#include <sys/types.h>

#include <errno.h>

extern int errno;

#include "cdb.h"

#ifndef SEEK_SET

#define SEEK_SET 0

#endif

int cdb_bread(fd,buf,len)

int fd;

char *buf;

int len;

{

  int r;

  while (len > 0) {

    do

      r = read(fd,buf,len);

    while ((r == -1) && (errno == EINTR));

    if (r == -1) return -1;

    if (r == 0) { errno = EIO; return -1; }

    buf += r;

    len -= r;

  }

  return 0;

}

static int match(fd,key,len)

int fd;

char *key;

unsigned int len;

{

  char buf[32];

  int n;

  int i;

  while (len > 0) {

    n = sizeof(buf);

    if (n > len) n = len;

    if (cdb_bread(fd,buf,n) == -1) return -1;

    for (i = 0;i < n;++i) if (buf[i] != key[i]) return 0;

    key += n;

    len -= n;

  }

  return 1;

}

int cdb_seek(fd,key,len,dlen)

int fd;

char *key;

unsigned int len;

uint32 *dlen;

{

  char packbuf[8];

  uint32 pos;

  uint32 h;

  uint32 lenhash;

  uint32 h2;

  uint32 loop;

  uint32 poskd;

  h = cdb_hash(key,len);

  pos = 8 * (h & 255);

  if (lseek(fd,(off_t) pos,SEEK_SET) == -1) return -1;

  if (cdb_bread(fd,packbuf,8) == -1) return -1;

  pos = cdb_unpack(packbuf);

  lenhash = cdb_unpack(packbuf + 4);

  if (!lenhash) return 0;

  h2 = (h >> 8) % lenhash;

  for (loop = 0;loop < lenhash;++loop) {

    if (lseek(fd,(off_t) (pos + 8 * h2),SEEK_SET) == -1) return -1;

    if (cdb_bread(fd,packbuf,8) == -1) return -1;

    poskd = cdb_unpack(packbuf + 4);

    if (!poskd) return 0;

    if (cdb_unpack(packbuf) == h) {

      if (lseek(fd,(off_t) poskd,SEEK_SET) == -1) return -1;

      if (cdb_bread(fd,packbuf,8) == -1) return -1;

      if (cdb_unpack(packbuf) == len)

	switch(match(fd,key,len)) {

	  case -1:

	    return -1;

	  case 1:

	    *dlen = cdb_unpack(packbuf + 4);

	    return 1;

	}

    }

    if (++h2 == lenhash) h2 = 0;

  }

  return 0;

}