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NAME

       libtar_hash_new,  libtar_hash_free, libtar_hash_next, libtar_hash_prev,
       libtar_hash_getkey,        libtar_hash_search,         libtar_hash_add,
       libtar_hash_del - hash table routines

SYNOPSIS

       #include <libtar.h>

       libtar_hash_t *libtar_hash_new(int num, int (*hashfunc)());
       void libtar_hash_free(libtar_hash_t *h, void (*freefunc)());
       int libtar_hash_next(libtar_hash_t *h, libtar_hashptr_t *hp);
       int libtar_hash_prev(libtar_hash_t *h, libtar_hashptr_t *hp);
       int  libtar_hash_search(libtar_hash_t  *h,  libtar_hashptr_t  *hp, void
       *data, int (*matchfunc)());
       int libtar_hash_getkey(libtar_hash_t  *h,  libtar_hashptr_t  *hp,  void
       *data, int (*matchfunc)());
       int libtar_hash_add(libtar_hash_t *h, void *data);
       int libtar_hash_del(libtar_hash_t *h, libtar_hashptr_t *hp);

DESCRIPTION

       The  libtar_hash_new() function creates a new hash with num buckets and
       using hash function pointed to by hashfunc.  If  hashfunc  is  NULL,  a
       default hash function designed for 7-bit ASCII strings is used.

       The  libtar_hash_free() function deallocates all memory associated with
       the hash structure h.  If freefunc is not NULL, it is  called  to  free
       memory associated with each node in the hash.

       The  libtar_hash_next()  and  libtar_hash_prev()  functions are used to
       iterate through the  hash.   The  libtar_hashptr_t  structure  has  two
       fields:  bucket,  which  indicates  the current bucket in the hash, and
       node, which is a pointer to the current node in the current bucket.  To
       start at the beginning or end of the hash, the caller should initialize
       hp.bucket to -1 and hp.node to NULL.

       The libtar_hash_search() function searches iteratively through the hash
       h  until  it  finds a node whose contents match data using the matching
       function matchfunc.  Searching begins at the location pointed to by hp.

       The  libtar_hash_getkey()  function  uses  the hash function associated
       with h to determine which bucket data should be in, and  searches  only
       that  bucket  for a matching node using matchfunc.  Searching begins at
       the location pointed to by hp.

       The libtar_hash_add() function adds data into hash h.

       The libtar_hash_del() function removes the node referenced by hp.

RETURN VALUE

       The libtar_hash_new() function  returns  a  pointer  to  the  new  hash
       structure, or NULL on error.

       The  libtar_hash_next()  and libtar_hash_prev() functions return 1 when
       valid data is returned, and 0 at the end of the hash.

       The libtar_hash_getkey() and libtar_hash_search()  functions  return  1
       when a match is found, or 0 otherwise.

       The  libtar_hash_add()  function  returns  0 on success, or -1 on error
       (and sets errno).

       The libtar_hash_del() function returns 0 on success,  or  -1  on  error
       (and sets errno).

SEE ALSO

       libtar_list_new(3)