Commit | Line | Data |
---|---|---|
dc0d77d7 CE |
1 | /* Public domain. */ |
2 | ||
3 | #include "seek.h" | |
4 | #include "error.h" | |
5 | #include "alloc.h" | |
6 | #include "cdb.h" | |
7 | #include "cdb_make.h" | |
8 | ||
9 | int cdb_make_start(struct cdb_make *c,int fd) | |
10 | { | |
11 | c->head = 0; | |
12 | c->split = 0; | |
13 | c->hash = 0; | |
14 | c->numentries = 0; | |
15 | c->fd = fd; | |
16 | c->pos = sizeof c->final; | |
17 | buffer_init(&c->b,buffer_unixwrite,fd,c->bspace,sizeof c->bspace); | |
18 | return seek_set(fd,c->pos); | |
19 | } | |
20 | ||
21 | static int posplus(struct cdb_make *c,uint32 len) | |
22 | { | |
23 | uint32 newpos = c->pos + len; | |
24 | if (newpos < len) { errno = error_nomem; return -1; } | |
25 | c->pos = newpos; | |
26 | return 0; | |
27 | } | |
28 | ||
29 | int cdb_make_addend(struct cdb_make *c,unsigned int keylen,unsigned int datalen,uint32 h) | |
30 | { | |
31 | struct cdb_hplist *head; | |
32 | ||
33 | head = c->head; | |
34 | if (!head || (head->num >= CDB_HPLIST)) { | |
35 | head = (struct cdb_hplist *) alloc(sizeof(struct cdb_hplist)); | |
36 | if (!head) return -1; | |
37 | head->num = 0; | |
38 | head->next = c->head; | |
39 | c->head = head; | |
40 | } | |
41 | head->hp[head->num].h = h; | |
42 | head->hp[head->num].p = c->pos; | |
43 | ++head->num; | |
44 | ++c->numentries; | |
45 | if (posplus(c,8) == -1) return -1; | |
46 | if (posplus(c,keylen) == -1) return -1; | |
47 | if (posplus(c,datalen) == -1) return -1; | |
48 | return 0; | |
49 | } | |
50 | ||
51 | int cdb_make_addbegin(struct cdb_make *c,unsigned int keylen,unsigned int datalen) | |
52 | { | |
53 | char buf[8]; | |
54 | ||
55 | if (keylen > 0xffffffff) { errno = error_nomem; return -1; } | |
56 | if (datalen > 0xffffffff) { errno = error_nomem; return -1; } | |
57 | ||
58 | uint32_pack(buf,keylen); | |
59 | uint32_pack(buf + 4,datalen); | |
60 | if (buffer_putalign(&c->b,buf,8) == -1) return -1; | |
61 | return 0; | |
62 | } | |
63 | ||
64 | int cdb_make_add(struct cdb_make *c,const char *key,unsigned int keylen,const char *data,unsigned int datalen) | |
65 | { | |
66 | if (cdb_make_addbegin(c,keylen,datalen) == -1) return -1; | |
67 | if (buffer_putalign(&c->b,key,keylen) == -1) return -1; | |
68 | if (buffer_putalign(&c->b,data,datalen) == -1) return -1; | |
69 | return cdb_make_addend(c,keylen,datalen,cdb_hash(key,keylen)); | |
70 | } | |
71 | ||
72 | int cdb_make_finish(struct cdb_make *c) | |
73 | { | |
74 | char buf[8]; | |
75 | int i; | |
76 | uint32 len; | |
77 | uint32 u; | |
78 | uint32 memsize; | |
79 | uint32 count; | |
80 | uint32 where; | |
81 | struct cdb_hplist *x; | |
82 | struct cdb_hp *hp; | |
83 | ||
84 | for (i = 0;i < 256;++i) | |
85 | c->count[i] = 0; | |
86 | ||
87 | for (x = c->head;x;x = x->next) { | |
88 | i = x->num; | |
89 | while (i--) | |
90 | ++c->count[255 & x->hp[i].h]; | |
91 | } | |
92 | ||
93 | memsize = 1; | |
94 | for (i = 0;i < 256;++i) { | |
95 | u = c->count[i] * 2; | |
96 | if (u > memsize) | |
97 | memsize = u; | |
98 | } | |
99 | ||
100 | memsize += c->numentries; /* no overflow possible up to now */ | |
101 | u = (uint32) 0 - (uint32) 1; | |
102 | u /= sizeof(struct cdb_hp); | |
103 | if (memsize > u) { errno = error_nomem; return -1; } | |
104 | ||
105 | c->split = (struct cdb_hp *) alloc(memsize * sizeof(struct cdb_hp)); | |
106 | if (!c->split) return -1; | |
107 | ||
108 | c->hash = c->split + c->numentries; | |
109 | ||
110 | u = 0; | |
111 | for (i = 0;i < 256;++i) { | |
112 | u += c->count[i]; /* bounded by numentries, so no overflow */ | |
113 | c->start[i] = u; | |
114 | } | |
115 | ||
116 | for (x = c->head;x;x = x->next) { | |
117 | i = x->num; | |
118 | while (i--) | |
119 | c->split[--c->start[255 & x->hp[i].h]] = x->hp[i]; | |
120 | } | |
121 | ||
122 | for (i = 0;i < 256;++i) { | |
123 | count = c->count[i]; | |
124 | ||
125 | len = count + count; /* no overflow possible */ | |
126 | uint32_pack(c->final + 8 * i,c->pos); | |
127 | uint32_pack(c->final + 8 * i + 4,len); | |
128 | ||
129 | for (u = 0;u < len;++u) | |
130 | c->hash[u].h = c->hash[u].p = 0; | |
131 | ||
132 | hp = c->split + c->start[i]; | |
133 | for (u = 0;u < count;++u) { | |
134 | where = (hp->h >> 8) % len; | |
135 | while (c->hash[where].p) | |
136 | if (++where == len) | |
137 | where = 0; | |
138 | c->hash[where] = *hp++; | |
139 | } | |
140 | ||
141 | for (u = 0;u < len;++u) { | |
142 | uint32_pack(buf,c->hash[u].h); | |
143 | uint32_pack(buf + 4,c->hash[u].p); | |
144 | if (buffer_putalign(&c->b,buf,8) == -1) return -1; | |
145 | if (posplus(c,8) == -1) return -1; | |
146 | } | |
147 | } | |
148 | ||
149 | if (buffer_flush(&c->b) == -1) return -1; | |
150 | if (seek_begin(c->fd) == -1) return -1; | |
151 | return buffer_putflush(&c->b,c->final,sizeof c->final); | |
152 | } |