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package storage
import ( "bytes" "errors" "fmt" "io" "os" "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" )
var ErrorNotFound = errors.New("not found")
// isFileUnchanged checks whether this needle to write is same as last one.
// It requires serialized access in the same volume.
func (v *Volume) isFileUnchanged(n *needle.Needle) bool { if v.Ttl.String() != "" { return false }
nv, ok := v.nm.Get(n.Id) if ok && !nv.Offset.IsZero() && nv.Size != TombstoneFileSize { oldNeedle := new(needle.Needle) err := oldNeedle.ReadData(v.DataBackend, nv.Offset.ToAcutalOffset(), nv.Size, v.Version()) if err != nil { glog.V(0).Infof("Failed to check updated file at offset %d size %d: %v", nv.Offset.ToAcutalOffset(), nv.Size, err) return false } if oldNeedle.Cookie == n.Cookie && oldNeedle.Checksum == n.Checksum && bytes.Equal(oldNeedle.Data, n.Data) { n.DataSize = oldNeedle.DataSize return true } } return false }
// Destroy removes everything related to this volume
func (v *Volume) Destroy() (err error) { if v.isCompacting { err = fmt.Errorf("volume %d is compacting", v.Id) return } v.Close() os.Remove(v.FileName() + ".dat") os.Remove(v.FileName() + ".idx") os.Remove(v.FileName() + ".tier") os.Remove(v.FileName() + ".sdx") os.Remove(v.FileName() + ".cpd") os.Remove(v.FileName() + ".cpx") os.RemoveAll(v.FileName() + ".ldb") return }
func (v *Volume) writeNeedle(n *needle.Needle) (offset uint64, size uint32, isUnchanged bool, err error) { glog.V(4).Infof("writing needle %s", needle.NewFileIdFromNeedle(v.Id, n).String()) v.dataFileAccessLock.Lock() defer v.dataFileAccessLock.Unlock() if v.isFileUnchanged(n) { size = n.DataSize isUnchanged = true return }
if n.Ttl == needle.EMPTY_TTL && v.Ttl != needle.EMPTY_TTL { n.SetHasTtl() n.Ttl = v.Ttl }
// check whether existing needle cookie matches
nv, ok := v.nm.Get(n.Id) if ok { existingNeedle, _, _, existingNeedleReadErr := needle.ReadNeedleHeader(v.DataBackend, v.Version(), nv.Offset.ToAcutalOffset()) if existingNeedleReadErr != nil { err = fmt.Errorf("reading existing needle: %v", existingNeedleReadErr) return } if existingNeedle.Cookie != n.Cookie { glog.V(0).Infof("write cookie mismatch: existing %x, new %x", existingNeedle.Cookie, n.Cookie) err = fmt.Errorf("mismatching cookie %x", n.Cookie) return } }
// append to dat file
n.AppendAtNs = uint64(time.Now().UnixNano()) if offset, size, _, err = n.Append(v.DataBackend, v.Version()); err != nil { return } v.lastAppendAtNs = n.AppendAtNs
// add to needle map
if !ok || uint64(nv.Offset.ToAcutalOffset()) < offset { if err = v.nm.Put(n.Id, ToOffset(int64(offset)), n.Size); err != nil { glog.V(4).Infof("failed to save in needle map %d: %v", n.Id, err) } } if v.lastModifiedTsSeconds < n.LastModified { v.lastModifiedTsSeconds = n.LastModified } return }
func (v *Volume) deleteNeedle(n *needle.Needle) (uint32, error) { glog.V(4).Infof("delete needle %s", needle.NewFileIdFromNeedle(v.Id, n).String()) v.dataFileAccessLock.Lock() defer v.dataFileAccessLock.Unlock() nv, ok := v.nm.Get(n.Id) //fmt.Println("key", n.Id, "volume offset", nv.Offset, "data_size", n.Size, "cached size", nv.Size)
if ok && nv.Size != TombstoneFileSize { size := nv.Size n.Data = nil n.AppendAtNs = uint64(time.Now().UnixNano()) offset, _, _, err := n.Append(v.DataBackend, v.Version()) if err != nil { return size, err } v.lastAppendAtNs = n.AppendAtNs if err = v.nm.Delete(n.Id, ToOffset(int64(offset))); err != nil { return size, err } return size, err } return 0, nil }
// read fills in Needle content by looking up n.Id from NeedleMapper
func (v *Volume) readNeedle(n *needle.Needle) (int, error) { v.dataFileAccessLock.RLock() defer v.dataFileAccessLock.RUnlock()
nv, ok := v.nm.Get(n.Id) if !ok || nv.Offset.IsZero() { return -1, ErrorNotFound } if nv.Size == TombstoneFileSize { return -1, errors.New("already deleted") } if nv.Size == 0 { return 0, nil } err := n.ReadData(v.DataBackend, nv.Offset.ToAcutalOffset(), nv.Size, v.Version()) 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 uint64(time.Now().Unix()) < n.LastModified+uint64(ttlMinutes*60) { return bytesRead, nil } return -1, ErrorNotFound }
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 NeedleMapType, 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() { if needleBody, err = n.ReadNeedleBody(datBackend, version, offset+NeedleHeaderSize, rest); err != nil { glog.V(0).Infof("cannot read needle body: %v", 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 }
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