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 <dstolee@xxxxxxxxxxxxx>
---
Documentation/config.txt | 6 ++++++
Documentation/git-gc.txt | 4 ++++
builtin/gc.c | 6 ++++++
t/t5318-commit-graph.sh | 14 ++++++++++++++
4 files changed, 30 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..efd214a59f 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -20,6 +20,7 @@
#include "argv-array.h"
#include "commit.h"
#include "packfile.h"
+#include "commit-graph.h"
#define FAILED_RUN "failed to run %s"
@@ -34,6 +35,7 @@ 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";
@@ -121,6 +123,7 @@ static void gc_config(void)
git_config_get_int("gc.aggressivedepth", &aggressive_depth);
git_config_get_int("gc.auto", &gc_auto_threshold);
git_config_get_int("gc.autopacklimit", &gc_auto_pack_limit);
+ git_config_get_bool("gc.commitgraph", &gc_commit_graph);
git_config_get_bool("gc.autodetach", &detach_auto);
git_config_get_expiry("gc.pruneexpire", &prune_expire);
git_config_get_expiry("gc.worktreepruneexpire", &prune_worktrees_expire);
@@ -480,6 +483,9 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
if (pack_garbage.nr > 0)
clean_pack_garbage();
+ if (gc_commit_graph)
+ write_commit_graph_reachable(get_object_directory(), 0);
+
if (auto_gc && too_many_loose_objects())
warning(_("There are too many unreachable loose objects; "
"run 'git prune' to remove them."));
diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index a659620332..d20b17586f 100755
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -245,6 +245,20 @@ test_expect_success 'perform fast-forward merge in full repo' '
test_cmp expect output
'
+test_expect_success 'check that gc clears commit-graph' '
+ cd "$TRASH_DIRECTORY/full" &&
+ git commit --allow-empty -m "blank" &&
+ git commit-graph write --reachable &&
+ cp $objdir/info/commit-graph commit-graph-before-gc &&
+ git reset --hard HEAD~1 &&
+ git config gc.commitGraph true &&
+ git gc &&
+ cp $objdir/info/commit-graph commit-graph-after-gc &&
+ ! test_cmp commit-graph-before-gc commit-graph-after-gc &&
+ git commit-graph write --reachable &&
+ test_cmp commit-graph-after-gc $objdir/info/commit-graph
+'
+
# the verify tests below expect the commit-graph to contain
# exactly the commits reachable from the commits/8 branch.
# If the file changes the set of commits in the list, then the
--
2.16.2.329.gfb62395de6
