vendor/google.golang.org/grpc/trace.go

   1 /*
   2  *
   3  * Copyright 2015 gRPC authors.
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  *
  17  */
  18
  19 package grpc
  20
  21 import (
  22         "bytes"
  23         "fmt"
  24         "io"
  25         "net"
  26         "strings"
  27         "time"
  28
  29         "golang.org/x/net/trace"
  30 )
  31
  32 // EnableTracing controls whether to trace RPCs using the golang.org/x/net/trace package.
  33 // This should only be set before any RPCs are sent or received by this program.
  34 var EnableTracing bool
  35
  36 // methodFamily returns the trace family for the given method.
  37 // It turns "/pkg.Service/GetFoo" into "pkg.Service".
  38 func methodFamily(m string) string {
  39         m = strings.TrimPrefix(m, "/") // remove leading slash
  40         if i := strings.Index(m, "/"); i >= 0 {
  41                 m = m[:i] // remove everything from second slash
  42         }
  43         if i := strings.LastIndex(m, "."); i >= 0 {
  44                 m = m[i+1:] // cut down to last dotted component
  45         }
  46         return m
  47 }
  48
  49 // traceInfo contains tracing information for an RPC.
  50 type traceInfo struct {
  51         tr        trace.Trace
  52         firstLine firstLine
  53 }
  54
  55 // firstLine is the first line of an RPC trace.
  56 type firstLine struct {
  57         client     bool // whether this is a client (outgoing) RPC
  58         remoteAddr net.Addr
  59         deadline   time.Duration // may be zero
  60 }
  61
  62 func (f *firstLine) String() string {
  63         var line bytes.Buffer
  64         io.WriteString(&line, "RPC: ")
  65         if f.client {
  66                 io.WriteString(&line, "to")
  67         } else {
  68                 io.WriteString(&line, "from")
  69         }
  70         fmt.Fprintf(&line, " %v deadline:", f.remoteAddr)
  71         if f.deadline != 0 {
  72                 fmt.Fprint(&line, f.deadline)
  73         } else {
  74                 io.WriteString(&line, "none")
  75         }
  76         return line.String()
  77 }
  78
  79 const truncateSize = 100
  80
  81 func truncate(x string, l int) string {
  82         if l > len(x) {
  83                 return x
  84         }
  85         return x[:l]
  86 }
  87
  88 // payload represents an RPC request or response payload.
  89 type payload struct {
  90         sent bool        // whether this is an outgoing payload
  91         msg  interface{} // e.g. a proto.Message
  92         // TODO(dsymonds): add stringifying info to codec, and limit how much we hold here?
  93 }
  94
  95 func (p payload) String() string {
  96         if p.sent {
  97                 return truncate(fmt.Sprintf("sent: %v", p.msg), truncateSize)
  98         }
  99         return truncate(fmt.Sprintf("recv: %v", p.msg), truncateSize)
 100 }
 101
 102 type fmtStringer struct {
 103         format string
 104         a      []interface{}
 105 }
 106
 107 func (f *fmtStringer) String() string {
 108         return fmt.Sprintf(f.format, f.a...)
 109 }
 110
 111 type stringer string
 112
 113 func (s stringer) String() string { return string(s) }