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add io.ByteReader.

Browse source 
add testing/iotest package.
make bufio return error on short write.

R=r
DELTA=423  (208 added, 154 deleted, 61 changed)
OCL=28997
CL=28999
This commit is contained in:
Russ Cox 2009-05-18 13:31:56 -07:00
parent 6b942c68cc
commit be869ba4d6
7 changed files with 269 additions and 210 deletions
Download patch file Download diff file Expand all files Collapse all files

4
src/lib/Makefile
View file

@ -45,6 +45,7 @@ DIRS=\
tabwriter\ tabwriter\
template\ template\
testing\ testing\
testing/iotest\
time\ time\
unicode\ unicode\
utf8\ utf8\
@ -115,6 +116,7 @@ nuke: nuke.dirs
bignum.install: fmt.install bignum.install: fmt.install
bufio.install: io.install os.install bufio.install: io.install os.install
crypto/aes.install: os.install
exec.install: os.install strings.install exec.install: os.install strings.install
exvar.install: fmt.install http.install log.install strconv.install sync.install exvar.install: fmt.install http.install log.install strconv.install sync.install
flag.install: fmt.install os.install strconv.install flag.install: fmt.install os.install strconv.install
@ -123,7 +125,7 @@ path.install: io.install
once.install: sync.install once.install: sync.install
strings.install: utf8.install strings.install: utf8.install
testing.install: flag.install fmt.install runtime.install testing.install: flag.install fmt.install runtime.install
testing/iotest.install: io.install os.install
fmt.install: io.install reflect.install strconv.install fmt.install: io.install reflect.install strconv.install
GODEPS=fmt.install io.install once.install regexp.install sort.install \ GODEPS=fmt.install io.install once.install regexp.install sort.install \
strconv.install strings.install unicode.install utf8.install container/vector.install strconv.install strings.install unicode.install utf8.install container/vector.install

28
src/lib/bufio/bufio.go
View file

@ -421,21 +421,17 @@ func (b *Writer) Flush() os.Error {
if b.err != nil { if b.err != nil {
return b.err return b.err
} }
n := 0; n, e := b.wr.Write(b.buf[0:b.n]);
for n < b.n { if n < b.n && e == nil {
m, e := b.wr.Write(b.buf[n:b.n]); e = io.ErrShortWrite;
n += m; }
if m == 0 && e == nil { if e != nil {
e = io.ErrShortWrite if n > 0 && n < b.n {
} copySlice(b.buf[0:b.n-n], b.buf[n:b.n])
if e != nil {
if n < b.n {
copySlice(b.buf[0:b.n-n], b.buf[n:b.n])
}
b.n -= n;
b.err = e;
return e
} }
b.n -= n;
b.err = e;
return e
} }
b.n = 0; b.n = 0;
return nil return nil
@ -505,14 +501,14 @@ func (b *Writer) WriteByte(c byte) os.Error {
// buffered input and output // buffered input and output
// ReadWriter stores (a pointer to) a Reader and a Writer. // ReadWriter stores pointers to a Reader and a Writer.
// It implements io.ReadWriter. // It implements io.ReadWriter.
type ReadWriter struct { type ReadWriter struct {
*Reader; *Reader;
*Writer; *Writer;
} }
// NewReadWriter allocates a new ReadWriter holding r and w. // NewReadWriter allocates a new ReadWriter that dispatches to r and w.
func NewReadWriter(r *Reader, w *Writer) *ReadWriter { func NewReadWriter(r *Reader, w *Writer) *ReadWriter {
return &ReadWriter{r, w} return &ReadWriter{r, w}
} }

303
src/lib/bufio/bufio_test.go
View file

@ -10,61 +10,9 @@ import (
"io"; "io";
"os"; "os";
"testing"; "testing";
"testing/iotest";
) )
// Should be in language!
func copy(p []byte, q []byte) {
for i := 0; i < len(p); i++ {
p[i] = q[i]
}
}
// Reads from p.
type byteReader struct {
p []byte
}
func newByteReader(p []byte) io.Reader {
b := new(byteReader);
b.p = p;
return b
}
func (b *byteReader) Read(p []byte) (int, os.Error) {
n := len(p);
if n > len(b.p) {
n = len(b.p)
}
copy(p[0:n], b.p[0:n]);
b.p = b.p[n:len(b.p)];
return n, nil
}
// Reads from p but only returns half of what you asked for.
type halfByteReader struct {
p []byte
}
func newHalfByteReader(p []byte) io.Reader {
b := new(halfByteReader);
b.p = p;
return b
}
func (b *halfByteReader) Read(p []byte) (int, os.Error) {
n := len(p)/2;
if n == 0 && len(p) > 0 {
n = 1
}
if n > len(b.p) {
n = len(b.p)
}
copy(p[0:n], b.p[0:n]);
b.p = b.p[n:len(b.p)];
return n, nil
}
// Reads from a reader and rot13s the result. // Reads from a reader and rot13s the result.
type rot13Reader struct { type rot13Reader struct {
r io.Reader r io.Reader
@ -82,24 +30,56 @@ func (r13 *rot13Reader) Read(p []byte) (int, os.Error) {
return n, e return n, e
} }
for i := 0; i < n; i++ { for i := 0; i < n; i++ {
if 'a' <= p[i] && p[i] <= 'z' || 'A' <= p[i] && p[i] <= 'Z' { c := p[i] | 0x20; // lowercase byte
if 'a' <= p[i] && p[i] <= 'm' || 'A' <= p[i] && p[i] <= 'M' { if 'a' <= c && c <= 'm' {
p[i] += 13; p[i] += 13;
} else { } else if 'n' <= c && c <= 'z' {
p[i] -= 13; p[i] -= 13;
}
} }
} }
return n, nil return n, nil
} }
// Call ReadByte to accumulate the text of a file
func readBytes(buf *Reader) string {
var b [1000]byte;
nb := 0;
for {
c, e := buf.ReadByte();
if e == io.ErrEOF {
break
}
if e != nil {
panic("Data: "+e.String())
}
b[nb] = c;
nb++;
}
return string(b[0:nb])
}
func TestReaderSimple(t *testing.T) {
data := io.StringBytes("hello world");
b := NewReader(io.NewByteReader(data));
if s := readBytes(b); s != "hello world" {
t.Errorf("simple hello world test failed: got %q", s);
}
b = NewReader(newRot13Reader(io.NewByteReader(data)));
if s := readBytes(b); s != "uryyb jbeyq" {
t.Error("rot13 hello world test failed: got %q", s);
}
}
type readMaker struct { type readMaker struct {
name string; name string;
fn func([]byte) io.Reader; fn func(io.Reader) io.Reader;
} }
var readMakers = []readMaker { var readMakers = []readMaker {
readMaker{ "full", func(p []byte) io.Reader { return newByteReader(p) } }, readMaker{ "full", func(r io.Reader) io.Reader { return r } },
readMaker{ "half", func(p []byte) io.Reader { return newHalfByteReader(p) } }, readMaker{ "byte", iotest.OneByteReader },
readMaker{ "half", iotest.HalfReader },
} }
// Call ReadLineString (which ends up calling everything else) // Call ReadLineString (which ends up calling everything else)
@ -119,25 +99,6 @@ func readLines(b *Reader) string {
return s return s
} }
// Call ReadByte to accumulate the text of a file
func readBytes(buf *Reader) string {
var b [1000]byte;
nb := 0;
for {
c, e := buf.ReadByte();
if e == io.ErrEOF {
break
}
if e != nil {
panic("GetBytes: "+e.String())
}
b[nb] = c;
nb++;
}
// BUG return string(b[0:nb]) ?
return string(b[0:nb])
}
// Call Read to accumulate the text of a file // Call Read to accumulate the text of a file
func reads(buf *Reader, m int) string { func reads(buf *Reader, m int) string {
var b [1000]byte; var b [1000]byte;
@ -172,18 +133,6 @@ var bufsizes = []int {
23, 32, 46, 64, 93, 128, 1024, 4096 23, 32, 46, 64, 93, 128, 1024, 4096
} }
func TestReaderSimple(t *testing.T) {
b := NewReader(newByteReader(io.StringBytes("hello world")));
if s := readBytes(b); s != "hello world" {
t.Errorf("simple hello world test failed: got %q", s);
}
b = NewReader(newRot13Reader(newByteReader(io.StringBytes("hello world"))));
if s := readBytes(b); s != "uryyb jbeyq" {
t.Error("rot13 hello world test failed: got %q", s);
}
}
func TestReader(t *testing.T) { func TestReader(t *testing.T) {
var texts [31]string; var texts [31]string;
str := ""; str := "";
@ -204,7 +153,7 @@ func TestReader(t *testing.T) {
readmaker := readMakers[i]; readmaker := readMakers[i];
bufreader := bufreaders[j]; bufreader := bufreaders[j];
bufsize := bufsizes[k]; bufsize := bufsizes[k];
read := readmaker.fn(textbytes); read := readmaker.fn(io.NewByteReader(textbytes));
buf, e := NewReaderSize(read, bufsize); buf, e := NewReaderSize(read, bufsize);
s := bufreader.fn(buf); s := bufreader.fn(buf);
if s != text { if s != text {
@ -217,122 +166,92 @@ func TestReader(t *testing.T) {
} }
} }
type writeBuffer interface {
Write(p []byte) (int, os.Error);
GetBytes() []byte
}
// Accumulates bytes into a byte array.
type byteWriter struct {
p []byte;
n int
}
func newByteWriter() writeBuffer {
return new(byteWriter)
}
func (w *byteWriter) Write(p []byte) (int, os.Error) {
if w.p == nil {
w.p = make([]byte, len(p)+100)
} else if w.n + len(p) >= len(w.p) {
newp := make([]byte, len(w.p)*2 + len(p));
copy(newp[0:w.n], w.p[0:w.n]);
w.p = newp
}
copy(w.p[w.n:w.n+len(p)], p);
w.n += len(p);
return len(p), nil
}
func (w *byteWriter) GetBytes() []byte {
return w.p[0:w.n]
}
// Accumulates bytes written into a byte array
// but Write only takes half of what you give it.
// TODO: Could toss this -- Write() is not supposed to do that.
type halfByteWriter struct {
bw writeBuffer
}
func newHalfByteWriter() writeBuffer {
w := new(halfByteWriter);
w.bw = newByteWriter();
return w
}
func (w *halfByteWriter) Write(p []byte) (int, os.Error) {
n := (len(p)+1) / 2;
// BUG return w.bw.Write(p[0:n])
r, e := w.bw.Write(p[0:n]);
return r, e
}
func (w *halfByteWriter) GetBytes() []byte {
return w.bw.GetBytes()
}
type writeMaker struct {
name string;
fn func()writeBuffer;
}
func TestWriter(t *testing.T) { func TestWriter(t *testing.T) {
var data [8192]byte; var data [8192]byte;
var writers = []writeMaker {
writeMaker{ "full", newByteWriter },
writeMaker{ "half", newHalfByteWriter },
};
for i := 0; i < len(data); i++ { for i := 0; i < len(data); i++ {
data[i] = byte(' '+ i%('~'-' ')); data[i] = byte(' '+ i%('~'-' '));
} }
w := new(io.ByteBuffer);
for i := 0; i < len(bufsizes); i++ { for i := 0; i < len(bufsizes); i++ {
for j := 0; j < len(bufsizes); j++ { for j := 0; j < len(bufsizes); j++ {
for k := 0; k < len(writers); k++ { nwrite := bufsizes[i];
nwrite := bufsizes[i]; bs := bufsizes[j];
bs := bufsizes[j];
// Write nwrite bytes using buffer size bs. // Write nwrite bytes using buffer size bs.
// Check that the right amount makes it out // Check that the right amount makes it out
// and that the data is correct. // and that the data is correct.
write := writers[k].fn(); w.Reset();
buf, e := NewWriterSize(write, bs); buf, e := NewWriterSize(w, bs);
context := fmt.Sprintf("write=%s nwrite=%d bufsize=%d", writers[k].name, nwrite, bs); context := fmt.Sprintf("nwrite=%d bufsize=%d", nwrite, bs);
if e != nil { if e != nil {
t.Errorf("%s: NewWriterSize %d: %v", context, bs, e); t.Errorf("%s: NewWriterSize %d: %v", context, bs, e);
continue; continue;
} }
n, e1 := buf.Write(data[0:nwrite]); n, e1 := buf.Write(data[0:nwrite]);
if e1 != nil || n != nwrite { if e1 != nil || n != nwrite {
t.Errorf("%s: buf.Write %d = %d, %v", context, nwrite, n, e1); t.Errorf("%s: buf.Write %d = %d, %v", context, nwrite, n, e1);
continue; continue;
} }
if e = buf.Flush(); e != nil { if e = buf.Flush(); e != nil {
t.Errorf("%s: buf.Flush = %v", context, e); t.Errorf("%s: buf.Flush = %v", context, e);
} }
written := write.GetBytes(); written := w.Data();
if len(written) != nwrite { if len(written) != nwrite {
t.Errorf("%s: %d bytes written", context, len(written)); t.Errorf("%s: %d bytes written", context, len(written));
} }
for l := 0; l < len(written); l++ { for l := 0; l < len(written); l++ {
if written[i] != data[i] { if written[i] != data[i] {
t.Errorf("%s: wrong bytes written"); t.Errorf("%s: wrong bytes written");
t.Errorf("want=%s", data[0:len(written)]); t.Errorf("want=%s", data[0:len(written)]);
t.Errorf("have=%s", written); t.Errorf("have=%s", written);
}
} }
} }
} }
} }
} }
// Check that write errors are returned properly.
type errorWriterTest struct {
n, m int;
err os.Error;
expect os.Error;
}
func (w errorWriterTest) Write(p []byte) (int, os.Error) {
return len(p)*w.n/w.m, w.err;
}
var errorWriterTests = []errorWriterTest {
errorWriterTest{ 0, 1, nil, io.ErrShortWrite },
errorWriterTest{ 1, 2, nil, io.ErrShortWrite },
errorWriterTest{ 1, 1, nil, nil },
errorWriterTest{ 0, 1, os.EPIPE, os.EPIPE },
errorWriterTest{ 1, 2, os.EPIPE, os.EPIPE },
errorWriterTest{ 1, 1, os.EPIPE, os.EPIPE },
}
func TestWriteErrors(t *testing.T) {
for i, w := range errorWriterTests {
buf := NewWriter(w);
n, e := buf.Write(io.StringBytes("hello world"));
if e != nil {
t.Errorf("Write hello to %v: %v", w, e);
continue;
}
e = buf.Flush();
if e != w.expect {
t.Errorf("Flush %v: got %v, wanted %v", w, e, w.expect);
}
}
}
func TestNewReaderSizeIdempotent(t *testing.T) { func TestNewReaderSizeIdempotent(t *testing.T) {
const BufSize = 1000; const BufSize = 1000;
b, err := NewReaderSize(newByteReader(io.StringBytes("hello world")), BufSize); b, err := NewReaderSize(io.NewByteReader(io.StringBytes("hello world")), BufSize);
if err != nil { if err != nil {
t.Error("NewReaderSize create fail", err); t.Error("NewReaderSize create fail", err);
} }
@ -356,7 +275,7 @@ func TestNewReaderSizeIdempotent(t *testing.T) {
func TestNewWriterSizeIdempotent(t *testing.T) { func TestNewWriterSizeIdempotent(t *testing.T) {
const BufSize = 1000; const BufSize = 1000;
b, err := NewWriterSize(newByteWriter(), BufSize); b, err := NewWriterSize(new(io.ByteBuffer), BufSize);
if err != nil { if err != nil {
t.Error("NewWriterSize create fail", err); t.Error("NewWriterSize create fail", err);
} }

6
src/lib/io/bytebuffer.go
View file

@ -42,13 +42,17 @@ func (b *ByteBuffer) Len() int {
// Truncate discards all but the first n unread bytes from the buffer. // Truncate discards all but the first n unread bytes from the buffer.
// It is an error to call b.Truncate(n) with n > b.Len(). // It is an error to call b.Truncate(n) with n > b.Len().
func (b *ByteBuffer) Truncate(n int) { func (b *ByteBuffer) Truncate(n int) {
if n == 0 {
// Reuse buffer space.
b.off = 0;
}
b.buf = b.buf[0 : b.off + n]; b.buf = b.buf[0 : b.off + n];
} }
// Reset resets the buffer so it has no content. // Reset resets the buffer so it has no content.
// b.Reset() is the same as b.Truncate(0). // b.Reset() is the same as b.Truncate(0).
func (b *ByteBuffer) Reset() { func (b *ByteBuffer) Reset() {
b.buf = b.buf[0 : b.off]; b.Truncate(0);
} }
// Write appends the contents of p to the buffer. The return // Write appends the contents of p to the buffer. The return

26
src/lib/io/io.go
View file

@ -185,3 +185,29 @@ func Copy(src Reader, dst Writer) (written int64, err os.Error) {
} }
return written, err return written, err
} }
// A ByteReader satisfies Reads by consuming data from a slice of bytes.
// Clients can call NewByteReader to create one or wrap pointers
// to their own slices: r := ByteReader{&data}.
type ByteReader struct {
Data *[]byte
}
func (r ByteReader) Read(p []byte) (int, os.Error) {
n := len(p);
b := r.Data;
if n > len(b) {
n = len(b);
}
for i := 0; i < n; i++ {
p[i] = b[i];
}
*b = b[n:len(b)];
return n, nil;
}
// NewByteReader returns a new ByteReader reading from data.
func NewByteReader(data []byte) ByteReader {
return ByteReader{ &data };
}

68
src/lib/testing/iotest/Makefile Normal file
View file

@ -0,0 +1,68 @@
# Copyright 2009 The Go Authors. All rights reserved.
# Use of this source code is governed by a BSD-style
# license that can be found in the LICENSE file.
# DO NOT EDIT. Automatically generated by gobuild.
# gobuild -m >Makefile
D=/testing/
O_arm=5
O_amd64=6
O_386=8
OS=568vq
O=$(O_$(GOARCH))
GC=$(O)g -I_obj
CC=$(O)c -FVw
AS=$(O)a
AR=6ar
default: packages
clean:
rm -rf *.[$(OS)] *.a [$(OS)].out _obj
test: packages
gotest
coverage: packages
gotest
6cov -g `pwd` | grep -v '_test\.go:'
%.$O: %.go
$(GC) $*.go
%.$O: %.c
$(CC) $*.c
%.$O: %.s
$(AS) $*.s
O1=\
reader.$O\
phases: a1
_obj$D/iotest.a: phases
a1: $(O1)
$(AR) grc _obj$D/iotest.a reader.$O
rm -f $(O1)
newpkg: clean
mkdir -p _obj$D
$(AR) grc _obj$D/iotest.a
$(O1): newpkg
$(O2): a1
nuke: clean
rm -f $(GOROOT)/pkg$D/iotest.a
packages: _obj$D/iotest.a
install: packages
test -d $(GOROOT)/pkg && mkdir -p $(GOROOT)/pkg$D
cp _obj$D/iotest.a $(GOROOT)/pkg$D/iotest.a

44
src/lib/testing/iotest/reader.go Normal file
View file

@ -0,0 +1,44 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// The iotest package implements Readers and Writers
// useful only for testing.
package iotest
import (
"io";
"os";
)
type oneByteReader struct {
r io.Reader;
}
func (r *oneByteReader) Read(p []byte) (int, os.Error) {
if len(p) == 0 {
return 0, nil;
}
return r.r.Read(p[0:1]);
}
// OneByteReader returns a Reader that implements
// each non-empty Read by reading one byte from r.
func OneByteReader(r io.Reader) io.Reader {
return &oneByteReader{r};
}
type halfReader struct {
r io.Reader;
}
func (r *halfReader) Read(p []byte) (int, os.Error) {
return r.r.Read(p[0:(len(p)+1)/2]);
}
// HalfReader returns a Reader that implements Read
// by reading half as many requested bytes from r.
func HalfReader(r io.Reader) io.Reader {
return &halfReader{r};
}