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4468d4435c
When the commit graph and generation numbers were introduced in commits177722b344(commit: integrate commit graph with commit parsing, 2018-04-10) and83073cc994(commit: add generation number to struct commit, 2018-04-25), they tried to make sure that the corresponding 'graph_pos' and 'generation' fields of 'struct commit' are initialized conservatively, as if the commit were not included in the commit-graph file. Alas, initializing those fields only in alloc_commit_node() missed the case when an object that happens to be a commit is first looked up via lookup_unknown_object(), and is then later converted to a 'struct commit' via the object_as_type() helper function (either calling it directly, or as part of a subsequent lookup_commit() call). Consequently, both of those fields incorrectly remain set to zero, which means e.g. that the commit is present in and is the first entry of the commit-graph file. This will result in wrong timestamp, parent and root tree hashes, if such a 'struct commit' instance is later filled from the commit-graph. Extract the initialization of 'struct commit's fields from alloc_commit_node() into a helper function, and call it from object_as_type() as well, to make sure that it properly initializes the two commit-graph-related fields, too. With this helper function it is hopefully less likely that any new fields added to 'struct commit' in the future would remain uninitialized. With this change alloc_commit_index() won't have any remaining callers outside of 'alloc.c', so mark it as static. Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
140 lines
3.2 KiB
C
140 lines
3.2 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, 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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#include "alloc.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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/* bookkeeping of allocations */
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void **slabs;
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int slab_nr, slab_alloc;
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};
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struct alloc_state *allocate_alloc_state(void)
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{
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return xcalloc(1, sizeof(struct alloc_state));
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}
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void clear_alloc_state(struct alloc_state *s)
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{
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while (s->slab_nr > 0) {
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s->slab_nr--;
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free(s->slabs[s->slab_nr]);
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}
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FREE_AND_NULL(s->slabs);
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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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ALLOC_GROW(s->slabs, s->slab_nr + 1, s->slab_alloc);
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s->slabs[s->slab_nr++] = s->p;
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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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void *alloc_blob_node(struct repository *r)
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{
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struct blob *b = alloc_node(r->parsed_objects->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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void *alloc_tree_node(struct repository *r)
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{
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struct tree *t = alloc_node(r->parsed_objects->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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void *alloc_tag_node(struct repository *r)
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{
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struct tag *t = alloc_node(r->parsed_objects->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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void *alloc_object_node(struct repository *r)
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{
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struct object *obj = alloc_node(r->parsed_objects->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 unsigned int alloc_commit_index(struct repository *r)
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{
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return r->parsed_objects->commit_count++;
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}
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void init_commit_node(struct repository *r, struct commit *c)
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{
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c->object.type = OBJ_COMMIT;
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c->index = alloc_commit_index(r);
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c->graph_pos = COMMIT_NOT_FROM_GRAPH;
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c->generation = GENERATION_NUMBER_INFINITY;
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}
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void *alloc_commit_node(struct repository *r)
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{
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struct commit *c = alloc_node(r->parsed_objects->commit_state, sizeof(struct commit));
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init_commit_node(r, c);
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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, r->parsed_objects->name##_state->count, \
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r->parsed_objects->name##_state->count * sizeof(type) >> 10)
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void alloc_report(struct repository *r)
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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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