package storage import ( "fmt" "io" "time" "github.com/chrislusf/seaweedfs/weed/glog" "github.com/chrislusf/seaweedfs/weed/storage/backend" "github.com/chrislusf/seaweedfs/weed/storage/needle" "github.com/chrislusf/seaweedfs/weed/storage/super_block" . "github.com/chrislusf/seaweedfs/weed/storage/types" ) // read fills in Needle content by looking up n.Id from NeedleMapper func (v *Volume) readNeedle(n *needle.Needle, readOption *ReadOption) (int, error) { v.dataFileAccessLock.RLock() defer v.dataFileAccessLock.RUnlock() nv, ok := v.nm.Get(n.Id) if !ok || nv.Offset.IsZero() { return -1, ErrorNotFound } readSize := nv.Size if readSize.IsDeleted() { if readOption != nil && readOption.ReadDeleted && readSize != TombstoneFileSize { glog.V(3).Infof("reading deleted %s", n.String()) readSize = -readSize } else { return -1, ErrorDeleted } } if readSize == 0 { return 0, nil } err := n.ReadData(v.DataBackend, nv.Offset.ToActualOffset(), readSize, v.Version()) if err == needle.ErrorSizeMismatch && OffsetSize == 4 { err = n.ReadData(v.DataBackend, nv.Offset.ToActualOffset()+int64(MaxPossibleVolumeSize), readSize, v.Version()) } v.checkReadWriteError(err) if err != nil { return 0, err } bytesRead := len(n.Data) if !n.HasTtl() { return bytesRead, nil } ttlMinutes := n.Ttl.Minutes() if ttlMinutes == 0 { return bytesRead, nil } if !n.HasLastModifiedDate() { return bytesRead, nil } if time.Now().Before(time.Unix(0, int64(n.AppendAtNs)).Add(time.Duration(ttlMinutes) * time.Minute)) { return bytesRead, nil } return -1, ErrorNotFound } // read fills in Needle content by looking up n.Id from NeedleMapper func (v *Volume) ReadNeedleBlob(offset int64, size Size) ([]byte, error) { v.dataFileAccessLock.RLock() defer v.dataFileAccessLock.RUnlock() return needle.ReadNeedleBlob(v.DataBackend, offset, size, v.Version()) } type VolumeFileScanner interface { VisitSuperBlock(super_block.SuperBlock) error ReadNeedleBody() bool VisitNeedle(n *needle.Needle, offset int64, needleHeader, needleBody []byte) error } func ScanVolumeFile(dirname string, collection string, id needle.VolumeId, needleMapKind NeedleMapKind, volumeFileScanner VolumeFileScanner) (err error) { var v *Volume if v, err = loadVolumeWithoutIndex(dirname, collection, id, needleMapKind); err != nil { return fmt.Errorf("failed to load volume %d: %v", id, err) } if err = volumeFileScanner.VisitSuperBlock(v.SuperBlock); err != nil { return fmt.Errorf("failed to process volume %d super block: %v", id, err) } defer v.Close() version := v.Version() offset := int64(v.SuperBlock.BlockSize()) return ScanVolumeFileFrom(version, v.DataBackend, offset, volumeFileScanner) } func ScanVolumeFileFrom(version needle.Version, datBackend backend.BackendStorageFile, offset int64, volumeFileScanner VolumeFileScanner) (err error) { n, nh, rest, e := needle.ReadNeedleHeader(datBackend, version, offset) if e != nil { if e == io.EOF { return nil } return fmt.Errorf("cannot read %s at offset %d: %v", datBackend.Name(), offset, e) } for n != nil { var needleBody []byte if volumeFileScanner.ReadNeedleBody() { // println("needle", n.Id.String(), "offset", offset, "size", n.Size, "rest", rest) if needleBody, err = n.ReadNeedleBody(datBackend, version, offset+NeedleHeaderSize, rest); err != nil { glog.V(0).Infof("cannot read needle head [%d, %d) body [%d, %d) body length %d: %v", offset, offset+NeedleHeaderSize, offset+NeedleHeaderSize, offset+NeedleHeaderSize+rest, rest, err) // err = fmt.Errorf("cannot read needle body: %v", err) // return } } err := volumeFileScanner.VisitNeedle(n, offset, nh, needleBody) if err == io.EOF { return nil } if err != nil { glog.V(0).Infof("visit needle error: %v", err) return fmt.Errorf("visit needle error: %v", err) } offset += NeedleHeaderSize + rest glog.V(4).Infof("==> new entry offset %d", offset) if n, nh, rest, err = needle.ReadNeedleHeader(datBackend, version, offset); err != nil { if err == io.EOF { return nil } return fmt.Errorf("cannot read needle header at offset %d: %v", offset, err) } glog.V(4).Infof("new entry needle size:%d rest:%d", n.Size, rest) } return nil }