Merged from trunk.

[awesomized/libmemcached] / libmemcached / memcached_hash.c

diff --git a/libmemcached/memcached_hash.c b/libmemcached/memcached_hash.c
index 75a1537a81e4547f67e8912261331e6dcec0e887..e6747db5f7b2de3ba64ae67a658c9e25a60ebba6 100644 (file)
--- a/libmemcached/memcached_hash.c
+++ b/libmemcached/memcached_hash.c
@@ -1,5 +1,6 @@
 #include "common.h"
 
+
 /* Defines */
 static uint64_t FNV_64_INIT= 0xcbf29ce484222325LL;
 static uint64_t FNV_64_PRIME= 0x100000001b3LL;
@@ -11,7 +12,7 @@ static uint32_t FNV_32_PRIME= 16777619;
 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_value(const char *key, size_t key_length, memcached_hash hash_algorithm)
+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;
@@ -76,7 +77,9 @@ uint32_t generate_hash_value(const char *key, size_t key_length, memcached_hash
     break;
     case MEMCACHED_HASH_HSIEH:
     {
+#ifdef HAVE_HSIEH_HASH
       hash= hsieh_hash(key, key_length);
+#endif
       break;
     }
     case MEMCACHED_HASH_MURMUR:
@@ -84,6 +87,11 @@ uint32_t generate_hash_value(const char *key, size_t key_length, memcached_hash
       hash= murmur_hash(key, key_length);
       break;
     }
+    case MEMCACHED_HASH_JENKINS:
+    {
+      hash=jenkins_hash(key, key_length, 13);
+      break;
+    }
   }
   return hash;
 }
@@ -98,12 +106,12 @@ uint32_t generate_hash(memcached_st *ptr, const char *key, size_t key_length)
   if (ptr->number_of_hosts == 1)
     return 0;
 
-  hash= generate_hash_value(key, key_length, ptr->hash);
+  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) 
   {
@@ -116,44 +124,31 @@ unsigned int dispatch_host(memcached_st *ptr, uint32_t hash)
       hash= hash;
       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)
       {
-        memcached_continuum_item_st *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_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;
   }
 
-  WATCHPOINT_ASSERT(0); /* We should never reach here */
-  return 0;
+  /* NOTREACHED */
 }
 
 /* 
@@ -163,17 +158,36 @@ unsigned int dispatch_host(memcached_st *ptr, uint32_t hash)
 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 */
-  uint32_t result= 1;
 
   WATCHPOINT_ASSERT(ptr->number_of_hosts);
 
   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);
 
+  if (memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_AUTO_EJECT_HOSTS) && ptr->next_distribution_rebuild) {
+    struct timeval now;
+
+    if (gettimeofday(&now, NULL) == 0 &&
+        now.tv_sec > ptr->next_distribution_rebuild)
+      run_distribution(ptr);
+  }
+
   return dispatch_host(ptr, hash);
 }
 
@@ -182,7 +196,7 @@ static uint32_t internal_generate_hash(const char *key, size_t key_length)
   const char *ptr= key;
   uint32_t value= 0;
 
-  while (--key_length) 
+  while (key_length--) 
   {
     value += *ptr++;
     value += (value << 10);