dubbo.apache.org/dubbo-go/v3@v3.1.1/filter/tps/filter.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  /*
    19  Package tps provides a filter for limiting the requests by TPS.
    20  
    21  	if you wish to use the TpsLimiter, please add the configuration into your service provider configuration:
    22  	for example:
    23  	"UserProvider":
    24  	  registry: "hangzhouzk"
    25  	  protocol : "dubbo"
    26  	  interface : "com.ikurento.user.UserProvider"
    27  	  ... # other configuration
    28  	  tps.limiter: "method-service", # it should be the name of limiter. if the value is 'default',
    29  	                                 # the MethodServiceTpsLimiter will be used.
    30  	  tps.limit.rejected.handler: "default", # optional, or the name of the implementation
    31  	  if the value of 'tps.limiter' is nil or empty string, the tps filter will do nothing
    32  */
    33  package tps
    34  
    35  import (
    36  	"context"
    37  	"sync"
    38  )
    39  
    40  import (
    41  	"github.com/dubbogo/gost/log/logger"
    42  )
    43  
    44  import (
    45  	"dubbo.apache.org/dubbo-go/v3/common/constant"
    46  	"dubbo.apache.org/dubbo-go/v3/common/extension"
    47  	"dubbo.apache.org/dubbo-go/v3/filter"
    48  	_ "dubbo.apache.org/dubbo-go/v3/filter/handler"
    49  	_ "dubbo.apache.org/dubbo-go/v3/filter/tps/limiter"
    50  	"dubbo.apache.org/dubbo-go/v3/protocol"
    51  )
    52  
    53  var (
    54  	once     sync.Once
    55  	tpsLimit *tpsLimitFilter
    56  )
    57  
    58  func init() {
    59  	extension.SetFilter(constant.TpsLimitFilterKey, newTpsLimitFilter)
    60  }
    61  
    62  type tpsLimitFilter struct{}
    63  
    64  func newTpsLimitFilter() filter.Filter {
    65  	if tpsLimit == nil {
    66  		once.Do(func() {
    67  			tpsLimit = &tpsLimitFilter{}
    68  		})
    69  	}
    70  	return tpsLimit
    71  }
    72  
    73  // Invoke gets the configured limter to impose TPS limiting
    74  func (t *tpsLimitFilter) Invoke(ctx context.Context, invoker protocol.Invoker, invocation protocol.Invocation) protocol.Result {
    75  	url := invoker.GetURL()
    76  	tpsLimiter := url.GetParam(constant.TPSLimiterKey, "")
    77  	rejectedExeHandler := url.GetParam(constant.TPSRejectedExecutionHandlerKey, constant.DefaultKey)
    78  	if len(tpsLimiter) > 0 {
    79  		limiter, err := extension.GetTpsLimiter(tpsLimiter)
    80  		if err != nil {
    81  			logger.Warn(err)
    82  			return invoker.Invoke(ctx, invocation)
    83  		}
    84  		allow := limiter.IsAllowable(invoker.GetURL(), invocation)
    85  		if allow {
    86  			return invoker.Invoke(ctx, invocation)
    87  		}
    88  		logger.Errorf("The invocation was rejected due to over the limiter limitation, url: %s ", url.String())
    89  		rejectedExecutionHandler, err := extension.GetRejectedExecutionHandler(rejectedExeHandler)
    90  		if err != nil {
    91  			logger.Warn(err)
    92  		} else {
    93  			return rejectedExecutionHandler.RejectedExecution(url, invocation)
    94  		}
    95  	}
    96  	return invoker.Invoke(ctx, invocation)
    97  }
    98  
    99  // OnResponse dummy process, returns the result directly
   100  func (t *tpsLimitFilter) OnResponse(_ context.Context, result protocol.Result, _ protocol.Invoker,
   101  	_ protocol.Invocation) protocol.Result {
   102  	return result
   103  }