reduce file seek when writing

weed/storage/needle_read_write.go

@@ -3,7 +3,6 @@ package storage
 import (
 	"errors"
 	"fmt"
-	"io"
 	"os"
 
 	"github.com/chrislusf/seaweedfs/weed/glog"
@@ -28,21 +27,20 @@ func (n *Needle) DiskSize(version Version) int64 {
 	return getActualSize(n.Size, version)
 }
 
-func (n *Needle) Append(w io.Writer, version Version) (size uint32, actualSize int64, err error) {
-	if s, ok := w.(io.Seeker); ok {
-		if end, e := s.Seek(0, 1); e == nil {
-			defer func(s io.Seeker, off int64) {
+func (n *Needle) Append(w *os.File, version Version) (offset Offset, size uint32, actualSize int64, err error) {
+	if end, e := w.Seek(0, 2); e == nil {
+		defer func(w *os.File, off int64) {
 			if err != nil {
-					if _, e = s.Seek(off, 0); e != nil {
-						glog.V(0).Infof("Failed to seek %s back to %d with error: %v", w, off, e)
+				if te := w.Truncate(end); te != nil {
+					glog.V(0).Infof("Failed to truncate %s back to %d with error: %v", w.Name(), end, te)
 				}
 			}
-			}(s, end)
+		}(w, end)
+		offset = Offset(end)
 	} else {
 		err = fmt.Errorf("Cannot Read Current Volume Position: %v", e)
 		return
 	}
-	}
 	switch version {
 	case Version1:
 		header := make([]byte, NeedleEntrySize)
@@ -159,9 +157,9 @@ func (n *Needle) Append(w io.Writer, version Version) (size uint32, actualSize i
 			_, err = w.Write(header[0 : NeedleChecksumSize+TimestampSize+padding])
 		}
 
-		return n.DataSize, getActualSize(n.Size, version), err
+		return offset, n.DataSize, getActualSize(n.Size, version), err
 	}
-	return 0, 0, fmt.Errorf("Unsupported Version! (%d)", version)
+	return 0, 0, 0, fmt.Errorf("Unsupported Version! (%d)", version)
 }
 
 func ReadNeedleBlob(r *os.File, offset int64, size uint32, version Version) (dataSlice []byte, err error) {

weed/storage/store.go

@@ -200,7 +200,7 @@ func (s *Store) Write(i VolumeId, n *Needle) (size uint32, err error) {
 		}
 		// TODO: count needle size ahead
 		if MaxPossibleVolumeSize >= v.ContentSize()+uint64(size) {
-			size, err = v.writeNeedle(n)
+			_, size, err = v.writeNeedle(n)
 		} else {
 			err = fmt.Errorf("Volume Size Limit %d Exceeded! Current size is %d", s.VolumeSizeLimit, v.ContentSize())
 		}

weed/storage/volume_read_write.go

@@ -74,7 +74,7 @@ func (v *Volume) AppendBlob(b []byte) (offset int64, err error) {
 	return
 }
 
-func (v *Volume) writeNeedle(n *Needle) (size uint32, err error) {
+func (v *Volume) writeNeedle(n *Needle) (offset Offset, size uint32, err error) {
 	glog.V(4).Infof("writing needle %s", NewFileIdFromNeedle(v.Id, n).String())
 	if v.readOnly {
 		err = fmt.Errorf("%s is read-only", v.dataFile.Name())
@@ -87,32 +87,15 @@ func (v *Volume) writeNeedle(n *Needle) (size uint32, err error) {
 		glog.V(4).Infof("needle is unchanged!")
 		return
 	}
-	var offset int64
-	if offset, err = v.dataFile.Seek(0, 2); err != nil {
-		glog.V(0).Infof("failed to seek the end of file: %v", err)
-		return
-	}
-
-	//ensure file writing starting from aligned positions
-	if offset%NeedlePaddingSize != 0 {
-		offset = offset + (NeedlePaddingSize - offset%NeedlePaddingSize)
-		if offset, err = v.dataFile.Seek(offset, 0); err != nil {
-			glog.V(0).Infof("failed to align in datafile %s: %v", v.dataFile.Name(), err)
-			return
-		}
-	}
 
 	n.AppendAtNs = uint64(time.Now().UnixNano())
-	if size, _, err = n.Append(v.dataFile, v.Version()); err != nil {
-		if e := v.dataFile.Truncate(offset); e != nil {
-			err = fmt.Errorf("%s\ncannot truncate %s: %v", err, v.dataFile.Name(), e)
-		}
+	if offset, size, _, err = n.Append(v.dataFile, v.Version()); err != nil {
 		return
 	}
 
 	nv, ok := v.nm.Get(n.Id)
-	if !ok || int64(nv.Offset)*NeedlePaddingSize < offset {
-		if err = v.nm.Put(n.Id, Offset(offset/NeedlePaddingSize), n.Size); err != nil {
+	if !ok || Offset(nv.Offset)*NeedlePaddingSize < offset {
+		if err = v.nm.Put(n.Id, offset/NeedlePaddingSize, n.Size); err != nil {
 			glog.V(4).Infof("failed to save in needle map %d: %v", n.Id, err)
 		}
 	}
@@ -133,16 +116,15 @@ func (v *Volume) deleteNeedle(n *Needle) (uint32, error) {
 	//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
-		offset, err := v.dataFile.Seek(0, 2)
+		n.Data = nil
+		n.AppendAtNs = uint64(time.Now().UnixNano())
+		offset, _, _, err := n.Append(v.dataFile, v.Version())
 		if err != nil {
 			return size, err
 		}
-		if err := v.nm.Delete(n.Id, Offset(offset/NeedlePaddingSize)); err != nil {
+		if err = v.nm.Delete(n.Id, offset/NeedlePaddingSize); err != nil {
 			return size, err
 		}
-		n.Data = nil
-		n.AppendAtNs = uint64(time.Now().UnixNano())
-		_, _, err = n.Append(v.dataFile, v.Version())
 		return size, err
 	}
 	return 0, nil

weed/storage/volume_vacuum.go

@@ -215,7 +215,7 @@ func (v *Volume) makeupDiff(newDatFileName, newIdxFileName, oldDatFileName, oldI
 			fakeDelNeedle.Id = key
 			fakeDelNeedle.Cookie = 0x12345678
 			fakeDelNeedle.AppendAtNs = uint64(time.Now().UnixNano())
-			_, _, err = fakeDelNeedle.Append(dst, v.Version())
+			_, _, _, err = fakeDelNeedle.Append(dst, v.Version())
 			if err != nil {
 				return fmt.Errorf("append deleted %d failed: %v", key, err)
 			}
@@ -269,7 +269,7 @@ func (v *Volume) copyDataAndGenerateIndexFile(dstName, idxName string, prealloca
 				if err = nm.Put(n.Id, Offset(new_offset/NeedlePaddingSize), n.Size); err != nil {
 					return fmt.Errorf("cannot put needle: %s", err)
 				}
-				if _, _, err := n.Append(dst, v.Version()); err != nil {
+				if _, _, _, err := n.Append(dst, v.Version()); err != nil {
 					return fmt.Errorf("cannot append needle: %s", err)
 				}
 				new_offset += n.DiskSize(version)
@@ -329,7 +329,7 @@ func (v *Volume) copyDataBasedOnIndexFile(dstName, idxName string) (err error) {
 			if err = nm.Put(n.Id, Offset(new_offset/NeedlePaddingSize), n.Size); err != nil {
 				return fmt.Errorf("cannot put needle: %s", err)
 			}
-			if _, _, err = n.Append(dst, v.Version()); err != nil {
+			if _, _, _, err = n.Append(dst, v.Version()); err != nil {
 				return fmt.Errorf("cannot append needle: %s", err)
 			}
 			new_offset += n.DiskSize(v.Version())

weed/storage/volume_vacuum_test.go

@@ -122,7 +122,7 @@ func TestCompaction(t *testing.T) {
 }
 func doSomeWritesDeletes(i int, v *Volume, t *testing.T, infos []*needleInfo) {
 	n := newRandomNeedle(uint64(i))
-	size, err := v.writeNeedle(n)
+	_, size, err := v.writeNeedle(n)
 	if err != nil {
 		t.Fatalf("write file %d: %v", i, err)
 	}