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 }