src/io/pipe_test.go - go - Git at Google

 // 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.

 package io_test

 import (
 	"bytes"
 	"fmt"
 	. "io"
 	"sort"
 	"strings"
 	"testing"
 	"time"
 )

 func checkWrite(t *testing.T, w Writer, data []byte, c chan int) {
 	n, err := w.Write(data)
 	if err != nil {
 		t.Errorf("write: %v", err)
 	}
 	if n != len(data) {
 		t.Errorf("short write: %d != %d", n, len(data))
 	}
 	c <- 0
 }

 // Test a single read/write pair.
 func TestPipe1(t *testing.T) {
 	c := make(chan int)
 	r, w := Pipe()
 	var buf = make([]byte, 64)
 	go checkWrite(t, w, []byte("hello, world"), c)
 	n, err := r.Read(buf)
 	if err != nil {
 		t.Errorf("read: %v", err)
 	} else if n != 12 || string(buf[0:12]) != "hello, world" {
 		t.Errorf("bad read: got %q", buf[0:n])
 	}
 	<-c
 	r.Close()
 	w.Close()
 }

 func reader(t *testing.T, r Reader, c chan int) {
 	var buf = make([]byte, 64)
 	for {
 		n, err := r.Read(buf)
 		if err == EOF {
 			c <- 0
 			break
 		}
 		if err != nil {
 			t.Errorf("read: %v", err)
 		}
 		c <- n
 	}
 }

 // Test a sequence of read/write pairs.
 func TestPipe2(t *testing.T) {
 	c := make(chan int)
 	r, w := Pipe()
 	go reader(t, r, c)
 	var buf = make([]byte, 64)
 	for i := 0; i < 5; i++ {
 		p := buf[0 : 5+i*10]
 		n, err := w.Write(p)
 		if n != len(p) {
 			t.Errorf("wrote %d, got %d", len(p), n)
 		}
 		if err != nil {
 			t.Errorf("write: %v", err)
 		}
 		nn := <-c
 		if nn != n {
 			t.Errorf("wrote %d, read got %d", n, nn)
 		}
 	}
 	w.Close()
 	nn := <-c
 	if nn != 0 {
 		t.Errorf("final read got %d", nn)
 	}
 }

 type pipeReturn struct {
 	n   int
 	err error
 }

 // Test a large write that requires multiple reads to satisfy.
 func writer(w WriteCloser, buf []byte, c chan pipeReturn) {
 	n, err := w.Write(buf)
 	w.Close()
 	c <- pipeReturn{n, err}
 }

 func TestPipe3(t *testing.T) {
 	c := make(chan pipeReturn)
 	r, w := Pipe()
 	var wdat = make([]byte, 128)
 	for i := 0; i < len(wdat); i++ {
 		wdat[i] = byte(i)
 	}
 	go writer(w, wdat, c)
 	var rdat = make([]byte, 1024)
 	tot := 0
 	for n := 1; n <= 256; n *= 2 {
 		nn, err := r.Read(rdat[tot : tot+n])
 		if err != nil && err != EOF {
 			t.Fatalf("read: %v", err)
 		}

 		// only final two reads should be short - 1 byte, then 0
 		expect := n
 		if n == 128 {
 			expect = 1
 		} else if n == 256 {
 			expect = 0
 			if err != EOF {
 				t.Fatalf("read at end: %v", err)
 			}
 		}
 		if nn != expect {
 			t.Fatalf("read %d, expected %d, got %d", n, expect, nn)
 		}
 		tot += nn
 	}
 	pr := <-c
 	if pr.n != 128 || pr.err != nil {
 		t.Fatalf("write 128: %d, %v", pr.n, pr.err)
 	}
 	if tot != 128 {
 		t.Fatalf("total read %d != 128", tot)
 	}
 	for i := 0; i < 128; i++ {
 		if rdat[i] != byte(i) {
 			t.Fatalf("rdat[%d] = %d", i, rdat[i])
 		}
 	}
 }

 // Test read after/before writer close.

 type closer interface {
 	CloseWithError(error) error
 	Close() error
 }

 type pipeTest struct {
 	async          bool
 	err            error
 	closeWithError bool
 }

 func (p pipeTest) String() string {
 	return fmt.Sprintf("async=%v err=%v closeWithError=%v", p.async, p.err, p.closeWithError)
 }

 var pipeTests = []pipeTest{
 	{true, nil, false},
 	{true, nil, true},
 	{true, ErrShortWrite, true},
 	{false, nil, false},
 	{false, nil, true},
 	{false, ErrShortWrite, true},
 }

 func delayClose(t *testing.T, cl closer, ch chan int, tt pipeTest) {
 	time.Sleep(1 * time.Millisecond)
 	var err error
 	if tt.closeWithError {
 		err = cl.CloseWithError(tt.err)
 	} else {
 		err = cl.Close()
 	}
 	if err != nil {
 		t.Errorf("delayClose: %v", err)
 	}
 	ch <- 0
 }

 func TestPipeReadClose(t *testing.T) {
 	for _, tt := range pipeTests {
 		c := make(chan int, 1)
 		r, w := Pipe()
 		if tt.async {
 			go delayClose(t, w, c, tt)
 		} else {
 			delayClose(t, w, c, tt)
 		}
 		var buf = make([]byte, 64)
 		n, err := r.Read(buf)
 		<-c
 		want := tt.err
 		if want == nil {
 			want = EOF
 		}
 		if err != want {
 			t.Errorf("read from closed pipe: %v want %v", err, want)
 		}
 		if n != 0 {
 			t.Errorf("read on closed pipe returned %d", n)
 		}
 		if err = r.Close(); err != nil {
 			t.Errorf("r.Close: %v", err)
 		}
 	}
 }

 // Test close on Read side during Read.
 func TestPipeReadClose2(t *testing.T) {
 	c := make(chan int, 1)
 	r, _ := Pipe()
 	go delayClose(t, r, c, pipeTest{})
 	n, err := r.Read(make([]byte, 64))
 	<-c
 	if n != 0 || err != ErrClosedPipe {
 		t.Errorf("read from closed pipe: %v, %v want %v, %v", n, err, 0, ErrClosedPipe)
 	}
 }

 // Test write after/before reader close.

 func TestPipeWriteClose(t *testing.T) {
 	for _, tt := range pipeTests {
 		c := make(chan int, 1)
 		r, w := Pipe()
 		if tt.async {
 			go delayClose(t, r, c, tt)
 		} else {
 			delayClose(t, r, c, tt)
 		}
 		n, err := WriteString(w, "hello, world")
 		<-c
 		expect := tt.err
 		if expect == nil {
 			expect = ErrClosedPipe
 		}
 		if err != expect {
 			t.Errorf("write on closed pipe: %v want %v", err, expect)
 		}
 		if n != 0 {
 			t.Errorf("write on closed pipe returned %d", n)
 		}
 		if err = w.Close(); err != nil {
 			t.Errorf("w.Close: %v", err)
 		}
 	}
 }

 // Test close on Write side during Write.
 func TestPipeWriteClose2(t *testing.T) {
 	c := make(chan int, 1)
 	_, w := Pipe()
 	go delayClose(t, w, c, pipeTest{})
 	n, err := w.Write(make([]byte, 64))
 	<-c
 	if n != 0 || err != ErrClosedPipe {
 		t.Errorf("write to closed pipe: %v, %v want %v, %v", n, err, 0, ErrClosedPipe)
 	}
 }

 func TestWriteEmpty(t *testing.T) {
 	r, w := Pipe()
 	go func() {
 		w.Write([]byte{})
 		w.Close()
 	}()
 	var b [2]byte
 	ReadFull(r, b[0:2])
 	r.Close()
 }

 func TestWriteNil(t *testing.T) {
 	r, w := Pipe()
 	go func() {
 		w.Write(nil)
 		w.Close()
 	}()
 	var b [2]byte
 	ReadFull(r, b[0:2])
 	r.Close()
 }

 func TestWriteAfterWriterClose(t *testing.T) {
 	r, w := Pipe()

 	done := make(chan bool)
 	var writeErr error
 	go func() {
 		_, err := w.Write([]byte("hello"))
 		if err != nil {
 			t.Errorf("got error: %q; expected none", err)
 		}
 		w.Close()
 		_, writeErr = w.Write([]byte("world"))
 		done <- true
 	}()

 	buf := make([]byte, 100)
 	var result string
 	n, err := ReadFull(r, buf)
 	if err != nil && err != ErrUnexpectedEOF {
 		t.Fatalf("got: %q; want: %q", err, ErrUnexpectedEOF)
 	}
 	result = string(buf[0:n])
 	<-done

 	if result != "hello" {
 		t.Errorf("got: %q; want: %q", result, "hello")
 	}
 	if writeErr != ErrClosedPipe {
 		t.Errorf("got: %q; want: %q", writeErr, ErrClosedPipe)
 	}
 }

 func TestPipeCloseError(t *testing.T) {
 	type testError1 struct{ error }
 	type testError2 struct{ error }

 	r, w := Pipe()
 	r.CloseWithError(testError1{})
 	if _, err := w.Write(nil); err != (testError1{}) {
 		t.Errorf("Write error: got %T, want testError1", err)
 	}
 	r.CloseWithError(testError2{})
 	if _, err := w.Write(nil); err != (testError1{}) {
 		t.Errorf("Write error: got %T, want testError1", err)
 	}

 	r, w = Pipe()
 	w.CloseWithError(testError1{})
 	if _, err := r.Read(nil); err != (testError1{}) {
 		t.Errorf("Read error: got %T, want testError1", err)
 	}
 	w.CloseWithError(testError2{})
 	if _, err := r.Read(nil); err != (testError1{}) {
 		t.Errorf("Read error: got %T, want testError1", err)
 	}
 }

 func TestPipeConcurrent(t *testing.T) {
 	const (
 		input    = "0123456789abcdef"
 		count    = 8
 		readSize = 2
 	)

 	t.Run("Write", func(t *testing.T) {
 		r, w := Pipe()

 		for i := 0; i < count; i++ {
 			go func() {
 				time.Sleep(time.Millisecond) // Increase probability of race
 				if n, err := w.Write([]byte(input)); n != len(input) || err != nil {
 					t.Errorf("Write() = (%d, %v); want (%d, nil)", n, err, len(input))
 				}
 			}()
 		}

 		buf := make([]byte, count*len(input))
 		for i := 0; i < len(buf); i += readSize {
 			if n, err := r.Read(buf[i : i+readSize]); n != readSize || err != nil {
 				t.Errorf("Read() = (%d, %v); want (%d, nil)", n, err, readSize)
 			}
 		}

 		// Since each Write is fully gated, if multiple Read calls were needed,
 		// the contents of Write should still appear together in the output.
 		got := string(buf)
 		want := strings.Repeat(input, count)
 		if got != want {
 			t.Errorf("got: %q; want: %q", got, want)
 		}
 	})

 	t.Run("Read", func(t *testing.T) {
 		r, w := Pipe()

 		c := make(chan []byte, count*len(input)/readSize)
 		for i := 0; i < cap(c); i++ {
 			go func() {
 				time.Sleep(time.Millisecond) // Increase probability of race
 				buf := make([]byte, readSize)
 				if n, err := r.Read(buf); n != readSize || err != nil {
 					t.Errorf("Read() = (%d, %v); want (%d, nil)", n, err, readSize)
 				}
 				c <- buf
 			}()
 		}

 		for i := 0; i < count; i++ {
 			if n, err := w.Write([]byte(input)); n != len(input) || err != nil {
 				t.Errorf("Write() = (%d, %v); want (%d, nil)", n, err, len(input))
 			}
 		}

 		// Since each read is independent, the only guarantee about the output
 		// is that it is a permutation of the input in readSized groups.
 		got := make([]byte, 0, count*len(input))
 		for i := 0; i < cap(c); i++ {
 			got = append(got, (<-c)...)
 		}
 		got = sortBytesInGroups(got, readSize)
 		want := bytes.Repeat([]byte(input), count)
 		want = sortBytesInGroups(want, readSize)
 		if string(got) != string(want) {
 			t.Errorf("got: %q; want: %q", got, want)
 		}
 	})
 }

 func sortBytesInGroups(b []byte, n int) []byte {
 	var groups [][]byte
 	for len(b) > 0 {
 		groups = append(groups, b[:n])
 		b = b[n:]
 	}
 	sort.Slice(groups, func(i, j int) bool { return bytes.Compare(groups[i], groups[j]) < 0 })
 	return bytes.Join(groups, nil)
 }
	// 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.

	package io_test

	import (
	"bytes"
	"fmt"
	. "io"
	"sort"
	"strings"
	"testing"
	"time"
	)

	func checkWrite(t *testing.T, w Writer, data []byte, c chan int) {
	n, err := w.Write(data)
	if err != nil {
	t.Errorf("write: %v", err)
	}
	if n != len(data) {
	t.Errorf("short write: %d != %d", n, len(data))
	}
	c <- 0
	}

	// Test a single read/write pair.
	func TestPipe1(t *testing.T) {
	c := make(chan int)
	r, w := Pipe()
	var buf = make([]byte, 64)
	go checkWrite(t, w, []byte("hello, world"), c)
	n, err := r.Read(buf)
	if err != nil {
	t.Errorf("read: %v", err)
	} else if n != 12 \|\| string(buf[0:12]) != "hello, world" {
	t.Errorf("bad read: got %q", buf[0:n])
	}
	<-c
	r.Close()
	w.Close()
	}

	func reader(t *testing.T, r Reader, c chan int) {
	var buf = make([]byte, 64)
	for {
	n, err := r.Read(buf)
	if err == EOF {
	c <- 0
	break
	}
	if err != nil {
	t.Errorf("read: %v", err)
	}
	c <- n
	}
	}

	// Test a sequence of read/write pairs.
	func TestPipe2(t *testing.T) {
	c := make(chan int)
	r, w := Pipe()
	go reader(t, r, c)
	var buf = make([]byte, 64)
	for i := 0; i < 5; i++ {
	p := buf[0 : 5+i*10]
	n, err := w.Write(p)
	if n != len(p) {
	t.Errorf("wrote %d, got %d", len(p), n)
	}
	if err != nil {
	t.Errorf("write: %v", err)
	}
	nn := <-c
	if nn != n {
	t.Errorf("wrote %d, read got %d", n, nn)
	}
	}
	w.Close()
	nn := <-c
	if nn != 0 {
	t.Errorf("final read got %d", nn)
	}
	}

	type pipeReturn struct {
	n int
	err error
	}

	// Test a large write that requires multiple reads to satisfy.
	func writer(w WriteCloser, buf []byte, c chan pipeReturn) {
	n, err := w.Write(buf)
	w.Close()
	c <- pipeReturn{n, err}
	}

	func TestPipe3(t *testing.T) {
	c := make(chan pipeReturn)
	r, w := Pipe()
	var wdat = make([]byte, 128)
	for i := 0; i < len(wdat); i++ {
	wdat[i] = byte(i)
	}
	go writer(w, wdat, c)
	var rdat = make([]byte, 1024)
	tot := 0
	for n := 1; n <= 256; n *= 2 {
	nn, err := r.Read(rdat[tot : tot+n])
	if err != nil && err != EOF {
	t.Fatalf("read: %v", err)
	}

	// only final two reads should be short - 1 byte, then 0
	expect := n
	if n == 128 {
	expect = 1
	} else if n == 256 {
	expect = 0
	if err != EOF {
	t.Fatalf("read at end: %v", err)
	}
	}
	if nn != expect {
	t.Fatalf("read %d, expected %d, got %d", n, expect, nn)
	}
	tot += nn
	}
	pr := <-c
	if pr.n != 128 \|\| pr.err != nil {
	t.Fatalf("write 128: %d, %v", pr.n, pr.err)
	}
	if tot != 128 {
	t.Fatalf("total read %d != 128", tot)
	}
	for i := 0; i < 128; i++ {
	if rdat[i] != byte(i) {
	t.Fatalf("rdat[%d] = %d", i, rdat[i])
	}
	}
	}

	// Test read after/before writer close.

	type closer interface {
	CloseWithError(error) error
	Close() error
	}

	type pipeTest struct {
	async bool
	err error
	closeWithError bool
	}

	func (p pipeTest) String() string {
	return fmt.Sprintf("async=%v err=%v closeWithError=%v", p.async, p.err, p.closeWithError)
	}

	var pipeTests = []pipeTest{
	{true, nil, false},
	{true, nil, true},
	{true, ErrShortWrite, true},
	{false, nil, false},
	{false, nil, true},
	{false, ErrShortWrite, true},
	}

	func delayClose(t *testing.T, cl closer, ch chan int, tt pipeTest) {
	time.Sleep(1 * time.Millisecond)
	var err error
	if tt.closeWithError {
	err = cl.CloseWithError(tt.err)
	} else {
	err = cl.Close()
	}
	if err != nil {
	t.Errorf("delayClose: %v", err)
	}
	ch <- 0
	}

	func TestPipeReadClose(t *testing.T) {
	for _, tt := range pipeTests {
	c := make(chan int, 1)
	r, w := Pipe()
	if tt.async {
	go delayClose(t, w, c, tt)
	} else {
	delayClose(t, w, c, tt)
	}
	var buf = make([]byte, 64)
	n, err := r.Read(buf)
	<-c
	want := tt.err
	if want == nil {
	want = EOF
	}
	if err != want {
	t.Errorf("read from closed pipe: %v want %v", err, want)
	}
	if n != 0 {
	t.Errorf("read on closed pipe returned %d", n)
	}
	if err = r.Close(); err != nil {
	t.Errorf("r.Close: %v", err)
	}
	}
	}

	// Test close on Read side during Read.
	func TestPipeReadClose2(t *testing.T) {
	c := make(chan int, 1)
	r, _ := Pipe()
	go delayClose(t, r, c, pipeTest{})
	n, err := r.Read(make([]byte, 64))
	<-c
	if n != 0 \|\| err != ErrClosedPipe {
	t.Errorf("read from closed pipe: %v, %v want %v, %v", n, err, 0, ErrClosedPipe)
	}
	}

	// Test write after/before reader close.

	func TestPipeWriteClose(t *testing.T) {
	for _, tt := range pipeTests {
	c := make(chan int, 1)
	r, w := Pipe()
	if tt.async {
	go delayClose(t, r, c, tt)
	} else {
	delayClose(t, r, c, tt)
	}
	n, err := WriteString(w, "hello, world")
	<-c
	expect := tt.err
	if expect == nil {
	expect = ErrClosedPipe
	}
	if err != expect {
	t.Errorf("write on closed pipe: %v want %v", err, expect)
	}
	if n != 0 {
	t.Errorf("write on closed pipe returned %d", n)
	}
	if err = w.Close(); err != nil {
	t.Errorf("w.Close: %v", err)
	}
	}
	}

	// Test close on Write side during Write.
	func TestPipeWriteClose2(t *testing.T) {
	c := make(chan int, 1)
	_, w := Pipe()
	go delayClose(t, w, c, pipeTest{})
	n, err := w.Write(make([]byte, 64))
	<-c
	if n != 0 \|\| err != ErrClosedPipe {
	t.Errorf("write to closed pipe: %v, %v want %v, %v", n, err, 0, ErrClosedPipe)
	}
	}

	func TestWriteEmpty(t *testing.T) {
	r, w := Pipe()
	go func() {
	w.Write([]byte{})
	w.Close()
	}()
	var b [2]byte
	ReadFull(r, b[0:2])
	r.Close()
	}

	func TestWriteNil(t *testing.T) {
	r, w := Pipe()
	go func() {
	w.Write(nil)
	w.Close()
	}()
	var b [2]byte
	ReadFull(r, b[0:2])
	r.Close()
	}

	func TestWriteAfterWriterClose(t *testing.T) {
	r, w := Pipe()

	done := make(chan bool)
	var writeErr error
	go func() {
	_, err := w.Write([]byte("hello"))
	if err != nil {
	t.Errorf("got error: %q; expected none", err)
	}
	w.Close()
	_, writeErr = w.Write([]byte("world"))
	done <- true
	}()

	buf := make([]byte, 100)
	var result string
	n, err := ReadFull(r, buf)
	if err != nil && err != ErrUnexpectedEOF {
	t.Fatalf("got: %q; want: %q", err, ErrUnexpectedEOF)
	}
	result = string(buf[0:n])
	<-done

	if result != "hello" {
	t.Errorf("got: %q; want: %q", result, "hello")
	}
	if writeErr != ErrClosedPipe {
	t.Errorf("got: %q; want: %q", writeErr, ErrClosedPipe)
	}
	}

	func TestPipeCloseError(t *testing.T) {
	type testError1 struct{ error }
	type testError2 struct{ error }

	r, w := Pipe()
	r.CloseWithError(testError1{})
	if _, err := w.Write(nil); err != (testError1{}) {
	t.Errorf("Write error: got %T, want testError1", err)
	}
	r.CloseWithError(testError2{})
	if _, err := w.Write(nil); err != (testError1{}) {
	t.Errorf("Write error: got %T, want testError1", err)
	}

	r, w = Pipe()
	w.CloseWithError(testError1{})
	if _, err := r.Read(nil); err != (testError1{}) {
	t.Errorf("Read error: got %T, want testError1", err)
	}
	w.CloseWithError(testError2{})
	if _, err := r.Read(nil); err != (testError1{}) {
	t.Errorf("Read error: got %T, want testError1", err)
	}
	}

	func TestPipeConcurrent(t *testing.T) {
	const (
	input = "0123456789abcdef"
	count = 8
	readSize = 2
	)

	t.Run("Write", func(t *testing.T) {
	r, w := Pipe()

	for i := 0; i < count; i++ {
	go func() {
	time.Sleep(time.Millisecond) // Increase probability of race
	if n, err := w.Write([]byte(input)); n != len(input) \|\| err != nil {
	t.Errorf("Write() = (%d, %v); want (%d, nil)", n, err, len(input))
	}
	}()
	}

	buf := make([]byte, count*len(input))
	for i := 0; i < len(buf); i += readSize {
	if n, err := r.Read(buf[i : i+readSize]); n != readSize \|\| err != nil {
	t.Errorf("Read() = (%d, %v); want (%d, nil)", n, err, readSize)
	}
	}

	// Since each Write is fully gated, if multiple Read calls were needed,
	// the contents of Write should still appear together in the output.
	got := string(buf)
	want := strings.Repeat(input, count)
	if got != want {
	t.Errorf("got: %q; want: %q", got, want)
	}
	})

	t.Run("Read", func(t *testing.T) {
	r, w := Pipe()

	c := make(chan []byte, count*len(input)/readSize)
	for i := 0; i < cap(c); i++ {
	go func() {
	time.Sleep(time.Millisecond) // Increase probability of race
	buf := make([]byte, readSize)
	if n, err := r.Read(buf); n != readSize \|\| err != nil {
	t.Errorf("Read() = (%d, %v); want (%d, nil)", n, err, readSize)
	}
	c <- buf
	}()
	}

	for i := 0; i < count; i++ {
	if n, err := w.Write([]byte(input)); n != len(input) \|\| err != nil {
	t.Errorf("Write() = (%d, %v); want (%d, nil)", n, err, len(input))
	}
	}

	// Since each read is independent, the only guarantee about the output
	// is that it is a permutation of the input in readSized groups.
	got := make([]byte, 0, count*len(input))
	for i := 0; i < cap(c); i++ {
	got = append(got, (<-c)...)
	}
	got = sortBytesInGroups(got, readSize)
	want := bytes.Repeat([]byte(input), count)
	want = sortBytesInGroups(want, readSize)
	if string(got) != string(want) {
	t.Errorf("got: %q; want: %q", got, want)
	}
	})
	}

	func sortBytesInGroups(b []byte, n int) []byte {
	var groups [][]byte
	for len(b) > 0 {
	groups = append(groups, b[:n])
	b = b[n:]
	}
	sort.Slice(groups, func(i, j int) bool { return bytes.Compare(groups[i], groups[j]) < 0 })
	return bytes.Join(groups, nil)
	}