[PATCH v3 2/5] repo-settings: add feature.manyCommits setting

From

Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com>

Date

Jul 30, 2019, 19:35 UTC

Message-ID

<c0129066a02b39535110ae592c16ca0e5d6d6c24.1564515324.git.gitgitgadget@gmail.com>

In-Reply-To

<pull.292.v3.git.gitgitgadget@gmail.com>

From: Derrick Stolee <dstolee@microsoft.com>

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
 Documentation/config.txt         |  2 ++
 Documentation/config/core.txt    |  3 ++-
 Documentation/config/feature.txt | 15 +++++++++++++++
 Documentation/config/gc.txt      |  4 ++--
 repo-settings.c                  |  7 +++++++
 5 files changed, 28 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/config/feature.txt

diff --git a/Documentation/config.txt b/Documentation/config.txt
index e3f5bc3396..77f3b1486b 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -345,6 +345,8 @@ include::config/difftool.txt[]
 
 include::config/fastimport.txt[]
 
+include::config/feature.txt[]
+
 include::config/fetch.txt[]
 
 include::config/format.txt[]
diff --git a/Documentation/config/core.txt b/Documentation/config/core.txt
index 75538d27e7..d80162681a 100644
--- a/Documentation/config/core.txt
+++ b/Documentation/config/core.txt
@@ -577,7 +577,8 @@ the `GIT_NOTES_REF` environment variable.  See linkgit:git-notes[1].
 
 core.commitGraph::
 	If true, then git will read the commit-graph file (if it exists)
-	to parse the graph structure of commits. Defaults to false. See
+	to parse the graph structure of commits. Defaults to false, unless
+	`feature.manyCommits` is enabled. See
 	linkgit:git-commit-graph[1] for more information.
 
 core.useReplaceRefs::
diff --git a/Documentation/config/feature.txt b/Documentation/config/feature.txt
new file mode 100644
index 0000000000..f74314ae90
--- /dev/null
+++ b/Documentation/config/feature.txt
@@ -0,0 +1,15 @@
+feature.*::
+	The config settings that start with `feature.` modify the defaults of
+	a group of other config settings. These groups are created by the Git
+	developer community as recommended defaults and are subject to change.
+	In particular, new config options may be added with different defaults.
+
+feature.manyCommits::
+	Enable config options that optimize for repos with many commits. This
+	setting is recommended for repos with at least 100,000 commits. The
+	new default values are:
++
+* `core.commitGraph=true` enables reading the commit-graph file.
++
+* `gc.writeCommitGraph=true` enables writing the commit-graph file during
+garbage collection.
\ No newline at end of file
diff --git a/Documentation/config/gc.txt b/Documentation/config/gc.txt
index 02b92b18b5..31a5fc4f75 100644
--- a/Documentation/config/gc.txt
+++ b/Documentation/config/gc.txt
@@ -63,8 +63,8 @@ gc.writeCommitGraph::
 	If true, then gc will rewrite the commit-graph file when
 	linkgit:git-gc[1] is run. When using `git gc --auto`
 	the commit-graph will be updated if housekeeping is
-	required. Default is false. See linkgit:git-commit-graph[1]
-	for details.
+	required. Default is false, unless `feature.manyCommits`
+	is enabled. See linkgit:git-commit-graph[1] for details.
 
 gc.logExpiry::
 	If the file gc.log exists, then `git gc --auto` will print
diff --git a/repo-settings.c b/repo-settings.c
index 309577f6bc..fc05f4fbc4 100644
--- a/repo-settings.c
+++ b/repo-settings.c
@@ -2,6 +2,8 @@
 #include "config.h"
 #include "repository.h"
 
+#define UPDATE_DEFAULT(s,v) do { if (s == -1) { s = v; } } while(0)
+
 void prepare_repo_settings(struct repository *r)
 {
 	int value;
@@ -22,4 +24,9 @@ void prepare_repo_settings(struct repository *r)
 
 	if (!repo_config_get_bool(r, "pack.usesparse", &value))
 		r->settings.pack_use_sparse = value;
+
+	if (!repo_config_get_bool(r, "feature.manycommits", &value) && value) {
+		UPDATE_DEFAULT(r->settings.core_commit_graph, 1);
+		UPDATE_DEFAULT(r->settings.gc_write_commit_graph, 1);
+	}
 }

-- 
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