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  	"slices"
    17  	"strings"
    18  )
    19  
    20  const debugText = `<html>
    21  	<body>
    22  	<title>Services</title>
    23  	{{range .}}
    24  	<hr>
    25  	Service {{.Name}}
    26  	<hr>
    27  		<table>
    28  		<th align=center>Method</th><th align=center>Calls</th>
    29  		{{range .Method}}
    30  			<tr>
    31  			<td align=left font=fixed>{{.Name}}({{.Type.ArgType}}, {{.Type.ReplyType}}) error</td>
    32  			<td align=center>{{.Type.NumCalls}}</td>
    33  			</tr>
    34  		{{end}}
    35  		</table>
    36  	{{end}}
    37  	</body>
    38  	</html>`
    39  
    40  var debug = template.Must(template.New("RPC debug").Parse(debugText))
    41  
    42  // If set, print log statements for internal and I/O errors.
    43  var debugLog = false
    44  
    45  type debugMethod struct {
    46  	Type *methodType
    47  	Name string
    48  }
    49  
    50  type methodArray []debugMethod
    51  
    52  type debugService struct {
    53  	Service *service
    54  	Name    string
    55  	Method  []debugMethod
    56  }
    57  
    58  type serviceArray []debugService
    59  
    60  func (s serviceArray) Len() int           { return len(s) }
    61  func (s serviceArray) Less(i, j int) bool { return s[i].Name < s[j].Name }
    62  func (s serviceArray) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
    63  
    64  func (m methodArray) Len() int           { return len(m) }
    65  func (m methodArray) Less(i, j int) bool { return m[i].Name < m[j].Name }
    66  func (m methodArray) Swap(i, j int)      { m[i], m[j] = m[j], m[i] }
    67  
    68  type debugHTTP struct {
    69  	*Server
    70  }
    71  
    72  // Runs at /debug/rpc
    73  func (server debugHTTP) ServeHTTP(w http.ResponseWriter, req *http.Request) {
    74  	// Build a sorted version of the data.
    75  	var services serviceArray
    76  	server.serviceMap.Range(func(snamei, svci any) bool {
    77  		svc := svci.(*service)
    78  		ds := debugService{svc, snamei.(string), make([]debugMethod, 0, len(svc.method))}
    79  		for mname, method := range svc.method {
    80  			ds.Method = append(ds.Method, debugMethod{method, mname})
    81  		}
    82  		slices.SortFunc(ds.Method, func(a, b debugMethod) int {
    83  			return strings.Compare(a.Name, b.Name)
    84  		})
    85  		services = append(services, ds)
    86  		return true
    87  	})
    88  	slices.SortFunc(services, func(a, b debugService) int {
    89  		return strings.Compare(a.Name, b.Name)
    90  	})
    91  	err := debug.Execute(w, services)
    92  	if err != nil {
    93  		fmt.Fprintln(w, "rpc: error executing template:", err.Error())
    94  	}
    95  }
    96
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