/
pd_codec.go
180 lines (162 loc) · 5.38 KB
/
pd_codec.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
// Copyright 2021 TiKV Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// NOTE: The code in this file is based on code from the
// TiDB project, licensed under the Apache License v 2.0
//
// https://github.com/pingcap/tidb/tree/cc5e161ac06827589c4966674597c137cc9e809c/store/tikv/locate/pd_codec.go
//
// Copyright 2016 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package locate
import (
"context"
"github.com/pingcap/kvproto/pkg/metapb"
"github.com/pkg/errors"
"github.com/tikv/client-go/v2/util/codec"
pd "github.com/tikv/pd/client"
)
var _ pd.Client = &CodecPDClient{}
// CodecPDClient wraps a PD Client to decode the encoded keys in region meta.
type CodecPDClient struct {
pd.Client
}
// NewCodeCPDClient creates a CodecPDClient.
func NewCodeCPDClient(client pd.Client) *CodecPDClient {
return &CodecPDClient{client}
}
// GetRegion encodes the key before send requests to pd-server and decodes the
// returned StartKey && EndKey from pd-server.
func (c *CodecPDClient) GetRegion(ctx context.Context, key []byte, opts ...pd.GetRegionOption) (*pd.Region, error) {
encodedKey := codec.EncodeBytes([]byte(nil), key)
region, err := c.Client.GetRegion(ctx, encodedKey, opts...)
return processRegionResult(region, err)
}
// GetPrevRegion encodes the key before send requests to pd-server and decodes the
// returned StartKey && EndKey from pd-server.
func (c *CodecPDClient) GetPrevRegion(ctx context.Context, key []byte, opts ...pd.GetRegionOption) (*pd.Region, error) {
encodedKey := codec.EncodeBytes([]byte(nil), key)
region, err := c.Client.GetPrevRegion(ctx, encodedKey, opts...)
return processRegionResult(region, err)
}
// GetRegionByID encodes the key before send requests to pd-server and decodes the
// returned StartKey && EndKey from pd-server.
func (c *CodecPDClient) GetRegionByID(ctx context.Context, regionID uint64, opts ...pd.GetRegionOption) (*pd.Region, error) {
region, err := c.Client.GetRegionByID(ctx, regionID, opts...)
return processRegionResult(region, err)
}
// ScanRegions encodes the key before send requests to pd-server and decodes the
// returned StartKey && EndKey from pd-server.
func (c *CodecPDClient) ScanRegions(ctx context.Context, startKey []byte, endKey []byte, limit int) ([]*pd.Region, error) {
startKey = codec.EncodeBytes([]byte(nil), startKey)
if len(endKey) > 0 {
endKey = codec.EncodeBytes([]byte(nil), endKey)
}
regions, err := c.Client.ScanRegions(ctx, startKey, endKey, limit)
if err != nil {
return nil, errors.WithStack(err)
}
for _, region := range regions {
if region != nil {
err = decodeRegionKeyInPlace(region)
if err != nil {
return nil, err
}
}
}
return regions, nil
}
func processRegionResult(region *pd.Region, err error) (*pd.Region, error) {
if err != nil {
return nil, errors.WithStack(err)
}
if region == nil || region.Meta == nil {
return nil, nil
}
err = decodeRegionKeyInPlace(region)
if err != nil {
return nil, err
}
return region, nil
}
// decodeError happens if the region range key is not well-formed.
// It indicates TiKV has bugs and the client can't handle such a case,
// so it should report the error to users soon.
type decodeError struct {
error
}
func isDecodeError(err error) bool {
_, ok := errors.Cause(err).(*decodeError)
if !ok {
_, ok = errors.Cause(err).(decodeError)
}
return ok
}
func decodeRegionKeyInPlace(r *pd.Region) error {
if len(r.Meta.StartKey) != 0 {
_, decoded, err := codec.DecodeBytes(r.Meta.StartKey, nil)
if err != nil {
return errors.WithStack(&decodeError{err})
}
r.Meta.StartKey = decoded
}
if len(r.Meta.EndKey) != 0 {
_, decoded, err := codec.DecodeBytes(r.Meta.EndKey, nil)
if err != nil {
return errors.WithStack(&decodeError{err})
}
r.Meta.EndKey = decoded
}
if r.Buckets != nil {
for i, k := range r.Buckets.Keys {
if len(k) == 0 {
continue
}
_, decoded, err := codec.DecodeBytes(k, nil)
if err != nil {
return errors.WithStack(&decodeError{err})
}
r.Buckets.Keys[i] = decoded
}
}
return nil
}
func decodeRegionMetaKeyWithShallowCopy(r *metapb.Region) (*metapb.Region, error) {
nr := *r
if len(r.StartKey) != 0 {
_, decoded, err := codec.DecodeBytes(r.StartKey, nil)
if err != nil {
return nil, err
}
nr.StartKey = decoded
}
if len(r.EndKey) != 0 {
_, decoded, err := codec.DecodeBytes(r.EndKey, nil)
if err != nil {
return nil, err
}
nr.EndKey = decoded
}
return &nr, nil
}