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better control for reader caching

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This commit is contained in:
chrislu
2022-02-26 02:16:47 -08:00
parent 3ad5fa6f6f
commit 28b395bef4
7 changed files with 240 additions and 250 deletions
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130
weed/filer/reader_at.go
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@@ -12,21 +12,15 @@ import (
"github.com/chrislusf/seaweedfs/weed/util"
"github.com/chrislusf/seaweedfs/weed/util/chunk_cache"
"github.com/chrislusf/seaweedfs/weed/wdclient"
"github.com/golang/groupcache/singleflight"
)
type ChunkReadAt struct {
masterClient *wdclient.MasterClient
chunkViews []*ChunkView
lookupFileId wdclient.LookupFileIdFunctionType
readerLock sync.Mutex
fileSize int64
fetchGroup singleflight.Group
chunkCache chunk_cache.ChunkCache
lastChunkFileId string
lastChunkData []byte
readerPattern *ReaderPattern
masterClient *wdclient.MasterClient
chunkViews []*ChunkView
readerLock sync.Mutex
fileSize int64
readerCache *ReaderCache
readerPattern *ReaderPattern
}
var _ = io.ReaderAt(&ChunkReadAt{})
@@ -90,16 +84,14 @@ func NewChunkReaderAtFromClient(lookupFn wdclient.LookupFileIdFunctionType, chun
return &ChunkReadAt{
chunkViews: chunkViews,
lookupFileId: lookupFn,
chunkCache: chunkCache,
fileSize: fileSize,
readerCache: newReaderCache(5, chunkCache, lookupFn),
readerPattern: NewReaderPattern(),
}
}
func (c *ChunkReadAt) Close() error {
c.lastChunkData = nil
c.lastChunkFileId = ""
c.readerCache.destroy()
return nil
}
@@ -142,16 +134,13 @@ func (c *ChunkReadAt) doReadAt(p []byte, offset int64) (n int, err error) {
continue
}
// glog.V(4).Infof("read [%d,%d), %d/%d chunk %s [%d,%d)", chunkStart, chunkStop, i, len(c.chunkViews), chunk.FileId, chunk.LogicOffset-chunk.Offset, chunk.LogicOffset-chunk.Offset+int64(chunk.Size))
var buffer []byte
bufferOffset := chunkStart - chunk.LogicOffset + chunk.Offset
bufferLength := chunkStop - chunkStart
buffer, err = c.readChunkSlice(chunk, nextChunk, uint64(bufferOffset), uint64(bufferLength))
copied, err := c.readChunkSliceAt(p[startOffset-offset:chunkStop-chunkStart+startOffset-offset], chunk, nextChunk, uint64(bufferOffset))
if err != nil {
glog.Errorf("fetching chunk %+v: %v\n", chunk, err)
return
return copied, err
}
copied := copy(p[startOffset-offset:chunkStop-chunkStart+startOffset-offset], buffer)
n += copied
startOffset, remaining = startOffset+int64(copied), remaining-int64(copied)
}
@@ -173,104 +162,15 @@ func (c *ChunkReadAt) doReadAt(p []byte, offset int64) (n int, err error) {
}
func (c *ChunkReadAt) readChunkSlice(chunkView *ChunkView, nextChunkViews *ChunkView, offset, length uint64) ([]byte, error) {
func (c *ChunkReadAt) readChunkSliceAt(buffer []byte, chunkView *ChunkView, nextChunkViews *ChunkView, offset uint64) (n int, err error) {
var chunkSlice []byte
if chunkView.LogicOffset == 0 {
chunkSlice = c.chunkCache.GetChunkSlice(chunkView.FileId, offset, length)
}
if len(chunkSlice) > 0 {
return chunkSlice, nil
}
if c.lookupFileId == nil {
return nil, nil
}
if c.readerPattern.IsRandomMode() {
return c.doFetchRangeChunkData(chunkView, offset, length)
}
chunkData, err := c.readFromWholeChunkData(chunkView, nextChunkViews)
if err != nil {
return nil, err
}
wanted := min(int64(length), int64(len(chunkData))-int64(offset))
return chunkData[offset : int64(offset)+wanted], nil
}
func (c *ChunkReadAt) readFromWholeChunkData(chunkView *ChunkView, nextChunkViews ...*ChunkView) (chunkData []byte, err error) {
if c.lastChunkFileId == chunkView.FileId {
return c.lastChunkData, nil
return c.readerCache.ReadChunkAt(buffer, chunkView.FileId, chunkView.CipherKey, chunkView.IsGzipped, int64(offset), int(chunkView.ChunkSize), chunkView.LogicOffset == 0)
}
v, doErr := c.readOneWholeChunk(chunkView)
if doErr != nil {
return nil, doErr
n, err = c.readerCache.ReadChunkAt(buffer, chunkView.FileId, chunkView.CipherKey, chunkView.IsGzipped, int64(offset), int(chunkView.ChunkSize), chunkView.LogicOffset == 0)
if nextChunkViews != nil {
c.readerCache.MaybeCache(nextChunkViews.FileId, nextChunkViews.CipherKey, nextChunkViews.IsGzipped, int(nextChunkViews.ChunkSize))
}
chunkData = v.([]byte)
c.lastChunkData = chunkData
c.lastChunkFileId = chunkView.FileId
for _, nextChunkView := range nextChunkViews {
if c.chunkCache != nil && nextChunkView != nil {
go c.readOneWholeChunk(nextChunkView)
}
}
return
}
func (c *ChunkReadAt) readOneWholeChunk(chunkView *ChunkView) (interface{}, error) {
var err error
return c.fetchGroup.Do(chunkView.FileId, func() (interface{}, error) {
glog.V(4).Infof("readFromWholeChunkData %s offset %d [%d,%d) size at least %d", chunkView.FileId, chunkView.Offset, chunkView.LogicOffset, chunkView.LogicOffset+int64(chunkView.Size), chunkView.ChunkSize)
var data []byte
if chunkView.LogicOffset == 0 {
data = c.chunkCache.GetChunk(chunkView.FileId, chunkView.ChunkSize)
}
if data != nil {
glog.V(4).Infof("cache hit %s [%d,%d)", chunkView.FileId, chunkView.LogicOffset-chunkView.Offset, chunkView.LogicOffset-chunkView.Offset+int64(len(data)))
} else {
var err error
data, err = c.doFetchFullChunkData(chunkView)
if err != nil {
return data, err
}
if chunkView.LogicOffset == 0 {
// only cache the first chunk
c.chunkCache.SetChunk(chunkView.FileId, data)
}
}
return data, err
})
}
func (c *ChunkReadAt) doFetchFullChunkData(chunkView *ChunkView) ([]byte, error) {
glog.V(4).Infof("+ doFetchFullChunkData %s", chunkView.FileId)
data, err := fetchChunk(c.lookupFileId, chunkView.FileId, chunkView.CipherKey, chunkView.IsGzipped)
glog.V(4).Infof("- doFetchFullChunkData %s", chunkView.FileId)
return data, err
}
func (c *ChunkReadAt) doFetchRangeChunkData(chunkView *ChunkView, offset, length uint64) ([]byte, error) {
glog.V(4).Infof("+ doFetchFullChunkData %s", chunkView.FileId)
data, err := fetchChunkRange(c.lookupFileId, chunkView.FileId, chunkView.CipherKey, chunkView.IsGzipped, int64(offset), int(length))
glog.V(4).Infof("- doFetchFullChunkData %s", chunkView.FileId)
return data, err
}