package filer import ( "bytes" "fmt" "io" "math" "strings" "github.com/chrislusf/seaweedfs/weed/glog" "github.com/chrislusf/seaweedfs/weed/pb/filer_pb" "github.com/chrislusf/seaweedfs/weed/util" "github.com/chrislusf/seaweedfs/weed/wdclient" ) func StreamContent(masterClient *wdclient.MasterClient, w io.Writer, chunks []*filer_pb.FileChunk, offset int64, size int64) error { // fmt.Printf("start to stream content for chunks: %+v\n", chunks) chunkViews := ViewFromChunks(masterClient.LookupFileId, chunks, offset, size) fileId2Url := make(map[string][]string) for _, chunkView := range chunkViews { urlStrings, err := masterClient.LookupFileId(chunkView.FileId) if err != nil { glog.V(1).Infof("operation LookupFileId %s failed, err: %v", chunkView.FileId, err) return err } fileId2Url[chunkView.FileId] = urlStrings } for _, chunkView := range chunkViews { urlStrings := fileId2Url[chunkView.FileId] data, err := retriedFetchChunkData(urlStrings, chunkView.CipherKey, chunkView.IsGzipped, chunkView.IsFullChunk(), chunkView.Offset, int(chunkView.Size)) if err != nil { glog.Errorf("read chunk: %v", err) return fmt.Errorf("read chunk: %v", err) } _, err = w.Write(data) if err != nil { glog.Errorf("write chunk: %v", err) return fmt.Errorf("write chunk: %v", err) } } return nil } // ---------------- ReadAllReader ---------------------------------- func ReadAll(masterClient *wdclient.MasterClient, chunks []*filer_pb.FileChunk) ([]byte, error) { buffer := bytes.Buffer{} lookupFileIdFn := func(fileId string) (targetUrls []string, err error) { return masterClient.LookupFileId(fileId) } chunkViews := ViewFromChunks(lookupFileIdFn, chunks, 0, math.MaxInt64) for _, chunkView := range chunkViews { urlStrings, err := lookupFileIdFn(chunkView.FileId) if err != nil { glog.V(1).Infof("operation LookupFileId %s failed, err: %v", chunkView.FileId, err) return nil, err } data, err := retriedFetchChunkData(urlStrings, chunkView.CipherKey, chunkView.IsGzipped, chunkView.IsFullChunk(), chunkView.Offset, int(chunkView.Size)) if err != nil { return nil, err } buffer.Write(data) } return buffer.Bytes(), nil } // ---------------- ChunkStreamReader ---------------------------------- type ChunkStreamReader struct { chunkViews []*ChunkView logicOffset int64 buffer []byte bufferOffset int64 bufferPos int chunkIndex int lookupFileId LookupFileIdFunctionType } var _ = io.ReadSeeker(&ChunkStreamReader{}) func NewChunkStreamReaderFromFiler(masterClient *wdclient.MasterClient, chunks []*filer_pb.FileChunk) *ChunkStreamReader { lookupFileIdFn := func(fileId string) (targetUrl []string, err error) { return masterClient.LookupFileId(fileId) } chunkViews := ViewFromChunks(lookupFileIdFn, chunks, 0, math.MaxInt64) return &ChunkStreamReader{ chunkViews: chunkViews, lookupFileId: lookupFileIdFn, } } func NewChunkStreamReader(filerClient filer_pb.FilerClient, chunks []*filer_pb.FileChunk) *ChunkStreamReader { lookupFileIdFn := LookupFn(filerClient) chunkViews := ViewFromChunks(lookupFileIdFn, chunks, 0, math.MaxInt64) return &ChunkStreamReader{ chunkViews: chunkViews, lookupFileId: lookupFileIdFn, } } func (c *ChunkStreamReader) Read(p []byte) (n int, err error) { for n < len(p) { if c.isBufferEmpty() { if c.chunkIndex >= len(c.chunkViews) { return n, io.EOF } chunkView := c.chunkViews[c.chunkIndex] c.fetchChunkToBuffer(chunkView) c.chunkIndex++ } t := copy(p[n:], c.buffer[c.bufferPos:]) c.bufferPos += t n += t } return } func (c *ChunkStreamReader) isBufferEmpty() bool { return len(c.buffer) <= c.bufferPos } func (c *ChunkStreamReader) Seek(offset int64, whence int) (int64, error) { var totalSize int64 for _, chunk := range c.chunkViews { totalSize += int64(chunk.Size) } var err error switch whence { case io.SeekStart: case io.SeekCurrent: offset += c.bufferOffset + int64(c.bufferPos) case io.SeekEnd: offset = totalSize + offset } if offset > totalSize { err = io.ErrUnexpectedEOF } for i, chunk := range c.chunkViews { if chunk.LogicOffset <= offset && offset < chunk.LogicOffset+int64(chunk.Size) { if c.isBufferEmpty() || c.bufferOffset != chunk.LogicOffset { c.fetchChunkToBuffer(chunk) c.chunkIndex = i + 1 break } } } c.bufferPos = int(offset - c.bufferOffset) return offset, err } func (c *ChunkStreamReader) fetchChunkToBuffer(chunkView *ChunkView) error { urlStrings, err := c.lookupFileId(chunkView.FileId) if err != nil { glog.V(1).Infof("operation LookupFileId %s failed, err: %v", chunkView.FileId, err) return err } var buffer bytes.Buffer var shouldRetry bool for _, urlString := range urlStrings { shouldRetry, err = util.ReadUrlAsStream(urlString, chunkView.CipherKey, chunkView.IsGzipped, chunkView.IsFullChunk(), chunkView.Offset, int(chunkView.Size), func(data []byte) { buffer.Write(data) }) if !shouldRetry { break } if err != nil { glog.V(1).Infof("read %s failed, err: %v", chunkView.FileId, err) buffer.Reset() } else { break } } if err != nil { return err } c.buffer = buffer.Bytes() c.bufferPos = 0 c.bufferOffset = chunkView.LogicOffset // glog.V(0).Infof("read %s [%d,%d)", chunkView.FileId, chunkView.LogicOffset, chunkView.LogicOffset+int64(chunkView.Size)) return nil } func (c *ChunkStreamReader) Close() { // TODO try to release and reuse buffer } func VolumeId(fileId string) string { lastCommaIndex := strings.LastIndex(fileId, ",") if lastCommaIndex > 0 { return fileId[:lastCommaIndex] } return fileId }