94 lines
2.4 KiB
Go
94 lines
2.4 KiB
Go
// Copyright 2015 PingCAP, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package structure
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import (
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"github.com/juju/errors"
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"github.com/pingcap/tidb/util/codec"
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)
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// TypeFlag is for data structure meta/data flag.
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type TypeFlag byte
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const (
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StringMeta TypeFlag = 'S'
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StringData TypeFlag = 's'
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HashMeta TypeFlag = 'H'
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HashData TypeFlag = 'h'
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ListMeta TypeFlag = 'L'
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ListData TypeFlag = 'l'
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)
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func encodeStringDataKey(key []byte) []byte {
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ek := make([]byte, 0, len(key)+4)
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ek = codec.EncodeBytes(ek, key)
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return codec.EncodeUint(ek, uint64(StringData))
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}
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func encodeHashMetaKey(key []byte) []byte {
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ek := make([]byte, 0, len(key)+4)
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ek = codec.EncodeBytes(ek, key)
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return codec.EncodeUint(ek, uint64(HashMeta))
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}
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func encodeHashDataKey(key []byte, field []byte) []byte {
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ek := make([]byte, 0, len(key)+len(field)+6)
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ek = codec.EncodeBytes(ek, key)
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ek = codec.EncodeUint(ek, uint64(HashData))
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return codec.EncodeBytes(ek, field)
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}
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func decodeHashDataKey(ek []byte) ([]byte, []byte, error) {
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var (
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key []byte
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field []byte
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err error
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tp uint64
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)
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ek, key, err = codec.DecodeBytes(ek)
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if err != nil {
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return nil, nil, errors.Trace(err)
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}
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ek, tp, err = codec.DecodeUint(ek)
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if err != nil {
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return nil, nil, errors.Trace(err)
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} else if TypeFlag(tp) != HashData {
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return nil, nil, errors.Errorf("invalid encoded hash data key flag %c", byte(tp))
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}
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_, field, err = codec.DecodeBytes(ek)
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return key, field, errors.Trace(err)
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}
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func hashDataKeyPrefix(key []byte) []byte {
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ek := make([]byte, 0, len(key)+4)
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ek = codec.EncodeBytes(ek, key)
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return codec.EncodeUint(ek, uint64(HashData))
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}
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func encodeListMetaKey(key []byte) []byte {
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ek := make([]byte, 0, len(key)+4)
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ek = codec.EncodeBytes(ek, key)
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return codec.EncodeUint(ek, uint64(ListMeta))
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}
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func encodeListDataKey(key []byte, index int64) []byte {
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ek := make([]byte, 0, len(key)+13)
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ek = codec.EncodeBytes(ek, key)
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ek = codec.EncodeUint(ek, uint64(ListData))
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return codec.EncodeInt(ek, index)
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}
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