[fix] add swap info propagate mode

1. original mode of swap info propagating only includes swap.info mode, which depends on X-pipe.
2. this commit extends ping argv for propagating swap info, which do not depend on any other component.

src/config.c

@@ -163,6 +163,12 @@ configEnum swap_info_supported_enum[] = {
     {NULL, 0}
 };
 
+configEnum swap_info_propagate_mode_enum[] = {
+ {"ping", SWAP_INFO_PROPAGATE_BY_PING},
+ {"swap.info", SWAP_INFO_PROPAGATE_BY_SWAP_INFO},
+ {NULL, 0}
+};
+
 /* Output buffer limits presets. */
 clientBufferLimitsConfig clientBufferLimitsDefaults[CLIENT_TYPE_OBUF_COUNT] = {
     {0, 0, 0}, /* normal */
@@ -2947,6 +2953,7 @@ standardConfig configs[] = {
     createEnumConfig("swap-cuckoo-filter-bit-per-key", NULL, IMMUTABLE_CONFIG, cuckoo_filter_bit_type_enum, server.swap_cuckoo_filter_bit_type, CUCKOO_FILTER_BITS_PER_TAG_8, NULL, NULL),
     createEnumConfig("swap-ratelimit-policy", NULL, MODIFIABLE_CONFIG, swap_ratelimit_policy_enum, server.swap_ratelimit_policy, SWAP_RATELIMIT_POLICY_PAUSE, NULL, NULL),
     createEnumConfig("swap-swap-info-supported", NULL, MODIFIABLE_CONFIG, swap_info_supported_enum, server.swap_swap_info_supported, SWAP_INFO_SUPPORTED_AUTO, NULL, NULL),
+    createEnumConfig("swap-swap-info-propagate-mode", NULL, MODIFIABLE_CONFIG, swap_info_propagate_mode_enum, server.swap_swap_info_propagate_mode, SWAP_INFO_PROPAGATE_BY_PING, NULL, NULL),
 
     /* Integer configs */
     createIntConfig("databases", NULL, IMMUTABLE_CONFIG, 1, INT_MAX, server.dbnum, 16, INTEGER_CONFIG, NULL, NULL),

src/ctrip_swap.c

@@ -788,6 +788,7 @@ int swapTest(int argc, char **argv, int accurate) {
   result += swapRordbTest(argc, argv, accurate);
   result += swapDataBitmapTest(argc, argv, accurate);
   result += wtdigestTest(argc, argv, accurate);
+  result += swapReplTest(argc, argv, accurate);
   return result;
 }
 #endif

src/ctrip_swap.h

@@ -1994,10 +1994,18 @@ sds genSwapTtlCompactInfoString(sds info);
 
 void swapInfoCommand(client *c);
 
+/* swap info propagate mode */
+#define SWAP_INFO_PROPAGATE_BY_PING 0
+#define SWAP_INFO_PROPAGATE_BY_SWAP_INFO 1
+
 void swapBuildSwapInfoSstAgeLimitCmd(robj *argv[3], long long sst_age_limit);
 void swapDestorySwapInfoSstAgeLimitCmd(robj *argv[3]);
 
-void swapPropagateSwapInfo(int argc, robj **argv);
+void swapPropagateSwapInfoCmd(int argc, robj **argv);
+
+sds swapEncodeSwapInfo(int swap_info_argc, sds *swap_info_argv);
+sds *swapDecodeSwapInfo(sds argv, int *swap_info_argc);
+void swapApplySwapInfo(int swap_info_argc, sds *swap_info_argv);
 
 /* Repl */
 int submitReplClientRequests(client *c);
@@ -2717,6 +2725,7 @@ int swapRordbTest(int argc, char *argv[], int accurate);
 int roaringBitmapTest(int argc, char *argv[], int accurate);
 int swapDataBitmapTest(int argc, char **argv, int accurate);
 int wtdigestTest(int argc, char **argv, int accurate);
+int swapReplTest(int argc, char **argv, int accurate);
 
 int swapTest(int argc, char **argv, int accurate);
 

src/ctrip_swap_cmd.c

@@ -1313,15 +1313,13 @@ void swapInfoCommand(client *c) {
             NULL};
         addReplyHelp(c, help);
         return;
-    } else if (c->argc == 3 && !strcasecmp(c->argv[1]->ptr,"SST-AGE-LIMIT")) {
-        /* SWAP.INFO SST-AGE-LIMIT <sst age limit> */
-        long long sst_age_limit = 0;
-        int res = isObjectRepresentableAsLongLong(c->argv[2], &sst_age_limit);
-        if (res == C_OK) {
-            server.swap_ttl_compact_ctx->expire_stats->sst_age_limit = sst_age_limit;
+    } else {
+        sds *swap_info_argv = (sds*)zmalloc(sizeof(sds)*c->argc);
+        for (int i = 0; i < c->argc; i++) {
+            swap_info_argv[i] = c->argv[i]->ptr;
         }
-        addReply(c,shared.ok);
-        return;
+        swapApplySwapInfo(c->argc, swap_info_argv);
+        zfree(swap_info_argv);
     }
 
     addReply(c,shared.ok);

src/ctrip_swap_repl.c

@@ -415,36 +415,106 @@ bool isSwapInfoSupported(void) {
     return true;
 }
 
-/* SWAP.INFO SST-AGE-LIMIT <sst age limit> */
+/* The swap.info command, propagate system info to slave.
+ * SWAP.INFO <subcommand> [<arg> [value] [opt] ...]
+ *
+ * subcommand supported:
+ * SWAP.INFO SST-AGE-LIMIT <sst age limit> */
 void swapBuildSwapInfoSstAgeLimitCmd(robj *argv[3], long long sst_age_limit) {
-
     argv[0] = shared.swap_info;
     argv[1] = shared.sst_age_limit;
-    argv[2] = createStringObjectFromLongLong(sst_age_limit);
+    argv[2] = createObject(OBJ_STRING, sdsfromlonglong(sst_age_limit));
 }
 
 void swapDestorySwapInfoSstAgeLimitCmd(robj *argv[3]) {
     decrRefCount(argv[2]);
 }
 
-/* The swap.info command, propagate system info to slave.
- * SWAP.INFO <subcommand> [<arg> [value] [opt] ...]
- *
- * subcommand supported:
- * SWAP.INFO SST-AGE-LIMIT <sst age limit> */
-void swapPropagateSwapInfo(int argc, robj **argv) {
+void swapPropagateSwapInfoCmd(int argc, robj **argv) {
+
+    if (server.swap_swap_info_propagate_mode == SWAP_INFO_PROPAGATE_BY_SWAP_INFO) {
+        if (!isSwapInfoSupported()) return;
+        replicationFeedSlaves(server.slaves, 0, argv, argc);
+        return;
+    }
+
+    /* SWAP_INFO_PROPAGATE_BY_PING */
+    sds *argv_str = zmalloc(sizeof(sds) * argc);
+    for (int i = 0; i < argc; i++) {
+        argv_str[i] = argv[i]->ptr;
+    }
+
+    sds ping_argv_str = swapEncodeSwapInfo(argc, argv_str);
+
+    robj *ping_argv[2];
+    ping_argv[0] = shared.ping;
+    ping_argv[1] = createObject(OBJ_STRING, ping_argv_str);
+
+    replicationFeedSlaves(server.slaves,0,ping_argv,2);
+    decrRefCount(ping_argv[1]);
+    zfree(argv_str);
+    return;
+}
 
-    if (!isSwapInfoSupported()) return; 
+sds swapEncodeSwapInfo(int swap_info_argc, sds *swap_info_argv) {
+    return sdsjoinsds(swap_info_argv, swap_info_argc, " ", 1);
+}
+
+sds *swapDecodeSwapInfo(sds argv, int *swap_info_argc) {
+    return sdssplitlen(argv, sdslen(argv), " ", 1, swap_info_argc);
+}
 
-    if (argc < 2) {
+void swapApplySwapInfo(int swap_info_argc, sds *swap_info_argv) {
+
+    if (strcasecmp(swap_info_argv[0],"swap.info")) {
         return;
-    } else if (argc == 3 && !strcasecmp(argv[1]->ptr,"SST-AGE-LIMIT")) {
+    }
+
+    if (swap_info_argc == 3 && !strcasecmp(swap_info_argv[1],"SST-AGE-LIMIT")) {
         /* SWAP.INFO SST-AGE-LIMIT <sst age limit> */
-        goto propagate;
+        long long sst_age_limit = 0;
+        if (isSdsRepresentableAsLongLong(swap_info_argv[2],&sst_age_limit) == C_OK) {
+            server.swap_ttl_compact_ctx->expire_stats->sst_age_limit = sst_age_limit;
+        }
+        return;
     }
-    return;
+}
 
-propagate:
-    replicationFeedSlaves(server.slaves,0,argv,argc);
-    return;
+#ifdef REDIS_TEST
+
+int swapReplTest(int argc, char *argv[], int accurate) {
+    UNUSED(argc);
+    UNUSED(argv);
+    UNUSED(accurate);
+
+    int error = 0;
+
+    TEST("swap info: sst-limit-age encode decode") {
+        sds *swap_info_argv = zmalloc(sizeof(sds) * 3);
+        swap_info_argv[0] = sdsnew("SWAP.INFO");
+        swap_info_argv[1] = sdsnew("SST-AGE-LIMIT");
+        swap_info_argv[2] = sdsfromlonglong(1111);
+        sds swap_info = swapEncodeSwapInfo(3, swap_info_argv);
+
+        int argc = 0;
+        sds *argv = swapDecodeSwapInfo(swap_info, &argc);
+
+        test_assert(argc == 3);
+        test_assert(!sdscmp(argv[2], swap_info_argv[2]));
+        test_assert(!sdscmp(argv[1], swap_info_argv[1]));
+        test_assert(!sdscmp(argv[0], swap_info_argv[0]));
+
+        sdsfree(swap_info_argv[0]);
+        sdsfree(swap_info_argv[1]);
+        sdsfree(swap_info_argv[2]);
+        zfree(swap_info_argv);
+
+        sdsfree(swap_info);
+
+        sdsfreesplitres(argv, argc);
+    }
+
+    return error;
 }
+
+#endif

src/server.c

@@ -2488,9 +2488,10 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
         if (server.swap_ttl_compact_enabled) {
             robj *argv[3];
             swapBuildSwapInfoSstAgeLimitCmd(argv, server.swap_ttl_compact_ctx->expire_stats->sst_age_limit);
-            swapPropagateSwapInfo(3, argv);
+            swapPropagateSwapInfoCmd(3, argv);
             swapDestorySwapInfoSstAgeLimitCmd(argv);
         }
+
     }
 
     /* Fire the cron loop modules event. */
@@ -4900,10 +4901,19 @@ void pingCommand(client *c) {
         else
             addReplyBulk(c,c->argv[1]);
     } else {
-        if (c->argc == 1)
+        if (c->argc == 1) {
             addReply(c,shared.pong);
-        else
+        } else {
+            /* extend ping argv for swap.info */
+            if (!strncasecmp(c->argv[1]->ptr, "swap.info", 9)) {
+                int swap_info_argc = 0;
+                sds *swap_info_argv = swapDecodeSwapInfo(c->argv[1]->ptr, &swap_info_argc);
+                swapApplySwapInfo(swap_info_argc, swap_info_argv);
+                sdsfreesplitres(swap_info_argv, swap_info_argc);
+            }
+
             addReplyBulk(c,c->argv[1]);
+        }
     }
 }
 

src/server.h

@@ -2010,6 +2010,7 @@ struct redisServer {
 
     /* for swap.info command, which propagate system info to replica */
     int swap_swap_info_supported;
+    int swap_swap_info_propagate_mode;
     unsigned long long swap_swap_info_slave_period;     /* Master send cmd swap.info to the slave every N seconds */
 };
 

tests/swap/unit/swap_info.tcl

@@ -1,4 +1,4 @@
-start_server {tags {"swap.info"}} {
+start_server {tags {"swap.info"} overrides {swap-swap-info-propagate-mode {swap.info} }}  {
     test "SST-AGE-LIMIT" {
         r swap.info SST-AGE-LIMIT 1111
         set sst_age_limit [get_info_property r Swap swap_ttl_compact sst_age_limit]
@@ -19,4 +19,45 @@ start_server {tags {"swap.info"}} {
         assert_equal OK [r swap.info SST-AGE-LIMIT 50 50]
         assert_equal OK [r swap.info SST-AGE-LIMIT 50 50 50 err]
     }
+}
+
+start_server {tags {"swap.info"} overrides {swap-swap-info-propagate-mode {ping} }}  {
+    test "SST-AGE-LIMIT with ping" {
+        r ping "swap.info SST-AGE-LIMIT 1111"
+        set sst_age_limit [get_info_property r Swap swap_ttl_compact sst_age_limit]
+        assert_equal $sst_age_limit 1111
+
+        r ping "swap.info SST-AGE-LIMIT 0"
+        set sst_age_limit [get_info_property r Swap swap_ttl_compact sst_age_limit]
+        assert_equal $sst_age_limit 0
+
+        r ping "swap.info SST-AGE-LIMIT -2222"
+        set sst_age_limit [get_info_property r Swap swap_ttl_compact sst_age_limit]
+        assert_equal $sst_age_limit -2222
+    }
+
+    test "no error for illegal ping argv of swap.info" {
+
+        r ping "swap.info SST-AGE-LIMIT 666"
+
+        assert_equal "swap.info SST-AGE 111" [r ping "swap.info SST-AGE 111"]
+        set sst_age_limit [get_info_property r Swap swap_ttl_compact sst_age_limit]
+        assert_equal $sst_age_limit 666
+
+        assert_equal "swap.info SST-AGE" [r ping "swap.info SST-AGE"]
+        set sst_age_limit [get_info_property r Swap swap_ttl_compact sst_age_limit]
+        assert_equal $sst_age_limit 666
+
+        assert_equal "swap.info" [r ping "swap.info"]
+        set sst_age_limit [get_info_property r Swap swap_ttl_compact sst_age_limit]
+        assert_equal $sst_age_limit 666
+
+        assert_equal "swap.info ss ss ss ss" [r ping "swap.info ss ss ss ss"]
+        set sst_age_limit [get_info_property r Swap swap_ttl_compact sst_age_limit]
+        assert_equal $sst_age_limit 666
+
+        assert_equal "swap.info  " [r ping "swap.info  "]
+        set sst_age_limit [get_info_property r Swap swap_ttl_compact sst_age_limit]
+        assert_equal $sst_age_limit 666
+    }
 }

tests/swap/unit/ttl_compact.tcl

@@ -264,7 +264,8 @@ start_server {tags {"ttl-compact master propagate"} overrides {save ""}} {
 
     start_server {overrides {swap-repl-rordb-sync {no} 
                              swap-debug-evict-keys {0}
-                             swap-ttl-compact-enabled {no} }} {
+                             swap-ttl-compact-enabled {no}
+                             swap-swap-info-propagate-mode {ping} }} {
 
         set master_host [srv 0 host]
         set master_port [srv 0 port]
@@ -312,6 +313,14 @@ start_server {tags {"ttl-compact master propagate"} overrides {save ""}} {
 
             set sst_age_limit2 [get_info_property $slave Swap swap_ttl_compact sst_age_limit]
             assert_equal $sst_age_limit1 $sst_age_limit2
+
+            $master config set swap-swap-info-propagate-mode swap.info
+            $master swap.info SST-AGE-LIMIT 2222
+
+            after 1200
+
+            set sst_age_limit2 [get_info_property $slave Swap swap_ttl_compact sst_age_limit]
+            assert_equal $sst_age_limit2 2222
         }
     }
 }