Bug fix in documentation Tim found.

[awesomized/libmemcached] / libmemcached / memcached_hash.c

diff --git a/libmemcached/memcached_hash.c b/libmemcached/memcached_hash.c
index 8d269faa69cac9672260391a3401e930686f0e66..cca7b5a40ab7e3ec3c6457a7cc0dda4e6c5fbafa 100644 (file)
--- a/libmemcached/memcached_hash.c
+++ b/libmemcached/memcached_hash.c
@@ -8,11 +8,10 @@ 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 generate_hash(memcached_st *ptr, const char *key, size_t key_length)
 {
   uint32_t hash= 1; /* Just here to remove compile warning */
   uint32_t x= 0;
@@ -81,11 +80,6 @@ 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);
@@ -109,16 +103,17 @@ unsigned int dispatch_host(memcached_st *ptr, uint32_t hash)
   case MEMCACHED_DISTRIBUTION_CONSISTENT:
   case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA:
     {
-      int num= ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER;
+      uint32_t num= ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER;
+      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);
 
       while (1)
       {
-        struct continuum_item *rmiddle;
+        memcached_continuum_item_st *rmiddle;
 
         middle = left + (right - left) / 2;
 
@@ -147,7 +142,7 @@ unsigned int dispatch_host(memcached_st *ptr, uint32_t hash)
     {
       unsigned int server_key;
 
-      server_key= hash % MEMCACHED_WHEEL_SIZE;
+      server_key= hash % MEMCACHED_STRIDE * ptr->wheel_count;
 
       return ptr->wheel[server_key];
     }
@@ -158,58 +153,15 @@ unsigned int dispatch_host(memcached_st *ptr, uint32_t hash)
     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);
-  }
+  WATCHPOINT_ASSERT(0); /* We should never reach here */
+  return 0;
 }
 
-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 */
 
@@ -224,9 +176,9 @@ unsigned int memcached_generate_hash(memcached_st *ptr, char *key, size_t key_le
   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) 
@@ -242,19 +194,7 @@ 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];