mirror of https://github.com/tikv/client-go.git
74 lines
2.1 KiB
Go
74 lines
2.1 KiB
Go
// Copyright 2021 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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// NOTE: The code in this file is based on code from the
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// TiDB project, licensed under the Apache License v 2.0
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//
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// https://github.com/pingcap/tidb/tree/cc5e161ac06827589c4966674597c137cc9e809c/store/tikv/util/rate_limit.go
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//
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// Copyright 2021 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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// 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 util
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// RateLimit wraps a fix sized channel to control concurrency.
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type RateLimit struct {
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capacity int
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token chan struct{}
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}
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// NewRateLimit creates a limit controller with capacity n.
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func NewRateLimit(n int) *RateLimit {
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return &RateLimit{
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capacity: n,
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token: make(chan struct{}, n),
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}
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}
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// GetToken acquires a token.
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func (r *RateLimit) GetToken(done <-chan struct{}) (exit bool) {
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select {
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case <-done:
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return true
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case r.token <- struct{}{}:
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return false
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}
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}
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// PutToken puts a token back.
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func (r *RateLimit) PutToken() {
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select {
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case <-r.token:
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default:
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panic("put a redundant token")
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}
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}
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// GetCapacity returns the token capacity.
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func (r *RateLimit) GetCapacity() int {
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return r.capacity
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}
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