51 lines
1.1 KiB
Go
51 lines
1.1 KiB
Go
// Copyright 2014 The Cayley Authors. All rights reserved.
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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 keys
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import (
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"github.com/google/cayley/graph"
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"strconv"
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"sync"
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)
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type Sequential struct {
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nextID int64
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mut sync.Mutex
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}
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func NewSequentialKey(horizon int64) graph.PrimaryKey {
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if horizon <= 0 {
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horizon = 1
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}
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return &Sequential{nextID: horizon}
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}
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func (s *Sequential) Next() graph.PrimaryKey {
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s.mut.Lock()
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defer s.mut.Unlock()
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s.nextID++
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if s.nextID <= 0 {
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s.nextID = 1
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}
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return s
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}
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func (s *Sequential) Int() int64 {
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return s.nextID
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}
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func (s *Sequential) String() string {
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return strconv.FormatInt(s.nextID, 10)
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}
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