libgo/runtime/go-type-string.c

   1 /* go-type-string.c -- hash and equality string functions.
   2
   3    Copyright 2009 The Go Authors. All rights reserved.
   4    Use of this source code is governed by a BSD-style
   5    license that can be found in the LICENSE file.  */
   6
   7 #include <stddef.h>
   8
   9 #include "go-string.h"
  10 #include "go-type.h"
  11
  12 /* A string hash function for a map.  */
  13
  14 uintptr_t
  15 __go_type_hash_string (const void *vkey,
  16                        uintptr_t key_size __attribute__ ((unused)))
  17 {
  18   uintptr_t ret;
  19   const struct __go_string *key;
  20   int len;
  21   int i;
  22   const unsigned char *p;
  23
  24   ret = 5381;
  25   key = (const struct __go_string *) vkey;
  26   len = key->__length;
  27   for (i = 0, p = key->__data; i < len; i++, p++)
  28     ret = ret * 33 + *p;
  29   return ret;
  30 }
  31
  32 /* A string equality function for a map.  */
  33
  34 _Bool
  35 __go_type_equal_string (const void *vk1, const void *vk2,
  36                         uintptr_t key_size __attribute__ ((unused)))
  37 {
  38   const struct __go_string *k1;
  39   const struct __go_string *k2;
  40
  41   k1 = (const struct __go_string *) vk1;
  42   k2 = (const struct __go_string *) vk2;
  43   return (k1->__length == k2->__length
  44           && __builtin_memcmp (k1->__data, k2->__data, k1->__length) == 0);
  45 }