Adding support for CRC Hashing

[awesomized/libmemcached] / lib / memcached_hash.c

diff --git a/lib/memcached_hash.c b/lib/memcached_hash.c
index 74cd636059cc267cee8cb8c1e1b9793916a6b00a..073b0c5d81b606f6a9f7730dd326b448eee5c88e 100644 (file)
--- a/lib/memcached_hash.c
+++ b/lib/memcached_hash.c
@@ -1,12 +1,35 @@
-#include <memcached.h>
+#include "common.h"
 
-unsigned int memcached_generate_hash(char *key, size_t key_length)
+/* Prototypes */
+static unsigned int internal_generate_hash(char *key, size_t key_length);
+static uint32_t internal_generate_md5(char *key, size_t key_length);
+
+unsigned int memcached_generate_hash(memcached_st *ptr, char *key, size_t key_length)
 {
-  unsigned int x = key_length;
-  char *ptr = key;
-  unsigned int value = 0;
+  uint32_t hash;
+
+  if (ptr->flags & MEM_USE_MD5)
+    hash= internal_generate_md5(key, key_length);
+  else if (ptr->flags & MEM_USE_CRC)
+    hash= hash_crc32(key, key_length);
+  else
+    hash= internal_generate_hash(key, key_length);
 
-  while (x--) 
+  if (ptr->flags & MEM_USE_KETAMA)
+  {
+    WATCHPOINT_ASSERT(0);
+    return 0;
+  }
+  else
+    return hash % ptr->number_of_hosts;
+}
+
+static uint32_t internal_generate_hash(char *key, size_t key_length)
+{
+  char *ptr= key;
+  unsigned int value= 0;
+
+  while (--key_length) 
   {
     value += *ptr++;
     value += (value << 10);
@@ -18,3 +41,15 @@ unsigned int memcached_generate_hash(char *key, size_t key_length)
 
   return value == 0 ? 1 : value;
 }
+
+static uint32_t internal_generate_md5(char *key, size_t key_length)
+{
+  unsigned char results[16];
+
+  md5_signature((unsigned char*)key, (unsigned int)key_length, results);
+
+  return (uint32_t)(( results[3] << 24 )
+                    | ( results[2] << 16 )
+                    | ( results[1] <<  8 )
+                    |   results[0] );
+}