seaweedfs/go/storage/needle_read_write.go

297 lines
8.3 KiB
Go

package storage
import (
"errors"
"fmt"
"io"
"os"
"github.com/chrislusf/seaweedfs/go/glog"
"github.com/chrislusf/seaweedfs/go/util"
)
const (
FlagGzip = 0x01
FlagHasName = 0x02
FlagHasMime = 0x04
FlagHasLastModifiedDate = 0x08
FlagHasTtl = 0x10
FlagIsChunkManifest = 0x80
LastModifiedBytesLength = 5
TtlBytesLength = 2
)
func (n *Needle) DiskSize() int64 {
padding := NeedlePaddingSize - ((NeedleHeaderSize + int64(n.Size) + NeedleChecksumSize) % NeedlePaddingSize)
return NeedleHeaderSize + int64(n.Size) + padding + NeedleChecksumSize
}
func (n *Needle) Append(w io.Writer, version Version) (size uint32, 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) {
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)
}
}
}(s, end)
} else {
err = fmt.Errorf("Cannot Read Current Volume Position: %v", e)
return
}
}
switch version {
case Version1:
header := make([]byte, NeedleHeaderSize)
util.Uint32toBytes(header[0:4], n.Cookie)
util.Uint64toBytes(header[4:12], n.Id)
n.Size = uint32(len(n.Data))
size = n.Size
util.Uint32toBytes(header[12:16], n.Size)
if _, err = w.Write(header); err != nil {
return
}
if _, err = w.Write(n.Data); err != nil {
return
}
padding := NeedlePaddingSize - ((NeedleHeaderSize + n.Size + NeedleChecksumSize) % NeedlePaddingSize)
util.Uint32toBytes(header[0:NeedleChecksumSize], n.Checksum.Value())
_, err = w.Write(header[0 : NeedleChecksumSize+padding])
return
case Version2:
header := make([]byte, NeedleHeaderSize)
util.Uint32toBytes(header[0:4], n.Cookie)
util.Uint64toBytes(header[4:12], n.Id)
n.DataSize, n.NameSize, n.MimeSize = uint32(len(n.Data)), uint8(len(n.Name)), uint8(len(n.Mime))
if n.DataSize > 0 {
n.Size = 4 + n.DataSize + 1
if n.HasName() {
n.Size = n.Size + 1 + uint32(n.NameSize)
}
if n.HasMime() {
n.Size = n.Size + 1 + uint32(n.MimeSize)
}
if n.HasLastModifiedDate() {
n.Size = n.Size + LastModifiedBytesLength
}
if n.HasTtl() {
n.Size = n.Size + TtlBytesLength
}
} else {
n.Size = 0
}
size = n.DataSize
util.Uint32toBytes(header[12:16], n.Size)
if _, err = w.Write(header); err != nil {
return
}
if n.DataSize > 0 {
util.Uint32toBytes(header[0:4], n.DataSize)
if _, err = w.Write(header[0:4]); err != nil {
return
}
if _, err = w.Write(n.Data); err != nil {
return
}
util.Uint8toBytes(header[0:1], n.Flags)
if _, err = w.Write(header[0:1]); err != nil {
return
}
if n.HasName() {
util.Uint8toBytes(header[0:1], n.NameSize)
if _, err = w.Write(header[0:1]); err != nil {
return
}
if _, err = w.Write(n.Name); err != nil {
return
}
}
if n.HasMime() {
util.Uint8toBytes(header[0:1], n.MimeSize)
if _, err = w.Write(header[0:1]); err != nil {
return
}
if _, err = w.Write(n.Mime); err != nil {
return
}
}
if n.HasLastModifiedDate() {
util.Uint64toBytes(header[0:8], n.LastModified)
if _, err = w.Write(header[8-LastModifiedBytesLength : 8]); err != nil {
return
}
}
if n.HasTtl() && n.Ttl != nil {
n.Ttl.ToBytes(header[0:TtlBytesLength])
if _, err = w.Write(header[0:TtlBytesLength]); err != nil {
return
}
}
}
padding := NeedlePaddingSize - ((NeedleHeaderSize + n.Size + NeedleChecksumSize) % NeedlePaddingSize)
util.Uint32toBytes(header[0:NeedleChecksumSize], n.Checksum.Value())
_, err = w.Write(header[0 : NeedleChecksumSize+padding])
return n.DataSize, err
}
return 0, fmt.Errorf("Unsupported Version! (%d)", version)
}
func ReadNeedleBlob(r *os.File, offset int64, size uint32) (dataSlice []byte, block *Block, err error) {
padding := NeedlePaddingSize - ((NeedleHeaderSize + size + NeedleChecksumSize) % NeedlePaddingSize)
readSize := NeedleHeaderSize + size + NeedleChecksumSize + padding
block, isNew := getBytesForFileBlock(r, offset, int(readSize))
dataSlice = block.Bytes[0:int(readSize)]
if isNew {
_, err = r.ReadAt(dataSlice, offset)
}
return dataSlice, block, err
}
func (n *Needle) ReadData(r *os.File, offset int64, size uint32, version Version) (err error) {
bytes, block, err := ReadNeedleBlob(r, offset, size)
n.rawBlock = block
if err != nil {
return err
}
n.ParseNeedleHeader(bytes)
if n.Size != size {
return fmt.Errorf("File Entry Not Found. Needle %d Memory %d", n.Size, size)
}
switch version {
case Version1:
n.Data = bytes[NeedleHeaderSize : NeedleHeaderSize+size]
case Version2:
n.readNeedleDataVersion2(bytes[NeedleHeaderSize : NeedleHeaderSize+int(n.Size)])
}
checksum := util.BytesToUint32(bytes[NeedleHeaderSize+size : NeedleHeaderSize+size+NeedleChecksumSize])
newChecksum := NewCRC(n.Data)
if checksum != newChecksum.Value() {
return errors.New("CRC error! Data On Disk Corrupted")
}
n.Checksum = newChecksum
return nil
}
func (n *Needle) ParseNeedleHeader(bytes []byte) {
n.Cookie = util.BytesToUint32(bytes[0:4])
n.Id = util.BytesToUint64(bytes[4:12])
n.Size = util.BytesToUint32(bytes[12:NeedleHeaderSize])
}
func (n *Needle) readNeedleDataVersion2(bytes []byte) {
index, lenBytes := 0, len(bytes)
if index < lenBytes {
n.DataSize = util.BytesToUint32(bytes[index : index+4])
index = index + 4
if int(n.DataSize)+index > lenBytes {
// this if clause is due to bug #87 and #93, fixed in v0.69
// remove this clause later
return
}
n.Data = bytes[index : index+int(n.DataSize)]
index = index + int(n.DataSize)
n.Flags = bytes[index]
index = index + 1
}
if index < lenBytes && n.HasName() {
n.NameSize = uint8(bytes[index])
index = index + 1
n.Name = bytes[index : index+int(n.NameSize)]
index = index + int(n.NameSize)
}
if index < lenBytes && n.HasMime() {
n.MimeSize = uint8(bytes[index])
index = index + 1
n.Mime = bytes[index : index+int(n.MimeSize)]
index = index + int(n.MimeSize)
}
if index < lenBytes && n.HasLastModifiedDate() {
n.LastModified = util.BytesToUint64(bytes[index : index+LastModifiedBytesLength])
index = index + LastModifiedBytesLength
}
if index < lenBytes && n.HasTtl() {
n.Ttl = LoadTTLFromBytes(bytes[index : index+TtlBytesLength])
index = index + TtlBytesLength
}
}
func ReadNeedleHeader(r *os.File, version Version, offset int64) (n *Needle, bodyLength uint32, err error) {
n = new(Needle)
if version == Version1 || version == Version2 {
bytes := make([]byte, NeedleHeaderSize)
var count int
count, err = r.ReadAt(bytes, offset)
if count <= 0 || err != nil {
return nil, 0, err
}
n.ParseNeedleHeader(bytes)
padding := NeedlePaddingSize - ((n.Size + NeedleHeaderSize + NeedleChecksumSize) % NeedlePaddingSize)
bodyLength = n.Size + NeedleChecksumSize + padding
}
return
}
//n should be a needle already read the header
//the input stream will read until next file entry
func (n *Needle) ReadNeedleBody(r *os.File, version Version, offset int64, bodyLength uint32) (err error) {
if bodyLength <= 0 {
return nil
}
switch version {
case Version1:
bytes := make([]byte, bodyLength)
if _, err = r.ReadAt(bytes, offset); err != nil {
return
}
n.Data = bytes[:n.Size]
n.Checksum = NewCRC(n.Data)
case Version2:
bytes := make([]byte, bodyLength)
if _, err = r.ReadAt(bytes, offset); err != nil {
return
}
n.readNeedleDataVersion2(bytes[0:n.Size])
n.Checksum = NewCRC(n.Data)
default:
err = fmt.Errorf("Unsupported Version! (%d)", version)
}
return
}
func (n *Needle) IsGzipped() bool {
return n.Flags&FlagGzip > 0
}
func (n *Needle) SetGzipped() {
n.Flags = n.Flags | FlagGzip
}
func (n *Needle) HasName() bool {
return n.Flags&FlagHasName > 0
}
func (n *Needle) SetHasName() {
n.Flags = n.Flags | FlagHasName
}
func (n *Needle) HasMime() bool {
return n.Flags&FlagHasMime > 0
}
func (n *Needle) SetHasMime() {
n.Flags = n.Flags | FlagHasMime
}
func (n *Needle) HasLastModifiedDate() bool {
return n.Flags&FlagHasLastModifiedDate > 0
}
func (n *Needle) SetHasLastModifiedDate() {
n.Flags = n.Flags | FlagHasLastModifiedDate
}
func (n *Needle) HasTtl() bool {
return n.Flags&FlagHasTtl > 0
}
func (n *Needle) SetHasTtl() {
n.Flags = n.Flags | FlagHasTtl
}
func (n *Needle) IsChunkedManifest() bool {
return n.Flags&FlagIsChunkManifest > 0
}
func (n *Needle) SetIsChunkManifest() {
n.Flags = n.Flags | FlagIsChunkManifest
}