git-commit-graph(1)

# git-commit-graph(1) Manual Page

## NAME

git-commit-graph - Write and verify Git commit-graph files

## SYNOPSIS

    git commit-graph verify [--object-dir <dir>] [--shallow] [--[no-]progress]
    git commit-graph write [--object-dir <dir>] [--append]
                            [--split[=<strategy>]] [--reachable | --stdin-packs | --stdin-commits]
                            [--changed-paths] [--[no-]max-new-filters <n>] [--[no-]progress]
                            <split-options>

## DESCRIPTION

Manage the serialized commit-graph file.

## OPTIONS

--object-dir

  Use given directory for the location of packfiles and commit-graph file. This parameter exists to specify the location of an alternate that only has the objects directory, not a full .`git` directory. The commit-graph file is expected to be in the <dir>`/info` directory and the packfiles are expected to be in <dir>`/pack`. If the directory could not be made into an absolute path, or does not match any known object directory, `git` `commit-graph` ... will exit with non-zero status.

--progress
--no-progress

  Turn progress on/off explicitly. If neither is specified, progress is shown if standard error is connected to a terminal.

## COMMANDS

write

  Write a commit-graph file based on the commits found in packfiles. If the config option `core.commitGraph` is disabled, then this command will output a warning, then return success without writing a commit-graph file.

  With the `--stdin-packs` option, generate the new commit graph by walking objects only in the specified pack-indexes. (Cannot be combined with `--stdin-commits` or `--reachable`.)

  With the `--stdin-commits` option, generate the new commit graph by walking commits starting at the commits specified in stdin as a list of OIDs in hex, one OID per line. OIDs that resolve to non-commits (either directly, or by peeling tags) are silently ignored. OIDs that are malformed, or do not exist generate an error. (Cannot be combined with `--stdin-packs` or `--reachable`.)

  With the `--reachable` option, generate the new commit graph by walking commits starting at all refs. (Cannot be combined with `--stdin-commits` or `--stdin-packs`.)

  With the `--append` option, include all commits that are present in the existing commit-graph file.

  With the `--changed-paths` option, compute and write information about the paths changed between a commit and its first parent. This operation can take a while on large repositories. It provides significant performance gains for getting history of a directory or a file with `git` `log` `--` <path>. If this option is given, future commit-graph writes will automatically assume that this option was intended. Use `--no-changed-paths` to stop storing this data. `--changed-paths` is implied by config `commitGraph.changedPaths=true`.

  With the `--max-new-filters=`<n> option, generate at most `n` new Bloom filters (if `--changed-paths` is specified). If `n` is `-1`, no limit is enforced. Only commits present in the new layer count against this limit. To retroactively compute Bloom filters over earlier layers, it is advised to use `--split=replace`. Overrides the `commitGraph.maxNewFilters` configuration.

  With the `--split`[`=`<strategy>] option, write the commit-graph as a chain of multiple commit-graph files stored in <dir>`/info/commit-graphs`. Commit-graph layers are merged based on the strategy and other splitting options. The new commits not already in the commit-graph are added in a new "tip" file. This file is merged with the existing file if the following merge conditions are met:

  - If `--split=no-merge` is specified, a merge is never performed, and the remaining options are ignored. `--split=replace` overwrites the existing chain with a new one. A bare `--split` defers to the remaining options. (Note that merging a chain of commit graphs replaces the existing chain with a length-1 chain where the first and only incremental holds the entire graph).

  - If `--size-multiple=`<X> is not specified, let `X` equal 2. If the new tip file would have `N` commits and the previous tip has `M` commits and `X` times `N` is greater than `M`, instead merge the two files into a single file.

  - If `--max-commits=`<M> is specified with `M` a positive integer, and the new tip file would have more than `M` commits, then instead merge the new tip with the previous tip.

    Finally, if `--expire-time=`<datetime> is not specified, let `datetime` be the current time. After writing the split commit-graph, delete all unused commit-graph whose modified times are older than `datetime`.

verify

  Read the commit-graph file and verify its contents against the object database. Used to check for corrupted data.

  With the `--shallow` option, only check the tip commit-graph file in a chain of split commit-graphs.

## EXAMPLES

- Write a commit-graph file for the packed commits in your local .`git` directory.

      $ git commit-graph write

- Write a commit-graph file, extending the current commit-graph file using commits in <pack-index>.

      $ echo <pack-index> | git commit-graph write --stdin-packs

- Write a commit-graph file containing all reachable commits.

      $ git show-ref -s | git commit-graph write --stdin-commits

- Write a commit-graph file containing all commits in the current commit-graph file along with those reachable from `HEAD`.

      $ git rev-parse HEAD | git commit-graph write --stdin-commits --append

## CAVEATS

The existence of replace objects or commit grafts turns off reading or writing to the commit-graph. See git-replace(1).

## CONFIGURATION

Everything below this line in this section is selectively included from the git-config(1) documentation. The content is the same as what’s found there:

commitGraph.generationVersion

  Specifies the type of generation number version to use when writing or reading the commit-graph file. If version 1 is specified, then the corrected commit dates will not be written or read. Defaults to 2.

commitGraph.maxNewFilters

  Specifies the default value for the `--max-new-filters` option of `git` `commit-graph` `write` (c.f., git-commit-graph(1)).

commitGraph.changedPaths

  If true, then `git` `commit-graph` `write` will compute and write changed-path Bloom filters by default, equivalent to passing `--changed-paths`. If false or unset, changed-paths Bloom filters will be written during `git` `commit-graph` `write` only if the filters already exist in the current commit-graph file. This matches the default behavior of `git` `commit-graph` `write` without any `--`[`no-`]`changed-paths` option. To rewrite a commit-graph file without any filters, use the `--no-changed-paths` option. Command-line option `--`[`no-`]`changed-paths` always takes precedence over this configuration. Defaults to unset.

commitGraph.readChangedPaths

  Deprecated. Equivalent to commitGraph.changedPathsVersion=-1 if true, and commitGraph.changedPathsVersion=0 if false. (If commitGraph.changedPathVersion is also set, commitGraph.changedPathsVersion takes precedence.)

commitGraph.changedPathsVersion

  Specifies the version of the changed-path Bloom filters that Git will read and write. May be -1, 0, 1, or 2. Note that values greater than 1 may be incompatible with older versions of Git which do not yet understand those versions. Use caution when operating in a mixed-version environment.

  Defaults to -1.

  If -1, Git will use the version of the changed-path Bloom filters in the repository, defaulting to 1 if there are none.

  If 0, Git will not read any Bloom filters, and will write version 1 Bloom filters when instructed to write.

  If 1, Git will only read version 1 Bloom filters, and will write version 1 Bloom filters.

  If 2, Git will only read version 2 Bloom filters, and will write version 2 Bloom filters.

  See git-commit-graph(1) for more information.

## FILE FORMAT

see gitformat-commit-graph(5).

## GIT

Part of the git(1) suite