Test "Turning off AOF kills the background writing child if any" is now more reliable.

[redis.git] / src / dict.c

diff --git a/src/dict.c b/src/dict.c
index 79c005b693aa24ebb597c419b80c5e5dd0b87c40..69656734c6085a9e28b51eb75df218e3dd71da7a 100644 (file)
--- a/src/dict.c
+++ b/src/dict.c
@@ -42,6 +42,7 @@
 #include <assert.h>
 #include <limits.h>
 #include <sys/time.h>
 #include <assert.h>
 #include <limits.h>
 #include <sys/time.h>

+#include <ctype.h>

 
 #include "dict.h"
 #include "zmalloc.h"
 
 #include "dict.h"
 #include "zmalloc.h"


@@ -49,35 +50,13 @@
 /* Using dictEnableResize() / dictDisableResize() we make possible to
  * enable/disable resizing of the hash table as needed. This is very important
  * for Redis, as we use copy-on-write and don't want to move too much memory
 /* Using dictEnableResize() / dictDisableResize() we make possible to
  * enable/disable resizing of the hash table as needed. This is very important
  * for Redis, as we use copy-on-write and don't want to move too much memory

- * around when there is a child performing saving operations. */
+ * around when there is a child performing saving operations.
+ *
+ * Note that even when dict_can_resize is set to 0, not all resizes are
+ * prevented: an hash table is still allowed to grow if the ratio between
+ * the number of elements and the buckets > dict_force_resize_ratio. */

 static int dict_can_resize = 1;
 static int dict_can_resize = 1;

-
-/* ---------------------------- Utility funcitons --------------------------- */
-
-static void _dictPanic(const char *fmt, ...)
-{
-    va_list ap;
-
-    va_start(ap, fmt);
-    fprintf(stderr, "\nDICT LIBRARY PANIC: ");
-    vfprintf(stderr, fmt, ap);
-    fprintf(stderr, "\n\n");
-    va_end(ap);
-}
-
-/* ------------------------- Heap Management Wrappers------------------------ */
-
-static void *_dictAlloc(size_t size)
-{
-    void *p = zmalloc(size);
-    if (p == NULL)
-        _dictPanic("Out of memory");
-    return p;
-}
-
-static void _dictFree(void *ptr) {
-    zfree(ptr);
-}
+static unsigned int dict_force_resize_ratio = 5;

 
 /* -------------------------- private prototypes ---------------------------- */
 
 
 /* -------------------------- private prototypes ---------------------------- */
 


@@ -106,16 +85,35 @@ unsigned int dictIdentityHashFunction(unsigned int key)
     return 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) {
 /* 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 */
     return hash;
 }
 
 
     while (len--)
         hash = ((hash << 5) + hash) + (*buf++); /* hash * 33 + c */
     return hash;
 }
 

+/* And a case insensitive version */
+unsigned int dictGenCaseHashFunction(const unsigned char *buf, int len) {
+    unsigned int hash = dict_hash_function_seed;
+
+    while (len--)
+        hash = ((hash << 5) + hash) + (tolower(*buf++)); /* hash * 33 + c */
+    return hash;
+}
+

 /* ----------------------------- API implementation ------------------------- */
 
 /* Reset an hashtable already initialized with ht_init().
 /* ----------------------------- API implementation ------------------------- */
 
 /* Reset an hashtable already initialized with ht_init().


@@ -132,7 +130,7 @@ static void _dictReset(dictht *ht)
 dict *dictCreate(dictType *type,
         void *privDataPtr)
 {
 dict *dictCreate(dictType *type,
         void *privDataPtr)
 {

-    dict *d = _dictAlloc(sizeof(*d));
+    dict *d = zmalloc(sizeof(*d));

 
     _dictInit(d,type,privDataPtr);
     return d;
 
     _dictInit(d,type,privDataPtr);
     return d;


@@ -152,7 +150,7 @@ int _dictInit(dict *d, dictType *type,
 }
 
 /* Resize the table to the minimal size that contains all the elements,
 }
 
 /* Resize the table to the minimal size that contains all the elements,

- * but with the invariant of a USER/BUCKETS ration near to <= 1 */
+ * but with the invariant of a USED/BUCKETS ratio near to <= 1 */

 int dictResize(dict *d)
 {
     int minimal;
 int dictResize(dict *d)
 {
     int minimal;


@@ -175,14 +173,12 @@ int dictExpand(dict *d, unsigned long size)
     if (dictIsRehashing(d) || d->ht[0].used > size)
         return DICT_ERR;
 
     if (dictIsRehashing(d) || d->ht[0].used > size)
         return DICT_ERR;
 

+    /* Allocate the new hashtable and initialize all pointers to NULL */

     n.size = realsize;
     n.sizemask = realsize-1;
     n.size = realsize;
     n.sizemask = realsize-1;

-    n.table = _dictAlloc(realsize*sizeof(dictEntry*));
+    n.table = zcalloc(realsize*sizeof(dictEntry*));

     n.used = 0;
 
     n.used = 0;
 

-    /* Initialize all the pointers to NULL */
-    memset(n.table, 0, realsize*sizeof(dictEntry*));
-

     /* Is this the first initialization? If so it's not really a rehashing
      * we just set the first hash table so that it can accept keys. */
     if (d->ht[0].table == NULL) {
     /* Is this the first initialization? If so it's not really a rehashing
      * we just set the first hash table so that it can accept keys. */
     if (d->ht[0].table == NULL) {


@@ -208,7 +204,7 @@ int dictRehash(dict *d, int n) {
 
         /* Check if we already rehashed the whole table... */
         if (d->ht[0].used == 0) {
 
         /* Check if we already rehashed the whole table... */
         if (d->ht[0].used == 0) {

-            _dictFree(d->ht[0].table);
+            zfree(d->ht[0].table);

             d->ht[0] = d->ht[1];
             _dictReset(&d->ht[1]);
             d->rehashidx = -1;
             d->ht[0] = d->ht[1];
             _dictReset(&d->ht[1]);
             d->rehashidx = -1;


@@ -217,6 +213,7 @@ int dictRehash(dict *d, int n) {
 
         /* Note that rehashidx can't overflow as we are sure there are more
          * elements because ht[0].used != 0 */
 
         /* Note that rehashidx can't overflow as we are sure there are more
          * elements because ht[0].used != 0 */

+        assert(d->ht[0].size > (unsigned)d->rehashidx);

         while(d->ht[0].table[d->rehashidx] == NULL) d->rehashidx++;
         de = d->ht[0].table[d->rehashidx];
         /* Move all the keys in this bucket from the old to the new hash HT */
         while(d->ht[0].table[d->rehashidx] == NULL) d->rehashidx++;
         de = d->ht[0].table[d->rehashidx];
         /* Move all the keys in this bucket from the old to the new hash HT */


@@ -258,9 +255,9 @@ int dictRehashMilliseconds(dict *d, int ms) {
 }
 
 /* This function performs just a step of rehashing, and only if there are
 }
 
 /* This function performs just a step of rehashing, and only if there are

- * not iterators bound to our hash table. When we have iterators in the middle
- * of a rehashing we can't mess with the two hash tables otherwise some element
- * can be missed or duplicated.
+ * no safe iterators bound to our hash table. When we have iterators in the
+ * middle of a rehashing we can't mess with the two hash tables otherwise
+ * some element can be missed or duplicated.

  *
  * This function is called by common lookup or update operations in the
  * dictionary so that the hash table automatically migrates from H1 to H2
  *
  * This function is called by common lookup or update operations in the
  * dictionary so that the hash table automatically migrates from H1 to H2


@@ -271,6 +268,30 @@ static void _dictRehashStep(dict *d) {
 
 /* Add an element to the target hash table */
 int dictAdd(dict *d, void *key, void *val)
 
 /* 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 expoed to 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;
 {
     int index;
     dictEntry *entry;


@@ -281,19 +302,18 @@ 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)
     /* 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;

 
 

-    /* Allocates the memory and stores key */
+    /* Allocate the memory and store the new entry */

     ht = dictIsRehashing(d) ? &d->ht[1] : &d->ht[0];
     ht = dictIsRehashing(d) ? &d->ht[1] : &d->ht[0];

-    entry = _dictAlloc(sizeof(*entry));
+    entry = zmalloc(sizeof(*entry));

     entry->next = ht->table[index];
     ht->table[index] = entry;
     ht->used++;
 
     /* Set the hash entry fields. */
     entry->next = ht->table[index];
     ht->table[index] = entry;
     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.
 }
 
 /* Add an element, discarding the old if the key already exists.


@@ -310,18 +330,29 @@ int dictReplace(dict *d, void *key, void *val)
         return 1;
     /* It already exists, get the entry */
     entry = dictFind(d, key);
         return 1;
     /* It already exists, get the entry */
     entry = dictFind(d, key);

-    /* Free the old value and set the new one */

     /* Set the new value and free the old one. Note that it is important
      * to do that in this order, as the value may just be exactly the same
      * as the previous one. In this context, think to reference counting,
      * you want to increment (set), and then decrement (free), and not the
      * reverse. */
     auxentry = *entry;
     /* Set the new value and free the old one. Note that it is important
      * to do that in this order, as the value may just be exactly the same
      * as the previous one. In this context, think to reference counting,
      * 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;
 }
 
     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)
 {
 /* Search and remove an element */
 static int dictGenericDelete(dict *d, const void *key, int nofree)
 {


@@ -338,17 +369,17 @@ static int dictGenericDelete(dict *d, const void *key, int nofree)
         he = d->ht[table].table[idx];
         prevHe = NULL;
         while(he) {
         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) {
                 /* 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);

                 }
                 }

-                _dictFree(he);
+                zfree(he);

                 d->ht[table].used--;
                 return DICT_OK;
             }
                 d->ht[table].used--;
                 return DICT_OK;
             }


@@ -380,15 +411,15 @@ int _dictClear(dict *d, dictht *ht)
         if ((he = ht->table[i]) == NULL) continue;
         while(he) {
             nextHe = he->next;
         if ((he = ht->table[i]) == NULL) continue;
         while(he) {
             nextHe = he->next;

-            dictFreeEntryKey(d, he);
-            dictFreeEntryVal(d, he);
-            _dictFree(he);
+            dictFreeKey(d, he);
+            dictFreeVal(d, he);
+            zfree(he);

             ht->used--;
             he = nextHe;
         }
     }
     /* Free the table and the allocated cache structure */
             ht->used--;
             he = nextHe;
         }
     }
     /* Free the table and the allocated cache structure */

-    _dictFree(ht->table);
+    zfree(ht->table);

     /* Re-initialize the table */
     _dictReset(ht);
     return DICT_OK; /* never fails */
     /* Re-initialize the table */
     _dictReset(ht);
     return DICT_OK; /* never fails */


@@ -399,7 +430,7 @@ void dictRelease(dict *d)
 {
     _dictClear(d,&d->ht[0]);
     _dictClear(d,&d->ht[1]);
 {
     _dictClear(d,&d->ht[0]);
     _dictClear(d,&d->ht[1]);

-    _dictFree(d);
+    zfree(d);

 }
 
 dictEntry *dictFind(dict *d, const void *key)
 }
 
 dictEntry *dictFind(dict *d, const void *key)


@@ -414,7 +445,7 @@ dictEntry *dictFind(dict *d, const void *key)
         idx = h & d->ht[table].sizemask;
         he = d->ht[table].table[idx];
         while(he) {
         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;
         }
                 return he;
             he = he->next;
         }


@@ -427,27 +458,36 @@ void *dictFetchValue(dict *d, const void *key) {
     dictEntry *he;
 
     he = dictFind(d,key);
     dictEntry *he;
 
     he = dictFind(d,key);

-    return he ? dictGetEntryVal(he) : NULL;
+    return he ? dictGetVal(he) : NULL;

 }
 
 dictIterator *dictGetIterator(dict *d)
 {
 }
 
 dictIterator *dictGetIterator(dict *d)
 {

-    dictIterator *iter = _dictAlloc(sizeof(*iter));
+    dictIterator *iter = zmalloc(sizeof(*iter));

 
     iter->d = d;
     iter->table = 0;
     iter->index = -1;
 
     iter->d = d;
     iter->table = 0;
     iter->index = -1;

+    iter->safe = 0;

     iter->entry = NULL;
     iter->nextEntry = NULL;
     return iter;
 }
 
     iter->entry = NULL;
     iter->nextEntry = NULL;
     return iter;
 }
 

+dictIterator *dictGetSafeIterator(dict *d) {
+    dictIterator *i = dictGetIterator(d);
+
+    i->safe = 1;
+    return i;
+}
+

 dictEntry *dictNext(dictIterator *iter)
 {
     while (1) {
         if (iter->entry == NULL) {
             dictht *ht = &iter->d->ht[iter->table];
 dictEntry *dictNext(dictIterator *iter)
 {
     while (1) {
         if (iter->entry == NULL) {
             dictht *ht = &iter->d->ht[iter->table];

-            if (iter->index == -1 && iter->table == 0) iter->d->iterators++;
+            if (iter->safe && iter->index == -1 && iter->table == 0)
+                iter->d->iterators++;

             iter->index++;
             if (iter->index >= (signed) ht->size) {
                 if (dictIsRehashing(iter->d) && iter->table == 0) {
             iter->index++;
             if (iter->index >= (signed) ht->size) {
                 if (dictIsRehashing(iter->d) && iter->table == 0) {


@@ -474,8 +514,9 @@ dictEntry *dictNext(dictIterator *iter)
 
 void dictReleaseIterator(dictIterator *iter)
 {
 
 void dictReleaseIterator(dictIterator *iter)
 {

-    if (!(iter->index == -1 && iter->table == 0)) iter->d->iterators--;
-    _dictFree(iter);
+    if (iter->safe && !(iter->index == -1 && iter->table == 0))
+        iter->d->iterators--;
+    zfree(iter);

 }
 
 /* Return a random entry from the hash table. Useful to
 }
 
 /* Return a random entry from the hash table. Useful to


@@ -522,14 +563,23 @@ dictEntry *dictGetRandomKey(dict *d)
 /* Expand the hash table if needed */
 static int _dictExpandIfNeeded(dict *d)
 {
 /* Expand the hash table if needed */
 static int _dictExpandIfNeeded(dict *d)
 {

-    /* If the hash table is empty expand it to the intial size,
-     * if the table is "full" dobule its size. */
+    /* Incremental rehashing already in progress. Return. */

     if (dictIsRehashing(d)) return DICT_OK;
     if (dictIsRehashing(d)) return DICT_OK;

-    if (d->ht[0].size == 0)
-        return dictExpand(d, DICT_HT_INITIAL_SIZE);
-    if (d->ht[0].used >= d->ht[0].size && dict_can_resize)
+
+    /* If the hash table is empty expand it to the intial size. */
+    if (d->ht[0].size == 0) return dictExpand(d, DICT_HT_INITIAL_SIZE);
+
+    /* If we reached the 1:1 ratio, and we are allowed to resize the hash
+     * table (global setting) or we should avoid it but the ratio between
+     * elements/buckets is over the "safe" threshold, we resize doubling
+     * the number of buckets. */
+    if (d->ht[0].used >= d->ht[0].size &&
+        (dict_can_resize ||
+         d->ht[0].used/d->ht[0].size > dict_force_resize_ratio))
+    {

         return dictExpand(d, ((d->ht[0].size > d->ht[0].used) ?
                                     d->ht[0].size : d->ht[0].used)*2);
         return dictExpand(d, ((d->ht[0].size > d->ht[0].used) ?
                                     d->ht[0].size : d->ht[0].used)*2);

+    }

     return DICT_OK;
 }
 
     return DICT_OK;
 }
 


@@ -567,7 +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) {
         /* 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;
         }
                 return -1;
             he = he->next;
         }


@@ -583,6 +633,21 @@ void dictEmpty(dict *d) {
     d->iterators = 0;
 }
 
     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;
 #define DICT_STATS_VECTLEN 50
 static void _dictPrintStatsHt(dictht *ht) {
     unsigned long i, slots = 0, chainlen, maxchainlen = 0;


@@ -636,14 +701,6 @@ void dictPrintStats(dict *d) {
     }
 }
 
     }
 }
 

-void dictEnableResize(void) {
-    dict_can_resize = 1;
-}
-
-void dictDisableResize(void) {
-    dict_can_resize = 0;
-}
-

 /* ----------------------- StringCopy Hash Table Type ------------------------*/
 
 static unsigned int _dictStringCopyHTHashFunction(const void *key)
 /* ----------------------- StringCopy Hash Table Type ------------------------*/
 
 static unsigned int _dictStringCopyHTHashFunction(const void *key)


@@ -654,7 +711,7 @@ static unsigned int _dictStringCopyHTHashFunction(const void *key)
 static void *_dictStringDup(void *privdata, const void *key)
 {
     int len = strlen(key);
 static void *_dictStringDup(void *privdata, const void *key)
 {
     int len = strlen(key);

-    char *copy = _dictAlloc(len+1);
+    char *copy = zmalloc(len+1);

     DICT_NOTUSED(privdata);
 
     memcpy(copy, key, len);
     DICT_NOTUSED(privdata);
 
     memcpy(copy, key, len);


@@ -674,7 +731,7 @@ static void _dictStringDestructor(void *privdata, void *key)
 {
     DICT_NOTUSED(privdata);
 
 {
     DICT_NOTUSED(privdata);
 

-    _dictFree(key);
+    zfree(key);

 }
 
 dictType dictTypeHeapStringCopyKey = {
 }
 
 dictType dictTypeHeapStringCopyKey = {


@@ -707,3 +764,4 @@ dictType dictTypeHeapStringCopyKeyValue = {
     _dictStringDestructor,         /* key destructor */
     _dictStringDestructor,         /* val destructor */
 };
     _dictStringDestructor,         /* key destructor */
     _dictStringDestructor,         /* val destructor */
 };

+#endif