bfs：弹出BFile的时候确保没有正在被使用

internal/utils/bfs/blocks_file.go

@@ -11,6 +11,7 @@ import (
 	"path/filepath"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 )
 
@@ -28,7 +29,8 @@ type BlocksFile struct {
 	fp    *os.File
 	mFile *MetaFile
 
-	isClosed bool
+	isClosing bool
+	isClosed  bool
 
 	mu *sync.RWMutex
 
@@ -36,7 +38,8 @@ type BlocksFile struct {
 	writingFileMap map[string]zero.Zero // hash => Zero
 	syncAt         time.Time
 
-	readerPool chan *FileReader
+	readerPool        chan *FileReader
+	countReadingFiles int32
 }
 
 func NewBlocksFileWithRawFile(fp *os.File, options *BlockFileOptions) (*BlocksFile, error) {
@@ -199,6 +202,7 @@ func (this *BlocksFile) OpenFileReader(fileHash string, isPartial bool) (*FileRe
 			return nil, ErrClosed
 		}
 		reader.Reset(header)
+		atomic.AddInt32(&this.countReadingFiles, 1)
 		return reader, nil
 	default:
 	}
@@ -209,10 +213,14 @@ func (this *BlocksFile) OpenFileReader(fileHash string, isPartial bool) (*FileRe
 	if err != nil {
 		return nil, err
 	}
+
+	atomic.AddInt32(&this.countReadingFiles, 1)
 	return NewFileReader(this, fp, header), nil
 }
 
 func (this *BlocksFile) CloseFileReader(reader *FileReader) error {
+	atomic.AddInt32(&this.countReadingFiles, -1)
+
 	select {
 	case this.readerPool <- reader:
 		return nil
@@ -286,6 +294,19 @@ func (this *BlocksFile) RemoveAll() error {
 	return os.Remove(this.fp.Name())
 }
 
+// CanClose 检查是否可以关闭
+func (this *BlocksFile) CanClose() bool {
+	this.mu.Lock()
+	defer this.mu.Unlock()
+
+	if len(this.writingFileMap) > 0 || atomic.LoadInt32(&this.countReadingFiles) > 0 {
+		return false
+	}
+
+	this.isClosing = true
+	return true
+}
+
 // Close 关闭当前文件
 func (this *BlocksFile) Close() error {
 	this.mu.Lock()
@@ -317,7 +338,7 @@ func (this *BlocksFile) removeWritingFile(hash string) {
 }
 
 func (this *BlocksFile) checkStatus() error {
-	if this.isClosed {
+	if this.isClosed || this.isClosing {
 		return ErrClosed
 	}
 	return nil