mirror of
https://github.com/seaweedfs/seaweedfs.git
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187 lines
4.7 KiB
Go
187 lines
4.7 KiB
Go
package filer2
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import (
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"bytes"
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"context"
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"fmt"
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"io"
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"math"
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"strings"
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"github.com/chrislusf/seaweedfs/weed/glog"
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"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
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"github.com/chrislusf/seaweedfs/weed/util"
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"github.com/chrislusf/seaweedfs/weed/wdclient"
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)
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func StreamContent(masterClient *wdclient.MasterClient, w io.Writer, chunks []*filer_pb.FileChunk, offset int64, size int64) error {
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chunkViews := ViewFromChunks(chunks, offset, size)
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fileId2Url := make(map[string]string)
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for _, chunkView := range chunkViews {
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urlString, err := masterClient.LookupFileId(chunkView.FileId)
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if err != nil {
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glog.V(1).Infof("operation LookupFileId %s failed, err: %v", chunkView.FileId, err)
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return err
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}
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fileId2Url[chunkView.FileId] = urlString
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}
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for _, chunkView := range chunkViews {
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urlString := fileId2Url[chunkView.FileId]
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err := util.ReadUrlAsStream(urlString, chunkView.CipherKey, chunkView.isGzipped, chunkView.IsFullChunk, chunkView.Offset, int(chunkView.Size), func(data []byte) {
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w.Write(data)
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})
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if err != nil {
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glog.V(1).Infof("read %s failed, err: %v", chunkView.FileId, err)
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return err
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}
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}
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return nil
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}
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type ChunkStreamReader struct {
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masterClient *wdclient.MasterClient
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chunkViews []*ChunkView
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logicOffset int64
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buffer []byte
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bufferOffset int64
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bufferPos int
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chunkIndex int
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lookupFileId func(fileId string) (targetUrl string, err error)
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}
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var _ = io.ReadSeeker(&ChunkStreamReader{})
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func NewChunkStreamReaderFromFiler(masterClient *wdclient.MasterClient, chunks []*filer_pb.FileChunk) *ChunkStreamReader {
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chunkViews := ViewFromChunks(chunks, 0, math.MaxInt32)
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return &ChunkStreamReader{
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chunkViews: chunkViews,
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lookupFileId: func(fileId string) (targetUrl string, err error) {
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return masterClient.LookupFileId(fileId)
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},
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}
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}
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func NewChunkStreamReaderFromClient(filerClient filer_pb.FilerClient, chunkViews []*ChunkView) *ChunkStreamReader {
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return &ChunkStreamReader{
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chunkViews: chunkViews,
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lookupFileId: func(fileId string) (targetUrl string, err error) {
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err = filerClient.WithFilerClient(func(client filer_pb.SeaweedFilerClient) error {
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vid := VolumeId(fileId)
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resp, err := client.LookupVolume(context.Background(), &filer_pb.LookupVolumeRequest{
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VolumeIds: []string{vid},
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})
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if err != nil {
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return err
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}
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locations := resp.LocationsMap[vid]
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if locations == nil || len(locations.Locations) == 0 {
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glog.V(0).Infof("failed to locate %s", fileId)
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return fmt.Errorf("failed to locate %s", fileId)
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}
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volumeServerAddress := filerClient.AdjustedUrl(locations.Locations[0].Url)
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targetUrl = fmt.Sprintf("http://%s/%s", volumeServerAddress, fileId)
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return nil
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})
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return
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},
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}
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}
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func (c *ChunkStreamReader) Read(p []byte) (n int, err error) {
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if c.isBufferEmpty() {
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if c.chunkIndex >= len(c.chunkViews) {
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return 0, io.EOF
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}
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chunkView := c.chunkViews[c.chunkIndex]
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c.fetchChunkToBuffer(chunkView)
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c.chunkIndex++
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}
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n = copy(p, c.buffer[c.bufferPos:])
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c.bufferPos += n
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return
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}
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func (c *ChunkStreamReader) isBufferEmpty() bool {
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return len(c.buffer) <= c.bufferPos
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}
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func (c *ChunkStreamReader) Seek(offset int64, whence int) (int64, error) {
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var totalSize int64
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for _, chunk := range c.chunkViews {
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totalSize += int64(chunk.Size)
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}
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var err error
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switch whence {
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case io.SeekStart:
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case io.SeekCurrent:
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offset += c.bufferOffset + int64(c.bufferPos)
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case io.SeekEnd:
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offset = totalSize + offset
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}
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if offset > totalSize {
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err = io.ErrUnexpectedEOF
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}
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for i, chunk := range c.chunkViews {
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if chunk.LogicOffset <= offset && offset < chunk.LogicOffset+int64(chunk.Size) {
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if c.isBufferEmpty() || c.bufferOffset != chunk.LogicOffset {
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c.fetchChunkToBuffer(chunk)
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c.chunkIndex = i + 1
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break
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}
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}
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}
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c.bufferPos = int(offset - c.bufferOffset)
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return offset, err
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}
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func (c *ChunkStreamReader) fetchChunkToBuffer(chunkView *ChunkView) error {
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urlString, err := c.lookupFileId(chunkView.FileId)
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if err != nil {
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glog.V(1).Infof("operation LookupFileId %s failed, err: %v", chunkView.FileId, err)
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return err
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}
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var buffer bytes.Buffer
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err = util.ReadUrlAsStream(urlString, chunkView.CipherKey, chunkView.isGzipped, chunkView.IsFullChunk, chunkView.Offset, int(chunkView.Size), func(data []byte) {
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buffer.Write(data)
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})
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if err != nil {
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glog.V(1).Infof("read %s failed, err: %v", chunkView.FileId, err)
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return err
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}
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c.buffer = buffer.Bytes()
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c.bufferPos = 0
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c.bufferOffset = chunkView.LogicOffset
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// glog.V(0).Infof("read %s [%d,%d)", chunkView.FileId, chunkView.LogicOffset, chunkView.LogicOffset+int64(chunkView.Size))
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return nil
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}
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func VolumeId(fileId string) string {
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lastCommaIndex := strings.LastIndex(fileId, ",")
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if lastCommaIndex > 0 {
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return fileId[:lastCommaIndex]
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}
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return fileId
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}
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