dubbo.apache.org/dubbo-go/v3@v3.1.1/filter/adaptivesvc/limiter/limiter.go (about)

     1  /*
     2   * Licensed to the Apache Software Foundation (ASF) under one or more
     3   * contributor license agreements.  See the NOTICE file distributed with
     4   * this work for additional information regarding copyright ownership.
     5   * The ASF licenses this file to You under the Apache License, Version 2.0
     6   * (the "License"); you may not use this file except in compliance with
     7   * the License.  You may obtain a copy of the License at
     8   *
     9   *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   */
    17  
    18  package limiter
    19  
    20  import (
    21  	"fmt"
    22  )
    23  
    24  var ErrReachLimitation = fmt.Errorf("reach limitation")
    25  
    26  var (
    27  	Verbose = false
    28  )
    29  
    30  const (
    31  	HillClimbingLimiter = iota
    32  )
    33  
    34  type Limiter interface {
    35  	Inflight() uint64
    36  	Remaining() uint64
    37  	// Acquire inspects the current status of the system:
    38  	// - if reaches the limitation, reject the request immediately.
    39  	// - if not, grant this request and return an Updater defined below.
    40  	Acquire() (Updater, error)
    41  }
    42  
    43  type Updater interface {
    44  	// DoUpdate is called once an invocation is finished, it tells Updater that the invocation is finished, and please
    45  	// update the Remaining, Inflight parameters of the Limiter.
    46  	DoUpdate() error
    47  }