From: Derrick Stolee <dstolee@xxxxxxxxxxxxx>
If a repo is large, then it probably has a very large working
directory. In this case, a typical developer's edits usually impact
many fewer paths than the full path set. The sparse treewalk
algorithm is optimized for this case, speeding up 'git push' calls.
Use pack.useSparse=true when core.featureAdoptionRate is at least
five. This is the first setting where the feature has only been
out for a single major version. This could be moved to the "at
least three" category after another major version.
Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx>
---
Documentation/config/core.txt | 9 +++++++++
Documentation/config/pack.txt | 3 ++-
builtin/pack-objects.c | 9 +++++----
repo-settings.c | 8 ++++++++
repo-settings.h | 1 +
5 files changed, 25 insertions(+), 5 deletions(-)
diff --git a/Documentation/config/core.txt b/Documentation/config/core.txt
index d16503a9d7..77fdd02660 100644
--- a/Documentation/config/core.txt
+++ b/Documentation/config/core.txt
@@ -623,3 +623,12 @@ not modify the user-facing output of porcelain commands.
+
* `index.version=4` uses prefix-compression to reduce the size of the
.git/index file.
++
+If the value is at least 5, then all of the defaults above are included,
+plus the defaults below. These represent new features that present
+significant performance benefits, but may not have been released for
+multiple major versions.
++
+* `pack.useSparse=true` uses the sparse tree-walk algorithm, which is
+optimized for enumerating objects during linkgit:git-push[1] from a
+client machine.
diff --git a/Documentation/config/pack.txt b/Documentation/config/pack.txt
index 9cdcfa7324..9c4f8ea9ff 100644
--- a/Documentation/config/pack.txt
+++ b/Documentation/config/pack.txt
@@ -112,7 +112,8 @@ pack.useSparse::
objects. This can have significant performance benefits when
computing a pack to send a small change. However, it is possible
that extra objects are added to the pack-file if the included
- commits contain certain types of direct renames.
+ commits contain certain types of direct renames. Defaults to
+ false, unless `core.featureAdoptionRate` is at least five.
pack.writeBitmaps (deprecated)::
This is a deprecated synonym for `repack.writeBitmaps`.
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 41d7fc5983..f26b3f2892 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -34,6 +34,7 @@
#include "dir.h"
#include "midx.h"
#include "trace2.h"
+#include "repo-settings.h"
#define IN_PACK(obj) oe_in_pack(&to_pack, obj)
#define SIZE(obj) oe_size(&to_pack, obj)
@@ -2707,10 +2708,6 @@ static int git_pack_config(const char *k, const char *v, void *cb)
use_bitmap_index_default = git_config_bool(k, v);
return 0;
}
- if (!strcmp(k, "pack.usesparse")) {
- sparse = git_config_bool(k, v);
- return 0;
- }
if (!strcmp(k, "pack.threads")) {
delta_search_threads = git_config_int(k, v);
if (delta_search_threads < 0)
@@ -3330,6 +3327,10 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
read_replace_refs = 0;
sparse = git_env_bool("GIT_TEST_PACK_SPARSE", 0);
+ prepare_repo_settings(the_repository);
+ if (!sparse && the_repository->settings->pack_use_sparse != -1)
+ sparse = the_repository->settings->pack_use_sparse;
+
reset_pack_idx_option(&pack_idx_opts);
git_config(git_pack_config, NULL);
diff --git a/repo-settings.c b/repo-settings.c
index 5753153a84..c700edc286 100644
--- a/repo-settings.c
+++ b/repo-settings.c
@@ -16,6 +16,9 @@ static int git_repo_config(const char *key, const char *value, void *cb)
UPDATE_DEFAULT(rs->gc_write_commit_graph, 1);
UPDATE_DEFAULT(rs->index_version, 4);
}
+ if (rate >= 5) {
+ UPDATE_DEFAULT(rs->pack_use_sparse, 1);
+ }
return 0;
}
if (!strcmp(key, "core.commitgraph")) {
@@ -26,6 +29,10 @@ static int git_repo_config(const char *key, const char *value, void *cb)
rs->gc_write_commit_graph = git_config_bool(key, value);
return 0;
}
+ if (!strcmp(key, "pack.usesparse")) {
+ rs->pack_use_sparse = git_config_bool(key, value);
+ return 0;
+ }
if (!strcmp(key, "index.version")) {
rs->index_version = git_config_int(key, value);
return 0;
@@ -44,6 +51,7 @@ void prepare_repo_settings(struct repository *r)
/* Defaults */
r->settings->core_commit_graph = -1;
r->settings->gc_write_commit_graph = -1;
+ r->settings->pack_use_sparse = -1;
r->settings->index_version = -1;
repo_config(r, git_repo_config, r->settings);
diff --git a/repo-settings.h b/repo-settings.h
index 9b8104042e..b50228f992 100644
--- a/repo-settings.h
+++ b/repo-settings.h
@@ -4,6 +4,7 @@
struct repo_settings {
char core_commit_graph;
char gc_write_commit_graph;
+ char pack_use_sparse;
int index_version;
};
--
gitgitgadget
