gitlab-com-seaweedfs/seaweedfs
1
0
Fork 0
mirror of https://github.com/seaweedfs/seaweedfs.git synced 2024-01-19 02:48:24 +00:00
Code Issues Projects Releases Wiki Activity

ensure multi-threaded correctness

Browse source
This commit is contained in:
Chris Lu 2021-08-25 17:28:50 -07:00
parent a7a914f120
commit 9bcf94b2b1
1 changed files with 45 additions and 29 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

74
weed/filer/stream.go
View file

@ -7,6 +7,7 @@ import (
"math"
"sort"
"strings"
"sync"
"time"
"github.com/chrislusf/seaweedfs/weed/glog"
@ -131,8 +132,8 @@ type ChunkStreamReader struct {
logicOffset int64
buffer []byte
bufferOffset int64
bufferPos int
nextChunkViewIndex int
bufferLock sync.Mutex
chunk string
lookupFileId wdclient.LookupFileIdFunctionType
}
@ -175,27 +176,29 @@ func NewChunkStreamReader(filerClient filer_pb.FilerClient, chunks []*filer_pb.F
}
func (c *ChunkStreamReader) ReadAt(p []byte, off int64) (n int, err error) {
c.bufferLock.Lock()
defer c.bufferLock.Unlock()
if err = c.prepareBufferFor(off); err != nil {
return
}
c.logicOffset = off
return c.Read(p)
return c.doRead(p)
}
func (c *ChunkStreamReader) Read(p []byte) (n int, err error) {
c.bufferLock.Lock()
defer c.bufferLock.Unlock()
return c.doRead(p)
}
func (c *ChunkStreamReader) doRead(p []byte) (n int, err error) {
// fmt.Printf("do read [%d,%d) at %s[%d,%d)\n", c.logicOffset, c.logicOffset+int64(len(p)), c.chunk, c.bufferOffset, c.bufferOffset+int64(len(c.buffer)))
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++
// println("read", c.logicOffset)
if err = c.prepareBufferFor(c.logicOffset); err != nil {
return
}
t := copy(p[n:], c.buffer[c.bufferPos:])
c.bufferPos += t
t := copy(p[n:], c.buffer[c.logicOffset-c.bufferOffset:])
n += t
c.logicOffset += int64(t)
}
@ -203,10 +206,12 @@ func (c *ChunkStreamReader) Read(p []byte) (n int, err error) {
}
func (c *ChunkStreamReader) isBufferEmpty() bool {
return len(c.buffer) <= c.bufferPos
return len(c.buffer) <= int(c.logicOffset - c.bufferOffset)
}
func (c *ChunkStreamReader) Seek(offset int64, whence int) (int64, error) {
c.bufferLock.Lock()
defer c.bufferLock.Unlock()
var err error
switch whence {
@ -226,48 +231,59 @@ func (c *ChunkStreamReader) Seek(offset int64, whence int) (int64, error) {
}
func insideChunk(offset int64, chunk *ChunkView) bool {
return chunk.LogicOffset <= offset && offset < chunk.LogicOffset+int64(chunk.Size)
}
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
}
if c.bufferOffset <= offset && offset < c.bufferOffset+int64(len(c.buffer)) {
return nil
}
// fmt.Printf("fetch for offset %d\n", offset)
// need to seek to a different chunk
currentChunkIndex := sort.Search(len(c.chunkViews), func(i int) bool {
return offset < c.chunkViews[i].LogicOffset
})
if currentChunkIndex == len(c.chunkViews) {
// not found
if c.chunkViews[0].LogicOffset <= offset {
if insideChunk(offset, c.chunkViews[0]) {
// fmt.Printf("select0 chunk %d %s\n", currentChunkIndex, c.chunkViews[currentChunkIndex].FileId)
currentChunkIndex = 0
} else if c.chunkViews[len(c.chunkViews)-1].LogicOffset <= offset {
currentChunkIndex = len(c.chunkViews) -1
} else if insideChunk(offset, c.chunkViews[len(c.chunkViews)-1]) {
currentChunkIndex = len(c.chunkViews) - 1
// fmt.Printf("select last chunk %d %s\n", currentChunkIndex, c.chunkViews[currentChunkIndex].FileId)
} else {
return io.EOF
}
} else if currentChunkIndex > 0 {
if c.chunkViews[currentChunkIndex-1].LogicOffset <= offset {
if insideChunk(offset, c.chunkViews[currentChunkIndex]) {
// good hit
} else if insideChunk(offset, c.chunkViews[currentChunkIndex-1]){
currentChunkIndex -= 1
// fmt.Printf("select -1 chunk %d %s\n", currentChunkIndex, c.chunkViews[currentChunkIndex].FileId)
} else {
// glog.Fatalf("unexpected1 offset %d", offset)
return fmt.Errorf("unexpected1 offset %d", offset)
}
} else {
// glog.Fatalf("unexpected2 offset %d", offset)
return fmt.Errorf("unexpected2 offset %d", offset)
}
// positioning within the new chunk
chunk := c.chunkViews[currentChunkIndex]
if chunk.LogicOffset <= offset && offset < chunk.LogicOffset+int64(chunk.Size) {
if insideChunk(offset, chunk) {
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)
} else {
// glog.Fatalf("unexpected3 offset %d in %s [%d,%d)", offset, chunk.FileId, chunk.LogicOffset, chunk.LogicOffset+int64(chunk.Size))
return fmt.Errorf("unexpected3 offset %d in %s [%d,%d)", offset, chunk.FileId, chunk.LogicOffset, chunk.LogicOffset+int64(chunk.Size))
}
return
}
@ -298,10 +314,10 @@ func (c *ChunkStreamReader) fetchChunkToBuffer(chunkView *ChunkView) error {
return err
}
c.buffer = buffer.Bytes()
c.bufferPos = 0
c.bufferOffset = chunkView.LogicOffset
c.chunk = chunkView.FileId
// glog.V(0).Infof("read %s [%d,%d)", chunkView.FileId, chunkView.LogicOffset, chunkView.LogicOffset+int64(chunkView.Size))
// glog.V(0).Infof("fetched %s [%d,%d)", chunkView.FileId, chunkView.LogicOffset, chunkView.LogicOffset+int64(chunkView.Size))
return nil
}