+
+/* This function returns the number of bytes that Redis is virtually
+ * using to store the reply still not read by the client.
+ * It is "virtual" since the reply output list may contain objects that
+ * are shared and are not really using additional memory.
+ *
+ * The function returns the total sum of the length of all the objects
+ * stored in the output list, plus the memory used to allocate every
+ * list node. The static reply buffer is not taken into account since it
+ * is allocated anyway.
+ *
+ * Note: this function is very fast so can be called as many time as
+ * the caller wishes. The main usage of this function currently is
+ * enforcing the client output lenght limits. */
+unsigned long getClientOutputBufferMemoryUsage(redisClient *c) {
+ unsigned long list_item_size = sizeof(listNode);
+
+ return c->reply_bytes + (list_item_size*listLength(c->reply));
+}
+
+/* Get the class of a client, used in order to envorce limits to different
+ * classes of clients.
+ *
+ * The function will return one of the following:
+ * REDIS_CLIENT_LIMIT_CLASS_NORMAL -> Normal client
+ * REDIS_CLIENT_LIMIT_CLASS_SLAVE -> Slave or client executing MONITOR command
+ * REDIS_CLIENT_LIMIT_CLASS_PUBSUB -> Client subscribed to Pub/Sub channels
+ */
+int getClientLimitClass(redisClient *c) {
+ if (c->flags & REDIS_SLAVE) return REDIS_CLIENT_LIMIT_CLASS_SLAVE;
+ if (dictSize(c->pubsub_channels) || listLength(c->pubsub_patterns))
+ return REDIS_CLIENT_LIMIT_CLASS_PUBSUB;
+ return REDIS_CLIENT_LIMIT_CLASS_NORMAL;
+}
+
+/* The function checks if the client reached output buffer soft or hard
+ * limit, and also update the state needed to check the soft limit as
+ * a side effect.
+ *
+ * Return value: non-zero if the client reached the soft or the hard limit.
+ * Otherwise zero is returned. */
+int checkClientOutputBufferLimits(redisClient *c) {
+ int soft = 0, hard = 0, class;
+ unsigned long used_mem = getClientOutputBufferMemoryUsage(c);
+
+ class = getClientLimitClass(c);
+ if (server.client_obuf_limits[class].hard_limit_bytes &&
+ used_mem >= server.client_obuf_limits[class].hard_limit_bytes)
+ hard = 1;
+ if (server.client_obuf_limits[class].soft_limit_bytes &&
+ used_mem >= server.client_obuf_limits[class].soft_limit_bytes)
+ soft = 1;
+
+ /* We need to check if the soft limit is reached continuously for the
+ * specified amount of seconds. */
+ if (soft) {
+ if (c->obuf_soft_limit_reached_time == 0) {
+ c->obuf_soft_limit_reached_time = server.unixtime;
+ soft = 0; /* First time we see the soft limit reached */
+ } else {
+ time_t elapsed = server.unixtime - c->obuf_soft_limit_reached_time;
+
+ if (elapsed <=
+ server.client_obuf_limits[class].soft_limit_seconds) {
+ soft = 0; /* The client still did not reached the max number of
+ seconds for the soft limit to be considered
+ reached. */
+ }
+ }
+ } else {
+ c->obuf_soft_limit_reached_time = 0;
+ }
+ return soft || hard;
+}
+
+/* Asynchronously close a client if soft or hard limit is reached on the
+ * output buffer size. The caller can check if the client will be closed
+ * checking if the client REDIS_CLOSE_ASAP flag is set.
+ *
+ * Note: we need to close the client asynchronously because this function is
+ * called from contexts where the client can't be freed safely, i.e. from the
+ * lower level functions pushing data inside the client output buffers. */
+void asyncCloseClientOnOutputBufferLimitReached(redisClient *c) {
+ if (c->flags & REDIS_CLOSE_ASAP) return;
+ if (checkClientOutputBufferLimits(c)) {
+ sds client = getClientInfoString(c);
+
+ freeClientAsync(c);
+ redisLog(REDIS_NOTICE,"Client %s scheduled to be closed ASAP for overcoming of output buffer limits.", client);
+ sdsfree(client);
+ }
+}
projects / redis.git / blobdiff