dubbo.apache.org/dubbo-go/v3@v3.1.1/filter/adaptivesvc/limiter_mapper.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 adaptivesvc
    19  
    20  import (
    21  	"fmt"
    22  	"sync"
    23  )
    24  
    25  import (
    26  	"dubbo.apache.org/dubbo-go/v3/common"
    27  	"dubbo.apache.org/dubbo-go/v3/filter/adaptivesvc/limiter"
    28  )
    29  
    30  var (
    31  	limiterMapperSingleton *limiterMapper
    32  
    33  	ErrLimiterNotFoundOnMapper = fmt.Errorf("limiter not found on mapper")
    34  	ErrLimiterTypeNotFound     = fmt.Errorf("limiter type not found")
    35  )
    36  
    37  func init() {
    38  	limiterMapperSingleton = newLimiterMapper()
    39  }
    40  
    41  type limiterMapper struct {
    42  	rwMutex *sync.RWMutex
    43  	mapper  map[string]limiter.Limiter
    44  }
    45  
    46  func newLimiterMapper() *limiterMapper {
    47  	return &limiterMapper{
    48  		rwMutex: new(sync.RWMutex),
    49  		mapper:  make(map[string]limiter.Limiter),
    50  	}
    51  }
    52  
    53  func (m *limiterMapper) newAndSetMethodLimiter(url *common.URL, methodName string, limiterType int) (limiter.Limiter, error) {
    54  	key := fmt.Sprintf("%s%s", url.Path, methodName)
    55  
    56  	var (
    57  		l  limiter.Limiter
    58  		ok bool
    59  	)
    60  	m.rwMutex.Lock()
    61  	defer m.rwMutex.Unlock()
    62  
    63  	if l, ok = limiterMapperSingleton.mapper[key]; ok {
    64  		return l, nil
    65  	}
    66  	switch limiterType {
    67  	case limiter.HillClimbingLimiter:
    68  		l = limiter.NewHillClimbing()
    69  	default:
    70  		return nil, ErrLimiterTypeNotFound
    71  	}
    72  	limiterMapperSingleton.mapper[key] = l
    73  	return l, nil
    74  }
    75  
    76  func (m *limiterMapper) getMethodLimiter(url *common.URL, methodName string) (
    77  	limiter.Limiter, error) {
    78  	key := fmt.Sprintf("%s%s", url.Path, methodName)
    79  	m.rwMutex.RLock()
    80  	l, ok := limiterMapperSingleton.mapper[key]
    81  	m.rwMutex.RUnlock()
    82  	if !ok {
    83  		return nil, ErrLimiterNotFoundOnMapper
    84  	}
    85  	return l, nil
    86  }