Re: [PATCH v2 11/12] gc: automatically write commit-graph files

[Martin Ågren]

On 11 May 2018 at 23:15, Derrick Stolee  wrote:
> The commit-graph file is a very helpful feature for speeding up git
> operations. In order to make it more useful, write the commit-graph file
> by default during standard garbage collection operations.

So does it really write by default...

> Add a 'gc.commitGraph' config setting that triggers writing a
> commit-graph file after any non-trivial 'git gc' command. Defaults to
> false while the commit-graph feature matures. We specifically do not

or not...? I guess the first paragraph has simply been there since
before you changed your mind about the default?

> want to turn this on by default until the commit-graph feature is fully
> integrated with history-modifying features like shallow clones.

So if someone would turn this on with a shallow clone, ... Do we want
some note (warning?) around that in the user documentation?

Martin

[PATCH v2 11/12] gc: automatically write commit-graph files

[Derrick Stolee]

The commit-graph file is a very helpful feature for speeding up git
operations. In order to make it more useful, write the commit-graph file
by default during standard garbage collection operations.

Add a 'gc.commitGraph' config setting that triggers writing a
commit-graph file after any non-trivial 'git gc' command. Defaults to
false while the commit-graph feature matures. We specifically do not
want to turn this on by default until the commit-graph feature is fully
integrated with history-modifying features like shallow clones.

Signed-off-by: Derrick Stolee 
---
 Documentation/config.txt | 6 ++
 Documentation/git-gc.txt | 4 
 builtin/gc.c | 8 
 3 files changed, 18 insertions(+)

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 11f027194e..9a3abd87e7 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -1553,6 +1553,12 @@ gc.autoDetach::
Make `git gc --auto` return immediately and run in background
if the system supports it. Default is true.
 
+gc.commitGraph::
+   If true, then gc will rewrite the commit-graph file after any
+   change to the object database. If '--auto' is used, then the
+   commit-graph will not be updated unless the threshold is met.
+   See linkgit:git-commit-graph[1] for details.
+
 gc.logExpiry::
If the file gc.log exists, then `git gc --auto` won't run
unless that file is more than 'gc.logExpiry' old.  Default is
diff --git a/Documentation/git-gc.txt b/Documentation/git-gc.txt
index 571b5a7e3c..17dd654a59 100644
--- a/Documentation/git-gc.txt
+++ b/Documentation/git-gc.txt
@@ -119,6 +119,10 @@ The optional configuration variable `gc.packRefs` 
determines if
 it within all non-bare repos or it can be set to a boolean value.
 This defaults to true.
 
+The optional configuration variable 'gc.commitGraph' determines if
+'git gc' runs 'git commit-graph write'. This can be set to a boolean
+value. This defaults to false.
+
 The optional configuration variable `gc.aggressiveWindow` controls how
 much time is spent optimizing the delta compression of the objects in
 the repository when the --aggressive option is specified.  The larger
diff --git a/builtin/gc.c b/builtin/gc.c
index 77fa720bd0..8403445738 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -34,6 +34,7 @@ static int aggressive_depth = 50;
 static int aggressive_window = 250;
 static int gc_auto_threshold = 6700;
 static int gc_auto_pack_limit = 50;
+static int gc_commit_graph = 0;
 static int detach_auto = 1;
 static timestamp_t gc_log_expire_time;
 static const char *gc_log_expire = "1.day.ago";
@@ -46,6 +47,7 @@ static struct argv_array repack = ARGV_ARRAY_INIT;
 static struct argv_array prune = ARGV_ARRAY_INIT;
 static struct argv_array prune_worktrees = ARGV_ARRAY_INIT;
 static struct argv_array rerere = ARGV_ARRAY_INIT;
+static struct argv_array commit_graph = ARGV_ARRAY_INIT;
 
 static struct tempfile *pidfile;
 static struct lock_file log_lock;
@@ -121,6 +123,7 @@ static void gc_config(void)
git_config_get_int("gc.aggressivedepth", _depth);
git_config_get_int("gc.auto", _auto_threshold);
git_config_get_int("gc.autopacklimit", _auto_pack_limit);
+   git_config_get_bool("gc.commitgraph", _commit_graph);
git_config_get_bool("gc.autodetach", _auto);
git_config_get_expiry("gc.pruneexpire", _expire);
git_config_get_expiry("gc.worktreepruneexpire", 
_worktrees_expire);
@@ -374,6 +377,7 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
argv_array_pushl(, "prune", "--expire", NULL);
argv_array_pushl(_worktrees, "worktree", "prune", "--expire", 
NULL);
argv_array_pushl(, "rerere", "gc", NULL);
+   argv_array_pushl(_graph, "commit-graph", "write", "--reachable", 
NULL);
 
/* default expiry time, overwritten in gc_config */
gc_config();
@@ -480,6 +484,10 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
if (pack_garbage.nr > 0)
clean_pack_garbage();
 
+   if (gc_commit_graph)
+   if (run_command_v_opt(commit_graph.argv, RUN_GIT_CMD))
+   return error(FAILED_RUN, commit_graph.argv[0]);
+
if (auto_gc && too_many_loose_objects())
warning(_("There are too many unreachable loose objects; "
"run 'git prune' to remove them."));
-- 
2.16.2.329.gfb62395de6