chrislu
3 years ago
7 changed files with 240 additions and 250 deletions
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30weed/filer/filechunk_manifest.go
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120weed/filer/reader_at.go
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17weed/filer/reader_at_test.go
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187weed/filer/reader_cache.go
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18weed/filer/stream.go
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5weed/server/filer_server_handlers_read.go
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103weed/util/chunk_cache/chunk_cache.go
@ -0,0 +1,187 @@ |
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package filer |
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|
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import ( |
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"fmt" |
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"github.com/chrislusf/seaweedfs/weed/glog" |
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"github.com/chrislusf/seaweedfs/weed/util/chunk_cache" |
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"github.com/chrislusf/seaweedfs/weed/util/mem" |
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"github.com/chrislusf/seaweedfs/weed/wdclient" |
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"sync" |
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"time" |
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) |
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|
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type ReaderCache struct { |
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chunkCache chunk_cache.ChunkCache |
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lookupFileIdFn wdclient.LookupFileIdFunctionType |
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sync.Mutex |
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downloaders map[string]*SingleChunkCacher |
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limit int |
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} |
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|
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type SingleChunkCacher struct { |
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sync.RWMutex |
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parent *ReaderCache |
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chunkFileId string |
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data []byte |
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err error |
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cipherKey []byte |
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isGzipped bool |
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chunkSize int |
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shouldCache bool |
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wg sync.WaitGroup |
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completedTime time.Time |
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} |
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|
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func newReaderCache(limit int, chunkCache chunk_cache.ChunkCache, lookupFileIdFn wdclient.LookupFileIdFunctionType) *ReaderCache { |
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return &ReaderCache{ |
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limit: limit, |
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chunkCache: chunkCache, |
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lookupFileIdFn: lookupFileIdFn, |
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downloaders: make(map[string]*SingleChunkCacher), |
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} |
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} |
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|
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func (rc *ReaderCache) MaybeCache(fileId string, cipherKey []byte, isGzipped bool, chunkSize int) { |
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rc.Lock() |
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defer rc.Unlock() |
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if _, found := rc.downloaders[fileId]; found { |
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return |
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} |
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if rc.lookupFileIdFn == nil { |
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return |
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} |
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|
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// if too many, delete one of them?
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glog.V(0).Infof("downloader2 %d", len(rc.downloaders)) |
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if len(rc.downloaders) >= rc.limit { |
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oldestFid, oldestTime := "", time.Now() |
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for fid, downloader := range rc.downloaders { |
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if !downloader.completedTime.IsZero() { |
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if downloader.completedTime.Before(oldestTime) { |
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oldestFid, oldestTime = fid, downloader.completedTime |
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} |
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} |
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} |
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if oldestFid != "" { |
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oldDownloader := rc.downloaders[oldestFid] |
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delete(rc.downloaders, oldestFid) |
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oldDownloader.destroy() |
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} else { |
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// if still no slots, return
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return |
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} |
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} |
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|
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cacher := newSingleChunkCacher(rc, fileId, cipherKey, isGzipped, chunkSize, false) |
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cacher.wg.Add(1) |
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go cacher.startCaching() |
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cacher.wg.Wait() |
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rc.downloaders[fileId] = cacher |
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|
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return |
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} |
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|
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func (rc *ReaderCache) ReadChunkAt(buffer []byte, fileId string, cipherKey []byte, isGzipped bool, offset int64, chunkSize int, shouldCache bool) (int, error) { |
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rc.Lock() |
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defer rc.Unlock() |
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if cacher, found := rc.downloaders[fileId]; found { |
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return cacher.readChunkAt(buffer, offset) |
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} |
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if shouldCache || rc.lookupFileIdFn == nil { |
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n, err := rc.chunkCache.ReadChunkAt(buffer, fileId, uint64(offset)) |
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if n > 0 { |
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return n, err |
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} |
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} |
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|
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glog.V(0).Infof("downloader1 %d", len(rc.downloaders)) |
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if len(rc.downloaders) >= rc.limit { |
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oldestFid, oldestTime := "", time.Now() |
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for fid, downloader := range rc.downloaders { |
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if !downloader.completedTime.IsZero() { |
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if downloader.completedTime.Before(oldestTime) { |
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oldestFid, oldestTime = fid, downloader.completedTime |
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} |
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} |
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} |
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if oldestFid != "" { |
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oldDownloader := rc.downloaders[oldestFid] |
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delete(rc.downloaders, oldestFid) |
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oldDownloader.destroy() |
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} |
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} |
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|
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cacher := newSingleChunkCacher(rc, fileId, cipherKey, isGzipped, chunkSize, shouldCache) |
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cacher.wg.Add(1) |
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go cacher.startCaching() |
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cacher.wg.Wait() |
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rc.downloaders[fileId] = cacher |
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return cacher.readChunkAt(buffer, offset) |
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} |
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func (rc *ReaderCache) destroy() { |
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rc.Lock() |
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defer rc.Unlock() |
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for _, downloader := range rc.downloaders { |
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downloader.destroy() |
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} |
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|
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} |
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|
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func newSingleChunkCacher(parent *ReaderCache, fileId string, cipherKey []byte, isGzipped bool, chunkSize int, shouldCache bool) *SingleChunkCacher { |
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t := &SingleChunkCacher{ |
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parent: parent, |
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chunkFileId: fileId, |
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cipherKey: cipherKey, |
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isGzipped: isGzipped, |
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chunkSize: chunkSize, |
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shouldCache: shouldCache, |
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} |
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return t |
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} |
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func (s *SingleChunkCacher) startCaching() { |
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s.Lock() |
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defer s.Unlock() |
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s.wg.Done() // means this has been started
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urlStrings, err := s.parent.lookupFileIdFn(s.chunkFileId) |
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if err != nil { |
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s.err = fmt.Errorf("operation LookupFileId %s failed, err: %v", s.chunkFileId, err) |
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return |
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} |
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s.data = mem.Allocate(s.chunkSize) |
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_, s.err = retriedFetchChunkData(s.data, urlStrings, s.cipherKey, s.isGzipped, true, 0) |
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if s.err != nil { |
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mem.Free(s.data) |
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s.data = nil |
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return |
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} |
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s.completedTime = time.Now() |
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if s.shouldCache { |
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s.parent.chunkCache.SetChunk(s.chunkFileId, s.data) |
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} |
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return |
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} |
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func (s *SingleChunkCacher) destroy() { |
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if s.data != nil { |
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mem.Free(s.data) |
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s.data = nil |
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} |
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} |
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func (s *SingleChunkCacher) readChunkAt(buf []byte, offset int64) (int, error) { |
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s.RLock() |
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defer s.RUnlock() |
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return copy(buf, s.data[offset:]), s.err |
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} |
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