138 lines
3.1 KiB
Go
138 lines
3.1 KiB
Go
package main
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"fmt"
|
|
|
|
"github.com/syndtr/goleveldb/leveldb/errors"
|
|
"github.com/syndtr/goleveldb/leveldb/storage"
|
|
)
|
|
|
|
type ErrIkeyCorrupted struct {
|
|
Ikey []byte
|
|
Reason string
|
|
}
|
|
|
|
func (e *ErrIkeyCorrupted) Error() string {
|
|
return fmt.Sprintf("leveldb: iKey %q corrupted: %s", e.Ikey, e.Reason)
|
|
}
|
|
|
|
func newErrIkeyCorrupted(ikey []byte, reason string) error {
|
|
return errors.NewErrCorrupted(storage.FileDesc{}, &ErrIkeyCorrupted{append([]byte{}, ikey...), reason})
|
|
}
|
|
|
|
type kType int
|
|
|
|
func (kt kType) String() string {
|
|
switch kt {
|
|
case ktDel:
|
|
return "d"
|
|
case ktVal:
|
|
return "v"
|
|
}
|
|
return "x"
|
|
}
|
|
|
|
// Value types encoded as the last component of internal keys.
|
|
// Don't modify; this value are saved to disk.
|
|
const (
|
|
ktDel kType = iota
|
|
ktVal
|
|
)
|
|
|
|
// ktSeek defines the kType that should be passed when constructing an
|
|
// internal key for seeking to a particular sequence number (since we
|
|
// sort sequence numbers in decreasing order and the value type is
|
|
// embedded as the low 8 bits in the sequence number in internal keys,
|
|
// we need to use the highest-numbered ValueType, not the lowest).
|
|
const ktSeek = ktVal
|
|
|
|
const (
|
|
// Maximum value possible for sequence number; the 8-bits are
|
|
// used by value type, so its can packed together in single
|
|
// 64-bit integer.
|
|
kMaxSeq uint64 = (uint64(1) << 56) - 1
|
|
// Maximum value possible for packed sequence number and type.
|
|
kMaxNum uint64 = (kMaxSeq << 8) | uint64(ktSeek)
|
|
)
|
|
|
|
// Maximum number encoded in bytes.
|
|
var kMaxNumBytes = make([]byte, 8)
|
|
|
|
func init() {
|
|
binary.LittleEndian.PutUint64(kMaxNumBytes, kMaxNum)
|
|
}
|
|
|
|
type iKey []byte
|
|
|
|
func newIkey(ukey []byte, seq uint64, kt kType) iKey {
|
|
if seq > kMaxSeq {
|
|
panic("leveldb: invalid sequence number")
|
|
} else if kt > ktVal {
|
|
panic("leveldb: invalid type")
|
|
}
|
|
|
|
ik := make(iKey, len(ukey)+8)
|
|
copy(ik, ukey)
|
|
binary.LittleEndian.PutUint64(ik[len(ukey):], (seq<<8)|uint64(kt))
|
|
return ik
|
|
}
|
|
|
|
func parseIkey(ik []byte) (ukey []byte, seq uint64, kt kType, err error) {
|
|
if len(ik) < 8 {
|
|
return nil, 0, 0, newErrIkeyCorrupted(ik, "invalid length")
|
|
}
|
|
num := binary.LittleEndian.Uint64(ik[len(ik)-8:])
|
|
seq, kt = uint64(num>>8), kType(num&0xff)
|
|
if kt > ktVal {
|
|
return nil, 0, 0, newErrIkeyCorrupted(ik, "invalid type")
|
|
}
|
|
ukey = ik[:len(ik)-8]
|
|
return
|
|
}
|
|
|
|
func validIkey(ik []byte) bool {
|
|
_, _, _, err := parseIkey(ik)
|
|
return err == nil
|
|
}
|
|
|
|
func (ik iKey) assert() {
|
|
if ik == nil {
|
|
panic("leveldb: nil iKey")
|
|
}
|
|
if len(ik) < 8 {
|
|
panic(fmt.Sprintf("leveldb: iKey %q, len=%d: invalid length", ik, len(ik)))
|
|
}
|
|
}
|
|
|
|
func (ik iKey) ukey() []byte {
|
|
ik.assert()
|
|
return ik[:len(ik)-8]
|
|
}
|
|
|
|
func (ik iKey) num() uint64 {
|
|
ik.assert()
|
|
return binary.LittleEndian.Uint64(ik[len(ik)-8:])
|
|
}
|
|
|
|
func (ik iKey) parseNum() (seq uint64, kt kType) {
|
|
num := ik.num()
|
|
seq, kt = uint64(num>>8), kType(num&0xff)
|
|
if kt > ktVal {
|
|
panic(fmt.Sprintf("leveldb: iKey %q, len=%d: invalid type %#x", ik, len(ik), kt))
|
|
}
|
|
return
|
|
}
|
|
|
|
func (ik iKey) String() string {
|
|
if ik == nil {
|
|
return "<nil>"
|
|
}
|
|
|
|
if ukey, seq, kt, err := parseIkey(ik); err == nil {
|
|
return fmt.Sprintf("%x,%s%d", ukey, kt, seq)
|
|
} else {
|
|
return "<invalid>"
|
|
}
|
|
}
|