package filer import ( "bytes" "fmt" "io" "math" "sort" "strings" "time" "github.com/chrislusf/seaweedfs/weed/glog" "github.com/chrislusf/seaweedfs/weed/pb/filer_pb" "github.com/chrislusf/seaweedfs/weed/stats" "github.com/chrislusf/seaweedfs/weed/util" "github.com/chrislusf/seaweedfs/weed/wdclient" ) func StreamContent(masterClient wdclient.HasLookupFileIdFunction, writer io.Writer, chunks []*filer_pb.FileChunk, offset int64, size int64) error { glog.V(9).Infof("start to stream content for chunks: %+v\n", chunks) chunkViews := ViewFromChunks(masterClient.GetLookupFileIdFunction(), chunks, offset, size) fileId2Url := make(map[string][]string) for _, chunkView := range chunkViews { urlStrings, err := masterClient.GetLookupFileIdFunction()(chunkView.FileId) if err != nil { glog.V(1).Infof("operation LookupFileId %s failed, err: %v", chunkView.FileId, err) return err } else if len(urlStrings) == 0 { glog.Errorf("operation LookupFileId %s failed, err: urls not found", chunkView.FileId) return fmt.Errorf("operation LookupFileId %s failed, err: urls not found", chunkView.FileId) } fileId2Url[chunkView.FileId] = urlStrings } for _, chunkView := range chunkViews { urlStrings := fileId2Url[chunkView.FileId] start := time.Now() err := retriedStreamFetchChunkData(writer, urlStrings, chunkView.CipherKey, chunkView.IsGzipped, chunkView.IsFullChunk(), chunkView.Offset, int(chunkView.Size)) stats.FilerRequestHistogram.WithLabelValues("chunkDownload").Observe(time.Since(start).Seconds()) if err != nil { stats.FilerRequestCounter.WithLabelValues("chunkDownloadError").Inc() return fmt.Errorf("read chunk: %v", err) } stats.FilerRequestCounter.WithLabelValues("chunkDownload").Inc() } 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 totalSize int64 logicOffset int64 buffer []byte bufferOffset int64 bufferPos int nextChunkViewIndex int lookupFileId wdclient.LookupFileIdFunctionType } var _ = io.ReadSeeker(&ChunkStreamReader{}) var _ = io.ReaderAt(&ChunkStreamReader{}) func doNewChunkStreamReader(lookupFileIdFn wdclient.LookupFileIdFunctionType, chunks []*filer_pb.FileChunk) *ChunkStreamReader { chunkViews := ViewFromChunks(lookupFileIdFn, chunks, 0, math.MaxInt64) sort.Slice(chunkViews, func(i, j int) bool { return chunkViews[i].LogicOffset < chunkViews[j].LogicOffset }) var totalSize int64 for _, chunk := range chunkViews { totalSize += int64(chunk.Size) } return &ChunkStreamReader{ chunkViews: chunkViews, lookupFileId: lookupFileIdFn, totalSize: totalSize, } } func NewChunkStreamReaderFromFiler(masterClient *wdclient.MasterClient, chunks []*filer_pb.FileChunk) *ChunkStreamReader { lookupFileIdFn := func(fileId string) (targetUrl []string, err error) { return masterClient.LookupFileId(fileId) } return doNewChunkStreamReader(lookupFileIdFn, chunks) } func NewChunkStreamReader(filerClient filer_pb.FilerClient, chunks []*filer_pb.FileChunk) *ChunkStreamReader { lookupFileIdFn := LookupFn(filerClient) return doNewChunkStreamReader(lookupFileIdFn, chunks) } func (c *ChunkStreamReader) ReadAt(p []byte, off int64) (n int, err error) { if err = c.prepareBufferFor(c.logicOffset); err != nil { return } return c.Read(p) } func (c *ChunkStreamReader) Read(p []byte) (n int, err error) { for n < len(p) { if c.isBufferEmpty() { if c.nextChunkViewIndex >= len(c.chunkViews) { return n, io.EOF } chunkView := c.chunkViews[c.nextChunkViewIndex] if err = c.fetchChunkToBuffer(chunkView); err != nil { return } c.nextChunkViewIndex++ } t := copy(p[n:], c.buffer[c.bufferPos:]) c.bufferPos += t n += t c.logicOffset += int64(t) } return } func (c *ChunkStreamReader) isBufferEmpty() bool { return len(c.buffer) <= c.bufferPos } func (c *ChunkStreamReader) Seek(offset int64, whence int) (int64, error) { var err error switch whence { case io.SeekStart: case io.SeekCurrent: offset += c.logicOffset case io.SeekEnd: offset = c.totalSize + offset } if offset > c.totalSize { err = io.ErrUnexpectedEOF } else { c.logicOffset = offset } return offset, err } func (c *ChunkStreamReader) prepareBufferFor(offset int64) (err error) { // stay in the same chunk if !c.isBufferEmpty() { if c.bufferOffset <= offset && offset < c.bufferOffset+int64(len(c.buffer)) { c.bufferPos = int(offset - c.bufferOffset) return nil } } // need to seek to a different chunk currentChunkIndex := sort.Search(len(c.chunkViews), func(i int) bool { return c.chunkViews[i].LogicOffset <= offset }) if currentChunkIndex == len(c.chunkViews) { return io.EOF } // positioning within the new chunk chunk := c.chunkViews[currentChunkIndex] if chunk.LogicOffset <= offset && offset < chunk.LogicOffset+int64(chunk.Size) { if c.isBufferEmpty() || c.bufferOffset != chunk.LogicOffset { if err = c.fetchChunkToBuffer(chunk); err != nil { return } c.nextChunkViewIndex = currentChunkIndex + 1 } c.bufferPos = int(offset - c.bufferOffset) } return } 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 }