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
141
142
143
144
145
146
147
148
149
150
151
152
|
/* Public domain. */
#include "seek.h"
#include "error.h"
#include "alloc.h"
#include "cdb.h"
#include "cdb_make.h"
int cdb_make_start(struct cdb_make *c,int fd)
{
c->head = 0;
c->split = 0;
c->hash = 0;
c->numentries = 0;
c->fd = fd;
c->pos = sizeof c->final;
buffer_init(&c->b,buffer_unixwrite,fd,c->bspace,sizeof c->bspace);
return seek_set(fd,c->pos);
}
static int posplus(struct cdb_make *c,uint32 len)
{
uint32 newpos = c->pos + len;
if (newpos < len) { errno = error_nomem; return -1; }
c->pos = newpos;
return 0;
}
int cdb_make_addend(struct cdb_make *c,unsigned int keylen,unsigned int datalen,uint32 h)
{
struct cdb_hplist *head;
head = c->head;
if (!head || (head->num >= CDB_HPLIST)) {
head = (struct cdb_hplist *) alloc(sizeof(struct cdb_hplist));
if (!head) return -1;
head->num = 0;
head->next = c->head;
c->head = head;
}
head->hp[head->num].h = h;
head->hp[head->num].p = c->pos;
++head->num;
++c->numentries;
if (posplus(c,8) == -1) return -1;
if (posplus(c,keylen) == -1) return -1;
if (posplus(c,datalen) == -1) return -1;
return 0;
}
int cdb_make_addbegin(struct cdb_make *c,unsigned int keylen,unsigned int datalen)
{
char buf[8];
if (keylen > 0xffffffff) { errno = error_nomem; return -1; }
if (datalen > 0xffffffff) { errno = error_nomem; return -1; }
uint32_pack(buf,keylen);
uint32_pack(buf + 4,datalen);
if (buffer_putalign(&c->b,buf,8) == -1) return -1;
return 0;
}
int cdb_make_add(struct cdb_make *c,const char *key,unsigned int keylen,const char *data,unsigned int datalen)
{
if (cdb_make_addbegin(c,keylen,datalen) == -1) return -1;
if (buffer_putalign(&c->b,key,keylen) == -1) return -1;
if (buffer_putalign(&c->b,data,datalen) == -1) return -1;
return cdb_make_addend(c,keylen,datalen,cdb_hash(key,keylen));
}
int cdb_make_finish(struct cdb_make *c)
{
char buf[8];
int i;
uint32 len;
uint32 u;
uint32 memsize;
uint32 count;
uint32 where;
struct cdb_hplist *x;
struct cdb_hp *hp;
for (i = 0;i < 256;++i)
c->count[i] = 0;
for (x = c->head;x;x = x->next) {
i = x->num;
while (i--)
++c->count[255 & x->hp[i].h];
}
memsize = 1;
for (i = 0;i < 256;++i) {
u = c->count[i] * 2;
if (u > memsize)
memsize = u;
}
memsize += c->numentries; /* no overflow possible up to now */
u = (uint32) 0 - (uint32) 1;
u /= sizeof(struct cdb_hp);
if (memsize > u) { errno = error_nomem; return -1; }
c->split = (struct cdb_hp *) alloc(memsize * sizeof(struct cdb_hp));
if (!c->split) return -1;
c->hash = c->split + c->numentries;
u = 0;
for (i = 0;i < 256;++i) {
u += c->count[i]; /* bounded by numentries, so no overflow */
c->start[i] = u;
}
for (x = c->head;x;x = x->next) {
i = x->num;
while (i--)
c->split[--c->start[255 & x->hp[i].h]] = x->hp[i];
}
for (i = 0;i < 256;++i) {
count = c->count[i];
len = count + count; /* no overflow possible */
uint32_pack(c->final + 8 * i,c->pos);
uint32_pack(c->final + 8 * i + 4,len);
for (u = 0;u < len;++u)
c->hash[u].h = c->hash[u].p = 0;
hp = c->split + c->start[i];
for (u = 0;u < count;++u) {
where = (hp->h >> 8) % len;
while (c->hash[where].p)
if (++where == len)
where = 0;
c->hash[where] = *hp++;
}
for (u = 0;u < len;++u) {
uint32_pack(buf,c->hash[u].h);
uint32_pack(buf + 4,c->hash[u].p);
if (buffer_putalign(&c->b,buf,8) == -1) return -1;
if (posplus(c,8) == -1) return -1;
}
}
if (buffer_flush(&c->b) == -1) return -1;
if (seek_begin(c->fd) == -1) return -1;
return buffer_putflush(&c->b,c->final,sizeof c->final);
}
|
