seaweedfs/weed/filer/stream.go
2021-08-07 15:35:27 -07:00

250 lines
6.9 KiB
Go

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, w 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()
data, err := retriedFetchChunkData(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)
}
_, err = w.Write(data)
if err != nil {
stats.FilerRequestCounter.WithLabelValues("chunkDownloadedError").Inc()
return fmt.Errorf("write 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
buffer []byte
bufferOffset int64
bufferPos int
nextChunkViewIndex int
lookupFileId wdclient.LookupFileIdFunctionType
}
var _ = io.ReadSeeker(&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) 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]
c.fetchChunkToBuffer(chunkView)
c.nextChunkViewIndex++
}
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 err error
switch whence {
case io.SeekStart:
case io.SeekCurrent:
offset += c.bufferOffset + int64(c.bufferPos)
case io.SeekEnd:
offset = c.totalSize + offset
}
if offset > c.totalSize {
err = io.ErrUnexpectedEOF
}
// 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 offset, 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 0, 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 {
c.fetchChunkToBuffer(chunk)
c.nextChunkViewIndex = currentChunkIndex + 1
}
c.bufferPos = int(offset - c.bufferOffset)
} else {
return 0, io.ErrUnexpectedEOF
}
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
}