/* Fixed size hash table with internal linking.   Copyright (C) 2000, 2001, 2002, 2004, 2005 Red Hat, Inc.   This file is part of elfutils.   Written by Ulrich Drepper <drepper@redhat.com>, 2000.    This file is free software; you can redistribute it and/or modify   it under the terms of either      * the GNU Lesser General Public License as published by the Free       Software Foundation; either version 3 of the License, or (at       your option) any later version    or      * the GNU General Public License as published by the Free       Software Foundation; either version 2 of the License, or (at       your option) any later version    or both in parallel, as here.    elfutils is distributed in the hope that it will be useful, but   WITHOUT ANY WARRANTY; without even the implied warranty of   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU   General Public License for more details.    You should have received copies of the GNU General Public License and   the GNU Lesser General Public License along with this program.  If   not, see <http://www.gnu.org/licenses/>.  */ #include <errno.h>#include <stdlib.h>#include <string.h>#include <sys/cdefs.h> #include <system.h> #ifdef __CONCAT#define CONCAT(t1,t2) __CONCAT (t1,t2)#else#define STROF(t2) t2#define CONCAT_EXPANDED(t1,t2) t1 ## t2#define CONCAT(t1,t2) CONCAT_EXPANDED(t1,t2)#endif /* Before including this file the following macros must be defined:    TYPE           data type of the hash table entries   HASHFCT        name of the hashing function to use   HASHTYPE       type used for the hashing value   COMPARE        comparison function taking two pointers to TYPE objects   CLASS          can be defined to `static' to avoid exporting the functions   PREFIX         prefix to be used for function and data type names   STORE_POINTER  if defined the table stores a pointer and not an element                  of type TYPE   INSERT_HASH    if defined alternate insert function which takes a hash                  value is defined   NO_FINI_FCT    if defined the fini function is not defined*/  /* Defined separately.  */extern size_t next_prime (size_t seed);  /* Set default values.  */#ifndef HASHTYPE# define HASHTYPE size_t#endif #ifndef CLASS# define CLASS#endif #ifndef PREFIX# define PREFIX#endif  /* The data structure.  */struct CONCAT(PREFIX,fshash){  size_t nslots;  struct CONCAT(PREFIX,fshashent)  {    HASHTYPE hval;#ifdef STORE_POINTER# define ENTRYP(el) (el).entry    TYPE *entry;#else# define ENTRYP(el) &(el).entry    TYPE entry;#endif  } table[0];};  /* Constructor for the hashing table.  */CLASS struct CONCAT(PREFIX,fshash) *CONCAT(PREFIX,fshash_init) (size_t nelems){  struct CONCAT(PREFIX,fshash) *result;  /* We choose a size for the hashing table 150% over the number of     entries.  This will guarantee short medium search lengths.  */  const size_t max_size_t = ~((size_t) 0);   if (nelems >= (max_size_t / 3) * 2)    {      errno = EINVAL;      return NULL;    }   /* Adjust the size to be used for the hashing table.  */  nelems = next_prime (MAX ((nelems * 3) / 2, 10));   /* Allocate the data structure for the result.  */  result = (struct CONCAT(PREFIX,fshash) *)    xcalloc (sizeof (struct CONCAT(PREFIX,fshash))	     + (nelems + 1) * sizeof (struct CONCAT(PREFIX,fshashent)), 1);  if (result == NULL)    return NULL;   result->nslots = nelems;   return result;}  #ifndef NO_FINI_FCTCLASS voidCONCAT(PREFIX,fshash_fini) (struct CONCAT(PREFIX,fshash) *htab){  free (htab);}#endif  static struct CONCAT(PREFIX,fshashent) *CONCAT(PREFIX,fshash_lookup) (struct CONCAT(PREFIX,fshash) *htab,			      HASHTYPE hval, TYPE *data){  size_t idx = 1 + hval % htab->nslots;   if (htab->table[idx].hval != 0)    {      HASHTYPE hash;       /* See whether this is the same entry.  */      if (htab->table[idx].hval == hval	  && COMPARE (data, ENTRYP (htab->table[idx])) == 0)	return &htab->table[idx];       /* Second hash function as suggested in [Knuth].  */      hash = 1 + hval % (htab->nslots - 2);       do	{	  if (idx <= hash)	    idx = htab->nslots + idx - hash;	  else	    idx -= hash; 	  if (htab->table[idx].hval == hval	      && COMPARE (data, ENTRYP(htab->table[idx])) == 0)	    return &htab->table[idx];	}      while (htab->table[idx].hval != 0);    }   return &htab->table[idx];}  CLASS int__attribute__ ((unused))CONCAT(PREFIX,fshash_insert) (struct CONCAT(PREFIX,fshash) *htab,			      const char *str,			      size_t len __attribute__ ((unused)), TYPE *data){  HASHTYPE hval = HASHFCT (str, len ?: strlen (str));  struct CONCAT(PREFIX,fshashent) *slot;   slot = CONCAT(PREFIX,fshash_lookup) (htab, hval, data); if (slot->hval != 0)    /* We don't want to overwrite the old value.  */    return -1;   slot->hval = hval;#ifdef STORE_POINTER  slot->entry = data;#else  slot->entry = *data;#endif   return 0;}  #ifdef INSERT_HASHCLASS int__attribute__ ((unused))CONCAT(PREFIX,fshash_insert_hash) (struct CONCAT(PREFIX,fshash) *htab,				   HASHTYPE hval, TYPE *data){  struct CONCAT(PREFIX,fshashent) *slot;   slot = CONCAT(PREFIX,fshash_lookup) (htab, hval, data);  if (slot->hval != 0)    /* We don't want to overwrite the old value.  */    return -1;   slot->hval = hval;#ifdef STORE_POINTER  slot->entry = data;#else  slot->entry = *data;#endif   return 0;}#endif  CLASS int__attribute__ ((unused))CONCAT(PREFIX,fshash_overwrite) (struct CONCAT(PREFIX,fshash) *htab,				 const char *str,				 size_t len __attribute__ ((unused)),				 TYPE *data){  HASHTYPE hval = HASHFCT (str, len ?: strlen (str));  struct CONCAT(PREFIX,fshashent) *slot;   slot = CONCAT(PREFIX,fshash_lookup) (htab, hval, data);  slot->hval = hval;#ifdef STORE_POINTER  slot->entry = data;#else  slot->entry = *data;#endif   return 0;}  CLASS const TYPE *CONCAT(PREFIX,fshash_find) (const struct CONCAT(PREFIX,fshash) *htab,			    const char *str,			    size_t len __attribute__ ((unused)), TYPE *data){  HASHTYPE hval = HASHFCT (str, len ?: strlen (str));  struct CONCAT(PREFIX,fshashent) *slot;   slot = CONCAT(PREFIX,fshash_lookup) ((struct CONCAT(PREFIX,fshash) *) htab,				       hval, data);  if (slot->hval == 0)    /* Not found.  */    return NULL;   return ENTRYP(*slot);}  /* Unset the macros we expect.  */#undef TYPE#undef HASHFCT#undef HASHTYPE#undef COMPARE#undef CLASS#undef PREFIX#undef INSERT_HASH#undef STORE_POINTER#undef NO_FINI_FCT