templates.go

Documentation: go.opencensus.io/zpages

     1  // Copyright 2017, OpenCensus Authors
     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  
    16  package zpages
    17  
    18  import (
    19  	"fmt"
    20  	"html/template"
    21  	"io/ioutil"
    22  	"log"
    23  	"strconv"
    24  	"time"
    25  
    26  	"go.opencensus.io/trace"
    27  	"go.opencensus.io/zpages/internal"
    28  )
    29  
    30  var (
    31  	fs                = internal.FS(false)
    32  	templateFunctions = template.FuncMap{
    33  		"count":    countFormatter,
    34  		"ms":       msFormatter,
    35  		"rate":     rateFormatter,
    36  		"datarate": dataRateFormatter,
    37  		"even":     even,
    38  		"traceid":  traceIDFormatter,
    39  	}
    40  	headerTemplate       = parseTemplate("header")
    41  	summaryTableTemplate = parseTemplate("summary")
    42  	statsTemplate        = parseTemplate("rpcz")
    43  	tracesTableTemplate  = parseTemplate("traces")
    44  	footerTemplate       = parseTemplate("footer")
    45  )
    46  
    47  func parseTemplate(name string) *template.Template {
    48  	f, err := fs.Open("/templates/" + name + ".html")
    49  	if err != nil {
    50  		log.Panicf("%v: %v", name, err)
    51  	}
    52  	defer f.Close()
    53  	text, err := ioutil.ReadAll(f)
    54  	if err != nil {
    55  		log.Panicf("%v: %v", name, err)
    56  	}
    57  	return template.Must(template.New(name).Funcs(templateFunctions).Parse(string(text)))
    58  }
    59  
    60  func countFormatter(num uint64) string {
    61  	if num <= 0 {
    62  		return " "
    63  	}
    64  	var floatVal float64
    65  	var suffix string
    66  
    67  	if num >= 1e18 {
    68  		floatVal = float64(num) / 1e18
    69  		suffix = " E "
    70  	} else if num >= 1e15 {
    71  		floatVal = float64(num) / 1e15
    72  		suffix = " P "
    73  	} else if num >= 1e12 {
    74  		floatVal = float64(num) / 1e12
    75  		suffix = " T "
    76  	} else if num >= 1e9 {
    77  		floatVal = float64(num) / 1e9
    78  		suffix = " G "
    79  	} else if num >= 1e6 {
    80  		floatVal = float64(num) / 1e6
    81  		suffix = " M "
    82  	}
    83  
    84  	if floatVal != 0 {
    85  		return fmt.Sprintf("%1.3f%s", floatVal, suffix)
    86  	}
    87  	return fmt.Sprint(num)
    88  }
    89  
    90  func msFormatter(d time.Duration) string {
    91  	if d == 0 {
    92  		return "0"
    93  	}
    94  	if d < 10*time.Millisecond {
    95  		return fmt.Sprintf("%.3f", float64(d)*1e-6)
    96  	}
    97  	return strconv.Itoa(int(d / time.Millisecond))
    98  }
    99  
   100  func rateFormatter(r float64) string {
   101  	return fmt.Sprintf("%.3f", r)
   102  }
   103  
   104  func dataRateFormatter(b float64) string {
   105  	return fmt.Sprintf("%.3f", b/1e6)
   106  }
   107  
   108  func traceIDFormatter(r traceRow) template.HTML {
   109  	sc := r.SpanContext
   110  	if sc == (trace.SpanContext{}) {
   111  		return ""
   112  	}
   113  	col := "black"
   114  	if sc.TraceOptions.IsSampled() {
   115  		col = "blue"
   116  	}
   117  	if r.ParentSpanID != (trace.SpanID{}) {
   118  		return template.HTML(fmt.Sprintf(`trace_id: <b style="color:%s">%s</b> span_id: %s parent_span_id: %s`, col, sc.TraceID, sc.SpanID, r.ParentSpanID))
   119  	}
   120  	return template.HTML(fmt.Sprintf(`trace_id: <b style="color:%s">%s</b> span_id: %s`, col, sc.TraceID, sc.SpanID))
   121  }
   122  
   123  func even(x int) bool {
   124  	return x%2 == 0
   125  }
   126
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