func (r *rdbReader) readString() ([]byte, error) {
length, encoded, err := r.readEncodedLength()
if err != nil {
return nil, err
}
if !encoded {
return r.readBytes(int(length))
}
switch t := uint8(length); t {
default:
return nil, errors.Errorf("invalid encoded-string %02x", t)
case rdbEncInt8:
i, err := r.readInt8()
return []byte(strconv.FormatInt(int64(i), 10)), err
case rdbEncInt16:
i, err := r.readInt16()
return []byte(strconv.FormatInt(int64(i), 10)), err
case rdbEncInt32:
i, err := r.readInt32()
return []byte(strconv.FormatInt(int64(i), 10)), err
case rdbEncLZF:
var inlen, outlen uint32
if inlen, err = r.readLength(); err != nil {
return nil, err
}
if outlen, err = r.readLength(); err != nil {
return nil, err
}
if in, err := r.readBytes(int(inlen)); err != nil {
return nil, err
} else {
return lzfDecompress(in, int(outlen))
}
}
}
func (r *rdbReader) readObjectValue(t byte) ([]byte, error) {
var b bytes.Buffer
r = newRdbReader(io.TeeReader(r, &b))
switch t {
default:
return nil, errors.Errorf("unknown object-type %02x", t)
case rdbTypeHashZipmap:
fallthrough
case rdbTypeListZiplist:
fallthrough
case rdbTypeSetIntset:
fallthrough
case rdbTypeZSetZiplist:
fallthrough
case rdbTypeHashZiplist:
fallthrough
case rdbTypeString:
if _, err := r.readString(); err != nil {
return nil, err
}
case rdbTypeList, rdbTypeSet:
if n, err := r.readLength(); err != nil {
return nil, err
} else {
for i := 0; i < int(n); i++ {
if _, err := r.readString(); err != nil {
return nil, err
}
}
}
case rdbTypeZSet:
if n, err := r.readLength(); err != nil {
return nil, err
} else {
for i := 0; i < int(n); i++ {
if _, err := r.readString(); err != nil {
return nil, err
}
if _, err := r.readFloat(); err != nil {
return nil, err
}
}
}
case rdbTypeHash:
if n, err := r.readLength(); err != nil {
return nil, err
} else {
for i := 0; i < int(n); i++ {
if _, err := r.readString(); err != nil {
return nil, err
}
if _, err := r.readString(); err != nil {
return nil, err
}
}
}
}
return b.Bytes(), nil
}
func parseInt(s string, min, max int) (int, error) {
n, err := strconv.Atoi(s)
if err != nil {
return 0, err
}
if n >= min && n <= max {
return n, nil
}
return 0, errors.Errorf("out of range [%d,%d], got %d", min, max, n)
}
func ParseArgs(resp Resp) (cmd string, args [][]byte, err error) {
var array []Resp
if o, ok := resp.(*Array); !ok {
return "", nil, errors.Errorf("expect array, but got type = '%s'", resp.Type())
} else if o == nil || len(o.Value) == 0 {
return "", nil, errors.New("request is an empty array")
} else {
array = o.Value
}
slices := make([][]byte, 0, len(array))
for i, resp := range array {
if o, ok := resp.(*BulkBytes); !ok {
return "", nil, errors.Errorf("args[%d], expect bulkbytes, but got '%s'", i, resp.Type())
} else if i == 0 && len(o.Value) == 0 {
return "", nil, errors.New("command is empty")
} else {
slices = append(slices, o.Value)
}
}
return strings.ToLower(string(slices[0])), slices[1:], nil
}
func lzfDecompress(in []byte, outlen int) (out []byte, err error) {
defer func() {
if x := recover(); x != nil {
err = errors.Errorf("decompress exception: %v", x)
}
}()
out = make([]byte, outlen)
i, o := 0, 0
for i < len(in) {
ctrl := int(in[i])
i++
if ctrl < 32 {
for x := 0; x <= ctrl; x++ {
out[o] = in[i]
i++
o++
}
} else {
length := ctrl >> 5
if length == 7 {
length = length + int(in[i])
i++
}
ref := o - ((ctrl & 0x1f) << 8) - int(in[i]) - 1
i++
for x := 0; x <= length+1; x++ {
out[o] = out[ref]
ref++
o++
}
}
}
if o != outlen {
return nil, errors.Errorf("decompress length is %d != expected %d", o, outlen)
}
return out, nil
}
func (l *Loader) Header() error {
header := make([]byte, 9)
if err := l.readFull(header); err != nil {
return err
}
if !bytes.Equal(header[:5], []byte("REDIS")) {
return errors.New("verify magic string, invalid file format")
}
if version, err := strconv.ParseInt(string(header[5:]), 10, 64); err != nil {
return errors.Trace(err)
} else if version <= 0 || version > Version {
return errors.Errorf("verify version, invalid RDB version number %d", version)
}
return nil
}
