Exemple #1
0
char *
db_nextrec(DB *db, char *key)
{
    char    c, *ptr;

        /* We read lock the free list so that we don't read
           a record in the middle of its being deleted. */
    if (readw_lock(db->idxfd, FREE_OFF, SEEK_SET, 1) < 0)
        err_dump("readw_lock error");

    do {
            /* read next sequential index record */
        if (_db_readidx(db, 0) < 0) {
            ptr = NULL;        /* end of index file, EOF */
            goto doreturn;
        }
            /* check if key is all blank (empty record) */
        ptr = db->idxbuf;
        while ( (c = *ptr++) != 0  &&  c == ' ')
            ;    /* skip until null byte or nonblank */
    } while (c == 0);    /* loop until a nonblank key is found */

    if (key != NULL)
        strcpy(key, db->idxbuf);    /* return key */
    ptr = _db_readdat(db);    /* return pointer to data buffer */

    db->cnt_nextrec++;
doreturn:
    if (un_lock(db->idxfd, FREE_OFF, SEEK_SET, 1) < 0)
        err_dump("un_lock error");

    return(ptr);
}
/* Returning the sequential record...
Just gotta step ahead through the index file where we gotta ignore deleted records.
db_rewind() essential to be called before this function at initial stage itself */
char *db_nextrec(DB *db, char *key)
{
	char c, *ptr;
	/* Locking the free list where we don't actually read a record in the mid of deletion*/
	if(readw_lock(db->idxfd, FREE_OFF, SEEK_SET, 1) < 0)
		err_dump("error");
	do
	{
		/* read next sequential index record */
		if(_db_readidx(db, 0) < 0)
		{
			ptr = NULL; /* end of index file --- EOF */
			goto doreturn;
		}
		/* Checking if the key is still blank or empty record */
		ptr = db->idxbuf;
		while((c = *ptr++) != 0 && c = ' ');
		/* skip if it's not blank */
	}
	while(c == 0) /* loop untill a non-empty key is found*/
		if(key != NULL)
			strcpy(key, db->idxbuf); /* return key */
	ptr = _db_readdat(db); /* return pointer to data buffer */
	db->cnt_nextrec++;
doreturn:
	if(un_lock(db->idxfd, FREE_OFF, SEEK_SET, 1) < 0)
		err_dump("error");
}
Exemple #3
0
char *
db_fetch(DB *db, const char *key)
{
    char    *ptr;

    if (_db_find(db, key, 0) < 0) {
        ptr = NULL;                /* error, record not found */
        db->cnt_fetcherr++;
    } else {
        ptr = _db_readdat(db);    /* return pointer to data */
        db->cnt_fetchok++;
    }
            /* Unlock the hash chain that _db_find() locked */
    if (un_lock(db->idxfd, db->chainoff, SEEK_SET, 1) < 0)
        err_dump("un_lock error");
    return(ptr);
}