git/alloc.c at master · gitgitgadget/git · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
/*
 * alloc.c - specialized allocator for internal objects
 *
 * Copyright (C) 2006 Linus Torvalds
 *
 * The standard malloc/free wastes too much space for objects, partly because
 * it maintains all the allocation infrastructure, but even more because it ends
 * up with maximal alignment because it doesn't know what the object alignment
 * for the new allocation is.
 */
#include"git-compat-util.h"
#include"object.h"
#include"blob.h"
#include"tree.h"
#include"commit.h"
#include"repository.h"
#include"tag.h"
#include"alloc.h"

#defineBLOCKING 1024

unionany_object {
structobjectobject;
structblobblob;
structtreetree;
structcommitcommit;
structtagtag;
};

structalloc_state {
intnr; /* number of nodes left in current allocation */
void*p; /* first free node in current allocation */

/* bookkeeping of allocations */
void**slabs;
intslab_nr, slab_alloc;
};

structalloc_state*alloc_state_alloc(void)
{
returnxcalloc(1, sizeof(structalloc_state));
}

voidalloc_state_free_and_null(structalloc_state**s_)
{
structalloc_state*s=*s_;

if (!s)
return;

while (s->slab_nr>0) {
s->slab_nr--;
free(s->slabs[s->slab_nr]);
	}

FREE_AND_NULL(s->slabs);
FREE_AND_NULL(*s_);
}

staticinlinevoid*alloc_node(structalloc_state*s, size_tnode_size)
{
void*ret;

if (!s->nr) {
s->nr=BLOCKING;
s->p=xmalloc(BLOCKING*node_size);

ALLOC_GROW(s->slabs, s->slab_nr+1, s->slab_alloc);
s->slabs[s->slab_nr++] =s->p;
	}
s->nr--;
ret=s->p;
s->p= (char*)s->p+node_size;
memset(ret, 0, node_size);

returnret;
}

void*alloc_blob_node(structrepository*r)
{
structblob*b=alloc_node(r->parsed_objects->blob_state, sizeof(structblob));
b->object.type=OBJ_BLOB;
returnb;
}

void*alloc_tree_node(structrepository*r)
{
structtree*t=alloc_node(r->parsed_objects->tree_state, sizeof(structtree));
t->object.type=OBJ_TREE;
returnt;
}

void*alloc_tag_node(structrepository*r)
{
structtag*t=alloc_node(r->parsed_objects->tag_state, sizeof(structtag));
t->object.type=OBJ_TAG;
returnt;
}

void*alloc_object_node(structrepository*r)
{
structobject*obj=alloc_node(r->parsed_objects->object_state, sizeof(unionany_object));
obj->type=OBJ_NONE;
returnobj;
}

/*
 * The returned count is to be used as an index into commit slabs,
 * that are *NOT* maintained per repository, and that is why a single
 * global counter is used.
 */
staticunsigned intalloc_commit_index(void)
{
staticunsigned intparsed_commits_count;
returnparsed_commits_count++;
}

voidinit_commit_node(structcommit*c)
{
c->object.type=OBJ_COMMIT;
c->index=alloc_commit_index();
}

void*alloc_commit_node(structrepository*r)
{
structcommit*c=alloc_node(r->parsed_objects->commit_state, sizeof(structcommit));
init_commit_node(c);
returnc;
}