X-Git-Url: https://git.m6w6.name/?a=blobdiff_plain;f=libmemcached%2Fmemcached_hash.c;h=c7bcb4bed35810cbad3ebbfb22475ddd8f0260ab;hb=3793fdb392266c08b59b2e5815f9db6a60c48fda;hp=8d269faa69cac9672260391a3401e930686f0e66;hpb=d48f4bbb5d5bee5ab3bed6f479558ef1fa74b58f;p=awesomized%2Flibmemcached

diff --git a/libmemcached/memcached_hash.c b/libmemcached/memcached_hash.c
index 8d269faa..c7bcb4be 100644
--- a/libmemcached/memcached_hash.c
+++ b/libmemcached/memcached_hash.c
@@ -8,22 +8,15 @@ static uint32_t FNV_32_INIT= 2166136261UL;
 static uint32_t FNV_32_PRIME= 16777619;
 
 /* Prototypes */
-static uint32_t 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_ketama_md5(char *key, size_t key_length);
+static uint32_t internal_generate_hash(const char *key, size_t key_length);
+static uint32_t internal_generate_md5(const char *key, size_t key_length);
 
-uint32_t generate_hash(memcached_st *ptr, char *key, size_t key_length)
+uint32_t memcached_generate_hash_value(const char *key, size_t key_length, memcached_hash hash_algorithm)
 {
   uint32_t hash= 1; /* Just here to remove compile warning */
   uint32_t x= 0;
 
-
-  WATCHPOINT_ASSERT(ptr->number_of_hosts);
-
-  if (ptr->number_of_hosts == 1)
-    return 0;
-
-  switch (ptr->hash)
+  switch (hash_algorithm)
   {
   case MEMCACHED_HASH_DEFAULT:
     hash= internal_generate_hash(key, key_length);
@@ -81,11 +74,6 @@ uint32_t generate_hash(memcached_st *ptr, char *key, size_t key_length)
       }
     }
     break;
-    case MEMCACHED_HASH_KETAMA: 
-    {
-      hash= internal_generate_ketama_md5(key, key_length);
-      break;
-    }
     case MEMCACHED_HASH_HSIEH:
     {
       hash= hsieh_hash(key, key_length);
@@ -96,120 +84,75 @@ uint32_t generate_hash(memcached_st *ptr, char *key, size_t key_length)
       hash= murmur_hash(key, key_length);
       break;
     }
+    case MEMCACHED_HASH_JENKINS:
+    {
+      hash=jenkins_hash(key, key_length, 13);
+      break;
+    }
   }
+  return hash;
+}
+
+uint32_t generate_hash(memcached_st *ptr, const char *key, size_t key_length)
+{
+  uint32_t hash= 1; /* Just here to remove compile warning */
 
+
+  WATCHPOINT_ASSERT(ptr->number_of_hosts);
+
+  if (ptr->number_of_hosts == 1)
+    return 0;
+
+  hash= memcached_generate_hash_value(key, key_length, ptr->hash);
   WATCHPOINT_ASSERT(hash);
   return hash;
 }
 
-unsigned int dispatch_host(memcached_st *ptr, uint32_t hash)
+static uint32_t dispatch_host(memcached_st *ptr, uint32_t hash)
 {
   switch (ptr->distribution) 
   {
   case MEMCACHED_DISTRIBUTION_CONSISTENT:
   case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA:
     {
-      int num= ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER;
+      uint32_t num= ptr->continuum_points_counter;
+      WATCHPOINT_ASSERT(ptr->continuum);
 
       hash= hash;
-      struct continuum_item *begin, *end, *left, *right, *middle;
+      memcached_continuum_item_st *begin, *end, *left, *right, *middle;
       begin= left= ptr->continuum;
-      end= right= ptr->continuum + (num - 1);
+      end= right= ptr->continuum + num;
 
-      while (1)
+      while (left < right)
       {
-        struct continuum_item *rmiddle;
-
-        middle = left + (right - left) / 2;
-
-        if (middle==end)
-          return begin->index;
-
-        if (middle==begin)
-          return end->index;
-
-        rmiddle = middle+1;
-
-        if (hash<rmiddle->value && hash>=middle->value)
-          return middle->index;
-
+        middle= left + (right - left) / 2;
         if (middle->value < hash)
-          left = middle + 1;
-        else if (middle->value > hash)
-          right = middle - 1;
-
-        if (left>right)
-          return left->index;
+          left= middle + 1;
+        else
+          right= middle;
       }
+      if (right == end)
+        right= begin;
+      return right->index;
     } 
     break;
-  case MEMCACHED_DISTRIBUTION_CONSISTENT_WHEEL:
-    {
-      unsigned int server_key;
-
-      server_key= hash % MEMCACHED_WHEEL_SIZE;
-
-      return ptr->wheel[server_key];
-    }
   case MEMCACHED_DISTRIBUTION_MODULA:
     return hash % ptr->number_of_hosts;
+  case MEMCACHED_DISTRIBUTION_RANDOM:
+    return random() % ptr->number_of_hosts;
   default:
     WATCHPOINT_ASSERT(0); /* We have added a distribution without extending the logic */
     return hash % ptr->number_of_hosts;
   }
 
-  if (ptr->distribution == MEMCACHED_DISTRIBUTION_MODULA)
-  {
-    return hash % ptr->number_of_hosts;
-  }
-  else if (ptr->distribution == MEMCACHED_DISTRIBUTION_CONSISTENT)
-  {
-    unsigned int server_key;
-
-    server_key= hash % MEMCACHED_WHEEL_SIZE;
-
-    return ptr->wheel[server_key];
-  }
-  else if (ptr->distribution == MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA)
-  {
-    int num = ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER;
-
-    hash = hash;
-    struct continuum_item *begin, *end, *left, *right, *middle;
-    begin = left = ptr->continuum;
-    end = right = ptr->continuum + (num - 1);
-    while(1)
-    {
-      middle = left + (right - left) / 2;
-      if(middle==end)
-      {
-        return begin->index;
-      }
-      if(middle==begin)
-      {
-        return end->index;
-      }
-      struct continuum_item *rmiddle = middle+1;
-      if(hash<rmiddle->value && hash>=middle->value)
-        return middle->index;
-
-      if(middle->value < hash) {
-        left = middle + 1;
-      }else if(middle->value > hash) {
-        right = middle - 1;
-      }
-
-      if (left>right)
-        return left->index;
-    }
-  } 
-  else 
-  {
-    WATCHPOINT_ASSERT(0);
-  }
+  /* NOTREACHED */
 }
 
-unsigned int memcached_generate_hash(memcached_st *ptr, char *key, size_t key_length)
+/* 
+  One day make this public, and have it return the actual memcached_server_st 
+  to the calling application.
+*/
+uint32_t memcached_generate_hash(memcached_st *ptr, const char *key, size_t key_length)
 {
   uint32_t hash= 1; /* Just here to remove compile warning */
 
@@ -218,18 +161,31 @@ unsigned int memcached_generate_hash(memcached_st *ptr, char *key, size_t key_le
   if (ptr->number_of_hosts == 1)
     return 0;
 
-  hash = generate_hash(ptr, key, key_length);
+  if (ptr->flags & MEM_HASH_WITH_PREFIX_KEY)
+  {
+    int temp_len= ptr->prefix_key_length + key_length;
+    char *temp= (char *)malloc(temp_len);
+    strncpy(temp, ptr->prefix_key, ptr->prefix_key_length);
+    strncpy(temp + ptr->prefix_key_length, key, key_length);
+    hash= generate_hash(ptr, temp, temp_len);
+    free(temp);
+  }
+  else
+  {
+    hash= generate_hash(ptr, key, key_length);
+  }
 
   WATCHPOINT_ASSERT(hash);
+
   return dispatch_host(ptr, hash);
 }
 
-static uint32_t internal_generate_hash(char *key, size_t key_length)
+static uint32_t internal_generate_hash(const char *key, size_t key_length)
 {
-  char *ptr= key;
+  const char *ptr= key;
   uint32_t value= 0;
 
-  while (--key_length) 
+  while (key_length--) 
   {
     value += *ptr++;
     value += (value << 10);
@@ -242,19 +198,7 @@ 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)
-{
-  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] );
-}
-
-static uint32_t internal_generate_ketama_md5(char *key, size_t key_length)
+static uint32_t internal_generate_md5(const char *key, size_t key_length)
 {
   unsigned char results[16];