that streams, with unknown function: brotli.decompress_with_callback.
#30904 (the pure-V module) compares only compress/decompress size/speed and never mentions the callback, so this looks like an oversight rather than an intentional carve-out. I searched issues and PRs for decompress_with_callback / x/compress/brotli parity and found nothing covering it (#24904 added the gzip callback before any brotli module existed).
Proposal: add DecompressCallback (same fn ([]u8, voidptr) int shape as the native one, so existing callbacks keep working) and decompress_with_callback(data, cb, userdata) decoding with default DecompressParams and delivering 32 KiB chunks like the native decoder, returning delivered bytes on early stop. I have a PR ready.
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Activity
metif12 commentedon Nov 13, 2026
Context/motivation: vox-browser/vox's Linux production build (unpinned V HEAD, FastC backend) fails with
unknown function: brotli.decompress_with_callbackwhen its HTTP compat layer swapscompress.brotlifor the pure-Vx/compress/brotli(see vox-browser/vox#68, which carries a local same-module shim as a workaround). An upstreamdecompress_with_callbackwith the native contract would let that shim go away. PR #32307 implements exactly the contract proposed above.