github.com/galamsiva2020/kubernetes-heapster-monitoring@v0.0.0-20210823134957-3c1baa7c1e70/metrics/sinks/statsd/statsd_client.go (about)

     1  // Copyright 2016 Google Inc. All Rights Reserved.
     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 statsd
    16  
    17  import (
    18  	"bytes"
    19  	"fmt"
    20  	"github.com/golang/glog"
    21  	"net"
    22  )
    23  
    24  type statsdClient interface {
    25  	open() error
    26  	close() error
    27  	send(messages []string) error
    28  }
    29  
    30  type statsdClientImpl struct {
    31  	host             string
    32  	numMetricsPerMsg int
    33  	conn             net.Conn
    34  }
    35  
    36  func (client *statsdClientImpl) open() error {
    37  	var err error
    38  	client.conn, err = net.Dial("udp", client.host)
    39  	if err != nil {
    40  		glog.Errorf("Failed to open statsd client connection : %v", err)
    41  	} else {
    42  		glog.V(2).Infof("statsd client connection opened : %+v", client.conn)
    43  	}
    44  	return err
    45  }
    46  
    47  func (client *statsdClientImpl) close() error {
    48  	if client.conn == nil {
    49  		glog.Info("statsd client connection already closed")
    50  		return nil
    51  	}
    52  	err := client.conn.Close()
    53  	client.conn = nil
    54  	glog.V(2).Infof("statsd client connection closed")
    55  	return err
    56  }
    57  
    58  func (client *statsdClientImpl) send(messages []string) error {
    59  	if client.conn == nil {
    60  		err := client.open()
    61  		if err != nil {
    62  			return fmt.Errorf("send() failed - %v", err)
    63  		}
    64  	}
    65  	var numMetrics = 0
    66  	var err, tmpErr error
    67  	buf := bytes.NewBufferString("")
    68  	for _, msg := range messages {
    69  		buf.WriteString(fmt.Sprintf("%s\n", msg))
    70  		numMetrics++
    71  		if numMetrics >= client.numMetricsPerMsg {
    72  			_, tmpErr = client.conn.Write(buf.Bytes())
    73  			if tmpErr != nil {
    74  				err = tmpErr
    75  			}
    76  			buf.Reset()
    77  			numMetrics = 0
    78  		}
    79  	}
    80  	if buf.Len() > 0 {
    81  		_, tmpErr = client.conn.Write(buf.Bytes())
    82  		if tmpErr != nil {
    83  			err = tmpErr
    84  		}
    85  	}
    86  	return err
    87  }
    88  
    89  func NewStatsdClient(host string, numMetricsPerMsg int) (client statsdClient, err error) {
    90  	if numMetricsPerMsg <= 0 {
    91  		return nil, fmt.Errorf("numMetricsPerMsg should be a positive integer : %d", numMetricsPerMsg)
    92  	}
    93  	glog.V(2).Infof("statsd client created")
    94  	return &statsdClientImpl{host: host, numMetricsPerMsg: numMetricsPerMsg}, nil
    95  }