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      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 interface{}) 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