+/* =========================== Keyspace access API ========================== */
+
+static robj *lookupKey(redisDb *db, robj *key) {
+ dictEntry *de = dictFind(db->dict,key->ptr);
+ if (de) {
+ robj *val = dictGetEntryVal(de);
+
+ if (server.vm_enabled) {
+ if (val->storage == REDIS_VM_MEMORY ||
+ val->storage == REDIS_VM_SWAPPING)
+ {
+ /* If we were swapping the object out, cancel the operation */
+ if (val->storage == REDIS_VM_SWAPPING)
+ vmCancelThreadedIOJob(val);
+ /* Update the access time for the aging algorithm. */
+ val->lru = server.lruclock;
+ } else {
+ int notify = (val->storage == REDIS_VM_LOADING);
+
+ /* Our value was swapped on disk. Bring it at home. */
+ redisAssert(val->type == REDIS_VMPOINTER);
+ val = vmLoadObject(val);
+ dictGetEntryVal(de) = val;
+
+ /* Clients blocked by the VM subsystem may be waiting for
+ * this key... */
+ if (notify) handleClientsBlockedOnSwappedKey(db,key);
+ }
+ }
+ return val;
+ } else {
+ return NULL;
+ }
+}
+
+static robj *lookupKeyRead(redisDb *db, robj *key) {
+ expireIfNeeded(db,key);
+ return lookupKey(db,key);
+}
+
+static robj *lookupKeyWrite(redisDb *db, robj *key) {
+ deleteIfVolatile(db,key);
+ touchWatchedKey(db,key);
+ return lookupKey(db,key);
+}
+
+static robj *lookupKeyReadOrReply(redisClient *c, robj *key, robj *reply) {
+ robj *o = lookupKeyRead(c->db, key);
+ if (!o) addReply(c,reply);
+ return o;
+}
+
+static robj *lookupKeyWriteOrReply(redisClient *c, robj *key, robj *reply) {
+ robj *o = lookupKeyWrite(c->db, key);
+ if (!o) addReply(c,reply);
+ return o;
+}
+
+/* Add the key to the DB. If the key already exists REDIS_ERR is returned,
+ * otherwise REDIS_OK is returned, and the caller should increment the
+ * refcount of 'val'. */
+static int dbAdd(redisDb *db, robj *key, robj *val) {
+ /* Perform a lookup before adding the key, as we need to copy the
+ * key value. */
+ if (dictFind(db->dict, key->ptr) != NULL) {
+ return REDIS_ERR;
+ } else {
+ sds copy = sdsdup(key->ptr);
+ dictAdd(db->dict, copy, val);
+ return REDIS_OK;
+ }
+}
+
+/* If the key does not exist, this is just like dbAdd(). Otherwise
+ * the value associated to the key is replaced with the new one.
+ *
+ * On update (key already existed) 0 is returned. Otherwise 1. */
+static int dbReplace(redisDb *db, robj *key, robj *val) {
+ if (dictFind(db->dict,key->ptr) == NULL) {
+ sds copy = sdsdup(key->ptr);
+ dictAdd(db->dict, copy, val);
+ return 1;
+ } else {
+ dictReplace(db->dict, key->ptr, val);
+ return 0;
+ }
+}
+
+static int dbExists(redisDb *db, robj *key) {
+ return dictFind(db->dict,key->ptr) != NULL;
+}
+
+/* Return a random key, in form of a Redis object.
+ * If there are no keys, NULL is returned.
+ *
+ * The function makes sure to return keys not already expired. */
+static robj *dbRandomKey(redisDb *db) {
+ struct dictEntry *de;
+
+ while(1) {
+ sds key;
+ robj *keyobj;
+
+ de = dictGetRandomKey(db->dict);
+ if (de == NULL) return NULL;
+
+ key = dictGetEntryKey(de);
+ keyobj = createStringObject(key,sdslen(key));
+ if (dictFind(db->expires,key)) {
+ if (expireIfNeeded(db,keyobj)) {
+ decrRefCount(keyobj);
+ continue; /* search for another key. This expired. */
+ }
+ }
+ return keyobj;
+ }
+}
+
+/* Delete a key, value, and associated expiration entry if any, from the DB */
+static int dbDelete(redisDb *db, robj *key) {
+ /* Deleting an entry from the expires dict will not free the sds of
+ * the key, because it is shared with the main dictionary. */
+ if (dictSize(db->expires) > 0) dictDelete(db->expires,key->ptr);
+ return dictDelete(db->dict,key->ptr) == DICT_OK;
+}
+
projects / redis.git / blobdiff