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| author | manuel <manuel@mausz.at> | 2013-02-04 00:08:53 +0100 |
|---|---|---|
| committer | manuel <manuel@mausz.at> | 2013-02-04 00:08:53 +0100 |
| commit | 69aec538b456402170dc723af417ba5c05389c32 (patch) | |
| tree | e6f34c543f17c6392447ea337b2e2868212424d1 /cdb_seek.c | |
| download | qmail-69aec538b456402170dc723af417ba5c05389c32.tar.gz qmail-69aec538b456402170dc723af417ba5c05389c32.tar.bz2 qmail-69aec538b456402170dc723af417ba5c05389c32.zip | |
qmail 1.03 import
Diffstat (limited to 'cdb_seek.c')
| -rw-r--r-- | cdb_seek.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/cdb_seek.c b/cdb_seek.c new file mode 100644 index 0000000..87ab614 --- /dev/null +++ b/cdb_seek.c | |||
| @@ -0,0 +1,95 @@ | |||
| 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 | } | ||
