Adding delete_by_key function to complete partitioning by key feature.

[awesomized/libmemcached] / lib / memcached_hash.c

diff --git a/lib/memcached_hash.c b/lib/memcached_hash.c
index 04319189a69b7d9c94e5be72a0e8d1cbb45a8027..87c59d510ae55cbc32cff6def7d1817acd8104b6 100644 (file)
--- a/lib/memcached_hash.c
+++ b/lib/memcached_hash.c
@@ -1,20 +1,23 @@
 #include "common.h"
 
 /* Defines */
-static uint64_t FNV_64_INIT= 0xcbf29ce484222325L;
-static uint64_t FNV_64_PRIME= 0x100000001b3L;
+static uint64_t FNV_64_INIT= 0xcbf29ce484222325LL;
+static uint64_t FNV_64_PRIME= 0x100000001b3LL;
 
-static uint32_t FNV_32_INIT= 2166136261L;
+static uint32_t FNV_32_INIT= 2166136261UL;
 static uint32_t FNV_32_PRIME= 16777619;
 
 /* 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);
-static uint32_t internal_generate_md5(char *key, size_t key_length);
+static uint64_t internal_generate_hash(char *key, size_t key_length);
+static uint64_t internal_generate_md5(char *key, size_t key_length);
+static uint64_t internal_generate_ketama_md5(char *key, size_t key_length);
 
 unsigned int memcached_generate_hash(memcached_st *ptr, char *key, size_t key_length)
 {
-  uint32_t hash;
+  uint64_t hash= 1; /* Just here to remove compile warning */
+  unsigned int x;
+
+  WATCHPOINT_ASSERT(ptr->number_of_hosts);
 
   switch (ptr->hash)
   {
@@ -25,23 +28,82 @@ unsigned int memcached_generate_hash(memcached_st *ptr, char *key, size_t key_le
     hash= internal_generate_md5(key, key_length);
     break;
   case MEMCACHED_HASH_CRC:
-    hash= hash_crc32(key, key_length);
+    hash= ((hash_crc32(key, key_length) >> 16) & 0x7fff);
+    break;
+    /* FNV hash'es lifted from Dustin Sallings work */
+  case MEMCACHED_HASH_FNV1_64: 
+    {
+      /* Thanks to pierre@demartines.com for the pointer */
+      hash= FNV_64_INIT;
+      for (x= 0; x < key_length; x++) 
+      {
+        hash *= FNV_64_PRIME;
+        hash ^= key[x];
+      }
+    }
+    break;
+  case MEMCACHED_HASH_FNV1A_64: 
+    {
+      hash= FNV_64_INIT;
+      for (x= 0; x < key_length; x++) 
+      {
+        hash ^= key[x];
+        hash *= FNV_64_PRIME;
+      }
+    }
+    break;
+  case MEMCACHED_HASH_FNV1_32: 
+    {
+      hash= FNV_32_INIT;
+      for (x= 0; x < key_length; x++) 
+      {
+        hash *= FNV_32_PRIME;
+        hash ^= key[x];
+      }
+    }
+    break;
+  case MEMCACHED_HASH_FNV1A_32: 
+    {
+      hash= FNV_32_INIT;
+      for (x= 0; x < key_length; x++) 
+      {
+        hash ^= key[x];
+        hash *= FNV_32_PRIME;
+      }
+    }
     break;
+    case MEMCACHED_HASH_KETAMA: 
+    {
+      hash= internal_generate_ketama_md5(key, key_length);
+      break;
+    }
+    case MEMCACHED_HASH_HSIEH:
+    {
+      hash= hsieh_hash(key, key_length);
+      break;
+    }
   }
 
-  if (ptr->flags & MEM_USE_KETAMA)
+  WATCHPOINT_ASSERT(hash);
+
+  if (ptr->distribution == MEMCACHED_DISTRIBUTION_MODULA)
   {
-    WATCHPOINT_ASSERT(0);
-    return 0;
+    return hash % ptr->number_of_hosts;
   }
   else
-    return hash % ptr->number_of_hosts;
+  {
+    unsigned int server_key;
+
+    server_key= hash % MEMCACHED_WHEEL_SIZE;
+
+    return ptr->wheel[server_key];
+  }
 }
 
-static uint32_t internal_generate_hash(char *key, size_t key_length)
+static uint64_t internal_generate_hash(char *key, size_t key_length)
 {
   char *ptr= key;
-  unsigned int value= 0;
+  uint64_t value= 0;
 
   while (--key_length) 
   {
@@ -56,14 +118,26 @@ static uint32_t internal_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)
+static uint64_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 )
+  return (uint64_t)(( results[3] << 24 )
                     | ( results[2] << 16 )
                     | ( results[1] <<  8 )
                     |   results[0] );
 }
+
+static uint64_t internal_generate_ketama_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] & 0xFF) << 24)
+    | ((uint32_t) (results[2] & 0xFF) << 16)
+    | ((uint32_t) (results[1] & 0xFF) << 8)
+    | (results[0] & 0xFF);
+}