| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package limiter |
| |
| import ( |
| "fmt" |
| ) |
| |
| var ErrReachLimitation = fmt.Errorf("reach limitation") |
| |
| var ( |
| Verbose = false |
| ) |
| |
| const ( |
| HillClimbingLimiter = iota |
| ) |
| |
| type Limiter interface { |
| Inflight() uint64 |
| Remaining() uint64 |
| // Acquire inspects the current status of the system: |
| // - if reaches the limitation, reject the request immediately. |
| // - if not, grant this request and return an Updater defined below. |
| Acquire() (Updater, error) |
| } |
| |
| type Updater interface { |
| // DoUpdate is called once an invocation is finished, it tells Updater that the invocation is finished, and please |
| // update the Remaining, Inflight parameters of the Limiter. |
| DoUpdate() error |
| } |