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![Derrick Stolee](/assets/img/avatar_default.png)
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>
117 lines
2.6 KiB
C
117 lines
2.6 KiB
C
/*
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* alloc.c - specialized allocator for internal objects
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*
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* Copyright (C) 2006 Linus Torvalds
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*
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* The standard malloc/free wastes too much space for objects, partly because
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* it maintains all the allocation infrastructure (which isn't needed, since
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* we never free an object descriptor anyway), but even more because it ends
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* up with maximal alignment because it doesn't know what the object alignment
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* for the new allocation is.
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*/
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#include "cache.h"
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#include "object.h"
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#include "blob.h"
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#include "tree.h"
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#include "commit.h"
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#include "tag.h"
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#define BLOCKING 1024
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union any_object {
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struct object object;
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struct blob blob;
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struct tree tree;
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struct commit commit;
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struct tag tag;
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};
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struct alloc_state {
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int count; /* total number of nodes allocated */
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int nr; /* number of nodes left in current allocation */
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void *p; /* first free node in current allocation */
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};
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static inline void *alloc_node(struct alloc_state *s, size_t node_size)
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{
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void *ret;
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if (!s->nr) {
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s->nr = BLOCKING;
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s->p = xmalloc(BLOCKING * node_size);
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}
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s->nr--;
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s->count++;
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ret = s->p;
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s->p = (char *)s->p + node_size;
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memset(ret, 0, node_size);
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return ret;
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}
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static struct alloc_state blob_state;
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void *alloc_blob_node(void)
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{
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struct blob *b = alloc_node(&blob_state, sizeof(struct blob));
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b->object.type = OBJ_BLOB;
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return b;
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}
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static struct alloc_state tree_state;
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void *alloc_tree_node(void)
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{
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struct tree *t = alloc_node(&tree_state, sizeof(struct tree));
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t->object.type = OBJ_TREE;
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return t;
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}
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static struct alloc_state tag_state;
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void *alloc_tag_node(void)
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{
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struct tag *t = alloc_node(&tag_state, sizeof(struct tag));
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t->object.type = OBJ_TAG;
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return t;
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}
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static struct alloc_state object_state;
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void *alloc_object_node(void)
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{
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struct object *obj = alloc_node(&object_state, sizeof(union any_object));
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obj->type = OBJ_NONE;
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return obj;
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}
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static struct alloc_state commit_state;
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unsigned int alloc_commit_index(void)
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{
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static unsigned int count;
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return count++;
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}
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void *alloc_commit_node(void)
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{
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struct commit *c = alloc_node(&commit_state, sizeof(struct commit));
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c->object.type = OBJ_COMMIT;
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c->index = alloc_commit_index();
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c->graph_pos = COMMIT_NOT_FROM_GRAPH;
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return c;
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}
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static void report(const char *name, unsigned int count, size_t size)
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{
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fprintf(stderr, "%10s: %8u (%"PRIuMAX" kB)\n",
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name, count, (uintmax_t) size);
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}
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#define REPORT(name, type) \
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report(#name, name##_state.count, name##_state.count * sizeof(type) >> 10)
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void alloc_report(void)
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{
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REPORT(blob, struct blob);
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REPORT(tree, struct tree);
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REPORT(commit, struct commit);
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REPORT(tag, struct tag);
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REPORT(object, union any_object);
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}
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