enh(sync): log entry cache for sync

include/libs/sync/sync.h

@@ -22,6 +22,7 @@ extern "C" {
 
 #include "cJSON.h"
 #include "tdef.h"
+#include "tlrucache.h"
 #include "tmsgcb.h"
 
 extern bool gRaftDetailLog;
@@ -153,7 +154,8 @@ typedef struct SSyncFSM {
 // abstract definition of log store in raft
 // SWal implements it
 typedef struct SSyncLogStore {
-  void* data;
+  SLRUCache* pCache;
+  void*      data;
 
   // append one log entry
   int32_t (*appendEntry)(struct SSyncLogStore* pLogStore, SSyncRaftEntry* pEntry);

source/libs/sync/src/syncCommit.c

@@ -69,15 +69,26 @@ void syncMaybeAdvanceCommitIndex(SSyncNode* pSyncNode) {
 
     if (agree) {
       // term
-      SSyncRaftEntry* pEntry = pSyncNode->pLogStore->getEntry(pSyncNode->pLogStore, index);
-      ASSERT(pEntry != NULL);
-
+      SSyncRaftEntry* pEntry = NULL;
+      SLRUCache*      pCache = pSyncNode->pLogStore->pCache;
+      LRUHandle*      h = taosLRUCacheLookup(pCache, &index, sizeof(index));
+      if (h) {
+        pEntry = (SSyncRaftEntry*)taosLRUCacheValue(pCache, h);
+      } else {
+        pEntry = pSyncNode->pLogStore->getEntry(pSyncNode->pLogStore, index);
+        ASSERT(pEntry != NULL);
+      }
       // cannot commit, even if quorum agree. need check term!
       if (pEntry->term <= pSyncNode->pRaftStore->currentTerm) {
         // update commit index
         newCommitIndex = index;
 
-        syncEntryDestory(pEntry);
+        if (h) {
+          taosLRUCacheRelease(pCache, h, false);
+        } else {
+          syncEntryDestory(pEntry);
+        }
+
         break;
       } else {
         do {
@@ -88,7 +99,11 @@ void syncMaybeAdvanceCommitIndex(SSyncNode* pSyncNode) {
         } while (0);
       }
 
-      syncEntryDestory(pEntry);
+      if (h) {
+        taosLRUCacheRelease(pCache, h, false);
+      } else {
+        syncEntryDestory(pEntry);
+      }
     }
   }
 

source/libs/sync/src/syncMain.c

@@ -2581,6 +2581,20 @@ static int32_t syncNodeEqNoop(SSyncNode* ths) {
   return ret;
 }
 
+static void deleteCacheEntry(const void* key, size_t keyLen, void* value) { taosMemoryFree(value); }
+
+static int32_t syncCacheEntry(SSyncLogStore* pLogStore, SSyncRaftEntry* pEntry, LRUHandle** h) {
+  int       code = 0;
+  int       entryLen = sizeof(*pEntry) + pEntry->dataLen;
+  LRUStatus status = taosLRUCacheInsert(pLogStore->pCache, &pEntry->index, sizeof(pEntry->index), pEntry, entryLen,
+                                        deleteCacheEntry, h, TAOS_LRU_PRIORITY_LOW);
+  if (status != TAOS_LRU_STATUS_OK) {
+    code = -1;
+  }
+
+  return code;
+}
+
 static int32_t syncNodeAppendNoop(SSyncNode* ths) {
   int32_t ret = 0;
 
@@ -2589,13 +2603,21 @@ static int32_t syncNodeAppendNoop(SSyncNode* ths) {
   SSyncRaftEntry* pEntry = syncEntryBuildNoop(term, index, ths->vgId);
   ASSERT(pEntry != NULL);
 
+  LRUHandle* h = NULL;
+  syncCacheEntry(ths->pLogStore, pEntry, &h);
+
   if (ths->state == TAOS_SYNC_STATE_LEADER) {
     int32_t code = ths->pLogStore->syncLogAppendEntry(ths->pLogStore, pEntry);
     ASSERT(code == 0);
     syncNodeReplicate(ths, false);
   }
 
-  syncEntryDestory(pEntry);
+  if (h) {
+    taosLRUCacheRelease(ths->pLogStore->pCache, h, false);
+  } else {
+    syncEntryDestory(pEntry);
+  }
+
   return ret;
 }
 
@@ -2654,6 +2676,9 @@ int32_t syncNodeOnClientRequestCb(SSyncNode* ths, SyncClientRequest* pMsg, SyncI
   SSyncRaftEntry* pEntry = syncEntryBuild2((SyncClientRequest*)pMsg, term, index);
   ASSERT(pEntry != NULL);
 
+  LRUHandle* h = NULL;
+  syncCacheEntry(ths->pLogStore, pEntry, &h);
+
   if (ths->state == TAOS_SYNC_STATE_LEADER) {
     // append entry
     code = ths->pLogStore->syncLogAppendEntry(ths->pLogStore, pEntry);
@@ -2685,7 +2710,12 @@ int32_t syncNodeOnClientRequestCb(SSyncNode* ths, SyncClientRequest* pMsg, SyncI
     }
   }
 
-  syncEntryDestory(pEntry);
+  if (h) {
+    taosLRUCacheRelease(ths->pLogStore->pCache, h, false);
+  } else {
+    syncEntryDestory(pEntry);
+  }
+
   return ret;
 }
 
@@ -2973,9 +3003,15 @@ int32_t syncNodeCommit(SSyncNode* ths, SyncIndex beginIndex, SyncIndex endIndex,
     for (SyncIndex i = beginIndex; i <= endIndex; ++i) {
       if (i != SYNC_INDEX_INVALID) {
         SSyncRaftEntry* pEntry;
-        code = ths->pLogStore->syncLogGetEntry(ths->pLogStore, i, &pEntry);
-        ASSERT(code == 0);
-        ASSERT(pEntry != NULL);
+        SLRUCache*      pCache = ths->pLogStore->pCache;
+        LRUHandle*      h = taosLRUCacheLookup(pCache, &i, sizeof(i));
+        if (h) {
+          pEntry = (SSyncRaftEntry*)taosLRUCacheValue(pCache, h);
+        } else {
+          code = ths->pLogStore->syncLogGetEntry(ths->pLogStore, i, &pEntry);
+          ASSERT(code == 0);
+          ASSERT(pEntry != NULL);
+        }
 
         SRpcMsg rpcMsg;
         syncEntry2OriginalRpc(pEntry, &rpcMsg);
@@ -3058,7 +3094,11 @@ int32_t syncNodeCommit(SSyncNode* ths, SyncIndex beginIndex, SyncIndex endIndex,
         }
 
         rpcFreeCont(rpcMsg.pCont);
-        syncEntryDestory(pEntry);
+        if (h) {
+          taosLRUCacheRelease(pCache, h, false);
+        } else {
+          syncEntryDestory(pEntry);
+        }
       }
     }
   }

source/libs/sync/src/syncRaftLog.c

@@ -53,6 +53,15 @@ SSyncLogStore* logStoreCreate(SSyncNode* pSyncNode) {
   SSyncLogStore* pLogStore = taosMemoryMalloc(sizeof(SSyncLogStore));
   ASSERT(pLogStore != NULL);
 
+  pLogStore->pCache = taosLRUCacheInit(10 * 1024 * 1024, 1, .5);
+  if (pLogStore->pCache == NULL) {
+    terrno = TSDB_CODE_WAL_OUT_OF_MEMORY;
+    taosMemoryFree(pLogStore);
+    return NULL;
+  }
+
+  taosLRUCacheSetStrictCapacity(pLogStore->pCache, false);
+
   pLogStore->data = taosMemoryMalloc(sizeof(SSyncLogStoreData));
   ASSERT(pLogStore->data != NULL);
 
@@ -102,6 +111,10 @@ void logStoreDestory(SSyncLogStore* pLogStore) {
     taosThreadMutexDestroy(&(pData->mutex));
 
     taosMemoryFree(pLogStore->data);
+
+    taosLRUCacheEraseUnrefEntries(pLogStore->pCache);
+    taosLRUCacheCleanup(pLogStore->pCache);
+
     taosMemoryFree(pLogStore);
   }
 }
@@ -243,7 +256,7 @@ static int32_t raftLogAppendEntry(struct SSyncLogStore* pLogStore, SSyncRaftEntr
 static int32_t raftLogGetEntry(struct SSyncLogStore* pLogStore, SyncIndex index, SSyncRaftEntry** ppEntry) {
   SSyncLogStoreData* pData = pLogStore->data;
   SWal*              pWal = pData->pWal;
-  int32_t            code;
+  int32_t            code = 0;
 
   *ppEntry = NULL;
 
@@ -257,6 +270,7 @@ static int32_t raftLogGetEntry(struct SSyncLogStore* pLogStore, SyncIndex index,
   taosThreadMutexLock(&(pData->mutex));
 
   code = walReadVer(pWalHandle, index);
+  // code = walReadVerCached(pWalHandle, index);
   if (code != 0) {
     int32_t     err = terrno;
     const char* errStr = tstrerror(err);
@@ -412,6 +426,7 @@ SSyncRaftEntry* logStoreGetEntry(SSyncLogStore* pLogStore, SyncIndex index) {
     ASSERT(pWalHandle != NULL);
 
     int32_t code = walReadVer(pWalHandle, index);
+    // int32_t code = walReadVerCached(pWalHandle, index);
     if (code != 0) {
       int32_t     err = terrno;
       const char* errStr = tstrerror(err);