trace.go

Documentation: cloud.google.com/go/internal/testutil

     1  // Copyright 2018 Google LLC
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package testutil
    16  
    17  import (
    18  	"log"
    19  	"sync"
    20  	"time"
    21  
    22  	"go.opencensus.io/plugin/ocgrpc"
    23  	"go.opencensus.io/stats/view"
    24  	"go.opencensus.io/trace"
    25  )
    26  
    27  // TestExporter is a test utility exporter. It should be created with NewtestExporter.
    28  type TestExporter struct {
    29  	mu    sync.Mutex
    30  	Spans []*trace.SpanData
    31  
    32  	Stats chan *view.Data
    33  	Views []*view.View
    34  }
    35  
    36  // NewTestExporter creates a TestExporter and registers it with OpenCensus.
    37  func NewTestExporter(views ...*view.View) *TestExporter {
    38  	if len(views) == 0 {
    39  		views = ocgrpc.DefaultClientViews
    40  	}
    41  	te := &TestExporter{Stats: make(chan *view.Data), Views: views}
    42  
    43  	view.RegisterExporter(te)
    44  	view.SetReportingPeriod(time.Millisecond)
    45  	if err := view.Register(views...); err != nil {
    46  		log.Fatal(err)
    47  	}
    48  
    49  	trace.RegisterExporter(te)
    50  	trace.ApplyConfig(trace.Config{DefaultSampler: trace.AlwaysSample()})
    51  
    52  	return te
    53  }
    54  
    55  // ExportSpan exports a span.
    56  func (te *TestExporter) ExportSpan(s *trace.SpanData) {
    57  	te.mu.Lock()
    58  	defer te.mu.Unlock()
    59  	te.Spans = append(te.Spans, s)
    60  }
    61  
    62  // ExportView exports a view.
    63  func (te *TestExporter) ExportView(vd *view.Data) {
    64  	if len(vd.Rows) > 0 {
    65  		select {
    66  		case te.Stats <- vd:
    67  		default:
    68  		}
    69  	}
    70  }
    71  
    72  // Unregister unregisters the exporter from OpenCensus.
    73  func (te *TestExporter) Unregister() {
    74  	view.Unregister(te.Views...)
    75  	view.UnregisterExporter(te)
    76  	trace.UnregisterExporter(te)
    77  	view.SetReportingPeriod(0) // reset to default value
    78  }
    79
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