github.com/rohankumardubey/aresdb@v0.0.2-0.20190517170215-e54e3ca06b9c/common/metrics.go (about)

     1  //  Copyright (c) 2017-2018 Uber Technologies, Inc.
     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 common
    16  
    17  import (
    18  	"io"
    19  
    20  	"io/ioutil"
    21  
    22  	"github.com/uber-go/tally"
    23  )
    24  
    25  // Metrics is the interface for stats reporting based on tally. The application call NewRootScope()
    26  // at start up time to get the root scope and calls closer.Close() before shutdown.
    27  type Metrics interface {
    28  	NewRootScope() (tally.Scope, io.Closer, error)
    29  }
    30  
    31  // NewNoopMetrics returns a Metrics that will do nothing for reporting.
    32  func NewNoopMetrics() Metrics {
    33  	return dummyMetrics{}
    34  }
    35  
    36  type dummyMetrics struct{}
    37  
    38  // NewRootScope returns a no-op scope will do nothing for reporting metrics. The closer will also be
    39  // a no-op closer.
    40  func (dummyMetrics) NewRootScope() (tally.Scope, io.Closer, error) {
    41  	return tally.NoopScope, ioutil.NopCloser(nil), nil
    42  }