From 7c4e58e191c9867689065bf288d71bf93cbca16f Mon Sep 17 00:00:00 2001
From: shenzhengntu <503699317@qq.com>
Date: Tue, 28 Mar 2023 16:32:40 +0800
Subject: [PATCH] wal query in mempry
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Code Source From: Self Code
Description:  【Optional】
Jira:  #【Optional】
市场项目编号（名称）：【Optional】
---
 src/backend/access/transam/ringbuffer.c |  2 +-
 src/backend/storage/buffer/bufmgr.c     | 18 ++++++++++++------
 src/backend/storage/smgr/md.c           | 21 ++++++++++-----------
 3 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/src/backend/access/transam/ringbuffer.c b/src/backend/access/transam/ringbuffer.c
index 81f1c89..2a377bf 100644
--- a/src/backend/access/transam/ringbuffer.c
+++ b/src/backend/access/transam/ringbuffer.c
@@ -151,7 +151,7 @@ int walRecordQuery(char**buffer,int* curpos,int* maxspace,uint64 lsn) {
 		xllen = record->xl_tot_len;
 	} else {
 		record = (XLogRecord*)gRingBufferManger->buffer[high].data;
-		if (gRingBufferManger->buffer[mid].startLsn + gRingBufferManger->buffer[mid].dataLen >= lsn) {
+		if (gRingBufferManger->buffer[high].startLsn + gRingBufferManger->buffer[high].dataLen <= lsn) {
 			return -1;
 		} else {
 			record = (XLogRecord*)(gRingBufferManger->buffer[high].data + (lsn-gRingBufferManger->buffer[high].startLsn));
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 7cfec67..0ffb108 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -1056,7 +1056,7 @@ ReadBuffer_common(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
 		!isLocalBuf) && IsBootstrapProcessingMode() != true && InitdbSingle != true)
 		{
 			if (EnableHotStandby == true || InRecovery) {
-				if (push_standby == false) {
+				if (EnableHotStandby == true && push_standby == false) {
 					BufferTag pageTag;
 					pageTag.rnode = smgr->smgr_rnode.node;
 					pageTag.forkNum = forkNum;
@@ -1065,7 +1065,9 @@ ReadBuffer_common(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
 					XLogRecPtr pageLsn = BufferGetLSN(bufHdr);
 					head = GetLogIndexByPage(&pageTag,pageLsn,replayLsn);
 					GetXLogReplayRecPtr(&tli);
-					tWalRecord = ReadWalsByPage(pageTag.rnode.dbNode,pageTag.rnode.relNode,forkNum,blockNum,tli,head);
+					if (head->next!=NULL) {
+						tWalRecord = ReadWalsByPage(pageTag.rnode.dbNode,pageTag.rnode.relNode,forkNum,blockNum,tli,head);
+					}
 				} else {
 					walRecord.cap = 8192;
 					walRecord.buf = malloc(walRecord.cap);
@@ -1116,8 +1118,10 @@ ReadBuffer_common(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
 						pageTag.blockNum = blockNum;
 						XLogRecPtr pageLsn = BufferGetLSN(bufHdr);
 						head = GetLogIndexByPage(&pageTag,pageLsn,replayLsn);
-						if (push_standby == false) {
-							tWalRecord = ReadWalsByPage(pageTag.rnode.dbNode,pageTag.rnode.relNode,forkNum,blockNum,tli,head);
+						if (EnableHotStandby == true && push_standby == false) {
+							if (head->next != NULL) {
+								tWalRecord = ReadWalsByPage(pageTag.rnode.dbNode,pageTag.rnode.relNode,forkNum,blockNum,tli,head);
+							}
 						} else {
 							walRecord.cap = 8192;
 							walRecord.buf = malloc(walRecord.cap);
@@ -1226,11 +1230,13 @@ ReadBuffer_common(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
 			if (pageXlogPtr != NULL) {
 				free(pageXlogPtr);
 				pageXlogPtr = NULL;
-			} else if (tWalRecord.buf != NULL) {
+			} else if (tWalRecord.count != 0) {
 				free_dataRead(tWalRecord.buf,tWalRecord.count,tWalRecord.cap);
 				FreeLsnNode(head);
 			} else {
-				free(walRecord.buf);
+				if (walRecord.buf != NULL) {
+					free(walRecord.buf);
+				}
 				FreeLsnNode(head);
 			}
 		}
diff --git a/src/backend/storage/smgr/md.c b/src/backend/storage/smgr/md.c
index 3e35237..08e7633 100644
--- a/src/backend/storage/smgr/md.c
+++ b/src/backend/storage/smgr/md.c
@@ -777,17 +777,18 @@ he3db_mdread_pagexlog(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknu
 			Assert(bufrd.count == BLCKSZ);
 			pageKey.pageLsn = PageGetLSN(*buffer);
 			LsnNode *head = GetLogIndexByPage(&pageTag, pageKey.pageLsn, pageKey.replyLsn);
-			Bufrd result;
-			result = ReadWalsByPage(pageKey.relfileNode.dbNode, pageKey.relfileNode.relNode,
-							pageKey.forkNo, pageKey.blkNo, ThisTimeLineID, head);
-			if (result.count !=0) {
+			if (head->next != NULL) {
+				Bufrd result;
+				result = ReadWalsByPage(pageKey.relfileNode.dbNode, pageKey.relfileNode.relNode,
+								pageKey.forkNo, pageKey.blkNo, ThisTimeLineID, head);				
 				*buffer = (uint8_t *)realloc(*buffer, BLCKSZ + result.count);
 				strcat(*buffer,result.buf);
 				free_dataRead(result.buf, result.count, result.cap);
+				return BLCKSZ + result.count;
 			}
 			//TODO free result
 			FreeLsnNode(head);
-			return BLCKSZ + result.count;
+			return bufrd.count;
 		}
 //		*buffer = bufrd.buf;
 		return bufrd.count;
@@ -833,12 +834,10 @@ he3db_mdread_pagexlog(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknu
 		    	result = ReadWalsByPage(pageKey.relfileNode.dbNode,pageKey.relfileNode.relNode,
 		                        pageKey.forkNo,pageKey.blkNo, ThisTimeLineID, head);
 			}
-			if (result.count !=0) {
-				buf = (uint8_t *)realloc(buf, BLCKSZ + result.count);
-				strcat(buf,result.buf);
-				//TODO free result
-				free_dataRead(result.buf, result.count, result.cap);
-			}
+			buf = (uint8_t *)realloc(buf, BLCKSZ + result.count);
+			strcat(buf,result.buf);
+			//TODO free result
+			free_dataRead(result.buf, result.count, result.cap);
 			*buffer = buf;
 			FreeLsnNode(head);
 			return BLCKSZ + result.count;