add segment file ext

options.go

@@ -10,6 +10,13 @@ type Options struct {
 	// SegmentSize specifies the maximum size of each segment file in bytes.
 	SegmentSize int64
 
+	// SegmentFileExt specifies the file extension of the segment files.
+	// The file extension must start with a dot ".", default value is ".SEG".
+	// It is used to identify the different types of files in the directory.
+	// Now it is used by rosedb to identify the segment files and hint files.
+	// Not a common usage for most users.
+	SementFileExt string
+
 	// BlockCache specifies the size of the block cache in number of bytes.
 	// A block cache is used to store recently accessed data blocks, improving read performance.
 	// If BlockCache is set to 0, no block cache will be used.
@@ -37,9 +44,10 @@ const (
 )
 
 var DefaultOptions = Options{
-	DirPath:      os.TempDir(),
-	SegmentSize:  GB,
-	BlockCache:   32 * KB * 10,
-	Sync:         false,
-	BytesPerSync: 0,
+	DirPath:       os.TempDir(),
+	SegmentSize:   GB,
+	SementFileExt: ".SEG",
+	BlockCache:    32 * KB * 10,
+	Sync:          false,
+	BytesPerSync:  0,
 }

segment.go

@@ -37,8 +37,6 @@ const (
 	blockSize = 32 * KB
 
 	fileModePerm = 0644
-
-	segmentFileSuffix = ".SEG"
 )
 
 // Segment represents a single segment file in WAL.
@@ -75,8 +73,8 @@ type ChunkPosition struct {
 }
 
 // openSegmentFile a new segment file.
-func openSegmentFile(dirPath string, id uint32, cache *lru.Cache[uint64, []byte]) (*segment, error) {
-	fileName := fmt.Sprintf("%09d"+segmentFileSuffix, id)
+func openSegmentFile(dirPath, extName string, id uint32, cache *lru.Cache[uint64, []byte]) (*segment, error) {
+	fileName := fmt.Sprintf("%09d"+extName, id)
 	fd, err := os.OpenFile(
 		filepath.Join(dirPath, fileName),
 		os.O_CREATE|os.O_RDWR|os.O_APPEND,
@@ -90,7 +88,7 @@ func openSegmentFile(dirPath string, id uint32, cache *lru.Cache[uint64, []byte]
 	// set the current block number and block size.
 	offset, err := fd.Seek(0, io.SeekEnd)
 	if err != nil {
-		panic(fmt.Errorf("seek to the end of segment file %d%s failed: %v", id, segmentFileSuffix, err))
+		panic(fmt.Errorf("seek to the end of segment file %d%s failed: %v", id, extName, err))
 	}
 
 	return &segment{

segment_test.go

@@ -12,7 +12,7 @@ import (
 
 func TestSegment_Write_FULL1(t *testing.T) {
 	dir, _ := os.MkdirTemp("", "seg-test-full1")
-	seg, err := openSegmentFile(dir, 1, nil)
+	seg, err := openSegmentFile(dir, ".SEG", 1, nil)
 	assert.Nil(t, err)
 	defer func() {
 		_ = seg.Remove()
@@ -46,7 +46,7 @@ func TestSegment_Write_FULL1(t *testing.T) {
 
 func TestSegment_Write_FULL2(t *testing.T) {
 	dir, _ := os.MkdirTemp("", "seg-test-full2")
-	seg, err := openSegmentFile(dir, 1, nil)
+	seg, err := openSegmentFile(dir, ".SEG", 1, nil)
 	assert.Nil(t, err)
 	defer func() {
 		_ = seg.Remove()
@@ -74,7 +74,7 @@ func TestSegment_Write_FULL2(t *testing.T) {
 
 func TestSegment_Write_Padding(t *testing.T) {
 	dir, _ := os.MkdirTemp("", "seg-test-padding")
-	seg, err := openSegmentFile(dir, 1, nil)
+	seg, err := openSegmentFile(dir, ".SEG", 1, nil)
 	assert.Nil(t, err)
 	defer func() {
 		_ = seg.Remove()
@@ -97,7 +97,7 @@ func TestSegment_Write_Padding(t *testing.T) {
 
 func TestSegment_Write_NOT_FULL(t *testing.T) {
 	dir, _ := os.MkdirTemp("", "seg-test-not-full")
-	seg, err := openSegmentFile(dir, 1, nil)
+	seg, err := openSegmentFile(dir, ".SEG", 1, nil)
 	assert.Nil(t, err)
 	defer func() {
 		_ = seg.Remove()
@@ -135,7 +135,7 @@ func TestSegment_Write_NOT_FULL(t *testing.T) {
 
 func TestSegment_Reader_FULL(t *testing.T) {
 	dir, _ := os.MkdirTemp("", "seg-test-reader-full")
-	seg, err := openSegmentFile(dir, 1, nil)
+	seg, err := openSegmentFile(dir, ".SEG", 1, nil)
 	assert.Nil(t, err)
 	defer func() {
 		_ = seg.Remove()
@@ -167,7 +167,7 @@ func TestSegment_Reader_FULL(t *testing.T) {
 
 func TestSegment_Reader_Padding(t *testing.T) {
 	dir, _ := os.MkdirTemp("", "seg-test-reader-padding")
-	seg, err := openSegmentFile(dir, 1, nil)
+	seg, err := openSegmentFile(dir, ".SEG", 1, nil)
 	assert.Nil(t, err)
 	defer func() {
 		_ = seg.Remove()
@@ -201,7 +201,7 @@ func TestSegment_Reader_Padding(t *testing.T) {
 
 func TestSegment_Reader_NOT_FULL(t *testing.T) {
 	dir, _ := os.MkdirTemp("", "seg-test-reader-not-full")
-	seg, err := openSegmentFile(dir, 1, nil)
+	seg, err := openSegmentFile(dir, ".SEG", 1, nil)
 	assert.Nil(t, err)
 	defer func() {
 		_ = seg.Remove()
@@ -248,7 +248,7 @@ func TestSegment_Reader_NOT_FULL(t *testing.T) {
 func TestSegment_Reader_ManyChunks_FULL(t *testing.T) {
 	dir, _ := os.MkdirTemp("", "seg-test-reader-ManyChunks_FULL")
 	cache, _ := lru.New[uint64, []byte](5)
-	seg, err := openSegmentFile(dir, 1, cache)
+	seg, err := openSegmentFile(dir, ".SEG", 1, cache)
 	assert.Nil(t, err)
 	defer func() {
 		_ = seg.Remove()
@@ -286,7 +286,7 @@ func TestSegment_Reader_ManyChunks_FULL(t *testing.T) {
 func TestSegment_Reader_ManyChunks_NOT_FULL(t *testing.T) {
 	dir, _ := os.MkdirTemp("", "seg-test-reader-ManyChunks_NOT_FULL")
 	cache, _ := lru.New[uint64, []byte](5)
-	seg, err := openSegmentFile(dir, 1, cache)
+	seg, err := openSegmentFile(dir, ".SEG", 1, cache)
 	assert.Nil(t, err)
 	defer func() {
 		_ = seg.Remove()

wal.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"os"
 	"sort"
+	"strings"
 	"sync"
 
 	lru "github.com/hashicorp/golang-lru/v2"
@@ -49,6 +50,9 @@ type Reader struct {
 }
 
 func Open(options Options) (*WAL, error) {
+	if !strings.HasPrefix(options.SementFileExt, ".") {
+		return nil, fmt.Errorf("segment file extension must start with '.'")
+	}
 	wal := &WAL{
 		options:       options,
 		olderSegments: make(map[SegmentID]*segment),
@@ -85,7 +89,7 @@ func Open(options Options) (*WAL, error) {
 			continue
 		}
 		var id int
-		_, err := fmt.Sscanf(entry.Name(), "%d"+segmentFileSuffix, &id)
+		_, err := fmt.Sscanf(entry.Name(), "%d"+options.SementFileExt, &id)
 		if err != nil {
 			continue
 		}
@@ -94,7 +98,8 @@ func Open(options Options) (*WAL, error) {
 
 	// empty directory, just initialize a new segment file.
 	if len(segmengIDs) == 0 {
-		segment, err := openSegmentFile(options.DirPath, initialSegmentFileID, wal.blockCache)
+		segment, err := openSegmentFile(options.DirPath, options.SementFileExt,
+			initialSegmentFileID, wal.blockCache)
 		if err != nil {
 			return nil, err
 		}
@@ -104,7 +109,8 @@ func Open(options Options) (*WAL, error) {
 		sort.Ints(segmengIDs)
 
 		for i, segId := range segmengIDs {
-			segment, err := openSegmentFile(options.DirPath, uint32(segId), wal.blockCache)
+			segment, err := openSegmentFile(options.DirPath, options.SementFileExt,
+				uint32(segId), wal.blockCache)
 			if err != nil {
 				return nil, err
 			}
@@ -133,7 +139,8 @@ func (wal *WAL) OpenNewActiveSegment() error {
 		return err
 	}
 	// create a new segment file and set it as the active one.
-	segment, err := openSegmentFile(wal.options.DirPath, wal.activeSegment.id+1, wal.blockCache)
+	segment, err := openSegmentFile(wal.options.DirPath, wal.options.SementFileExt,
+		wal.activeSegment.id+1, wal.blockCache)
 	if err != nil {
 		return err
 	}
@@ -215,7 +222,8 @@ func (wal *WAL) Write(data []byte) (*ChunkPosition, error) {
 			return nil, err
 		}
 
-		segment, err := openSegmentFile(wal.options.DirPath, wal.activeSegment.id+1, wal.blockCache)
+		segment, err := openSegmentFile(wal.options.DirPath, wal.options.SementFileExt,
+			wal.activeSegment.id+1, wal.blockCache)
 		if err != nil {
 			return nil, err
 		}
@@ -260,7 +268,7 @@ func (wal *WAL) Read(pos *ChunkPosition) ([]byte, error) {
 	}
 
 	if segment == nil {
-		return nil, fmt.Errorf("segment file %d%s not found", pos.SegmentId, segmentFileSuffix)
+		return nil, fmt.Errorf("segment file %d%s not found", pos.SegmentId, wal.options.SementFileExt)
 	}
 
 	// read the data from the segment file.

wal_test.go

@@ -18,8 +18,9 @@ func destroyWAL(wal *WAL) {
 func TestWAL_Write(t *testing.T) {
 	dir, _ := os.MkdirTemp("", "wal-test-write1")
 	opts := Options{
-		DirPath:     dir,
-		SegmentSize: 32 * 1024 * 1024,
+		DirPath:       dir,
+		SementFileExt: ".SEG",
+		SegmentSize:   32 * 1024 * 1024,
 	}
 	wal, err := Open(opts)
 	assert.Nil(t, err)
@@ -51,6 +52,7 @@ func TestWAL_Write_large(t *testing.T) {
 	dir, _ := os.MkdirTemp("", "wal-test-write2")
 	opts := Options{
 		DirPath:     dir,
+		SementFileExt: ".SEG",
 		SegmentSize: 32 * 1024 * 1024,
 	}
 	wal, err := Open(opts)
@@ -64,6 +66,7 @@ func TestWAL_Write_large2(t *testing.T) {
 	dir, _ := os.MkdirTemp("", "wal-test-write3")
 	opts := Options{
 		DirPath:     dir,
+		SementFileExt: ".SEG",
 		SegmentSize: 32 * 1024 * 1024,
 	}
 	wal, err := Open(opts)
@@ -77,6 +80,7 @@ func TestWAL_OpenNewActiveSegment(t *testing.T) {
 	dir, _ := os.MkdirTemp("", "wal-test-new-active-segment")
 	opts := Options{
 		DirPath:     dir,
+		SementFileExt: ".SEG",
 		SegmentSize: 32 * 1024 * 1024,
 	}
 	wal, err := Open(opts)