global sort: bench merge step (#49376)

ref #48952

br/pkg/lightning/backend/external/bench_test.go

@@ -33,6 +33,7 @@ import (
 	"github.com/pingcap/tidb/br/pkg/storage"
 	"github.com/pingcap/tidb/pkg/kv"
 	"github.com/pingcap/tidb/pkg/util/intest"
+	"github.com/pingcap/tidb/pkg/util/size"
 	"github.com/stretchr/testify/require"
 	"go.uber.org/atomic"
 	"golang.org/x/sync/errgroup"
@@ -574,11 +575,10 @@ func readFileConcurrently(t *testing.T, s *readTestSuite) {
 }
 
 func createEvenlyDistributedFiles(
-	t *testing.T,
+	store storage.ExternalStorage,
 	fileSize, fileCount int,
 	subDir string,
-) (storage.ExternalStorage, int) {
-	store := openTestingStorage(t)
+) int {
 	ctx := context.Background()
 
 	cleanOldFiles(ctx, store, "/"+subDir)
@@ -608,7 +608,7 @@ func createEvenlyDistributedFiles(
 		err := writer.Close(ctx)
 		intest.AssertNoError(err)
 	}
-	return store, kvCnt
+	return kvCnt
 }
 
 func readMergeIter(t *testing.T, s *readTestSuite) {
@@ -655,7 +655,9 @@ func TestCompareReaderEvenlyDistributedContent(t *testing.T) {
 	fileSize := 50 * 1024 * 1024
 	fileCnt := 24
 	subDir := "evenly_distributed"
-	store, kvCnt := createEvenlyDistributedFiles(t, fileSize, fileCnt, subDir)
+	store := openTestingStorage(t)
+
+	kvCnt := createEvenlyDistributedFiles(store, fileSize, fileCnt, subDir)
 	memoryLimit := 64 * 1024 * 1024
 	fileIdx := 0
 	var (
@@ -763,29 +765,32 @@ var (
 )
 
 func TestReadFileConcurrently(t *testing.T) {
-	testCompareReaderAscendingContent(t, readFileConcurrently)
+	testCompareReaderWithContent(t, createAscendingFiles, readFileConcurrently)
 }
 
 func TestReadFileSequential(t *testing.T) {
-	testCompareReaderAscendingContent(t, readFileSequential)
+	testCompareReaderWithContent(t, createAscendingFiles, readFileSequential)
 }
 
 func TestReadMergeIterCheckHotspot(t *testing.T) {
-	testCompareReaderAscendingContent(t, func(t *testing.T, suite *readTestSuite) {
+	testCompareReaderWithContent(t, createAscendingFiles, func(t *testing.T, suite *readTestSuite) {
 		suite.mergeIterHotspot = true
 		readMergeIter(t, suite)
 	})
 }
 
 func TestReadMergeIterWithoutCheckHotspot(t *testing.T) {
-	testCompareReaderAscendingContent(t, readMergeIter)
+	testCompareReaderWithContent(t, createAscendingFiles, readMergeIter)
 }
 
-func testCompareReaderAscendingContent(t *testing.T, fn func(t *testing.T, suite *readTestSuite)) {
+func testCompareReaderWithContent(
+	t *testing.T,
+	createFn func(store storage.ExternalStorage, fileSize int, fileCount int, objectPrefix string) int,
+	fn func(t *testing.T, suite *readTestSuite)) {
 	store := openTestingStorage(t)
 	kvCnt := 0
 	if !*skipCreate {
-		kvCnt = createAscendingFiles(store, *fileSize, *fileCount, *objectPrefix)
+		kvCnt = createFn(store, *fileSize, *fileCount, *objectPrefix)
 	}
 	fileIdx := 0
 	var (
@@ -896,3 +901,108 @@ func TestPrepareLargeData(t *testing.T) {
 	t.Logf("total %d data files, first file size: %.2f MB, last file size: %.2f MB",
 		len(dataFiles), float64(firstFileSize)/1024/1024, float64(lastFileSize)/1024/1024)
 }
+
+type mergeTestSuite struct {
+	store            storage.ExternalStorage
+	subDir           string
+	totalKVCnt       int
+	concurrency      int
+	memoryLimit      int
+	mergeIterHotspot bool
+	minKey           kv.Key
+	maxKey           kv.Key
+	beforeMerge      func()
+	afterMerge       func()
+}
+
+func mergeStep(t *testing.T, s *mergeTestSuite) {
+	ctx := context.Background()
+	datas, _, err := GetAllFileNames(ctx, s.store, "/"+s.subDir)
+	intest.AssertNoError(err)
+
+	mergeOutput := "merge_output"
+	totalSize := atomic.NewUint64(0)
+	onClose := func(s *WriterSummary) {
+		totalSize.Add(s.TotalSize)
+	}
+	if s.beforeMerge != nil {
+		s.beforeMerge()
+	}
+
+	now := time.Now()
+	err = MergeOverlappingFiles(
+		ctx,
+		datas,
+		s.store,
+		int64(5*size.MB),
+		64*1024,
+		mergeOutput,
+		DefaultBlockSize,
+		8*1024,
+		1*size.MB,
+		8*1024,
+		onClose,
+		s.concurrency,
+		s.mergeIterHotspot,
+	)
+
+	intest.AssertNoError(err)
+	if s.afterMerge != nil {
+		s.afterMerge()
+	}
+	elapsed := time.Since(now)
+	t.Logf(
+		"merge speed for %d bytes in %s, speed: %.2f MB/s",
+		totalSize.Load(),
+		elapsed,
+		float64(totalSize.Load())/elapsed.Seconds()/1024/1024,
+	)
+}
+
+func testCompareMergeWithContent(
+	t *testing.T,
+	createFn func(store storage.ExternalStorage, fileSize int, fileCount int, objectPrefix string) int,
+	fn func(t *testing.T, suite *mergeTestSuite)) {
+	store := openTestingStorage(t)
+	kvCnt := 0
+	var minKey, maxKey kv.Key
+	if !*skipCreate {
+		kvCnt = createFn(store, *fileSize, *fileCount, *objectPrefix)
+	}
+
+	fileIdx := 0
+	var (
+		file *os.File
+		err  error
+	)
+	beforeTest := func() {
+		file, err = os.Create(fmt.Sprintf("cpu-profile-%d.prof", fileIdx))
+		intest.AssertNoError(err)
+		err = pprof.StartCPUProfile(file)
+		intest.AssertNoError(err)
+	}
+
+	afterTest := func() {
+		pprof.StopCPUProfile()
+	}
+
+	suite := &mergeTestSuite{
+		store:            store,
+		totalKVCnt:       kvCnt,
+		concurrency:      *concurrency,
+		memoryLimit:      *memoryLimit,
+		beforeMerge:      beforeTest,
+		afterMerge:       afterTest,
+		subDir:           *objectPrefix,
+		minKey:           minKey,
+		maxKey:           maxKey,
+		mergeIterHotspot: true,
+	}
+
+	fn(t, suite)
+}
+
+func TestMergeBench(t *testing.T) {
+	testCompareMergeWithContent(t, createAscendingFiles, mergeStep)
+	testCompareMergeWithContent(t, createEvenlyDistributedFiles, mergeStep)
+}