From bfd125f64f86e78894d67c9eafdbae38779484bc Mon Sep 17 00:00:00 2001 From: Kristoffer Haugsbakk Date: Sat, 14 Feb 2026 12:55:41 +0100 Subject: [PATCH] doc: patch-id: emphasize multi-patch processing MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Emphasize that you can pass multiple patches or diffs to this command. git-patch-id(1) is an efficient pID–commit mapper, able to map thousands of commits in seconds. But discussions on the command seem to typically[1] use the standard loop-over-rev-list-and- shell-out pattern: for commit in rev-list: prepare a diff from commit | git patch-id This is unnecessary; we can bulk-process the patches: git rev-list --no-merges | git diff-tree --patch --stdin | git patch-id --stable The first version (translated to shell) takes a little over nine minutes for a commit history of about 78K commits.[2] The other one, by contrast, takes slightly less than a minute. Also drop “the” from “standard input”. † 1: https://stackoverflow.com/a/19758159 † 2: This is `master` of this repository on 2025-10-02 Signed-off-by: Kristoffer Haugsbakk Signed-off-by: Junio C Hamano --- Documentation/git-patch-id.adoc | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/Documentation/git-patch-id.adoc b/Documentation/git-patch-id.adoc index 013e1a6190..e95391cd25 100644 --- a/Documentation/git-patch-id.adoc +++ b/Documentation/git-patch-id.adoc @@ -3,7 +3,7 @@ git-patch-id(1) NAME ---- -git-patch-id - Compute unique ID for a patch +git-patch-id - Compute unique IDs for patches SYNOPSIS -------- @@ -12,7 +12,7 @@ git patch-id [--stable | --unstable | --verbatim] DESCRIPTION ----------- -Read a patch from the standard input and compute the patch ID for it. +Read patches from standard input and compute the patch IDs. A "patch ID" is nothing but a sum of SHA-1 of the file diffs associated with a patch, with line numbers ignored. As such, it's "reasonably stable", but at @@ -25,7 +25,8 @@ When dealing with `git diff-tree --patch` output, it takes advantage of the fact that the patch is prefixed with the object name of the commit, and outputs two 40-byte hexadecimal strings. The first string is the patch ID, and the second string is the commit ID. -This can be used to make a mapping from patch ID to commit ID. +This can be used to make a mapping from patch ID to commit ID for a +set or range of commits. OPTIONS -------