refactoring

This commit is contained in:
Chris Lu 2012-12-21 00:36:55 -08:00
parent 79a49ada39
commit 11cc489ca5
4 changed files with 72 additions and 52 deletions

View file

@ -52,7 +52,7 @@ func runFix(cmd *Command, args []string) bool {
ver, _, _ := storage.ParseSuperBlock(header)
n, rest := storage.ReadNeedle(dataFile, ver)
n, rest := storage.ReadNeedleHeader(dataFile, ver)
dataFile.Seek(int64(rest), 1)
nm := storage.NewNeedleMap(indexFile)
offset := uint32(storage.SuperBlockSize)
@ -63,7 +63,7 @@ func runFix(cmd *Command, args []string) bool {
debug("saved", count, "with error", pe)
}
offset += rest + 16
n, rest = storage.ReadNeedle(dataFile, ver)
n, rest = storage.ReadNeedleHeader(dataFile, ver)
dataFile.Seek(int64(rest), 1)
}
return true

View file

@ -11,16 +11,22 @@ import (
"strings"
)
const (
NeedleHeaderSize = 16 //should never change this
NeedlePaddingSize = 8
)
type Needle struct {
Cookie uint32 "random number to mitigate brute force lookups"
Id uint64 "needle id"
Size uint32 "sum of DataSize,Data,NameSize,Name,MimeSize,Mime"
// DataSize uint32 "Data size"
Data []byte "The actual file data"
// NameSize uint16
// Name []byte "maximum 256 characters"
// MimeSize uint16
// Mime []byte "maximum 256 characters"
Cookie uint32 "random number to mitigate brute force lookups"
Id uint64 "needle id"
Size uint32 "sum of DataSize,Data,NameSize,Name,MimeSize,Mime"
Flags byte "boolean flags" //version2
DataSize uint32 "Data size" //version2
Data []byte "The actual file data"
NameSize uint8 //version2
Name []byte "maximum 256 characters" //version2
MimeSize uint8 //version2
Mime []byte "maximum 256 characters" //version2
Checksum CRC "CRC32 to check integrity"
Padding []byte "Aligned to 8 bytes"
}
@ -87,13 +93,13 @@ func (n *Needle) ParsePath(fid string) {
}
}
func ParseKeyHash(key_hash_string string) (uint64, uint32) {
key_hash_bytes, khe := hex.DecodeString(key_hash_string)
key_hash_len := len(key_hash_bytes)
if khe != nil || key_hash_len <= 4 {
println("Invalid key_hash", key_hash_string, "length:", key_hash_len, "error", khe)
return 0, 0
}
key := util.BytesToUint64(key_hash_bytes[0 : key_hash_len-4])
hash := util.BytesToUint32(key_hash_bytes[key_hash_len-4 : key_hash_len])
return key, hash
key_hash_bytes, khe := hex.DecodeString(key_hash_string)
key_hash_len := len(key_hash_bytes)
if khe != nil || key_hash_len <= 4 {
println("Invalid key_hash", key_hash_string, "length:", key_hash_len, "error", khe)
return 0, 0
}
key := util.BytesToUint64(key_hash_bytes[0 : key_hash_len-4])
hash := util.BytesToUint32(key_hash_bytes[key_hash_len-4 : key_hash_len])
return key, hash
}

View file

@ -7,22 +7,25 @@ import (
"pkg/util"
)
func (n *Needle) Append(w io.Writer) uint32 {
header := make([]byte, 16)
util.Uint32toBytes(header[0:4], n.Cookie)
util.Uint64toBytes(header[4:12], n.Id)
n.Size = uint32(len(n.Data))
util.Uint32toBytes(header[12:16], n.Size)
w.Write(header)
w.Write(n.Data)
rest := 8 - ((16 + n.Size + 4) % 8)
util.Uint32toBytes(header[0:4], n.Checksum.Value())
w.Write(header[0 : 4+rest])
func (n *Needle) Append(w io.Writer, version Version) uint32 {
if version == 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))
util.Uint32toBytes(header[12:16], n.Size)
w.Write(header)
w.Write(n.Data)
rest := NeedlePaddingSize - ((NeedleHeaderSize + n.Size + 4) % NeedlePaddingSize)
util.Uint32toBytes(header[0:4], n.Checksum.Value())
w.Write(header[0 : 4+rest])
} else if version == Version2 {
}
return n.Size
}
func (n *Needle) Read(r io.Reader, size uint32, version Version) (int, error) {
if version == Version1 {
bytes := make([]byte, 16+size+4)
bytes := make([]byte, NeedleHeaderSize+size+4)
ret, e := r.Read(bytes)
n.Cookie = util.BytesToUint32(bytes[0:4])
n.Id = util.BytesToUint64(bytes[4:12])
@ -37,10 +40,10 @@ func (n *Needle) Read(r io.Reader, size uint32, version Version) (int, error) {
}
return 0, errors.New("Unsupported Version!")
}
func ReadNeedle(r *os.File, version Version) (n *Needle, bytesTillNextFile uint32) {
func ReadNeedleHeader(r *os.File, version Version) (n *Needle, bodyLength uint32) {
n = new(Needle)
if version == Version1 {
bytes := make([]byte, 16)
bytes := make([]byte, NeedleHeaderSize)
count, e := r.Read(bytes)
if count <= 0 || e != nil {
return nil, 0
@ -48,8 +51,21 @@ func ReadNeedle(r *os.File, version Version) (n *Needle, bytesTillNextFile uint3
n.Cookie = util.BytesToUint32(bytes[0:4])
n.Id = util.BytesToUint64(bytes[4:12])
n.Size = util.BytesToUint32(bytes[12:16])
rest := 8 - ((n.Size + 16 + 4) % 8)
bytesTillNextFile = n.Size + 4 + rest
rest := NeedlePaddingSize - ((n.Size + 16 + 4) % NeedlePaddingSize)
bodyLength = n.Size + 4 + rest
} else if version == Version2 {
}
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, bodyLength uint32) {
if version == Version1 {
bytes := make([]byte, bodyLength)
r.Read(bytes)
n.Data = bytes[:n.Size]
n.Checksum = NewCRC(n.Data)
} else if version == Version2 {
}
return

View file

@ -105,7 +105,7 @@ func (v *Volume) write(n *Needle) uint32 {
v.accessLock.Lock()
defer v.accessLock.Unlock()
offset, _ := v.dataFile.Seek(0, 2)
ret := n.Append(v.dataFile)
ret := n.Append(v.dataFile, v.version)
nv, ok := v.nm.Get(n.Id)
if !ok || int64(nv.Offset)*8 < offset {
v.nm.Put(n.Id, uint32(offset/8), n.Size)
@ -119,8 +119,8 @@ func (v *Volume) delete(n *Needle) uint32 {
//log.Println("key", n.Id, "volume offset", nv.Offset, "data_size", n.Size, "cached size", nv.Size)
if ok {
v.nm.Delete(n.Id)
v.dataFile.Seek(int64(nv.Offset*8), 0)
n.Append(v.dataFile)
v.dataFile.Seek(int64(nv.Offset*NeedlePaddingSize), 0)
n.Append(v.dataFile, v.version)
return nv.Size
}
return 0
@ -131,7 +131,7 @@ func (v *Volume) read(n *Needle) (int, error) {
defer v.accessLock.Unlock()
nv, ok := v.nm.Get(n.Id)
if ok && nv.Offset > 0 {
v.dataFile.Seek(int64(nv.Offset)*8, 0)
v.dataFile.Seek(int64(nv.Offset)*NeedlePaddingSize, 0)
return n.Read(v.dataFile, nv.Size, v.version)
}
return -1, errors.New("Not Found")
@ -192,30 +192,28 @@ func (v *Volume) copyDataAndGenerateIndexFile(srcName, dstName, idxName string)
version, _, _ := ParseSuperBlock(header)
n, rest := ReadNeedle(src, version)
n, rest := ReadNeedleHeader(src, version)
nm := NewNeedleMap(idx)
old_offset := uint32(SuperBlockSize)
new_offset := uint32(SuperBlockSize)
for n != nil {
nv, ok := v.nm.Get(n.Id)
//log.Println("file size is", n.Size, "rest", rest)
if !ok || nv.Offset*8 != old_offset {
if !ok || nv.Offset*NeedlePaddingSize != old_offset {
src.Seek(int64(rest), 1)
} else {
if nv.Size > 0 {
nm.Put(n.Id, new_offset/8, n.Size)
bytes := make([]byte, n.Size+4)
src.Read(bytes)
n.Data = bytes[:n.Size]
n.Checksum = NewCRC(n.Data)
n.Append(dst)
new_offset += rest + 16
nm.Put(n.Id, new_offset/NeedlePaddingSize, n.Size)
n.ReadNeedleBody(src, version, rest)
n.Append(dst, v.version)
new_offset += rest + NeedleHeaderSize
//log.Println("saving key", n.Id, "volume offset", old_offset, "=>", new_offset, "data_size", n.Size, "rest", rest)
} else {
src.Seek(int64(rest), 1)
}
src.Seek(int64(rest-n.Size-4), 1)
}
old_offset += rest + 16
n, rest = ReadNeedle(src, version)
old_offset += rest + NeedleHeaderSize
n, rest = ReadNeedleHeader(src, version)
}
return nil