From 3ac79e104fd0378bf9d4243f0f17ad2ff7cd214b Mon Sep 17 00:00:00 2001
From: MoCuishle28 <32541204+MoCuishle28@users.noreply.github.com>
Date: Wed, 31 Aug 2022 19:26:24 +0800
Subject: [PATCH] br: Fix backupmeta division bug (#37246)

close pingcap/tidb#37244
---
 br/pkg/metautil/metafile.go      | 31 +++++++++++++++++---------
 br/pkg/metautil/metafile_test.go | 38 ++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+), 11 deletions(-)

diff --git a/br/pkg/metautil/metafile.go b/br/pkg/metautil/metafile.go
index be6d51305f67..77b3c4de8b6f 100644
--- a/br/pkg/metautil/metafile.go
+++ b/br/pkg/metautil/metafile.go
@@ -427,11 +427,12 @@ func (op AppendOp) name() string {
 }
 
 // appends item to MetaFile
-func (op AppendOp) appendFile(a *backuppb.MetaFile, b interface{}) (size int, itemCount int) {
+func (op AppendOp) appendFile(a *backuppb.MetaFile, b interface{}) (dataFileSize int, size int, itemCount int) {
 	switch op {
 	case AppendMetaFile:
-		a.MetaFiles = append(a.MetaFiles, b.(*backuppb.File))
-		size += int(b.(*backuppb.File).Size_)
+		metaFile := b.(*backuppb.File)
+		a.MetaFiles = append(a.MetaFiles, metaFile)
+		size += metaFile.Size()
 		itemCount++
 	case AppendDataFile:
 		// receive a batch of file because we need write and default sst are adjacent.
@@ -439,7 +440,8 @@ func (op AppendOp) appendFile(a *backuppb.MetaFile, b interface{}) (size int, it
 		a.DataFiles = append(a.DataFiles, files...)
 		for _, f := range files {
 			itemCount++
-			size += int(f.Size_)
+			size += f.Size()
+			dataFileSize += int(f.Size_)
 		}
 	case AppendSchema:
 		a.Schemas = append(a.Schemas, b.(*backuppb.Schema))
@@ -450,15 +452,16 @@ func (op AppendOp) appendFile(a *backuppb.MetaFile, b interface{}) (size int, it
 		itemCount++
 		size += len(b.([]byte))
 	}
-	return size, itemCount
+	return dataFileSize, size, itemCount
 }
 
 type sizedMetaFile struct {
 	// A stack like array, we always append to the last node.
-	root      *backuppb.MetaFile
-	size      int
-	itemNum   int
-	sizeLimit int
+	root         *backuppb.MetaFile
+	dataFileSize int
+	size         int
+	itemNum      int
+	sizeLimit    int
 }
 
 // NewSizedMetaFile represents the sizedMetaFile.
@@ -476,9 +479,10 @@ func NewSizedMetaFile(sizeLimit int) *sizedMetaFile {
 func (f *sizedMetaFile) append(file interface{}, op AppendOp) bool {
 	// append to root
 	// 	TODO maybe use multi level index
-	size, itemCount := op.appendFile(f.root, file)
+	dataFileSize, size, itemCount := op.appendFile(f.root, file)
 	f.itemNum += itemCount
 	f.size += size
+	f.dataFileSize += dataFileSize
 	// f.size would reset outside
 	return f.size > f.sizeLimit
 }
@@ -510,6 +514,9 @@ type MetaWriter struct {
 	metaFileName string
 
 	cipher *backuppb.CipherInfo
+
+	// records the total datafile size
+	totalDataFileSize int
 }
 
 // NewMetaWriter creates MetaWriter.
@@ -716,6 +723,8 @@ func (writer *MetaWriter) flushMetasV2(ctx context.Context, op AppendOp) error {
 
 	name := op.name()
 	writer.metafileSizes[name] += writer.metafiles.size
+	writer.totalDataFileSize += writer.metafiles.dataFileSize
+
 	// Flush metafiles to external storage.
 	writer.metafileSeqNum["metafiles"]++
 	fname := fmt.Sprintf("backupmeta.%s.%09d", name, writer.metafileSeqNum["metafiles"])
@@ -748,7 +757,7 @@ func (writer *MetaWriter) ArchiveSize() uint64 {
 	for _, file := range writer.backupMeta.Files {
 		total += file.Size_
 	}
-	total += uint64(writer.metafileSizes["datafile"])
+	total += uint64(writer.totalDataFileSize)
 	return total
 }
 
diff --git a/br/pkg/metautil/metafile_test.go b/br/pkg/metautil/metafile_test.go
index 70ebe5df90c8..249f76cbd865 100644
--- a/br/pkg/metautil/metafile_test.go
+++ b/br/pkg/metautil/metafile_test.go
@@ -215,3 +215,41 @@ func TestEncryptAndDecrypt(t *testing.T) {
 		}
 	}
 }
+
+func TestMetaFileSize(t *testing.T) {
+	files := []*backuppb.File{
+		{Name: "f0", Size_: 99999}, // Size() is 8
+		{Name: "f1", Size_: 99999},
+		{Name: "f2", Size_: 99999},
+		{Name: "f3", Size_: 99999},
+		{Name: "f4", Size_: 99999},
+		{Name: "f5", Size_: 99999},
+	}
+	metafiles := NewSizedMetaFile(50) // >= 50, then flush
+
+	needFlush := metafiles.append(files, AppendDataFile)
+	t.Logf("needFlush: %v, %+v", needFlush, metafiles)
+	require.False(t, needFlush)
+
+	needFlush = metafiles.append([]*backuppb.File{
+		{Name: "f5", Size_: 99999},
+	}, AppendDataFile)
+	t.Logf("needFlush: %v, %+v", needFlush, metafiles)
+	require.True(t, needFlush)
+
+	metas := []*backuppb.File{
+		{Name: "meta0", Size_: 99999}, // Size() is 11
+		{Name: "meta1", Size_: 99999},
+		{Name: "meta2", Size_: 99999},
+		{Name: "meta3", Size_: 99999},
+	}
+	metafiles = NewSizedMetaFile(50)
+	for _, meta := range metas {
+		needFlush = metafiles.append(meta, AppendMetaFile)
+		t.Logf("needFlush: %v, %+v", needFlush, metafiles)
+		require.False(t, needFlush)
+	}
+	needFlush = metafiles.append(&backuppb.File{Name: "meta4", Size_: 99999}, AppendMetaFile)
+	t.Logf("needFlush: %v, %+v", needFlush, metafiles)
+	require.True(t, needFlush)
+}