Replace dict with hashtable in kvstore and db

* Add functions for embedding key and expire in robj (object.c)
  * Always embed key in robj
  * Embed expire in robj, only if needed or if there is unused space in the allocation
* Update db functions (db.c)
  * dbAdd, setKey and setExpire return the reallocated object with embedded key
  * setKey does not increment the reference counter, since it would require
    duplicating the object
  * Handle dbAdd and dbReplaceValue return value
* Replace dict in kvstore
* defrag
* Fix some things including MOVE, RENAME commands
* Fix test case "expire scan should skip dictionaries with lot's of empty buckets"
* Fix resize allowed maxmemory check
* Fix kvstore unit tests
* Fix maxmemory test (increase size)
* Delete test cases about shared integers
* Scan single step in active expire
* Seed hashtable hash function on startup
* Set resize policy when a fork is active, and fix test case
* Fix rehashing test case in unit/info suite
* Fix more resize test cases in unit/other
* Fix scan testcases not expecting duplicates
* Another run at the unit/expire test suite
* Fix typo in defrag pubsub channels
* Make dbAddRDBLoad return the (maybe reallocated) object
* Add unit test file test_object.c
* Account for scan duplicates in valkey-cli test
* Optimize INCR (can't use shared object)
* Remove code for shared integer objects (When key is embedded in object, all
  objects in the database need to be unique so we can't use shared objects as
  values.)

Signed-off-by: Viktor Söderqvist <viktor.soderqvist@est.tech>

src/aof.c

@@ -2190,7 +2190,7 @@ static int rewriteFunctions(rio *aof) {
 }
 
 int rewriteAppendOnlyFileRio(rio *aof) {
-    dictEntry *de;
+    valkey *o;
     int j;
     long key_count = 0;
     long long updated_time = 0;
@@ -2219,17 +2219,16 @@ int rewriteAppendOnlyFileRio(rio *aof) {
 
         kvs_it = kvstoreIteratorInit(db->keys);
         /* Iterate this DB writing every entry */
-        while ((de = kvstoreIteratorNext(kvs_it)) != NULL) {
+        while (kvstoreIteratorNext(kvs_it, (void **)&o)) {
             sds keystr;
-            robj key, *o;
+            robj key;
             long long expiretime;
             size_t aof_bytes_before_key = aof->processed_bytes;
 
-            keystr = dictGetKey(de);
-            o = dictGetVal(de);
+            keystr = objectGetKey(o);
             initStaticStringObject(key, keystr);
 
-            expiretime = getExpire(db, &key);
+            expiretime = objectGetExpire(o);
 
             /* Save the key and associated value */
             if (o->type == OBJ_STRING) {

src/bitops.c

@@ -486,7 +486,7 @@ robj *lookupStringForBitCommand(client *c, uint64_t maxbit, int *dirty) {
 
     if (o == NULL) {
         o = createObject(OBJ_STRING, sdsnewlen(NULL, byte + 1));
-        dbAdd(c->db, c->argv[1], o);
+        o = dbAdd(c->db, c->argv[1], o);
         if (dirty) *dirty = 1;
     } else {
         o = dbUnshareStringValue(c->db, c->argv[1], o);
@@ -772,9 +772,8 @@ void bitopCommand(client *c) {
     /* Store the computed value into the target key */
     if (maxlen) {
         o = createObject(OBJ_STRING, res);
-        setKey(c, c->db, targetkey, o, 0);
+        o = setKey(c, c->db, targetkey, o, 0);
         notifyKeyspaceEvent(NOTIFY_STRING, "set", targetkey, c->db->id);
-        decrRefCount(o);
         server.dirty++;
     } else if (dbDelete(c->db, targetkey)) {
         signalModifiedKey(c, c->db, targetkey);

src/cluster.c

@@ -276,9 +276,9 @@ void restoreCommand(client *c) {
     }
 
     /* Create the key and set the TTL if any */
-    dbAdd(c->db, key, obj);
+    obj = dbAdd(c->db, key, obj);
     if (ttl) {
-        setExpire(c, c->db, key, ttl);
+        obj = setExpire(c, c->db, key, ttl);
         if (!absttl) {
             /* Propagate TTL as absolute timestamp */
             robj *ttl_obj = createStringObjectFromLongLong(ttl);
@@ -811,7 +811,7 @@ static int shouldReturnTlsInfo(void) {
 }
 
 unsigned int countKeysInSlot(unsigned int slot) {
-    return kvstoreDictSize(server.db->keys, slot);
+    return kvstoreHashtableSize(server.db->keys, slot);
 }
 
 void clusterCommandHelp(client *c) {
@@ -908,16 +908,15 @@ void clusterCommand(client *c) {
         unsigned int keys_in_slot = countKeysInSlot(slot);
         unsigned int numkeys = maxkeys > keys_in_slot ? keys_in_slot : maxkeys;
         addReplyArrayLen(c, numkeys);
-        kvstoreDictIterator *kvs_di = NULL;
-        dictEntry *de = NULL;
-        kvs_di = kvstoreGetDictIterator(server.db->keys, slot);
+        kvstoreHashtableIterator *kvs_di = NULL;
+        valkey *valkey = NULL;
+        kvs_di = kvstoreGetHashtableIterator(server.db->keys, slot);
         for (unsigned int i = 0; i < numkeys; i++) {
-            de = kvstoreDictIteratorNext(kvs_di);
-            serverAssert(de != NULL);
-            sds sdskey = dictGetKey(de);
+            serverAssert(kvstoreHashtableIteratorNext(kvs_di, (void **)&valkey));
+            sds sdskey = objectGetKey(valkey);
             addReplyBulkCBuffer(c, sdskey, sdslen(sdskey));
         }
-        kvstoreReleaseDictIterator(kvs_di);
+        kvstoreReleaseHashtableIterator(kvs_di);
     } else if ((!strcasecmp(c->argv[1]->ptr, "slaves") || !strcasecmp(c->argv[1]->ptr, "replicas")) && c->argc == 3) {
         /* CLUSTER REPLICAS <NODE ID> */
         clusterNode *n = clusterLookupNode(c->argv[2]->ptr, sdslen(c->argv[2]->ptr));

src/cluster_legacy.c

@@ -6094,12 +6094,12 @@ unsigned int delKeysInSlot(unsigned int hashslot) {
     server.server_del_keys_in_slot = 1;
     unsigned int j = 0;
 
-    kvstoreDictIterator *kvs_di = NULL;
-    dictEntry *de = NULL;
-    kvs_di = kvstoreGetDictSafeIterator(server.db->keys, hashslot);
-    while ((de = kvstoreDictIteratorNext(kvs_di)) != NULL) {
+    kvstoreHashtableIterator *kvs_di = NULL;
+    valkey *valkey = NULL;
+    kvs_di = kvstoreGetHashtableSafeIterator(server.db->keys, hashslot);
+    while (kvstoreHashtableIteratorNext(kvs_di, (void **)&valkey)) {
         enterExecutionUnit(1, 0);
-        sds sdskey = dictGetKey(de);
+        sds sdskey = objectGetKey(valkey);
         robj *key = createStringObject(sdskey, sdslen(sdskey));
         dbDelete(&server.db[0], key);
         propagateDeletion(&server.db[0], key, server.lazyfree_lazy_server_del);
@@ -6114,7 +6114,7 @@ unsigned int delKeysInSlot(unsigned int hashslot) {
         j++;
         server.dirty++;
     }
-    kvstoreReleaseDictIterator(kvs_di);
+    kvstoreReleaseHashtableIterator(kvs_di);
 
     server.server_del_keys_in_slot = 0;
     serverAssert(server.execution_nesting == 0);
@@ -6123,7 +6123,7 @@ unsigned int delKeysInSlot(unsigned int hashslot) {
 
 /* Get the count of the channels for a given slot. */
 unsigned int countChannelsInSlot(unsigned int hashslot) {
-    return kvstoreDictSize(server.pubsubshard_channels, hashslot);
+    return kvstoreHashtableSize(server.pubsubshard_channels, hashslot);
 }
 
 clusterNode *getMyClusterNode(void) {