| 1 | #include <sys/types.h> |
| 2 | #include <errno.h> |
| 3 | extern int errno; |
| 4 | #include "cdb.h" |
| 5 | |
| 6 | #ifndef SEEK_SET |
| 7 | #define SEEK_SET 0 |
| 8 | #endif |
| 9 | |
| 10 | int cdb_bread(fd,buf,len) |
| 11 | int fd; |
| 12 | char *buf; |
| 13 | int len; |
| 14 | { |
| 15 | int r; |
| 16 | while (len > 0) { |
| 17 | do |
| 18 | r = read(fd,buf,len); |
| 19 | while ((r == -1) && (errno == EINTR)); |
| 20 | if (r == -1) return -1; |
| 21 | if (r == 0) { errno = EIO; return -1; } |
| 22 | buf += r; |
| 23 | len -= r; |
| 24 | } |
| 25 | return 0; |
| 26 | } |
| 27 | |
| 28 | static int match(fd,key,len) |
| 29 | int fd; |
| 30 | char *key; |
| 31 | unsigned int len; |
| 32 | { |
| 33 | char buf[32]; |
| 34 | int n; |
| 35 | int i; |
| 36 | |
| 37 | while (len > 0) { |
| 38 | n = sizeof(buf); |
| 39 | if (n > len) n = len; |
| 40 | if (cdb_bread(fd,buf,n) == -1) return -1; |
| 41 | for (i = 0;i < n;++i) if (buf[i] != key[i]) return 0; |
| 42 | key += n; |
| 43 | len -= n; |
| 44 | } |
| 45 | return 1; |
| 46 | } |
| 47 | |
| 48 | int cdb_seek(fd,key,len,dlen) |
| 49 | int fd; |
| 50 | char *key; |
| 51 | unsigned int len; |
| 52 | uint32 *dlen; |
| 53 | { |
| 54 | char packbuf[8]; |
| 55 | uint32 pos; |
| 56 | uint32 h; |
| 57 | uint32 lenhash; |
| 58 | uint32 h2; |
| 59 | uint32 loop; |
| 60 | uint32 poskd; |
| 61 | |
| 62 | h = cdb_hash(key,len); |
| 63 | |
| 64 | pos = 8 * (h & 255); |
| 65 | if (lseek(fd,(off_t) pos,SEEK_SET) == -1) return -1; |
| 66 | |
| 67 | if (cdb_bread(fd,packbuf,8) == -1) return -1; |
| 68 | |
| 69 | pos = cdb_unpack(packbuf); |
| 70 | lenhash = cdb_unpack(packbuf + 4); |
| 71 | |
| 72 | if (!lenhash) return 0; |
| 73 | h2 = (h >> 8) % lenhash; |
| 74 | |
| 75 | for (loop = 0;loop < lenhash;++loop) { |
| 76 | if (lseek(fd,(off_t) (pos + 8 * h2),SEEK_SET) == -1) return -1; |
| 77 | if (cdb_bread(fd,packbuf,8) == -1) return -1; |
| 78 | poskd = cdb_unpack(packbuf + 4); |
| 79 | if (!poskd) return 0; |
| 80 | if (cdb_unpack(packbuf) == h) { |
| 81 | if (lseek(fd,(off_t) poskd,SEEK_SET) == -1) return -1; |
| 82 | if (cdb_bread(fd,packbuf,8) == -1) return -1; |
| 83 | if (cdb_unpack(packbuf) == len) |
| 84 | switch(match(fd,key,len)) { |
| 85 | case -1: |
| 86 | return -1; |
| 87 | case 1: |
| 88 | *dlen = cdb_unpack(packbuf + 4); |
| 89 | return 1; |
| 90 | } |
| 91 | } |
| 92 | if (++h2 == lenhash) h2 = 0; |
| 93 | } |
| 94 | return 0; |
| 95 | } |