volume: checksum remove the hashing step in Value()

7 files changed, 26 insertions, 22 deletions

diff --git a/weed/storage/needle/crc.go b/weed/storage/needle/crc.go
index b7d3edd83..65a45293e 100644
--- a/weed/storage/needle/crc.go
+++ b/weed/storage/needle/crc.go
@@ -21,6 +21,7 @@ func (c CRC) Update(b []byte) CRC {
 	return CRC(crc32.Update(uint32(c), table, b))
 }
 
+// Value Deprecated. Just use the raw uint32 value to compare.
 func (c CRC) Value() uint32 {
 	return uint32(c>>15|c<<17) + 0xa282ead8
 }
@@ -51,4 +52,4 @@ func (c *CRCwriter) Write(p []byte) (n int, err error) {
 	return
 }
 
-func (c *CRCwriter) Sum() uint32 { return c.crc.Value() } // final hash
+func (c *CRCwriter) Sum() uint32 { return uint32(c.crc) } // final hash
diff --git a/weed/storage/needle/needle_read.go b/weed/storage/needle/needle_read.go
index 77c7e88dc..e94c34ff0 100644
--- a/weed/storage/needle/needle_read.go
+++ b/weed/storage/needle/needle_read.go
@@ -72,7 +72,8 @@ func (n *Needle) ReadBytes(bytes []byte, offset int64, size Size, version Versio
 	if size > 0 {
 		checksum := util.BytesToUint32(bytes[NeedleHeaderSize+size : NeedleHeaderSize+size+NeedleChecksumSize])
 		newChecksum := NewCRC(n.Data)
-		if checksum != newChecksum.Value() {
+		if checksum != newChecksum.Value() && checksum != uint32(newChecksum) {
+			// the crc.Value() function is to be deprecated. this double checking is for backward compatible.
 			stats.VolumeServerRequestCounter.WithLabelValues(stats.ErrorCRC).Inc()
 			return errors.New("CRC error! Data On Disk Corrupted")
 		}
diff --git a/weed/storage/needle/needle_read_page.go b/weed/storage/needle/needle_read_page.go
index 1fe40f847..c00195e93 100644
--- a/weed/storage/needle/needle_read_page.go
+++ b/weed/storage/needle/needle_read_page.go
@@ -10,7 +10,7 @@ import (
 )
 
 // ReadNeedleDataInto uses a needle without n.Data to read the content into an io.Writer
-func (n *Needle) ReadNeedleDataInto(r backend.BackendStorageFile, volumeOffset int64, buf []byte, writer io.Writer, needleOffset int64, size int64, expectedChecksumValue uint32) (err error) {
+func (n *Needle) ReadNeedleDataInto(r backend.BackendStorageFile, volumeOffset int64, buf []byte, writer io.Writer, needleOffset int64, size int64) (err error) {
 	crc := CRC(0)
 	for x := needleOffset; x < needleOffset+size; x += int64(len(buf)) {
 		count, err := n.ReadNeedleData(r, volumeOffset, buf, x)
@@ -31,8 +31,9 @@ func (n *Needle) ReadNeedleDataInto(r backend.BackendStorageFile, volumeOffset i
 			break
 		}
 	}
-	if needleOffset == 0 && size == int64(n.DataSize) && expectedChecksumValue != crc.Value() {
-		return fmt.Errorf("ReadNeedleData checksum %v expected %v", crc.Value(), expectedChecksumValue)
+	if needleOffset == 0 && size == int64(n.DataSize) && (n.Checksum != crc && uint32(n.Checksum) != crc.Value()) {
+		// the crc.Value() function is to be deprecated. this double checking is for backward compatible.
+		return fmt.Errorf("ReadNeedleData checksum %v expected %v", crc, n.Checksum)
 	}
 	return nil
 }
@@ -58,18 +59,18 @@ func (n *Needle) ReadNeedleData(r backend.BackendStorageFile, volumeOffset int64
 }
 
 // ReadNeedleMeta fills all metadata except the n.Data
-func (n *Needle) ReadNeedleMeta(r backend.BackendStorageFile, offset int64, size Size, version Version) (checksumValue uint32, err error) {
+func (n *Needle) ReadNeedleMeta(r backend.BackendStorageFile, offset int64, size Size, version Version) (err error) {
 
 	bytes := make([]byte, NeedleHeaderSize+DataSizeSize)
 
 	count, err := r.ReadAt(bytes, offset)
 	if count != NeedleHeaderSize+DataSizeSize || err != nil {
-		return 0, err
+		return err
 	}
 	n.ParseNeedleHeader(bytes)
 	if n.Size != size {
 		if OffsetSize == 4 && offset < int64(MaxPossibleVolumeSize) {
-			return 0, ErrorSizeMismatch
+			return ErrorSizeMismatch
 		}
 	}
 
@@ -86,18 +87,18 @@ func (n *Needle) ReadNeedleMeta(r backend.BackendStorageFile, offset int64, size
 		err = nil
 	}
 	if err != nil {
-		return 0, err
+		return err
 	}
 
 	var index int
 	index, err = n.readNeedleDataVersion2NonData(metaSlice)
 
-	checksumValue = util.BytesToUint32(metaSlice[index : index+NeedleChecksumSize])
+	n.Checksum = CRC(util.BytesToUint32(metaSlice[index : index+NeedleChecksumSize]))
 	if version == Version3 {
 		n.AppendAtNs = util.BytesToUint64(metaSlice[index+NeedleChecksumSize : index+NeedleChecksumSize+TimestampSize])
 	}
 
-	return checksumValue, err
+	return err
 
 }
 
diff --git a/weed/storage/needle/needle_read_test.go b/weed/storage/needle/needle_read_test.go
index 9ffd8836e..e2e69574a 100644
--- a/weed/storage/needle/needle_read_test.go
+++ b/weed/storage/needle/needle_read_test.go
@@ -57,7 +57,7 @@ func TestPageRead(t *testing.T) {
 
 	{
 		n := new(Needle)
-		checksumValue, err := n.ReadNeedleMeta(datBackend, offset, size, Version3)
+		err := n.ReadNeedleMeta(datBackend, offset, size, Version3)
 		if err != nil {
 			t.Fatalf("ReadNeedleHeader: %v", err)
 		}
diff --git a/weed/storage/needle/needle_write.go b/weed/storage/needle/needle_write.go
index dd48edea8..fd2e33ad9 100644
--- a/weed/storage/needle/needle_write.go
+++ b/weed/storage/needle/needle_write.go
@@ -31,7 +31,7 @@ func (n *Needle) prepareWriteBuffer(version Version, writeBytes *bytes.Buffer) (
 		writeBytes.Write(header)
 		writeBytes.Write(n.Data)
 		padding := PaddingLength(n.Size, version)
-		util.Uint32toBytes(header[0:NeedleChecksumSize], n.Checksum.Value())
+		util.Uint32toBytes(header[0:NeedleChecksumSize], uint32(n.Checksum))
 		writeBytes.Write(header[0 : NeedleChecksumSize+padding])
 		return size, actualSize, nil
 	case Version2, Version3:
@@ -97,7 +97,7 @@ func (n *Needle) prepareWriteBuffer(version Version, writeBytes *bytes.Buffer) (
 			}
 		}
 		padding := PaddingLength(n.Size, version)
-		util.Uint32toBytes(header[0:NeedleChecksumSize], n.Checksum.Value())
+		util.Uint32toBytes(header[0:NeedleChecksumSize], uint32(n.Checksum))
 		if version == Version2 {
 			writeBytes.Write(header[0 : NeedleChecksumSize+padding])
 		} else {
diff --git a/weed/storage/store.go b/weed/storage/store.go
index 81e69aaa2..f833f1b15 100644
--- a/weed/storage/store.go
+++ b/weed/storage/store.go
@@ -27,13 +27,14 @@ const (
 )
 
 type ReadOption struct {
+	// request
 	ReadDeleted     bool
 	AttemptMetaOnly bool
 	MustMetaOnly    bool
-	IsMetaOnly      bool   // read status
-	ChecksumValue   uint32 // read status
-	VolumeRevision  uint16
-	IsOutOfRange    bool // whether need to read over MaxPossibleVolumeSize
+	// response
+	IsMetaOnly     bool // read status
+	VolumeRevision uint16
+	IsOutOfRange   bool // whether read over MaxPossibleVolumeSize
 }
 
 /*
diff --git a/weed/storage/volume_read.go b/weed/storage/volume_read.go
index ced3fcb8f..6b17eea0a 100644
--- a/weed/storage/volume_read.go
+++ b/weed/storage/volume_read.go
@@ -41,10 +41,10 @@ func (v *Volume) readNeedle(n *needle.Needle, readOption *ReadOption, onReadSize
 	}
 	if readOption != nil && readOption.AttemptMetaOnly && readSize > PagedReadLimit {
 		readOption.VolumeRevision = v.SuperBlock.CompactionRevision
-		readOption.ChecksumValue, err = n.ReadNeedleMeta(v.DataBackend, nv.Offset.ToActualOffset(), readSize, v.Version())
+		err = n.ReadNeedleMeta(v.DataBackend, nv.Offset.ToActualOffset(), readSize, v.Version())
 		if err == needle.ErrorSizeMismatch && OffsetSize == 4 {
 			readOption.IsOutOfRange = true
-			readOption.ChecksumValue, err = n.ReadNeedleMeta(v.DataBackend, nv.Offset.ToActualOffset()+int64(MaxPossibleVolumeSize), readSize, v.Version())
+			err = n.ReadNeedleMeta(v.DataBackend, nv.Offset.ToActualOffset()+int64(MaxPossibleVolumeSize), readSize, v.Version())
 		}
 		if err != nil {
 			return 0, err
@@ -105,7 +105,7 @@ func (v *Volume) readNeedleDataInto(n *needle.Needle, readOption *ReadOption, wr
 	if readOption.VolumeRevision != v.SuperBlock.CompactionRevision {
 		// the volume is compacted
 		readOption.IsOutOfRange = false
-		readOption.ChecksumValue, err = n.ReadNeedleMeta(v.DataBackend, nv.Offset.ToActualOffset(), readSize, v.Version())
+		err = n.ReadNeedleMeta(v.DataBackend, nv.Offset.ToActualOffset(), readSize, v.Version())
 	}
 	buf := mem.Allocate(1024 * 1024)
 	defer mem.Free(buf)
@@ -114,7 +114,7 @@ func (v *Volume) readNeedleDataInto(n *needle.Needle, readOption *ReadOption, wr
 		actualOffset += int64(MaxPossibleVolumeSize)
 	}
 
-	return n.ReadNeedleDataInto(v.DataBackend, actualOffset, buf, writer, offset, size, readOption.ChecksumValue)
+	return n.ReadNeedleDataInto(v.DataBackend, actualOffset, buf, writer, offset, size)
 }
 
 // read fills in Needle content by looking up n.Id from NeedleMapper