commit: integrate commit graph with commit parsing
Teach Git to inspect a commit graph file to supply the contents of a
struct commit when calling parse_commit_gently(). This implementation
satisfies all post-conditions on the struct commit, including loading
parents, the root tree, and the commit date.
If core.commitGraph is false, then do not check graph files.
In test script t5318-commit-graph.sh, add output-matching conditions on
read-only graph operations.
By loading commits from the graph instead of parsing commit buffers, we
save a lot of time on long commit walks. Here are some performance
results for a copy of the Linux repository where 'master' has 678,653
reachable commits and is behind 'origin/master' by 59,929 commits.
| Command | Before | After | Rel % |
|----------------------------------|--------|--------|-------|
| log --oneline --topo-order -1000 | 8.31s | 0.94s | -88% |
| branch -vv | 1.02s | 0.14s | -86% |
| rev-list --all | 5.89s | 1.07s | -81% |
| rev-list --all --objects | 66.15s | 58.45s | -11% |
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/commit.h b/commit.h
index 0fb8271..e57ae4b 100644
--- a/commit.h
+++ b/commit.h
@@ -9,6 +9,8 @@
#include "string-list.h"
#include "pretty.h"
+#define COMMIT_NOT_FROM_GRAPH 0xFFFFFFFF
+
struct commit_list {
struct commit *item;
struct commit_list *next;
@@ -21,6 +23,7 @@ struct commit {
timestamp_t date;
struct commit_list *parents;
struct tree *tree;
+ uint32_t graph_pos;
};
extern int save_commit_buffer;
