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1 | /* | |
2 | * alloc.c - specialized allocator for internal objects | |
3 | * | |
4 | * Copyright (C) 2006 Linus Torvalds | |
5 | * | |
6 | * The standard malloc/free wastes too much space for objects, partly because | |
7 | * it maintains all the allocation infrastructure, but even more because it ends | |
8 | * up with maximal alignment because it doesn't know what the object alignment | |
9 | * for the new allocation is. | |
10 | */ | |
11 | #include "cache.h" | |
12 | #include "object.h" | |
13 | #include "blob.h" | |
14 | #include "tree.h" | |
15 | #include "commit.h" | |
16 | #include "tag.h" | |
17 | #include "alloc.h" | |
18 | ||
19 | #define BLOCKING 1024 | |
20 | ||
21 | union any_object { | |
22 | struct object object; | |
23 | struct blob blob; | |
24 | struct tree tree; | |
25 | struct commit commit; | |
26 | struct tag tag; | |
27 | }; | |
28 | ||
29 | struct alloc_state { | |
30 | int count; /* total number of nodes allocated */ | |
31 | int nr; /* number of nodes left in current allocation */ | |
32 | void *p; /* first free node in current allocation */ | |
33 | ||
34 | /* bookkeeping of allocations */ | |
35 | void **slabs; | |
36 | int slab_nr, slab_alloc; | |
37 | }; | |
38 | ||
39 | struct alloc_state *allocate_alloc_state(void) | |
40 | { | |
41 | return xcalloc(1, sizeof(struct alloc_state)); | |
42 | } | |
43 | ||
44 | void clear_alloc_state(struct alloc_state *s) | |
45 | { | |
46 | while (s->slab_nr > 0) { | |
47 | s->slab_nr--; | |
48 | free(s->slabs[s->slab_nr]); | |
49 | } | |
50 | ||
51 | FREE_AND_NULL(s->slabs); | |
52 | } | |
53 | ||
54 | static inline void *alloc_node(struct alloc_state *s, size_t node_size) | |
55 | { | |
56 | void *ret; | |
57 | ||
58 | if (!s->nr) { | |
59 | s->nr = BLOCKING; | |
60 | s->p = xmalloc(BLOCKING * node_size); | |
61 | ||
62 | ALLOC_GROW(s->slabs, s->slab_nr + 1, s->slab_alloc); | |
63 | s->slabs[s->slab_nr++] = s->p; | |
64 | } | |
65 | s->nr--; | |
66 | s->count++; | |
67 | ret = s->p; | |
68 | s->p = (char *)s->p + node_size; | |
69 | memset(ret, 0, node_size); | |
70 | ||
71 | return ret; | |
72 | } | |
73 | ||
74 | void *alloc_blob_node(struct repository *r) | |
75 | { | |
76 | struct blob *b = alloc_node(r->parsed_objects->blob_state, sizeof(struct blob)); | |
77 | b->object.type = OBJ_BLOB; | |
78 | return b; | |
79 | } | |
80 | ||
81 | void *alloc_tree_node(struct repository *r) | |
82 | { | |
83 | struct tree *t = alloc_node(r->parsed_objects->tree_state, sizeof(struct tree)); | |
84 | t->object.type = OBJ_TREE; | |
85 | return t; | |
86 | } | |
87 | ||
88 | void *alloc_tag_node(struct repository *r) | |
89 | { | |
90 | struct tag *t = alloc_node(r->parsed_objects->tag_state, sizeof(struct tag)); | |
91 | t->object.type = OBJ_TAG; | |
92 | return t; | |
93 | } | |
94 | ||
95 | void *alloc_object_node(struct repository *r) | |
96 | { | |
97 | struct object *obj = alloc_node(r->parsed_objects->object_state, sizeof(union any_object)); | |
98 | obj->type = OBJ_NONE; | |
99 | return obj; | |
100 | } | |
101 | ||
102 | static unsigned int alloc_commit_index(struct repository *r) | |
103 | { | |
104 | return r->parsed_objects->commit_count++; | |
105 | } | |
106 | ||
107 | void init_commit_node(struct repository *r, struct commit *c) | |
108 | { | |
109 | c->object.type = OBJ_COMMIT; | |
110 | c->index = alloc_commit_index(r); | |
111 | c->graph_pos = COMMIT_NOT_FROM_GRAPH; | |
112 | c->generation = GENERATION_NUMBER_INFINITY; | |
113 | } | |
114 | ||
115 | void *alloc_commit_node(struct repository *r) | |
116 | { | |
117 | struct commit *c = alloc_node(r->parsed_objects->commit_state, sizeof(struct commit)); | |
118 | init_commit_node(r, c); | |
119 | return c; | |
120 | } | |
121 | ||
122 | static void report(const char *name, unsigned int count, size_t size) | |
123 | { | |
124 | fprintf(stderr, "%10s: %8u (%"PRIuMAX" kB)\n", | |
125 | name, count, (uintmax_t) size); | |
126 | } | |
127 | ||
128 | #define REPORT(name, type) \ | |
129 | report(#name, r->parsed_objects->name##_state->count, \ | |
130 | r->parsed_objects->name##_state->count * sizeof(type) >> 10) | |
131 | ||
132 | void alloc_report(struct repository *r) | |
133 | { | |
134 | REPORT(blob, struct blob); | |
135 | REPORT(tree, struct tree); | |
136 | REPORT(commit, struct commit); | |
137 | REPORT(tag, struct tag); | |
138 | REPORT(object, union any_object); | |
139 | } |