func (m cdbMap) Visit(visit func(NeedleValue) error) (err error) {
fh, err := os.Open(m.fn1)
if err != nil {
return fmt.Errorf("cannot open %s: %s", m.fn1, err)
}
defer fh.Close()
walk := func(elt cdb.Element) error {
if len(elt.Key) != 8 {
return nil
}
return visit(NeedleValue{Key: Key(util.BytesToUint64(elt.Key)),
Offset: util.BytesToUint32(elt.Data[:4]),
Size: util.BytesToUint32(elt.Data[4:8])})
}
if err = cdb.DumpMap(fh, walk); err != nil {
return err
}
//只有一张表
if m.c2 == nil {
return nil
}
fh.Close()
if fh, err = os.Open(m.fn2); err != nil {
return fmt.Errorf("cannot open %s: %s", m.fn2, err)
}
return cdb.DumpMap(fh, walk)
}
func LoadNewNeedleMap(file *os.File) CompactMap {
m := NewCompactMap()
bytes := make([]byte, 16*1024)
count, e := file.Read(bytes)
if count > 0 {
fstat, _ := file.Stat()
glog.V(0).Infoln("Loading index file", fstat.Name(), "size", fstat.Size())
}
for count > 0 && e == nil {
for i := 0; i < count; i += 16 {
key := util.BytesToUint64(bytes[i : i+8])
offset := util.BytesToUint32(bytes[i+8 : i+12])
size := util.BytesToUint32(bytes[i+12 : i+16])
if offset > 0 {
m.Set(Key(key), offset, size)
} else {
//delete(m, key)
}
}
count, e = file.Read(bytes)
}
return m
}
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
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 (n *Needle) Read(r *os.File, offset int64, size uint32, version Version) (ret int, err error) {
switch version {
case Version1:
bytes := make([]byte, NeedleHeaderSize+size+NeedleChecksumSize)
if ret, err = r.ReadAt(bytes, offset); err != nil {
return
}
n.readNeedleHeader(bytes)
n.Data = bytes[NeedleHeaderSize : NeedleHeaderSize+size]
checksum := util.BytesToUint32(bytes[NeedleHeaderSize+size : NeedleHeaderSize+size+NeedleChecksumSize])
newChecksum := NewCRC(n.Data)
if checksum != newChecksum.Value() {
return 0, errors.New("CRC error! Data On Disk Corrupted!")
}
n.Checksum = newChecksum
return
case Version2:
if size == 0 {
return 0, nil
}
bytes := make([]byte, NeedleHeaderSize+size+NeedleChecksumSize)
if ret, err = r.ReadAt(bytes, offset); err != nil {
return
}
if ret != int(NeedleHeaderSize+size+NeedleChecksumSize) {
return 0, errors.New("File Entry Not Found!")
}
n.readNeedleHeader(bytes)
if n.Size != size {
return 0, fmt.Errorf("File Entry Not Found! Needle %d Memory %d", n.Size, size)
}
n.readNeedleDataVersion2(bytes[NeedleHeaderSize : NeedleHeaderSize+int(n.Size)])
checksum := util.BytesToUint32(bytes[NeedleHeaderSize+n.Size : NeedleHeaderSize+n.Size+NeedleChecksumSize])
newChecksum := NewCRC(n.Data)
if checksum != newChecksum.Value() {
return 0, errors.New("CRC error! Data On Disk Corrupted!")
}
n.Checksum = newChecksum
return
}
return 0, fmt.Errorf("Unsupported Version! (%d)", version)
}
func (m cdbMap) Get(key uint64) (element *NeedleValue, ok bool) {
var (
data []byte
k []byte = make([]byte, 8)
err error
)
util.Uint64toBytes(k, key)
//优先从c1读取,如果失败则尝试读c2,因为每个表只能存储有限数量的records
if data, err = m.c1.Data(k); err != nil || data == nil {
if m.c2 == nil {
return nil, false
}
if data, err = m.c2.Data(k); err != nil || data == nil {
return nil, false
}
}
return &NeedleValue{Key: Key(key), Offset: util.BytesToUint32(data[:4]),
Size: util.BytesToUint32(data[4:])}, true
}
func ParseKeyHash(key_hash_string string) (uint64, uint32, error) {
key_hash_bytes, khe := hex.DecodeString(key_hash_string)
key_hash_len := len(key_hash_bytes)
if khe != nil || key_hash_len <= 4 {
glog.V(0).Infoln("Invalid key_hash", key_hash_string, "length:", key_hash_len, "error", khe)
return 0, 0, errors.New("Invalid key and hash:" + key_hash_string)
}
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, nil
}
func (n *Needle) readNeedleHeader(bytes []byte) {
n.Cookie = util.BytesToUint32(bytes[0:4])
n.Id = util.BytesToUint64(bytes[4:12])
n.Size = util.BytesToUint32(bytes[12:NeedleHeaderSize])
}