diff options
author | Derrick Stolee <dstolee@microsoft.com> | 2018-04-06 22:09:46 +0300 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2018-04-11 04:47:16 +0300 |
commit | 7b8a21dba1bce44d64bd86427d3d92437adc4707 (patch) | |
tree | e45261ae8a002fdd4bab8ffc632740b5cee55c8c /commit.h | |
parent | 2e27bd7731d47b374c1c14b53af07b3bfa39fcac (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 <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'commit.h')
-rw-r--r-- | commit.h | 6 |
1 files changed, 6 insertions, 0 deletions
@@ -22,6 +22,12 @@ struct commit { unsigned int index; timestamp_t date; struct commit_list *parents; + + /* + * If the commit is loaded from the commit-graph file, then this + * member may be NULL. Only access it through get_commit_tree() + * or get_commit_tree_oid(). + */ struct tree *maybe_tree; uint32_t graph_pos; }; |