* gcc-interface/decl.c (warn_on_field_placement): Issue the warning

[official-gcc.git] / libgo / go / bytes / buffer_test.go

// 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 bytes_test

import (
        . "bytes"
        "io"
        "math/rand"
        "runtime"
        "testing"
        "unicode/utf8"
)

const N = 10000      // make this bigger for a larger (and slower) test
var data string      // test data for write tests
var testBytes []byte // test data; same as data but as a slice.

func init() {
        testBytes = make([]byte, N)
        for i := 0; i < N; i++ {
                testBytes[i] = 'a' + byte(i%26)
        }
        data = string(testBytes)
}

// Verify that contents of buf match the string s.
func check(t *testing.T, testname string, buf *Buffer, s string) {
        bytes := buf.Bytes()
        str := buf.String()
        if buf.Len() != len(bytes) {
                t.Errorf("%s: buf.Len() == %d, len(buf.Bytes()) == %d", testname, buf.Len(), len(bytes))
        }

        if buf.Len() != len(str) {
                t.Errorf("%s: buf.Len() == %d, len(buf.String()) == %d", testname, buf.Len(), len(str))
        }

        if buf.Len() != len(s) {
                t.Errorf("%s: buf.Len() == %d, len(s) == %d", testname, buf.Len(), len(s))
        }

        if string(bytes) != s {
                t.Errorf("%s: string(buf.Bytes()) == %q, s == %q", testname, string(bytes), s)
        }
}

// Fill buf through n writes of string fus.
// The initial contents of buf corresponds to the string s;
// the result is the final contents of buf returned as a string.
func fillString(t *testing.T, testname string, buf *Buffer, s string, n int, fus string) string {
        check(t, testname+" (fill 1)", buf, s)
        for ; n > 0; n-- {
                m, err := buf.WriteString(fus)
                if m != len(fus) {
                        t.Errorf(testname+" (fill 2): m == %d, expected %d", m, len(fus))
                }
                if err != nil {
                        t.Errorf(testname+" (fill 3): err should always be nil, found err == %s", err)
                }
                s += fus
                check(t, testname+" (fill 4)", buf, s)
        }
        return s
}

// Fill buf through n writes of byte slice fub.
// The initial contents of buf corresponds to the string s;
// the result is the final contents of buf returned as a string.
func fillBytes(t *testing.T, testname string, buf *Buffer, s string, n int, fub []byte) string {
        check(t, testname+" (fill 1)", buf, s)
        for ; n > 0; n-- {
                m, err := buf.Write(fub)
                if m != len(fub) {
                        t.Errorf(testname+" (fill 2): m == %d, expected %d", m, len(fub))
                }
                if err != nil {
                        t.Errorf(testname+" (fill 3): err should always be nil, found err == %s", err)
                }
                s += string(fub)
                check(t, testname+" (fill 4)", buf, s)
        }
        return s
}

func TestNewBuffer(t *testing.T) {
        buf := NewBuffer(testBytes)
        check(t, "NewBuffer", buf, data)
}

func TestNewBufferString(t *testing.T) {
        buf := NewBufferString(data)
        check(t, "NewBufferString", buf, data)
}

// Empty buf through repeated reads into fub.
// The initial contents of buf corresponds to the string s.
func empty(t *testing.T, testname string, buf *Buffer, s string, fub []byte) {
        check(t, testname+" (empty 1)", buf, s)

        for {
                n, err := buf.Read(fub)
                if n == 0 {
                        break
                }
                if err != nil {
                        t.Errorf(testname+" (empty 2): err should always be nil, found err == %s", err)
                }
                s = s[n:]
                check(t, testname+" (empty 3)", buf, s)
        }

        check(t, testname+" (empty 4)", buf, "")
}

func TestBasicOperations(t *testing.T) {
        var buf Buffer

        for i := 0; i < 5; i++ {
                check(t, "TestBasicOperations (1)", &buf, "")

                buf.Reset()
                check(t, "TestBasicOperations (2)", &buf, "")

                buf.Truncate(0)
                check(t, "TestBasicOperations (3)", &buf, "")

                n, err := buf.Write([]byte(data[0:1]))
                if n != 1 {
                        t.Errorf("wrote 1 byte, but n == %d", n)
                }
                if err != nil {
                        t.Errorf("err should always be nil, but err == %s", err)
                }
                check(t, "TestBasicOperations (4)", &buf, "a")

                buf.WriteByte(data[1])
                check(t, "TestBasicOperations (5)", &buf, "ab")

                n, err = buf.Write([]byte(data[2:26]))
                if n != 24 {
                        t.Errorf("wrote 25 bytes, but n == %d", n)
                }
                check(t, "TestBasicOperations (6)", &buf, string(data[0:26]))

                buf.Truncate(26)
                check(t, "TestBasicOperations (7)", &buf, string(data[0:26]))

                buf.Truncate(20)
                check(t, "TestBasicOperations (8)", &buf, string(data[0:20]))

                empty(t, "TestBasicOperations (9)", &buf, string(data[0:20]), make([]byte, 5))
                empty(t, "TestBasicOperations (10)", &buf, "", make([]byte, 100))

                buf.WriteByte(data[1])
                c, err := buf.ReadByte()
                if err != nil {
                        t.Error("ReadByte unexpected eof")
                }
                if c != data[1] {
                        t.Errorf("ReadByte wrong value c=%v", c)
                }
                c, err = buf.ReadByte()
                if err == nil {
                        t.Error("ReadByte unexpected not eof")
                }
        }
}

func TestLargeStringWrites(t *testing.T) {
        var buf Buffer
        limit := 30
        if testing.Short() {
                limit = 9
        }
        for i := 3; i < limit; i += 3 {
                s := fillString(t, "TestLargeWrites (1)", &buf, "", 5, data)
                empty(t, "TestLargeStringWrites (2)", &buf, s, make([]byte, len(data)/i))
        }
        check(t, "TestLargeStringWrites (3)", &buf, "")
}

func TestLargeByteWrites(t *testing.T) {
        var buf Buffer
        limit := 30
        if testing.Short() {
                limit = 9
        }
        for i := 3; i < limit; i += 3 {
                s := fillBytes(t, "TestLargeWrites (1)", &buf, "", 5, testBytes)
                empty(t, "TestLargeByteWrites (2)", &buf, s, make([]byte, len(data)/i))
        }
        check(t, "TestLargeByteWrites (3)", &buf, "")
}

func TestLargeStringReads(t *testing.T) {
        var buf Buffer
        for i := 3; i < 30; i += 3 {
                s := fillString(t, "TestLargeReads (1)", &buf, "", 5, data[0:len(data)/i])
                empty(t, "TestLargeReads (2)", &buf, s, make([]byte, len(data)))
        }
        check(t, "TestLargeStringReads (3)", &buf, "")
}

func TestLargeByteReads(t *testing.T) {
        var buf Buffer
        for i := 3; i < 30; i += 3 {
                s := fillBytes(t, "TestLargeReads (1)", &buf, "", 5, testBytes[0:len(testBytes)/i])
                empty(t, "TestLargeReads (2)", &buf, s, make([]byte, len(data)))
        }
        check(t, "TestLargeByteReads (3)", &buf, "")
}

func TestMixedReadsAndWrites(t *testing.T) {
        var buf Buffer
        s := ""
        for i := 0; i < 50; i++ {
                wlen := rand.Intn(len(data))
                if i%2 == 0 {
                        s = fillString(t, "TestMixedReadsAndWrites (1)", &buf, s, 1, data[0:wlen])
                } else {
                        s = fillBytes(t, "TestMixedReadsAndWrites (1)", &buf, s, 1, testBytes[0:wlen])
                }

                rlen := rand.Intn(len(data))
                fub := make([]byte, rlen)
                n, _ := buf.Read(fub)
                s = s[n:]
        }
        empty(t, "TestMixedReadsAndWrites (2)", &buf, s, make([]byte, buf.Len()))
}

func TestCapWithPreallocatedSlice(t *testing.T) {
        buf := NewBuffer(make([]byte, 10))
        n := buf.Cap()
        if n != 10 {
                t.Errorf("expected 10, got %d", n)
        }
}

func TestCapWithSliceAndWrittenData(t *testing.T) {
        buf := NewBuffer(make([]byte, 0, 10))
        buf.Write([]byte("test"))
        n := buf.Cap()
        if n != 10 {
                t.Errorf("expected 10, got %d", n)
        }
}

func TestNil(t *testing.T) {
        var b *Buffer
        if b.String() != "<nil>" {
                t.Errorf("expected <nil>; got %q", b.String())
        }
}

func TestReadFrom(t *testing.T) {
        var buf Buffer
        for i := 3; i < 30; i += 3 {
                s := fillBytes(t, "TestReadFrom (1)", &buf, "", 5, testBytes[0:len(testBytes)/i])
                var b Buffer
                b.ReadFrom(&buf)
                empty(t, "TestReadFrom (2)", &b, s, make([]byte, len(data)))
        }
}

func TestWriteTo(t *testing.T) {
        var buf Buffer
        for i := 3; i < 30; i += 3 {
                s := fillBytes(t, "TestWriteTo (1)", &buf, "", 5, testBytes[0:len(testBytes)/i])
                var b Buffer
                buf.WriteTo(&b)
                empty(t, "TestWriteTo (2)", &b, s, make([]byte, len(data)))
        }
}

func TestRuneIO(t *testing.T) {
        const NRune = 1000
        // Built a test slice while we write the data
        b := make([]byte, utf8.UTFMax*NRune)
        var buf Buffer
        n := 0
        for r := rune(0); r < NRune; r++ {
                size := utf8.EncodeRune(b[n:], r)
                nbytes, err := buf.WriteRune(r)
                if err != nil {
                        t.Fatalf("WriteRune(%U) error: %s", r, err)
                }
                if nbytes != size {
                        t.Fatalf("WriteRune(%U) expected %d, got %d", r, size, nbytes)
                }
                n += size
        }
        b = b[0:n]

        // Check the resulting bytes
        if !Equal(buf.Bytes(), b) {
                t.Fatalf("incorrect result from WriteRune: %q not %q", buf.Bytes(), b)
        }

        p := make([]byte, utf8.UTFMax)
        // Read it back with ReadRune
        for r := rune(0); r < NRune; r++ {
                size := utf8.EncodeRune(p, r)
                nr, nbytes, err := buf.ReadRune()
                if nr != r || nbytes != size || err != nil {
                        t.Fatalf("ReadRune(%U) got %U,%d not %U,%d (err=%s)", r, nr, nbytes, r, size, err)
                }
        }

        // Check that UnreadRune works
        buf.Reset()
        buf.Write(b)
        for r := rune(0); r < NRune; r++ {
                r1, size, _ := buf.ReadRune()
                if err := buf.UnreadRune(); err != nil {
                        t.Fatalf("UnreadRune(%U) got error %q", r, err)
                }
                r2, nbytes, err := buf.ReadRune()
                if r1 != r2 || r1 != r || nbytes != size || err != nil {
                        t.Fatalf("ReadRune(%U) after UnreadRune got %U,%d not %U,%d (err=%s)", r, r2, nbytes, r, size, err)
                }
        }
}

func TestNext(t *testing.T) {
        b := []byte{0, 1, 2, 3, 4}
        tmp := make([]byte, 5)
        for i := 0; i <= 5; i++ {
                for j := i; j <= 5; j++ {
                        for k := 0; k <= 6; k++ {
                                // 0 <= i <= j <= 5; 0 <= k <= 6
                                // Check that if we start with a buffer
                                // of length j at offset i and ask for
                                // Next(k), we get the right bytes.
                                buf := NewBuffer(b[0:j])
                                n, _ := buf.Read(tmp[0:i])
                                if n != i {
                                        t.Fatalf("Read %d returned %d", i, n)
                                }
                                bb := buf.Next(k)
                                want := k
                                if want > j-i {
                                        want = j - i
                                }
                                if len(bb) != want {
                                        t.Fatalf("in %d,%d: len(Next(%d)) == %d", i, j, k, len(bb))
                                }
                                for l, v := range bb {
                                        if v != byte(l+i) {
                                                t.Fatalf("in %d,%d: Next(%d)[%d] = %d, want %d", i, j, k, l, v, l+i)
                                        }
                                }
                        }
                }
        }
}

var readBytesTests = []struct {
        buffer   string
        delim    byte
        expected []string
        err      error
}{
        {"", 0, []string{""}, io.EOF},
        {"a\x00", 0, []string{"a\x00"}, nil},
        {"abbbaaaba", 'b', []string{"ab", "b", "b", "aaab"}, nil},
        {"hello\x01world", 1, []string{"hello\x01"}, nil},
        {"foo\nbar", 0, []string{"foo\nbar"}, io.EOF},
        {"alpha\nbeta\ngamma\n", '\n', []string{"alpha\n", "beta\n", "gamma\n"}, nil},
        {"alpha\nbeta\ngamma", '\n', []string{"alpha\n", "beta\n", "gamma"}, io.EOF},
}

func TestReadBytes(t *testing.T) {
        for _, test := range readBytesTests {
                buf := NewBufferString(test.buffer)
                var err error
                for _, expected := range test.expected {
                        var bytes []byte
                        bytes, err = buf.ReadBytes(test.delim)
                        if string(bytes) != expected {
                                t.Errorf("expected %q, got %q", expected, bytes)
                        }
                        if err != nil {
                                break
                        }
                }
                if err != test.err {
                        t.Errorf("expected error %v, got %v", test.err, err)
                }
        }
}

func TestReadString(t *testing.T) {
        for _, test := range readBytesTests {
                buf := NewBufferString(test.buffer)
                var err error
                for _, expected := range test.expected {
                        var s string
                        s, err = buf.ReadString(test.delim)
                        if s != expected {
                                t.Errorf("expected %q, got %q", expected, s)
                        }
                        if err != nil {
                                break
                        }
                }
                if err != test.err {
                        t.Errorf("expected error %v, got %v", test.err, err)
                }
        }
}

func BenchmarkReadString(b *testing.B) {
        const n = 32 << 10

        data := make([]byte, n)
        data[n-1] = 'x'
        b.SetBytes(int64(n))
        for i := 0; i < b.N; i++ {
                buf := NewBuffer(data)
                _, err := buf.ReadString('x')
                if err != nil {
                        b.Fatal(err)
                }
        }
}

func TestGrow(t *testing.T) {
        x := []byte{'x'}
        y := []byte{'y'}
        tmp := make([]byte, 72)
        for _, startLen := range []int{0, 100, 1000, 10000, 100000} {
                xBytes := Repeat(x, startLen)
                for _, growLen := range []int{0, 100, 1000, 10000, 100000} {
                        buf := NewBuffer(xBytes)
                        // If we read, this affects buf.off, which is good to test.
                        readBytes, _ := buf.Read(tmp)
                        buf.Grow(growLen)
                        yBytes := Repeat(y, growLen)
                        // Check no allocation occurs in write, as long as we're single-threaded.
                        var m1, m2 runtime.MemStats
                        runtime.ReadMemStats(&m1)
                        buf.Write(yBytes)
                        runtime.ReadMemStats(&m2)
                        if runtime.GOMAXPROCS(-1) == 1 && m1.Mallocs != m2.Mallocs {
                                t.Errorf("allocation occurred during write")
                        }
                        // Check that buffer has correct data.
                        if !Equal(buf.Bytes()[0:startLen-readBytes], xBytes[readBytes:]) {
                                t.Errorf("bad initial data at %d %d", startLen, growLen)
                        }
                        if !Equal(buf.Bytes()[startLen-readBytes:startLen-readBytes+growLen], yBytes) {
                                t.Errorf("bad written data at %d %d", startLen, growLen)
                        }
                }
        }
}

// Was a bug: used to give EOF reading empty slice at EOF.
func TestReadEmptyAtEOF(t *testing.T) {
        b := new(Buffer)
        slice := make([]byte, 0)
        n, err := b.Read(slice)
        if err != nil {
                t.Errorf("read error: %v", err)
        }
        if n != 0 {
                t.Errorf("wrong count; got %d want 0", n)
        }
}

func TestUnreadByte(t *testing.T) {
        b := new(Buffer)
        b.WriteString("abcdefghijklmnopqrstuvwxyz")

        _, err := b.ReadBytes('m')
        if err != nil {
                t.Fatalf("ReadBytes: %v", err)
        }

        err = b.UnreadByte()
        if err != nil {
                t.Fatalf("UnreadByte: %v", err)
        }
        c, err := b.ReadByte()
        if err != nil {
                t.Fatalf("ReadByte: %v", err)
        }
        if c != 'm' {
                t.Errorf("ReadByte = %q; want %q", c, 'm')
        }
}

// Tests that we occasionally compact. Issue 5154.
func TestBufferGrowth(t *testing.T) {
        var b Buffer
        buf := make([]byte, 1024)
        b.Write(buf[0:1])
        var cap0 int
        for i := 0; i < 5<<10; i++ {
                b.Write(buf)
                b.Read(buf)
                if i == 0 {
                        cap0 = b.Cap()
                }
        }
        cap1 := b.Cap()
        // (*Buffer).grow allows for 2x capacity slop before sliding,
        // so set our error threshold at 3x.
        if cap1 > cap0*3 {
                t.Errorf("buffer cap = %d; too big (grew from %d)", cap1, cap0)
        }
}

func BenchmarkWriteRune(b *testing.B) {
        const n = 4 << 10
        const r = '☺'
        b.SetBytes(int64(n * utf8.RuneLen(r)))
        buf := NewBuffer(make([]byte, n*utf8.UTFMax))
        for i := 0; i < b.N; i++ {
                buf.Reset()
                for i := 0; i < n; i++ {
                        buf.WriteRune(r)
                }
        }
}

// From Issue 5154.
func BenchmarkBufferNotEmptyWriteRead(b *testing.B) {
        buf := make([]byte, 1024)
        for i := 0; i < b.N; i++ {
                var b Buffer
                b.Write(buf[0:1])
                for i := 0; i < 5<<10; i++ {
                        b.Write(buf)
                        b.Read(buf)
                }
        }
}

// Check that we don't compact too often. From Issue 5154.
func BenchmarkBufferFullSmallReads(b *testing.B) {
        buf := make([]byte, 1024)
        for i := 0; i < b.N; i++ {
                var b Buffer
                b.Write(buf)
                for b.Len()+20 < b.Cap() {
                        b.Write(buf[:10])
                }
                for i := 0; i < 5<<10; i++ {
                        b.Read(buf[:1])
                        b.Write(buf[:1])
                }
        }
}