Initial commit (code only without large binaries)

EdgeNode/internal/utils/bfs/file_writer.go

@@ -0,0 +1,112 @@
+// Copyright 2024 GoEdge CDN goedge.cdn@gmail.com. All rights reserved. Official site: https://goedge.cn .
+
+package bfs
+
+import "errors"
+
+// FileWriter file writer
+// not thread-safe
+type FileWriter struct {
+	bFile   *BlocksFile
+	hasMeta bool
+	hash    string
+
+	bodySize     int64
+	originOffset int64
+
+	realHeaderSize int64
+	realBodySize   int64
+	isPartial      bool
+}
+
+func NewFileWriter(bFile *BlocksFile, hash string, bodySize int64, isPartial bool) (*FileWriter, error) {
+	if isPartial && bodySize <= 0 {
+		return nil, errors.New("invalid body size for partial content")
+	}
+
+	return &FileWriter{
+		bFile:     bFile,
+		hash:      hash,
+		bodySize:  bodySize,
+		isPartial: isPartial,
+	}, nil
+}
+
+func (this *FileWriter) WriteMeta(status int, expiresAt int64, expectedFileSize int64) error {
+	this.hasMeta = true
+	return this.bFile.mFile.WriteMeta(this.hash, status, expiresAt, expectedFileSize)
+}
+
+func (this *FileWriter) WriteHeader(b []byte) (n int, err error) {
+	if !this.isPartial && !this.hasMeta {
+		err = errors.New("no meta found")
+		return
+	}
+
+	n, err = this.bFile.Write(this.hash, BlockTypeHeader, b, -1)
+	this.realHeaderSize += int64(n)
+	return
+}
+
+func (this *FileWriter) WriteBody(b []byte) (n int, err error) {
+	if !this.isPartial && !this.hasMeta {
+		err = errors.New("no meta found")
+		return
+	}
+
+	n, err = this.bFile.Write(this.hash, BlockTypeBody, b, this.originOffset)
+	this.originOffset += int64(n)
+	this.realBodySize += int64(n)
+	return
+}
+
+func (this *FileWriter) WriteBodyAt(b []byte, offset int64) (n int, err error) {
+	if !this.hasMeta {
+		err = errors.New("no meta found")
+		return
+	}
+
+	if !this.isPartial {
+		err = errors.New("can not write body at specified offset: it is not a partial file")
+		return
+	}
+
+	// still 'Write()' NOT 'WriteAt()'
+	this.originOffset = offset
+	n, err = this.bFile.Write(this.hash, BlockTypeBody, b, offset)
+	this.originOffset += int64(n)
+	return
+}
+
+func (this *FileWriter) Close() error {
+	defer func() {
+		this.bFile.removeWritingFile(this.hash)
+	}()
+
+	if !this.isPartial && !this.hasMeta {
+		return errors.New("no meta found")
+	}
+
+	if this.isPartial {
+		if this.originOffset > this.bodySize {
+			return errors.New("unexpected body size")
+		}
+		this.realBodySize = this.bodySize
+	} else {
+		if this.bodySize > 0 && this.bodySize != this.realBodySize {
+			return errors.New("unexpected body size")
+		}
+	}
+
+	err := this.bFile.mFile.WriteClose(this.hash, this.realHeaderSize, this.realBodySize)
+	if err != nil {
+		return err
+	}
+
+	return this.bFile.Sync()
+}
+
+func (this *FileWriter) Discard() error {
+	// TODO 需要测试
+	return this.bFile.mFile.RemoveFile(this.hash)
+}