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7b8a21dba1
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>
49 lines
1.1 KiB
C
49 lines
1.1 KiB
C
#ifndef COMMIT_GRAPH_H
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#define COMMIT_GRAPH_H
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#include "git-compat-util.h"
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char *get_commit_graph_filename(const char *obj_dir);
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/*
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* Given a commit struct, try to fill the commit struct info, including:
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* 1. tree object
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* 2. date
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* 3. parents.
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*
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* Returns 1 if and only if the commit was found in the packed graph.
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*
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* See parse_commit_buffer() for the fallback after this call.
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*/
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int parse_commit_in_graph(struct commit *item);
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struct tree *get_commit_tree_in_graph(const struct commit *c);
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struct commit_graph {
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int graph_fd;
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const unsigned char *data;
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size_t data_len;
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unsigned char hash_len;
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unsigned char num_chunks;
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uint32_t num_commits;
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struct object_id oid;
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const uint32_t *chunk_oid_fanout;
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const unsigned char *chunk_oid_lookup;
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const unsigned char *chunk_commit_data;
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const unsigned char *chunk_large_edges;
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};
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struct commit_graph *load_commit_graph_one(const char *graph_file);
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void write_commit_graph(const char *obj_dir,
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const char **pack_indexes,
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int nr_packs,
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const char **commit_hex,
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int nr_commits,
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int append);
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#endif
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