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// 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,
// See the License for the specific language governing permissions and
// limitations under the License.
package tikv
import (
"context"
"github.com/pingcap/errors"
"github.com/pingcap/kvproto/pkg/metapb"
"github.com/pingcap/tidb/util/codec"
"github.com/tikv/pd/client"
)
type codecPDClient struct {
pd.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) (*pd.Region, error) {
encodedKey := codec.EncodeBytes([]byte(nil), key)
region, err := c.Client.GetRegion(ctx, encodedKey)
return processRegionResult(region, err)
}
func (c *codecPDClient) GetPrevRegion(ctx context.Context, key []byte) (*pd.Region, error) {
encodedKey := codec.EncodeBytes([]byte(nil), key)
region, err := c.Client.GetPrevRegion(ctx, encodedKey)
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) (*pd.Region, error) {
region, err := c.Client.GetRegionByID(ctx, regionID)
return processRegionResult(region, err)
}
func (c *codecPDClient) ScanRegions(ctx context.Context, startKey []byte, endKey []byte, limit int) ([]*metapb.Region, []*metapb.Peer, error) {
startKey = codec.EncodeBytes([]byte(nil), startKey)
if len(endKey) > 0 {
endKey = codec.EncodeBytes([]byte(nil), endKey)
}
regions, peers, err := c.Client.ScanRegions(ctx, startKey, endKey, limit)
if err != nil {
return nil, nil, errors.Trace(err)
}
for _, region := range regions {
if region != nil {
err = decodeRegionMetaKeyInPlace(region)
if err != nil {
return nil, nil, errors.Trace(err)
}
}
}
return regions, peers, nil
}
func processRegionResult(region *pd.Region, err error) (*pd.Region, error) {
if err != nil {
return nil, errors.Trace(err)
}
if region == nil || region.Meta == nil {
return nil, nil
}
err = decodeRegionMetaKeyInPlace(region.Meta)
if err != nil {
return nil, errors.Trace(err)
}
return region, nil
}
func decodeRegionMetaKeyInPlace(r *metapb.Region) error {
if len(r.StartKey) != 0 {
_, decoded, err := codec.DecodeBytes(r.StartKey, nil)
if err != nil {
return errors.Trace(err)
}
r.StartKey = decoded
}
if len(r.EndKey) != 0 {
_, decoded, err := codec.DecodeBytes(r.EndKey, nil)
if err != nil {
return errors.Trace(err)
}
r.EndKey = 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, errors.Trace(err)
}
nr.StartKey = decoded
}
if len(r.EndKey) != 0 {
_, decoded, err := codec.DecodeBytes(r.EndKey, nil)
if err != nil {
return nil, errors.Trace(err)
}
nr.EndKey = decoded
}
return &nr, nil
}