+/* Test if the key exists in the given hash. Returns 1 if the key
+ * exists and 0 when it doesn't. */
+static int hashExists(robj *o, robj *key) {
+ if (o->encoding == REDIS_ENCODING_ZIPMAP) {
+ key = getDecodedObject(key);
+ if (zipmapExists(o->ptr,key->ptr,sdslen(key->ptr))) {
+ decrRefCount(key);
+ return 1;
+ }
+ decrRefCount(key);
+ } else {
+ if (dictFind(o->ptr,key) != NULL) {
+ return 1;
+ }
+ }
+ return 0;
+}
+
+/* Add an element, discard the old if the key already exists.
+ * Return 0 on insert and 1 on update. */
+static int hashSet(robj *o, robj *key, robj *value) {
+ int update = 0;
+ if (o->encoding == REDIS_ENCODING_ZIPMAP) {
+ key = getDecodedObject(key);
+ value = getDecodedObject(value);
+ o->ptr = zipmapSet(o->ptr,
+ key->ptr,sdslen(key->ptr),
+ value->ptr,sdslen(value->ptr), &update);
+ decrRefCount(key);
+ decrRefCount(value);
+
+ /* Check if the zipmap needs to be upgraded to a real hash table */
+ if (zipmapLen(o->ptr) > server.hash_max_zipmap_entries)
+ convertToRealHash(o);
+ } else {
+ if (dictReplace(o->ptr,key,value)) {
+ /* Insert */
+ incrRefCount(key);
+ } else {
+ /* Update */
+ update = 1;
+ }
+ incrRefCount(value);
+ }
+ return update;
+}
+
+/* Delete an element from a hash.
+ * Return 1 on deleted and 0 on not found. */
+static int hashDelete(robj *o, robj *key) {
+ int deleted = 0;
+ if (o->encoding == REDIS_ENCODING_ZIPMAP) {
+ key = getDecodedObject(key);
+ o->ptr = zipmapDel(o->ptr,key->ptr,sdslen(key->ptr), &deleted);
+ decrRefCount(key);
+ } else {
+ deleted = dictDelete((dict*)o->ptr,key) == DICT_OK;
+ /* Always check if the dictionary needs a resize after a delete. */
+ if (deleted && htNeedsResize(o->ptr)) dictResize(o->ptr);
+ }
+ return deleted;
+}
+
+/* Return the number of elements in a hash. */
+static unsigned long hashLength(robj *o) {
+ return (o->encoding == REDIS_ENCODING_ZIPMAP) ?
+ zipmapLen((unsigned char*)o->ptr) : dictSize((dict*)o->ptr);
+}
+
+/* Structure to hold hash iteration abstration. Note that iteration over
+ * hashes involves both fields and values. Because it is possible that
+ * not both are required, store pointers in the iterator to avoid
+ * unnecessary memory allocation for fields/values. */
+typedef struct {
+ int encoding;
+ unsigned char *zi;
+ unsigned char *zk, *zv;
+ unsigned int zklen, zvlen;
+
+ dictIterator *di;
+ dictEntry *de;
+} hashIterator;
+
+static hashIterator *hashInitIterator(robj *subject) {
+ hashIterator *hi = zmalloc(sizeof(hashIterator));
+ hi->encoding = subject->encoding;
+ if (hi->encoding == REDIS_ENCODING_ZIPMAP) {
+ hi->zi = zipmapRewind(subject->ptr);
+ } else if (hi->encoding == REDIS_ENCODING_HT) {
+ hi->di = dictGetIterator(subject->ptr);
+ } else {
+ redisAssert(NULL);
+ }
+ return hi;
+}
+
+static void hashReleaseIterator(hashIterator *hi) {
+ if (hi->encoding == REDIS_ENCODING_HT) {
+ dictReleaseIterator(hi->di);
+ }
+ zfree(hi);
+}