Tracking: optin/out implemented.

src/networking.c

@@ -1365,6 +1365,12 @@ void resetClient(client *c) {
     if (!(c->flags & CLIENT_MULTI) && prevcmd != askingCommand)
         c->flags &= ~CLIENT_ASKING;
 
+    /* We do the same for the CACHING command as well. It also affects
+     * the next command or transaction executed, in a way very similar
+     * to ASKING. */
+    if (!(c->flags & CLIENT_MULTI) && prevcmd != clientCommand)
+        c->flags &= ~CLIENT_TRACKING_CACHING;
+
     /* Remove the CLIENT_REPLY_SKIP flag if any so that the reply
      * to the next command will be sent, but set the flag if the command
      * we just processed was "CLIENT REPLY SKIP". */
@@ -2044,7 +2050,7 @@ void clientCommand(client *c) {
 "REPLY (on|off|skip)    -- Control the replies sent to the current connection.",
 "SETNAME <name>         -- Assign the name <name> to the current connection.",
 "UNBLOCK <clientid> [TIMEOUT|ERROR] -- Unblock the specified blocked client.",
-"TRACKING (on|off) [REDIRECT <id>] [BCAST] [PREFIX first] [PREFIX second] ... -- Enable client keys tracking for client side caching.",
+"TRACKING (on|off) [REDIRECT <id>] [BCAST] [PREFIX first] [PREFIX second] [OPTIN] [OPTOUT]... -- Enable client keys tracking for client side caching.",
 "GETREDIR               -- Return the client ID we are redirecting to when tracking is enabled.",
 NULL
         };
@@ -2221,9 +2227,9 @@ NULL
         addReply(c,shared.ok);
     } else if (!strcasecmp(c->argv[1]->ptr,"tracking") && c->argc >= 3) {
         /* CLIENT TRACKING (on|off) [REDIRECT <id>] [BCAST] [PREFIX first]
-         *                          [PREFIX second] ... */
+         *                          [PREFIX second] [OPTIN] [OPTOUT] ... */
         long long redir = 0;
-        int bcast = 0;
+        uint64_t options = 0;
         robj **prefix = NULL;
         size_t numprefix = 0;
 
@@ -2256,7 +2262,11 @@ NULL
                     return;
                 }
             } else if (!strcasecmp(c->argv[j]->ptr,"bcast")) {
-                bcast = 1;
+                options |= CLIENT_TRACKING_BCAST;
+            } else if (!strcasecmp(c->argv[j]->ptr,"optin")) {
+                options |= CLIENT_TRACKING_OPTIN;
+            } else if (!strcasecmp(c->argv[j]->ptr,"optout")) {
+                options |= CLIENT_TRACKING_OPTOUT;
             } else if (!strcasecmp(c->argv[j]->ptr,"prefix") && moreargs) {
                 j++;
                 prefix = zrealloc(prefix,sizeof(robj*)*(numprefix+1));
@@ -2272,7 +2282,7 @@ NULL
         if (!strcasecmp(c->argv[2]->ptr,"on")) {
             /* Before enabling tracking, make sure options are compatible
              * among each other and with the current state of the client. */
-            if (!bcast && numprefix) {
+            if (!(options & CLIENT_TRACKING_BCAST) && numprefix) {
                 addReplyError(c,
                     "PREFIX option requires BCAST mode to be enabled");
                 zfree(prefix);
@@ -2281,7 +2291,8 @@ NULL
 
             if (c->flags & CLIENT_TRACKING) {
                 int oldbcast = !!(c->flags & CLIENT_TRACKING_BCAST);
-                if (oldbcast != bcast) {
+                int newbcast = !!(options & CLIENT_TRACKING_BCAST);
+                if (oldbcast != newbcast) {
                     addReplyError(c,
                     "You can't switch BCAST mode on/off before disabling "
                     "tracking for this client, and then re-enabling it with "
@@ -2290,7 +2301,17 @@ NULL
                     return;
                 }
             }
-            enableTracking(c,redir,bcast,prefix,numprefix);
+
+            if (options & CLIENT_TRACKING_BCAST &&
+                options & (CLIENT_TRACKING_OPTIN|CLIENT_TRACKING_OPTOUT))
+            {
+                addReplyError(c,
+                "OPTIN and OPTOUT are not compatible with BCAST");
+                zfree(prefix);
+                return;
+            }
+
+            enableTracking(c,redir,options,prefix,numprefix);
         } else if (!strcasecmp(c->argv[2]->ptr,"off")) {
             disableTracking(c);
         } else {
@@ -2300,6 +2321,36 @@ NULL
         }
         zfree(prefix);
         addReply(c,shared.ok);
+    } else if (!strcasecmp(c->argv[1]->ptr,"caching") && c->argc >= 3) {
+        if (!(c->flags & CLIENT_TRACKING)) {
+            addReplyError(c,"CLIENT CACHING can be called only when the "
+                            "client is in tracking mode with OPTIN or "
+                            "OPTOUT mode enabled");
+            return;
+        }
+
+        char *opt = c->argv[2]->ptr;
+        if (!strcasecmp(opt,"yes")) {
+            if (c->flags & CLIENT_TRACKING_OPTIN) {
+                c->flags |= CLIENT_TRACKING_CACHING;
+            } else {
+                addReplyError(c,"CLIENT CACHING YES is only valid when tracking is enabled in OPTIN mode.");
+                return;
+            }
+        } else if (!strcasecmp(opt,"no")) {
+            if (c->flags & CLIENT_TRACKING_OPTOUT) {
+                c->flags |= CLIENT_TRACKING_CACHING;
+            } else {
+                addReplyError(c,"CLIENT CACHING NO is only valid when tracking is enabled in OPTOUT mode.");
+                return;
+            }
+        } else {
+            addReply(c,shared.syntaxerr);
+            return;
+        }
+
+        /* Common reply for when we succeeded. */
+        addReply(c,shared.ok);
     } else if (!strcasecmp(c->argv[1]->ptr,"getredir") && c->argc == 2) {
         /* CLIENT GETREDIR */
         if (c->flags & CLIENT_TRACKING) {

src/server.h

@@ -248,6 +248,10 @@ typedef long long ustime_t; /* microsecond time type. */
                                    perform client side caching. */
 #define CLIENT_TRACKING_BROKEN_REDIR (1ULL<<32) /* Target client is invalid. */
 #define CLIENT_TRACKING_BCAST (1ULL<<33) /* Tracking in BCAST mode. */
+#define CLIENT_TRACKING_OPTIN (1ULL<<34)  /* Tracking in opt-in mode. */
+#define CLIENT_TRACKING_OPTOUT (1ULL<<35) /* Tracking in opt-out mode. */
+#define CLIENT_TRACKING_CACHING (1ULL<<36) /* CACHING yes/no was given,
+                                              depending on optin/optout mode. */
 
 /* Client block type (btype field in client structure)
  * if CLIENT_BLOCKED flag is set. */
@@ -1651,7 +1655,7 @@ void addReplyStatusFormat(client *c, const char *fmt, ...);
 #endif
 
 /* Client side caching (tracking mode) */
-void enableTracking(client *c, uint64_t redirect_to, int bcast, robj **prefix, size_t numprefix);
+void enableTracking(client *c, uint64_t redirect_to, uint64_t options, robj **prefix, size_t numprefix);
 void disableTracking(client *c);
 void trackingRememberKeys(client *c);
 void trackingInvalidateKey(robj *keyobj);

src/tracking.c

@@ -93,7 +93,8 @@ void disableTracking(client *c) {
     if (c->flags & CLIENT_TRACKING) {
         server.tracking_clients--;
         c->flags &= ~(CLIENT_TRACKING|CLIENT_TRACKING_BROKEN_REDIR|
-                      CLIENT_TRACKING_BCAST);
+                      CLIENT_TRACKING_BCAST|CLIENT_TRACKING_OPTIN|
+                      CLIENT_TRACKING_OPTOUT);
     }
 }
 
@@ -124,10 +125,11 @@ void enableBcastTrackingForPrefix(client *c, char *prefix, size_t plen) {
  * eventually get freed, we'll send a message to the original client to
  * inform it of the condition. Multiple clients can redirect the invalidation
  * messages to the same client ID. */
-void enableTracking(client *c, uint64_t redirect_to, int bcast, robj **prefix, size_t numprefix) {
+void enableTracking(client *c, uint64_t redirect_to, uint64_t options, robj **prefix, size_t numprefix) {
     if (!(c->flags & CLIENT_TRACKING)) server.tracking_clients++;
     c->flags |= CLIENT_TRACKING;
-    c->flags &= ~(CLIENT_TRACKING_BROKEN_REDIR|CLIENT_TRACKING_BCAST);
+    c->flags &= ~(CLIENT_TRACKING_BROKEN_REDIR|CLIENT_TRACKING_BCAST|
+                  CLIENT_TRACKING_OPTIN|CLIENT_TRACKING_OPTOUT);
     c->client_tracking_redirection = redirect_to;
     if (TrackingTable == NULL) {
         TrackingTable = raxNew();
@@ -135,7 +137,7 @@ void enableTracking(client *c, uint64_t redirect_to, int bcast, robj **prefix, s
         TrackingChannelName = createStringObject("__redis__:invalidate",20);
     }
 
-    if (bcast) {
+    if (options & CLIENT_TRACKING_BCAST) {
         c->flags |= CLIENT_TRACKING_BCAST;
         if (numprefix == 0) enableBcastTrackingForPrefix(c,"",0);
         for (size_t j = 0; j < numprefix; j++) {
@@ -143,14 +145,23 @@ void enableTracking(client *c, uint64_t redirect_to, int bcast, robj **prefix, s
             enableBcastTrackingForPrefix(c,sdsprefix,sdslen(sdsprefix));
         }
     }
+    c->flags |= options & (CLIENT_TRACKING_OPTIN|CLIENT_TRACKING_OPTOUT);
 }
 
 /* This function is called after the execution of a readonly command in the
- * case the client 'c' has keys tracking enabled. It will populate the
- * tracking invalidation table according to the keys the user fetched, so that
- * Redis will know what are the clients that should receive an invalidation
- * message with certain groups of keys are modified. */
+ * case the client 'c' has keys tracking enabled and the tracking is not
+ * in BCAST mode. It will populate the tracking invalidation table according
+ * to the keys the user fetched, so that Redis will know what are the clients
+ * that should receive an invalidation message with certain groups of keys
+ * are modified. */
 void trackingRememberKeys(client *c) {
+    /* Return if we are in optin/out mode and the right CACHING command
+     * was/wasn't given in order to modify the default behavior. */
+    uint64_t optin = c->flags & CLIENT_TRACKING_OPTIN;
+    uint64_t optout = c->flags & CLIENT_TRACKING_OPTOUT;
+    uint64_t caching_given = c->flags & CLIENT_TRACKING_CACHING;
+    if ((optin && !caching_given) || (optout && caching_given)) return;
+
     int numkeys;
     int *keys = getKeysFromCommand(c->cmd,c->argv,c->argc,&numkeys);
     if (keys == NULL) return;