new(jmacd/xdelta): VCDIFF (RFC 3284) delta compression — open-vcdiff alternative#13146
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tannevaled wants to merge 1 commit into
Open
new(jmacd/xdelta): VCDIFF (RFC 3284) delta compression — open-vcdiff alternative#13146tannevaled wants to merge 1 commit into
tannevaled wants to merge 1 commit into
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Joshua MacDonald's xdelta3 — the most widely used VCDIFF implementation outside Google's now-archived open-vcdiff. Used by Chromium auto-update channels and many embedded firmware delta pipelines. C autotools build, GPL-2.0+. Upstream is dormant (last push 2020) but unarchived; the algorithm and CLI surface are RFC-stable. Builds from the modern xdelta3/ subdir; the older xdelta1/ proto is left out (1998 historical only). Test: round-trip encode/decode with a small source/target pair. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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Summary
Adds Joshua MacDonald's xdelta3 — the most widely used VCDIFF (RFC 3284) implementation outside Google's now-archived open-vcdiff.
Why now
Google's `open-vcdiff` was archived 2023-08-26 (see #13141 where I attempted to package it and parked due to vendored gflags submodule problems). xdelta is the credible alternative:
Build
Standard autotools, GPL-2.0+. Builds from the modern `xdelta3/` subdir; `xdelta1/` (1998 prototype) intentionally skipped.
Test plan
Related
🤖 Generated with Claude Code