From: Derrick Stolee <dsto...@microsoft.com>
The commit-graph feature is now on by default, and is being
written during 'git gc' by default. Typically, Git only writes
a commit-graph when a 'git gc --auto' command passes the gc.auto
setting to actualy do work. This means that a commit-graph will
typically fall behind the commits that are being used every day.
To stay updated with the latest commits, add a step to 'git
fetch' to write a commit-graph after fetching new objects. The
fetch.writeCommitGraph config setting enables writing a split
commit-graph, so on average the cost of writing this file is
very small. Occasionally, the commit-graph chain will collapse
to a single level, and this could be slow for very large repos.
For additional use, adjust the default to be true when
feature.experimental is enabled.
Signed-off-by: Derrick Stolee <dsto...@microsoft.com>
---
Documentation/config/feature.txt | 8 ++++++++
Documentation/config/fetch.txt | 10 ++++++++++
builtin/fetch.c | 15 +++++++++++++++
repo-settings.c | 4 ++++
repository.h | 1 +
t/t5510-fetch.sh | 13 +++++++++++++
6 files changed, 51 insertions(+)
diff --git a/Documentation/config/feature.txt b/Documentation/config/feature.txt
index 545522f306..875f8c8a66 100644
--- a/Documentation/config/feature.txt
+++ b/Documentation/config/feature.txt
@@ -17,6 +17,14 @@ which can improve `git push` performance in repos with many
files.
+
* `fetch.negotiationAlgorithm=skipping` may improve fetch negotiation times by
skipping more commits at a time, reducing the number of round trips.
++
+* `fetch.writeCommitGraph=true` writes a commit-graph after every `git fetch`
+command that downloads a pack-file from a remote. Using the `--split` option,
+most executions will create a very small commit-graph file on top of the
+existing commit-graph file(s). Occasionally, these files will merge and the
+write may take longer. Having an updated commit-graph file helps performance
+of many Git commands, including `git merge-base`, `git push -f`, and
+`git log --graph`.
feature.manyFiles::
Enable config options that optimize for repos with many files in the
diff --git a/Documentation/config/fetch.txt b/Documentation/config/fetch.txt
index d402110638..e8cb20547c 100644
--- a/Documentation/config/fetch.txt
+++ b/Documentation/config/fetch.txt
@@ -69,3 +69,13 @@ fetch.showForcedUpdates::
Set to false to enable `--no-show-forced-updates` in
linkgit:git-fetch[1] and linkgit:git-pull[1] commands.
Defaults to true.
+
+fetch.writeCommitGraph::
+ Set to true to write a commit-graph after every `git fetch` command
+ that downloads a pack-file from a remote. Using the `--split` option,
+ most executions will create a very small commit-graph file on top of
+ the existing commit-graph file(s). Occasionally, these files will
+ merge and the write may take longer. Having an updated commit-graph
+ file helps performance of many Git commands, including `git merge-base`,
+ `git push -f`, and `git log --graph`. Defaults to false, unless
+ `feature.experimental` is true.
diff --git a/builtin/fetch.c b/builtin/fetch.c
index 53ce99d2bb..d36a403859 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -23,6 +23,7 @@
#include "packfile.h"
#include "list-objects-filter-options.h"
#include "commit-reach.h"
+#include "commit-graph.h"
#define FORCED_UPDATES_DELAY_WARNING_IN_MS (10 * 1000)
@@ -1715,6 +1716,20 @@ int cmd_fetch(int argc, const char **argv, const char
*prefix)
string_list_clear(&list, 0);
+ prepare_repo_settings(the_repository);
+ if (the_repository->settings.fetch_write_commit_graph) {
+ int commit_graph_flags = COMMIT_GRAPH_SPLIT;
+ struct split_commit_graph_opts split_opts;
+ memset(&split_opts, 0, sizeof(struct split_commit_graph_opts));
+
+ if (progress)
+ commit_graph_flags |= COMMIT_GRAPH_PROGRESS;
+
+ write_commit_graph_reachable(get_object_directory(),
+ commit_graph_flags,
+ &split_opts);
+ }
+
close_object_store(the_repository->objects);
if (enable_auto_gc) {
diff --git a/repo-settings.c b/repo-settings.c
index 3779b85c17..05546db98e 100644
--- a/repo-settings.c
+++ b/repo-settings.c
@@ -49,10 +49,14 @@ void prepare_repo_settings(struct repository *r)
UPDATE_DEFAULT_BOOL(r->settings.index_version, 4);
UPDATE_DEFAULT_BOOL(r->settings.core_untracked_cache,
UNTRACKED_CACHE_WRITE);
}
+ if (!repo_config_get_bool(r, "fetch.writecommitgraph", &value))
+ r->settings.fetch_write_commit_graph = value;
if (!repo_config_get_bool(r, "feature.experimental", &value) && value) {
UPDATE_DEFAULT_BOOL(r->settings.pack_use_sparse, 1);
UPDATE_DEFAULT_BOOL(r->settings.fetch_negotiation_algorithm,
FETCH_NEGOTIATION_SKIPPING);
+ UPDATE_DEFAULT_BOOL(r->settings.fetch_write_commit_graph, 1);
}
+ UPDATE_DEFAULT_BOOL(r->settings.fetch_write_commit_graph, 0);
/* Hack for test programs like test-dump-untracked-cache */
if (ignore_untracked_cache_config)
diff --git a/repository.h b/repository.h
index 4da275e73f..fe0b5f5dc6 100644
--- a/repository.h
+++ b/repository.h
@@ -30,6 +30,7 @@ struct repo_settings {
int core_commit_graph;
int gc_write_commit_graph;
+ int fetch_write_commit_graph;
int index_version;
enum untracked_cache_setting core_untracked_cache;
diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh
index 139f7106f7..91ede622f0 100755
--- a/t/t5510-fetch.sh
+++ b/t/t5510-fetch.sh
@@ -570,6 +570,19 @@ test_expect_success 'LHS of refspec follows ref
disambiguation rules' '
)
'
+test_expect_success 'fetch.writeCommitGraph' '
+ git clone three write &&
+ (
+ cd three &&
+ test_commit new
+ ) &&
+ (
+ cd write &&
+ git -c fetch.writeCommitGraph fetch origin &&
+ test_path_is_file
.git/objects/info/commit-graphs/commit-graph-chain
+ )
+'
+
# configured prune tests
set_config_tristate () {
--
gitgitgadget
