path: root/commit-graph.h
diff options
authorDerrick Stolee <>2018-04-06 19:09:46 (GMT)
committerJunio C Hamano <>2018-04-11 01:47:16 (GMT)
commit7b8a21dba1bce44d64bd86427d3d92437adc4707 (patch)
treee45261ae8a002fdd4bab8ffc632740b5cee55c8c /commit-graph.h
parent2e27bd7731d47b374c1c14b53af07b3bfa39fcac (diff)
commit-graph: lazy-load trees for commits
The commit-graph file provides quick access to commit data, including the OID of the root tree for each commit in the graph. When performing a deep commit-graph walk, we may not need to load most of the trees for these commits. Delay loading the tree object for a commit loaded from the graph until requested via get_commit_tree(). Do not lazy-load trees for commits not in the graph, since that requires duplicate parsing and the relative peformance improvement when trees are not needed is small. On the Linux repository, performance tests were run for the following command: git log --graph --oneline -1000 Before: 0.92s After: 0.66s Rel %: -28.3% Adding '-- kernel/' to the command requires loading the root tree for every commit that is walked. There was no measureable performance change as a result of this patch. Signed-off-by: Derrick Stolee <> Signed-off-by: Junio C Hamano <>
Diffstat (limited to 'commit-graph.h')
1 files changed, 2 insertions, 0 deletions
diff --git a/commit-graph.h b/commit-graph.h
index e1d8580..260a468 100644
--- a/commit-graph.h
+++ b/commit-graph.h
@@ -17,6 +17,8 @@ char *get_commit_graph_filename(const char *obj_dir);
int parse_commit_in_graph(struct commit *item);
+struct tree *get_commit_tree_in_graph(const struct commit *c);
struct commit_graph {
int graph_fd;