mirror of
https://github.com/seaweedfs/seaweedfs.git
synced 2024-01-19 02:48:24 +00:00
89 lines
2.5 KiB
Go
89 lines
2.5 KiB
Go
package needle
|
|
|
|
import (
|
|
"fmt"
|
|
"github.com/seaweedfs/seaweedfs/weed/glog"
|
|
"github.com/seaweedfs/seaweedfs/weed/storage/backend"
|
|
. "github.com/seaweedfs/seaweedfs/weed/storage/types"
|
|
"github.com/seaweedfs/seaweedfs/weed/util"
|
|
"io"
|
|
)
|
|
|
|
// ReadNeedleData uses a needle without n.Data to read the content
|
|
// volumeOffset: the offset within the volume
|
|
// needleOffset: the offset within the needle Data
|
|
func (n *Needle) ReadNeedleData(r backend.BackendStorageFile, volumeOffset int64, data []byte, needleOffset int64) (count int, err error) {
|
|
|
|
sizeToRead := min(int64(len(data)), int64(n.DataSize)-needleOffset)
|
|
if sizeToRead <= 0 {
|
|
return 0, io.EOF
|
|
}
|
|
startOffset := volumeOffset + NeedleHeaderSize + DataSizeSize + needleOffset
|
|
|
|
count, err = r.ReadAt(data[:sizeToRead], startOffset)
|
|
if err != nil {
|
|
fileSize, _, _ := r.GetStat()
|
|
glog.Errorf("%s read %d %d size %d at offset %d fileSize %d: %v", r.Name(), n.Id, needleOffset, sizeToRead, volumeOffset, fileSize, err)
|
|
}
|
|
return
|
|
|
|
}
|
|
|
|
// ReadNeedleMeta fills all metadata except the n.Data
|
|
func (n *Needle) ReadNeedleMeta(r backend.BackendStorageFile, offset int64, size Size, version Version) (err error) {
|
|
defer func() {
|
|
if r := recover(); r != nil {
|
|
err = fmt.Errorf("panic occurred: %+v", r)
|
|
}
|
|
}()
|
|
|
|
bytes := make([]byte, NeedleHeaderSize+DataSizeSize)
|
|
|
|
count, err := r.ReadAt(bytes, offset)
|
|
if count != NeedleHeaderSize+DataSizeSize || err != nil {
|
|
return err
|
|
}
|
|
n.ParseNeedleHeader(bytes)
|
|
if n.Size != size {
|
|
if OffsetSize == 4 && offset < int64(MaxPossibleVolumeSize) {
|
|
return ErrorSizeMismatch
|
|
}
|
|
}
|
|
n.DataSize = util.BytesToUint32(bytes[NeedleHeaderSize : NeedleHeaderSize+DataSizeSize])
|
|
startOffset := offset + NeedleHeaderSize
|
|
if size.IsValid() {
|
|
startOffset = offset + NeedleHeaderSize + DataSizeSize + int64(n.DataSize)
|
|
}
|
|
dataSize := GetActualSize(size, version)
|
|
stopOffset := offset + dataSize
|
|
metaSize := stopOffset - startOffset
|
|
metaSlice := make([]byte, int(metaSize))
|
|
|
|
count, err = r.ReadAt(metaSlice, startOffset)
|
|
if err != nil && int64(count) == metaSize {
|
|
err = nil
|
|
}
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
var index int
|
|
if size.IsValid() {
|
|
index, err = n.readNeedleDataVersion2NonData(metaSlice)
|
|
}
|
|
|
|
n.Checksum = CRC(util.BytesToUint32(metaSlice[index : index+NeedleChecksumSize]))
|
|
if version == Version3 {
|
|
n.AppendAtNs = util.BytesToUint64(metaSlice[index+NeedleChecksumSize : index+NeedleChecksumSize+TimestampSize])
|
|
}
|
|
return err
|
|
|
|
}
|
|
|
|
func min(x, y int64) int64 {
|
|
if x < y {
|
|
return x
|
|
}
|
|
return y
|
|
}
|