check if *value is non-NULL before setting it

[redis.git] / dict.h

diff --git a/dict.h b/dict.h
index ae634b4938d2a070d7579fe6f655cf980a7d8942..30ace4db7cba3df6bae3ac01d4a55d4f43ecc733 100644 (file)
--- a/dict.h
+++ b/dict.h
@@ -5,7 +5,7 @@
  * tables of power of two in size are used, collisions are handled by
  * chaining. See the source code for more information... :)
  *
- * Copyright (c) 2006-2009, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2006-2010, Salvatore Sanfilippo <antirez at gmail dot com>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -57,76 +57,91 @@ typedef struct dictType {
     void (*valDestructor)(void *privdata, void *obj);
 } dictType;
 
-typedef struct dict {
+/* This is our hash table structure. Every dictionary has two of this as we
+ * implement incremental rehashing, for the old to the new table. */
+typedef struct dictht {
     dictEntry **table;
+    unsigned long size;
+    unsigned long sizemask;
+    unsigned long used;
+} dictht;
+
+typedef struct dict {
     dictType *type;
-    unsigned int size;
-    unsigned int sizemask;
-    unsigned int used;
     void *privdata;
+    dictht ht[2];
+    int rehashidx; /* rehashing not in progress if rehashidx == -1 */
+    int iterators; /* number of iterators currently running */
 } dict;
 
 typedef struct dictIterator {
-    dict *ht;
+    dict *d;
+    int table;
     int index;
     dictEntry *entry, *nextEntry;
 } dictIterator;
 
 /* This is the initial size of every hash table */
-#define DICT_HT_INITIAL_SIZE     16
+#define DICT_HT_INITIAL_SIZE     4
 
 /* ------------------------------- Macros ------------------------------------*/
-#define dictFreeEntryVal(ht, entry) \
-    if ((ht)->type->valDestructor) \
-        (ht)->type->valDestructor((ht)->privdata, (entry)->val)
+#define dictFreeEntryVal(d, entry) \
+    if ((d)->type->valDestructor) \
+        (d)->type->valDestructor((d)->privdata, (entry)->val)
 
-#define dictSetHashVal(ht, entry, _val_) do { \
-    if ((ht)->type->valDup) \
-        entry->val = (ht)->type->valDup((ht)->privdata, _val_); \
+#define dictSetHashVal(d, entry, _val_) do { \
+    if ((d)->type->valDup) \
+        entry->val = (d)->type->valDup((d)->privdata, _val_); \
     else \
         entry->val = (_val_); \
 } while(0)
 
-#define dictFreeEntryKey(ht, entry) \
-    if ((ht)->type->keyDestructor) \
-        (ht)->type->keyDestructor((ht)->privdata, (entry)->key)
+#define dictFreeEntryKey(d, entry) \
+    if ((d)->type->keyDestructor) \
+        (d)->type->keyDestructor((d)->privdata, (entry)->key)
 
-#define dictSetHashKey(ht, entry, _key_) do { \
-    if ((ht)->type->keyDup) \
-        entry->key = (ht)->type->keyDup((ht)->privdata, _key_); \
+#define dictSetHashKey(d, entry, _key_) do { \
+    if ((d)->type->keyDup) \
+        entry->key = (d)->type->keyDup((d)->privdata, _key_); \
     else \
         entry->key = (_key_); \
 } while(0)
 
-#define dictCompareHashKeys(ht, key1, key2) \
-    (((ht)->type->keyCompare) ? \
-        (ht)->type->keyCompare((ht)->privdata, key1, key2) : \
+#define dictCompareHashKeys(d, key1, key2) \
+    (((d)->type->keyCompare) ? \
+        (d)->type->keyCompare((d)->privdata, key1, key2) : \
         (key1) == (key2))
 
-#define dictHashKey(ht, key) (ht)->type->hashFunction(key)
+#define dictHashKey(d, key) (d)->type->hashFunction(key)
 
 #define dictGetEntryKey(he) ((he)->key)
 #define dictGetEntryVal(he) ((he)->val)
-#define dictGetHashTableSize(ht) ((ht)->size)
-#define dictGetHashTableUsed(ht) ((ht)->used)
+#define dictSlots(d) ((d)->ht[0].size+(d)->ht[1].size)
+#define dictSize(d) ((d)->ht[0].used+(d)->ht[1].used)
+#define dictIsRehashing(ht) ((ht)->rehashidx != -1)
 
 /* API */
 dict *dictCreate(dictType *type, void *privDataPtr);
-int dictExpand(dict *ht, unsigned int size);
-int dictAdd(dict *ht, void *key, void *val);
-int dictReplace(dict *ht, void *key, void *val);
-int dictDelete(dict *ht, const void *key);
-int dictDeleteNoFree(dict *ht, const void *key);
-void dictRelease(dict *ht);
-dictEntry * dictFind(dict *ht, const void *key);
-int dictResize(dict *ht);
-dictIterator *dictGetIterator(dict *ht);
+int dictExpand(dict *d, unsigned long size);
+int dictAdd(dict *d, void *key, void *val);
+int dictReplace(dict *d, void *key, void *val);
+int dictDelete(dict *d, const void *key);
+int dictDeleteNoFree(dict *d, const void *key);
+void dictRelease(dict *d);
+dictEntry * dictFind(dict *d, const void *key);
+void *dictFetchValue(dict *d, const void *key);
+int dictResize(dict *d);
+dictIterator *dictGetIterator(dict *d);
 dictEntry *dictNext(dictIterator *iter);
 void dictReleaseIterator(dictIterator *iter);
-dictEntry *dictGetRandomKey(dict *ht);
-void dictPrintStats(dict *ht);
+dictEntry *dictGetRandomKey(dict *d);
+void dictPrintStats(dict *d);
 unsigned int dictGenHashFunction(const unsigned char *buf, int len);
-void dictEmpty(dict *ht);
+void dictEmpty(dict *d);
+void dictEnableResize(void);
+void dictDisableResize(void);
+int dictRehash(dict *d, int n);
+int dictRehashMilliseconds(dict *d, int ms);
 
 /* Hash table types */
 extern dictType dictTypeHeapStringCopyKey;