Re: [PATCH v2 09/11] commit-graph: add --changed-paths option to write subcommand

>
> From: Garima Singh <garima.singh@microsoft.com>
>
> Add --changed-paths option to git commit-graph write. This option will
> allow users to compute information about the paths that have changed
> between a commit and its first parent, and write it into the commit graph
> file. If the option is passed to the write subcommand we set the
> COMMIT_GRAPH_WRITE_BLOOM_FILTERS flag and pass it down to the
> commit-graph logic.
>
> Helped-by: Derrick Stolee <dstolee@microsoft.com>
> Signed-off-by: Garima Singh <garima.singh@microsoft.com>
> ---
>  Documentation/git-commit-graph.txt | 5 +++++
>  builtin/commit-graph.c             | 9 +++++++--
>  2 files changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/git-commit-graph.txt b/Documentation/git-commit-graph.txt
> index bcd85c1976..907d703b30 100644
> --- a/Documentation/git-commit-graph.txt
> +++ b/Documentation/git-commit-graph.txt
> @@ -54,6 +54,11 @@ 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 it's 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>`.
> ++
>  With the `--split` option, write the commit-graph as a chain of multiple
>  commit-graph files stored in `<dir>/info/commit-graphs`. The new commits
>  not already in the commit-graph are added in a new "tip" file. This file
> diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
> index e0c6fc4bbf..261dcce091 100644
> --- a/builtin/commit-graph.c
> +++ b/builtin/commit-graph.c
> @@ -9,7 +9,7 @@
>
>  static char const * const builtin_commit_graph_usage[] = {
>         N_("git commit-graph verify [--object-dir <objdir>] [--shallow] [--[no-]progress]"),
> -       N_("git commit-graph write [--object-dir <objdir>] [--append|--split] [--reachable|--stdin-packs|--stdin-commits] [--[no-]progress] <split options>"),
> +       N_("git commit-graph write [--object-dir <objdir>] [--append|--split] [--reachable|--stdin-packs|--stdin-commits] [--changed-paths] [--[no-]progress] <split options>"),
>         NULL
>  };
>
> @@ -19,7 +19,7 @@ static const char * const builtin_commit_graph_verify_usage[] = {
>  };
>
>  static const char * const builtin_commit_graph_write_usage[] = {
> -       N_("git commit-graph write [--object-dir <objdir>] [--append|--split] [--reachable|--stdin-packs|--stdin-commits] [--[no-]progress] <split options>"),
> +       N_("git commit-graph write [--object-dir <objdir>] [--append|--split] [--reachable|--stdin-packs|--stdin-commits] [--changed-paths] [--[no-]progress] <split options>"),
>         NULL
>  };
>
> @@ -32,6 +32,7 @@ static struct opts_commit_graph {
>         int split;
>         int shallow;
>         int progress;
> +       int enable_changed_paths;
>  } opts;
>
>  static int graph_verify(int argc, const char **argv)
> @@ -110,6 +111,8 @@ static int graph_write(int argc, const char **argv)
>                         N_("start walk at commits listed by stdin")),
>                 OPT_BOOL(0, "append", &opts.append,
>                         N_("include all commits already in the commit-graph file")),
> +               OPT_BOOL(0, "changed-paths", &opts.enable_changed_paths,
> +                       N_("enable computation for changed paths")),
>                 OPT_BOOL(0, "progress", &opts.progress, N_("force progress reporting")),
>                 OPT_BOOL(0, "split", &opts.split,
>                         N_("allow writing an incremental commit-graph file")),
> @@ -143,6 +146,8 @@ static int graph_write(int argc, const char **argv)
>                 flags |= COMMIT_GRAPH_WRITE_SPLIT;
>         if (opts.progress)
>                 flags |= COMMIT_GRAPH_WRITE_PROGRESS;
> +       if (opts.enable_changed_paths)
> +               flags |= COMMIT_GRAPH_WRITE_BLOOM_FILTERS;
>
>         read_replace_refs = 0;
>
> --
> gitgitgadget
>