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
130
131
132
133
134
135
136
137
138
139
140
|
/* Copyright Abandoned 1996 TCX DataKonsult AB & Monty Program KB & Detron HB
This file is public domain and comes with NO WARRANTY of any kind */
/* Routines to handle mallocing of results which will be freed the same time */
#include <global.h>
#include <my_sys.h>
#include <m_string.h>
void init_alloc_root(MEM_ROOT *mem_root, uint block_size, uint pre_alloc_size)
{
mem_root->free=mem_root->used=0;
mem_root->min_malloc=32;
mem_root->block_size=block_size-MALLOC_OVERHEAD-sizeof(USED_MEM)-8;
mem_root->error_handler=0;
#if !(defined(HAVE_purify) && defined(EXTRA_DEBUG))
if (pre_alloc_size)
{
if ((mem_root->free = mem_root->pre_alloc=
(USED_MEM*) my_malloc(pre_alloc_size+ ALIGN_SIZE(sizeof(USED_MEM)),
MYF(0))))
{
mem_root->free->size=pre_alloc_size+ALIGN_SIZE(sizeof(USED_MEM));
mem_root->free->left=pre_alloc_size;
mem_root->free->next=0;
}
}
#endif
}
gptr alloc_root(MEM_ROOT *mem_root,unsigned int Size)
{
#if defined(HAVE_purify) && defined(EXTRA_DEBUG)
reg1 USED_MEM *next;
Size+=ALIGN_SIZE(sizeof(USED_MEM));
if (!(next = (USED_MEM*) my_malloc(Size,MYF(MY_WME))))
{
if (mem_root->error_handler)
(*mem_root->error_handler)();
return((gptr) 0); /* purecov: inspected */
}
next->next=mem_root->used;
mem_root->used=next;
return (gptr) (((char*) next)+ALIGN_SIZE(sizeof(USED_MEM)));
#else
uint get_size,max_left;
gptr point;
reg1 USED_MEM *next;
reg2 USED_MEM **prev;
Size= ALIGN_SIZE(Size);
prev= &mem_root->free;
max_left=0;
for (next= *prev ; next && next->left < Size ; next= next->next)
{
if (next->left > max_left)
max_left=next->left;
prev= &next->next;
}
if (! next)
{ /* Time to alloc new block */
get_size= Size+ALIGN_SIZE(sizeof(USED_MEM));
if (max_left*4 < mem_root->block_size && get_size < mem_root->block_size)
get_size=mem_root->block_size; /* Normal alloc */
if (!(next = (USED_MEM*) my_malloc(get_size,MYF(MY_WME))))
{
if (mem_root->error_handler)
(*mem_root->error_handler)();
return((gptr) 0); /* purecov: inspected */
}
next->next= *prev;
next->size= get_size;
next->left= get_size-ALIGN_SIZE(sizeof(USED_MEM));
*prev=next;
}
point= (gptr) ((char*) next+ (next->size-next->left));
if ((next->left-= Size) < mem_root->min_malloc)
{ /* Full block */
*prev=next->next; /* Remove block from list */
next->next=mem_root->used;
mem_root->used=next;
}
return(point);
#endif
}
/* deallocate everything used by alloc_root */
void free_root(MEM_ROOT *root, myf MyFlags)
{
reg1 USED_MEM *next,*old;
DBUG_ENTER("free_root");
if (!root)
DBUG_VOID_RETURN; /* purecov: inspected */
if (!(MyFlags & MY_KEEP_PREALLOC))
root->pre_alloc=0;
for ( next=root->used; next ;)
{
old=next; next= next->next ;
if (old != root->pre_alloc)
my_free((gptr) old,MYF(0));
}
for (next= root->free ; next ; )
{
old=next; next= next->next ;
if (old != root->pre_alloc)
my_free((gptr) old,MYF(0));
}
root->used=root->free=0;
if (root->pre_alloc)
{
root->free=root->pre_alloc;
root->free->left=root->pre_alloc->size-ALIGN_SIZE(sizeof(USED_MEM));
root->free->next=0;
}
DBUG_VOID_RETURN;
}
char *strdup_root(MEM_ROOT *root,const char *str)
{
uint len= (uint) strlen(str)+1;
char *pos;
if ((pos=alloc_root(root,len)))
memcpy(pos,str,len);
return pos;
}
char *memdup_root(MEM_ROOT *root,const char *str,uint len)
{
char *pos;
if ((pos=alloc_root(root,len)))
memcpy(pos,str,len);
return pos;
}
|
