X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/66d8818cb751ab23e70e82fc5ab1017399f49109..d310fbedabd3101505b694f5c25a2e48480a3c2b:/src/dict.c?ds=sidebyside diff --git a/src/dict.c b/src/dict.c index f98fdd0e..e6668082 100644 --- a/src/dict.c +++ b/src/dict.c @@ -85,10 +85,20 @@ unsigned int dictIdentityHashFunction(unsigned int key) return key; } +static int dict_hash_function_seed = 5381; + +void dictSetHashFunctionSeed(unsigned int seed) { + dict_hash_function_seed = seed; +} + +unsigned int dictGetHashFunctionSeed(void) { + return dict_hash_function_seed; +} + /* Generic hash function (a popular one from Bernstein). * I tested a few and this was the best. */ unsigned int dictGenHashFunction(const unsigned char *buf, int len) { - unsigned int hash = 5381; + unsigned int hash = dict_hash_function_seed; while (len--) hash = ((hash << 5) + hash) + (*buf++); /* hash * 33 + c */ @@ -97,7 +107,7 @@ unsigned int dictGenHashFunction(const unsigned char *buf, int len) { /* And a case insensitive version */ unsigned int dictGenCaseHashFunction(const unsigned char *buf, int len) { - unsigned int hash = 5381; + unsigned int hash = dict_hash_function_seed; while (len--) hash = ((hash << 5) + hash) + (tolower(*buf++)); /* hash * 33 + c */ @@ -106,8 +116,8 @@ unsigned int dictGenCaseHashFunction(const unsigned char *buf, int len) { /* ----------------------------- API implementation ------------------------- */ -/* Reset an hashtable already initialized with ht_init(). - * NOTE: This function should only called by ht_destroy(). */ +/* Reset a hash table already initialized with ht_init(). + * NOTE: This function should only be called by ht_destroy(). */ static void _dictReset(dictht *ht) { ht->table = NULL; @@ -140,7 +150,7 @@ int _dictInit(dict *d, dictType *type, } /* Resize the table to the minimal size that contains all the elements, - * but with the invariant of a USER/BUCKETS ratio near to <= 1 */ + * but with the invariant of a USED/BUCKETS ratio near to <= 1 */ int dictResize(dict *d) { int minimal; @@ -152,18 +162,18 @@ int dictResize(dict *d) return dictExpand(d, minimal); } -/* Expand or create the hashtable */ +/* Expand or create the hash table */ int dictExpand(dict *d, unsigned long size) { - dictht n; /* the new hashtable */ + dictht n; /* the new hash table */ unsigned long realsize = _dictNextPower(size); /* the size is invalid if it is smaller than the number of - * elements already inside the hashtable */ + * elements already inside the hash table */ if (dictIsRehashing(d) || d->ht[0].used > size) return DICT_ERR; - /* Allocate the new hashtable and initialize all pointers to NULL */ + /* Allocate the new hash table and initialize all pointers to NULL */ n.size = realsize; n.sizemask = realsize-1; n.table = zcalloc(realsize*sizeof(dictEntry*)); @@ -258,6 +268,30 @@ static void _dictRehashStep(dict *d) { /* Add an element to the target hash table */ int dictAdd(dict *d, void *key, void *val) +{ + dictEntry *entry = dictAddRaw(d,key); + + if (!entry) return DICT_ERR; + dictSetVal(d, entry, val); + return DICT_OK; +} + +/* Low level add. This function adds the entry but instead of setting + * a value returns the dictEntry structure to the user, that will make + * sure to fill the value field as he wishes. + * + * This function is also directly exposed to the user API to be called + * mainly in order to store non-pointers inside the hash value, example: + * + * entry = dictAddRaw(dict,mykey); + * if (entry != NULL) dictSetSignedIntegerVal(entry,1000); + * + * Return values: + * + * If key already exists NULL is returned. + * If key was added, the hash entry is returned to be manipulated by the caller. + */ +dictEntry *dictAddRaw(dict *d, void *key) { int index; dictEntry *entry; @@ -268,7 +302,7 @@ int dictAdd(dict *d, void *key, void *val) /* Get the index of the new element, or -1 if * the element already exists. */ if ((index = _dictKeyIndex(d, key)) == -1) - return DICT_ERR; + return NULL; /* Allocate the memory and store the new entry */ ht = dictIsRehashing(d) ? &d->ht[1] : &d->ht[0]; @@ -278,9 +312,8 @@ int dictAdd(dict *d, void *key, void *val) ht->used++; /* Set the hash entry fields. */ - dictSetHashKey(d, entry, key); - dictSetHashVal(d, entry, val); - return DICT_OK; + dictSetKey(d, entry, key); + return entry; } /* Add an element, discarding the old if the key already exists. @@ -303,11 +336,23 @@ int dictReplace(dict *d, void *key, void *val) * you want to increment (set), and then decrement (free), and not the * reverse. */ auxentry = *entry; - dictSetHashVal(d, entry, val); - dictFreeEntryVal(d, &auxentry); + dictSetVal(d, entry, val); + dictFreeVal(d, &auxentry); return 0; } +/* dictReplaceRaw() is simply a version of dictAddRaw() that always + * returns the hash entry of the specified key, even if the key already + * exists and can't be added (in that case the entry of the already + * existing key is returned.) + * + * See dictAddRaw() for more information. */ +dictEntry *dictReplaceRaw(dict *d, void *key) { + dictEntry *entry = dictFind(d,key); + + return entry ? entry : dictAddRaw(d,key); +} + /* Search and remove an element */ static int dictGenericDelete(dict *d, const void *key, int nofree) { @@ -324,15 +369,15 @@ static int dictGenericDelete(dict *d, const void *key, int nofree) he = d->ht[table].table[idx]; prevHe = NULL; while(he) { - if (dictCompareHashKeys(d, key, he->key)) { + if (dictCompareKeys(d, key, he->key)) { /* Unlink the element from the list */ if (prevHe) prevHe->next = he->next; else d->ht[table].table[idx] = he->next; if (!nofree) { - dictFreeEntryKey(d, he); - dictFreeEntryVal(d, he); + dictFreeKey(d, he); + dictFreeVal(d, he); } zfree(he); d->ht[table].used--; @@ -366,8 +411,8 @@ int _dictClear(dict *d, dictht *ht) if ((he = ht->table[i]) == NULL) continue; while(he) { nextHe = he->next; - dictFreeEntryKey(d, he); - dictFreeEntryVal(d, he); + dictFreeKey(d, he); + dictFreeVal(d, he); zfree(he); ht->used--; he = nextHe; @@ -400,7 +445,7 @@ dictEntry *dictFind(dict *d, const void *key) idx = h & d->ht[table].sizemask; he = d->ht[table].table[idx]; while(he) { - if (dictCompareHashKeys(d, key, he->key)) + if (dictCompareKeys(d, key, he->key)) return he; he = he->next; } @@ -413,7 +458,7 @@ void *dictFetchValue(dict *d, const void *key) { dictEntry *he; he = dictFind(d,key); - return he ? dictGetEntryVal(he) : NULL; + return he ? dictGetVal(he) : NULL; } dictIterator *dictGetIterator(dict *d) @@ -562,7 +607,7 @@ static int _dictKeyIndex(dict *d, const void *key) unsigned int h, idx, table; dictEntry *he; - /* Expand the hashtable if needed */ + /* Expand the hash table if needed */ if (_dictExpandIfNeeded(d) == DICT_ERR) return -1; /* Compute the key hash value */ @@ -572,7 +617,7 @@ static int _dictKeyIndex(dict *d, const void *key) /* Search if this slot does not already contain the given key */ he = d->ht[table].table[idx]; while(he) { - if (dictCompareHashKeys(d, key, he->key)) + if (dictCompareKeys(d, key, he->key)) return -1; he = he->next; } @@ -588,6 +633,21 @@ void dictEmpty(dict *d) { d->iterators = 0; } +void dictEnableResize(void) { + dict_can_resize = 1; +} + +void dictDisableResize(void) { + dict_can_resize = 0; +} + +#if 0 + +/* The following is code that we don't use for Redis currently, but that is part +of the library. */ + +/* ----------------------- Debugging ------------------------*/ + #define DICT_STATS_VECTLEN 50 static void _dictPrintStatsHt(dictht *ht) { unsigned long i, slots = 0, chainlen, maxchainlen = 0; @@ -641,20 +701,6 @@ void dictPrintStats(dict *d) { } } -void dictEnableResize(void) { - dict_can_resize = 1; -} - -void dictDisableResize(void) { - dict_can_resize = 0; -} - -#if 0 - -/* The following are just example hash table types implementations. - * Not useful for Redis so they are commented out. - */ - /* ----------------------- StringCopy Hash Table Type ------------------------*/ static unsigned int _dictStringCopyHTHashFunction(const void *key)