logger.go

Documentation: testing/iotest

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