示例#1
0
func sequenceCacheKeyPrint(key roachpb.Key) string {
	b, id, err := encoding.DecodeBytesAscending([]byte(key), nil)
	if err != nil {
		return fmt.Sprintf("/%q/err:%v", key, err)
	}

	txnID, err := uuid.FromBytes(id)
	if err != nil {
		return fmt.Sprintf("/%q/err:%v", key, err)
	}

	if len(b) == 0 {
		return fmt.Sprintf("/%q", txnID)
	}

	b, epoch, err := encoding.DecodeUint32Descending(b)
	if err != nil {
		return fmt.Sprintf("/%q/err:%v", txnID, err)
	}

	_, seq, err := encoding.DecodeUint32Descending(b)
	if err != nil {
		return fmt.Sprintf("/%q/epoch:%d/err:%v", txnID, epoch, err)
	}

	return fmt.Sprintf("/%q/epoch:%d/seq:%d", txnID, epoch, seq)
}
示例#2
0
文件: keys.go 项目: nieyy/cockroach
// DecodeSequenceCacheKey decodes the provided sequence cache entry,
// returning the transaction ID, the epoch, and the sequence number.
func DecodeSequenceCacheKey(key roachpb.Key, dest []byte) (*uuid.UUID, uint32, uint32, error) {
	// TODO(tschottdorf): redundant check.
	if !bytes.HasPrefix(key, LocalRangeIDPrefix) {
		return nil, 0, 0, util.Errorf("key %s does not have %s prefix", key, LocalRangeIDPrefix)
	}
	// Cut the prefix, the Range ID, and the infix specifier.
	b := key[len(LocalRangeIDPrefix):]
	b, _, err := encoding.DecodeUvarintAscending(b)
	if err != nil {
		return nil, 0, 0, err
	}
	b = b[1:]
	if !bytes.HasPrefix(b, LocalSequenceCacheSuffix) {
		return nil, 0, 0, util.Errorf("key %s does not contain the sequence cache suffix %s",
			key, LocalSequenceCacheSuffix)
	}
	// Cut the sequence cache suffix.
	b = b[len(LocalSequenceCacheSuffix):]
	// Decode the id.
	b, idBytes, err := encoding.DecodeBytesAscending(b, dest)
	if err != nil {
		return nil, 0, 0, err
	}
	// Decode the epoch.
	b, epoch, err := encoding.DecodeUint32Descending(b)
	if err != nil {
		return nil, 0, 0, err
	}
	// Decode the sequence number.
	b, seq, err := encoding.DecodeUint32Descending(b)
	if err != nil {
		return nil, 0, 0, err
	}
	if len(b) > 0 {
		return nil, 0, 0, util.Errorf("key %q has leftover bytes after decode: %s; indicates corrupt key",
			key, b)
	}
	txnID, err := uuid.FromBytes(idBytes)
	return txnID, epoch, seq, err
}