libgo/go/testing/iotest/logger.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 iotest
   6
   7 import (
   8         "io"
   9         "log"
  10         "os"
  11 )
  12
  13 type writeLogger struct {
  14         prefix string
  15         w      io.Writer
  16 }
  17
  18 func (l *writeLogger) Write(p []byte) (n int, err os.Error) {
  19         n, err = l.w.Write(p)
  20         if err != nil {
  21                 log.Printf("%s %x: %v", l.prefix, p[0:n], err)
  22         } else {
  23                 log.Printf("%s %x", l.prefix, p[0:n])
  24         }
  25         return
  26 }
  27
  28 // NewWriteLogger returns a writer that behaves like w except
  29 // that it logs (using log.Printf) each write to standard error,
  30 // printing the prefix and the hexadecimal data written.
  31 func NewWriteLogger(prefix string, w io.Writer) io.Writer {
  32         return &writeLogger{prefix, w}
  33 }
  34
  35 type readLogger struct {
  36         prefix string
  37         r      io.Reader
  38 }
  39
  40 func (l *readLogger) Read(p []byte) (n int, err os.Error) {
  41         n, err = l.r.Read(p)
  42         if err != nil {
  43                 log.Printf("%s %x: %v", l.prefix, p[0:n], err)
  44         } else {
  45                 log.Printf("%s %x", l.prefix, p[0:n])
  46         }
  47         return
  48 }
  49
  50 // NewReadLogger returns a reader that behaves like r except
  51 // that it logs (using log.Print) each read to standard error,
  52 // printing the prefix and the hexadecimal data written.
  53 func NewReadLogger(prefix string, r io.Reader) io.Reader {
  54         return &readLogger{prefix, r}
  55 }