debug.go

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package rpc
     6  
     7  /*
     8  	Some HTML presented at http://machine:port/debug/rpc
     9  	Lists services, their methods, and some statistics, still rudimentary.
    10  */
    11  
    12  import (
    13  	"fmt"
    14  	"html/template"
    15  	"net/http"
    16  	"sort"
    17  )
    18  
    19  const debugText = `<html>
    20  	<body>
    21  	<title>Services</title>
    22  	{{range .}}
    23  	<hr>
    24  	Service {{.Name}}
    25  	<hr>
    26  		<table>
    27  		<th align=center>Method</th><th align=center>Calls</th>
    28  		{{range .Method}}
    29  			<tr>
    30  			<td align=left font=fixed>{{.Name}}({{.Type.ArgType}}, {{.Type.ReplyType}}) error</td>
    31  			<td align=center>{{.Type.NumCalls}}</td>
    32  			</tr>
    33  		{{end}}
    34  		</table>
    35  	{{end}}
    36  	</body>
    37  	</html>`
    38  
    39  var debug = template.Must(template.New("RPC debug").Parse(debugText))
    40  
    41  // If set, print log statements for internal and I/O errors.
    42  var debugLog = false
    43  
    44  type debugMethod struct {
    45  	Type *methodType
    46  	Name string
    47  }
    48  
    49  type methodArray []debugMethod
    50  
    51  type debugService struct {
    52  	Service *service
    53  	Name    string
    54  	Method  methodArray
    55  }
    56  
    57  type serviceArray []debugService
    58  
    59  func (s serviceArray) Len() int           { return len(s) }
    60  func (s serviceArray) Less(i, j int) bool { return s[i].Name < s[j].Name }
    61  func (s serviceArray) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
    62  
    63  func (m methodArray) Len() int           { return len(m) }
    64  func (m methodArray) Less(i, j int) bool { return m[i].Name < m[j].Name }
    65  func (m methodArray) Swap(i, j int)      { m[i], m[j] = m[j], m[i] }
    66  
    67  type debugHTTP struct {
    68  	*Server
    69  }
    70  
    71  // Runs at /debug/rpc
    72  func (server debugHTTP) ServeHTTP(w http.ResponseWriter, req *http.Request) {
    73  	// Build a sorted version of the data.
    74  	var services serviceArray
    75  	server.serviceMap.Range(func(snamei, svci any) bool {
    76  		svc := svci.(*service)
    77  		ds := debugService{svc, snamei.(string), make(methodArray, 0, len(svc.method))}
    78  		for mname, method := range svc.method {
    79  			ds.Method = append(ds.Method, debugMethod{method, mname})
    80  		}
    81  		sort.Sort(ds.Method)
    82  		services = append(services, ds)
    83  		return true
    84  	})
    85  	sort.Sort(services)
    86  	err := debug.Execute(w, services)
    87  	if err != nil {
    88  		fmt.Fprintln(w, "rpc: error executing template:", err.Error())
    89  	}
    90  }
    91
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