git.m6w6.name Git - awesomized/libmemcached/blob - libhashkit/hashkit.c

   1 /* HashKit
   2  * Copyright (C) 2006-2009 Brian Aker
   3  * All rights reserved.
   4  *
   5  * Use and distribution licensed under the BSD license.  See
   6  * the COPYING file in the parent directory for full text.
   7  */
   8
   9 #include "common.h"
  10
  11 static const hashkit_st global_default_hash= {
  12   .base_hash= {
  13     .type= HASHKIT_HASH_DEFAULT,
  14     .function= hashkit_one_at_a_time,
  15     .context= NULL
  16   },
  17 };
  18
  19 /**
  20   @note We make no assumptions that "hashk" has been, or not been allocated from heap/stack. We just know we didn't do it.
  21 */
  22 hashkit_st *hashkit_create(hashkit_st *self)
  23 {
  24   if (self == NULL)
  25   {
  26     self= (hashkit_st *)malloc(sizeof(hashkit_st));
  27     if (self == NULL)
  28     {
  29       return NULL;
  30     }
  31
  32     self->options.is_allocated= true;
  33   }
  34   else
  35   {
  36     self->options.is_allocated= false;
  37   }
  38
  39   self->base_hash= global_default_hash.base_hash;
  40
  41   return self;
  42 }
  43
  44
  45 void hashkit_free(hashkit_st *self)
  46 {
  47   if (hashkit_is_allocated(self))
  48   {
  49     free(self);
  50   }
  51 }
  52
  53 /**
  54   @note We do assume source is valid. If source does not exist, we allocate.
  55 */
  56 hashkit_st *hashkit_clone(hashkit_st *destination, const hashkit_st *source)
  57 {
  58   if (source == NULL)
  59   {
  60     return hashkit_create(destination);
  61   }
  62
  63   /* new_clone will be a pointer to destination */
  64   destination= hashkit_create(destination);
  65
  66   // Should only happen on allocation failure.
  67   if (destination == NULL)
  68   {
  69     return NULL;
  70   }
  71
  72   destination->base_hash= source->base_hash;
  73
  74   return destination;
  75 }
  76
  77
  78 uint32_t hashkit_generate_value(const hashkit_st *self, const char *key, size_t key_length)
  79 {
  80   return self->base_hash.function(key, key_length);
  81 }
  82
  83 uint32_t libhashkit_generate_value(const char *key, size_t key_length, hashkit_hash_algorithm_t hash_algorithm)
  84 {
  85   switch (hash_algorithm)
  86   {
  87   case HASHKIT_HASH_DEFAULT:
  88     return hashkit_one_at_a_time(key, key_length);
  89   case HASHKIT_HASH_MD5:
  90     return hashkit_md5(key, key_length);
  91   case HASHKIT_HASH_CRC:
  92     return hashkit_crc32(key, key_length);
  93   case HASHKIT_HASH_FNV1_64:
  94     return hashkit_fnv1_64(key, key_length);
  95   case HASHKIT_HASH_FNV1A_64:
  96     return hashkit_fnv1a_64(key, key_length);
  97   case HASHKIT_HASH_FNV1_32:
  98     return hashkit_fnv1_32(key, key_length);
  99   case HASHKIT_HASH_FNV1A_32:
 100     return hashkit_fnv1a_32(key, key_length);
 101   case HASHKIT_HASH_HSIEH:
 102 #ifdef HAVE_HSIEH_HASH
 103     return hashkit_hsieh(key, key_length);
 104 #else
 105     return 1;
 106 #endif
 107   case HASHKIT_HASH_MURMUR:
 108     return hashkit_murmur(key, key_length);
 109   case HASHKIT_HASH_JENKINS:
 110     return hashkit_jenkins(key, key_length);
 111   case HASHKIT_HASH_MAX:
 112   default:
 113 #ifdef HAVE_DEBUG
 114     fprintf(stderr, "hashkit_hash_t was extended but libhashkit_generate_value was not updated\n");
 115     fflush(stderr);
 116     assert(0);
 117 #endif
 118     break;
 119   }
 120
 121   return 1;
 122 }