52 lines
1.3 KiB
Go
52 lines
1.3 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 kv
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import "math"
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// VersionProvider provides increasing IDs.
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type VersionProvider interface {
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CurrentVersion() (Version, error)
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}
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// Version is the wrapper of KV's version.
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type Version struct {
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Ver uint64
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}
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var (
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// MaxVersion is the maximum version, notice that it's not a valid version.
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MaxVersion = Version{Ver: math.MaxUint64}
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// MinVersion is the minimum version, it's not a valid version, too.
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MinVersion = Version{Ver: 0}
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)
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// NewVersion creates a new Version struct.
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func NewVersion(v uint64) Version {
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return Version{
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Ver: v,
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}
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}
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// Cmp returns the comparison result of two versions.
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// The result will be 0 if a==b, -1 if a < b, and +1 if a > b.
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func (v Version) Cmp(another Version) int {
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if v.Ver > another.Ver {
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return 1
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} else if v.Ver < another.Ver {
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return -1
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}
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return 0
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}
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