rw.go

/*
The MIT License (MIT)

Copyright (c) 2014 Henry

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

package gosam

import (
	"encoding/hex"
	"io"
	"log"
)

/*
Copy of testing/iotest Read- and WriteLogger, but using %q instead of %x for printing
*/

type writeLogger struct {
	prefix string
	w      io.Writer
}

func (l *writeLogger) Write(p []byte) (n int, err error) {
	n, err = l.w.Write(p)
	if err != nil {
		log.Printf("%s %q: %v", l.prefix, string(p[0:n]), err)
	} else {
		log.Printf("%s %q", l.prefix, string(p[0:n]))
	}
	return
}

// NewWriteLogger returns a writer that behaves like w except
// that it logs (using log.Printf) each write to standard error,
// printing the prefix and the hexadecimal data written.
func NewWriteLogger(prefix string, w io.Writer) io.Writer {
	return &writeLogger{prefix, w}
}

type readLogger struct {
	prefix string
	r      io.Reader
}

func (l *readLogger) Read(p []byte) (n int, err error) {
	n, err = l.r.Read(p)
	if err != nil {
		log.Printf("%s %q: %v", l.prefix, string(p[0:n]), err)
	} else {
		log.Printf("%s %q", l.prefix, string(p[0:n]))
	}
	return
}

// NewReadLogger returns a reader that behaves like r except
// that it logs (using log.Print) each read to standard error,
// printing the prefix and the hexadecimal data written.
func NewReadLogger(prefix string, r io.Reader) io.Reader {
	return &readLogger{prefix, r}
}

type readHexLogger struct {
	prefix string
	r      io.Reader
}

func (l *readHexLogger) Read(p []byte) (n int, err error) {
	n, err = l.r.Read(p)
	if err != nil {
		log.Printf("%s (%d bytes) Error: %v", l.prefix, n, err)
	} else {
		log.Printf("%s (%d bytes)", l.prefix, n)
	}
	log.Print("\n" + hex.Dump(p[:n]))
	return
}

// NewReadHexLogger returns a reader that behaves like r except
// that it logs to stderr using ecoding/hex.
func NewReadHexLogger(prefix string, r io.Reader) io.Reader {
	return &readHexLogger{prefix, r}
}