dubbo.apache.org/dubbo-go/v3@v3.1.1/filter/metrics/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  package metrics
    19  
    20  import (
    21  	"context"
    22  	"time"
    23  )
    24  
    25  import (
    26  	"dubbo.apache.org/dubbo-go/v3/common/constant"
    27  	"dubbo.apache.org/dubbo-go/v3/common/extension"
    28  	"dubbo.apache.org/dubbo-go/v3/filter"
    29  	"dubbo.apache.org/dubbo-go/v3/metrics"
    30  	"dubbo.apache.org/dubbo-go/v3/metrics/rpc"
    31  	"dubbo.apache.org/dubbo-go/v3/protocol"
    32  )
    33  
    34  // must initialize before using the filter and after loading configuration
    35  var metricFilterInstance *metricsFilter
    36  
    37  func init() {
    38  	extension.SetFilter(constant.MetricsFilterKey, newFilter)
    39  }
    40  
    41  // metricsFilter will report RPC metrics to the metrics bus and implements the filter.Filter interface
    42  type metricsFilter struct{}
    43  
    44  // Invoke publish the BeforeInvokeEvent and AfterInvokeEvent to metrics bus
    45  func (mf *metricsFilter) Invoke(ctx context.Context, invoker protocol.Invoker, invocation protocol.Invocation) protocol.Result {
    46  	metrics.Publish(rpc.NewBeforeInvokeEvent(invoker, invocation))
    47  	start := time.Now()
    48  	res := invoker.Invoke(ctx, invocation)
    49  	end := time.Now()
    50  	duration := end.Sub(start)
    51  	metrics.Publish(rpc.NewAfterInvokeEvent(invoker, invocation, duration, res))
    52  	return res
    53  }
    54  
    55  // OnResponse do nothing and return the result
    56  func (mf *metricsFilter) OnResponse(ctx context.Context, res protocol.Result, invoker protocol.Invoker, invocation protocol.Invocation) protocol.Result {
    57  	return res
    58  }
    59  
    60  // newFilter creates a new metricsFilter instance.
    61  //
    62  // It's lazy initialization,
    63  // and make sure that the configuration had been loaded before invoking this method.
    64  func newFilter() filter.Filter {
    65  	if metricFilterInstance == nil {
    66  		metricFilterInstance = &metricsFilter{}
    67  	}
    68  	return metricFilterInstance
    69  }