From 50e8cee88d57e2db35be3696dc589e4b32ba7cc5 Mon Sep 17 00:00:00 2001
From: Victor <weicheng.king@qq.com>
Date: Fri, 20 Dec 2024 05:47:33 +0000
Subject: [PATCH] [WIP] ping with swap_info

---
 src/ctrip_swap.h      |  4 ++-
 src/ctrip_swap_repl.c | 72 +++++++++++++++++++------------------------
 src/server.c          | 13 +++++---
 3 files changed, 44 insertions(+), 45 deletions(-)

diff --git a/src/ctrip_swap.h b/src/ctrip_swap.h
index 5d2e2ca3fb5..a21960693ad 100644
--- a/src/ctrip_swap.h
+++ b/src/ctrip_swap.h
@@ -1997,7 +1997,9 @@ void swapInfoCommand(client *c);
 void swapBuildSwapInfoSstAgeLimitCmd(robj *argv[3], long long sst_age_limit);
 void swapDestorySwapInfoSstAgeLimitCmd(robj *argv[3]);
 
-void swapPropagateSwapInfo(int argc, robj **argv);
+void swapPropagateSwapInfo(sds ping_argv);
+sds swapEncodeSwapInfo(int argc, sds *argv);
+sds *swapDecodeSwapInfo(sds argv);
 
 /* Repl */
 int submitReplClientRequests(client *c);
diff --git a/src/ctrip_swap_repl.c b/src/ctrip_swap_repl.c
index 44ba38b148c..06b4be87ed4 100644
--- a/src/ctrip_swap_repl.c
+++ b/src/ctrip_swap_repl.c
@@ -392,59 +392,51 @@ sds genSwapReplInfoString(sds info) {
     return info;
 }
 
-bool isSwapInfoSupported(void) {
+/* SWAP.INFO SST-AGE-LIMIT <sst-age-limit> */
+void swapBuildSwapInfoSstAgeLimitCmd(sds *argv[3], long long sst_age_limit) {
 
-    if (server.swap_swap_info_supported == SWAP_INFO_SUPPORTED_YES) return true;
-    if (server.swap_swap_info_supported == SWAP_INFO_SUPPORTED_NO) return false;
+    argv[0] = shared.swap_info->ptr;
+    argv[1] = shared.sst_age_limit->ptr;
+    argv[2] = sdsfromlonglong(sst_age_limit);
+}
 
-    /* SWAP_INFO_SUPPORTED_AUTO */
-    /* depends on capa of all slaves, 
-     * once there is one slave without capa of swap.info, return false. */
+void swapDestorySwapInfoSstAgeLimitCmd(sds *argv[3]) {
+    sdsfree(argv[2]);
+}
 
-    listNode *ln;
-    listIter li;
+/* The swap.info argv, propagate system info to slave with ping command.
+ * SWAP.INFO <subcommand> [<arg> [value] [opt] ...]
+ *
+ * subcommand supported:
+ * SWAP.INFO SST-AGE-LIMIT <sst-age-limit> */
+sds swapEncodeSwapInfo(int argc, sds *argv) {
 
-    listRewind(server.slaves,&li);
-    while((ln = listNext(&li))) {
-        client *slave = ln->value;
+    sds ping_argv = sdsempty();
 
-        if (!(slave->slave_capa & SLAVE_CAPA_SWAP_INFO)) {
-            return false;
-        }
+
+    for (int i = 0; i< argc; i++) {
+        ping_argv = sdscat(ping_argv, argv);
+        ping_argv = sdscat(ping_argv, " "); /* spilt by space */
     }
-    return true;
+
+    return ping_argv;
 }
 
-/* SWAP.INFO SST-AGE-LIMIT <sst age limit> */
-void swapBuildSwapInfoSstAgeLimitCmd(robj *argv[3], long long sst_age_limit) {
+sds *swapDecodeSwapInfo(sds argv) {
 
-    argv[0] = shared.swap_info;
-    argv[1] = shared.sst_age_limit;
-    argv[2] = createStringObjectFromLongLong(sst_age_limit);
-}
 
-void swapDestorySwapInfoSstAgeLimitCmd(robj *argv[3]) {
-    decrRefCount(argv[2]);
-}
+    /* 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 swapPropagateSwapInfo(int argc, robj **argv) {
+    return NULL ;
+}
 
-    if (!isSwapInfoSupported()) return; 
+void swapPropagateSwapInfo(sds ping_argv) {
 
-    if (argc < 2) {
-        return;
-    } else if (argc == 3 && !strcasecmp(argv[1]->ptr,"SST-AGE-LIMIT")) {
-        /* SWAP.INFO SST-AGE-LIMIT <sst age limit> */
-        goto propagate;
-    }
-    return;
+    robj *argv[2];
 
-propagate:
-    replicationFeedSlaves(server.slaves,0,argv,argc);
+    argv[0] = shared.ping;
+    argv[1] = createStringObject(ping_argv, sdslen(ping_argv));
+    
+    replicationFeedSlaves(server.slaves,0,argv,2);
     return;
 }
diff --git a/src/server.c b/src/server.c
index 779d0a9a58e..a01f4843405 100644
--- a/src/server.c
+++ b/src/server.c
@@ -2486,9 +2486,10 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
     run_with_period(1000*(int)server.swap_swap_info_slave_period) {
         /* propagate sst age limit */
         if (server.swap_ttl_compact_enabled) {
-            robj *argv[3];
+            sds *argv[3];
             swapBuildSwapInfoSstAgeLimitCmd(argv, server.swap_ttl_compact_ctx->expire_stats->sst_age_limit);
-            swapPropagateSwapInfo(3, argv);
+            sds swap_info = swapEncodeSwapInfo(3, argv);
+            swapPropagateSwapInfo(swap_info);
             swapDestorySwapInfoSstAgeLimitCmd(argv);
         }
     }
@@ -4900,10 +4901,14 @@ 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 {
+            sds *swap_info = swapDecodeSwapInfo(c->argv[1]->ptr);
+            /* apply swap info ... */
+            /* ... */
             addReplyBulk(c,c->argv[1]);
+        }
     }
 }