mirror of https://github.com/tikv/client-go.git
55 lines
1.5 KiB
Go
55 lines
1.5 KiB
Go
// Copyright 2022 TiKV Authors
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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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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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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 oracles
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import (
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"context"
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"github.com/pkg/errors"
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"github.com/tikv/client-go/v2/oracle"
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"go.uber.org/atomic"
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)
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type localExternalTimestamp struct {
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externalTimestamp atomic.Uint64
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}
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func (l *localExternalTimestamp) setExternalTimestamp(ctx context.Context, o oracle.Oracle, newTimestamp uint64) error {
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currentTSO, err := o.GetTimestamp(ctx, nil)
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if err != nil {
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return err
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}
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if newTimestamp > currentTSO {
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return errors.New("external timestamp is greater than global tso")
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}
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for {
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externalTimestamp := l.externalTimestamp.Load()
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if externalTimestamp > newTimestamp {
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return errors.New("cannot decrease the external timestamp")
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} else if externalTimestamp == newTimestamp {
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return nil
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}
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if l.externalTimestamp.CompareAndSwap(externalTimestamp, newTimestamp) {
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return nil
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}
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}
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}
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func (l *localExternalTimestamp) getExternalTimestamp(ctx context.Context) (uint64, error) {
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return l.externalTimestamp.Load(), nil
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}
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