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-rw-r--r--src/bytes/buffer_test.go663
1 files changed, 663 insertions, 0 deletions
diff --git a/src/bytes/buffer_test.go b/src/bytes/buffer_test.go
new file mode 100644
index 0000000..fec5ef8
--- /dev/null
+++ b/src/bytes/buffer_test.go
@@ -0,0 +1,663 @@
+// 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"
+ "testing"
+ "unicode/utf8"
+)
+
+const N = 10000 // make this bigger for a larger (and slower) test
+var testString string // test data for write tests
+var testBytes []byte // test data; same as testString but as a slice.
+
+type negativeReader struct{}
+
+func (r *negativeReader) Read([]byte) (int, error) { return -1, nil }
+
+func init() {
+ testBytes = make([]byte, N)
+ for i := 0; i < N; i++ {
+ testBytes[i] = 'a' + byte(i%26)
+ }
+ testString = 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, testString)
+}
+
+func TestNewBufferString(t *testing.T) {
+ buf := NewBufferString(testString)
+ check(t, "NewBufferString", buf, testString)
+}
+
+// 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(testBytes[0:1])
+ if want := 1; err != nil || n != want {
+ t.Errorf("Write: got (%d, %v), want (%d, %v)", n, err, want, nil)
+ }
+ check(t, "TestBasicOperations (4)", &buf, "a")
+
+ buf.WriteByte(testString[1])
+ check(t, "TestBasicOperations (5)", &buf, "ab")
+
+ n, err = buf.Write(testBytes[2:26])
+ if want := 24; err != nil || n != want {
+ t.Errorf("Write: got (%d, %v), want (%d, %v)", n, err, want, nil)
+ }
+ check(t, "TestBasicOperations (6)", &buf, testString[0:26])
+
+ buf.Truncate(26)
+ check(t, "TestBasicOperations (7)", &buf, testString[0:26])
+
+ buf.Truncate(20)
+ check(t, "TestBasicOperations (8)", &buf, testString[0:20])
+
+ empty(t, "TestBasicOperations (9)", &buf, testString[0:20], make([]byte, 5))
+ empty(t, "TestBasicOperations (10)", &buf, "", make([]byte, 100))
+
+ buf.WriteByte(testString[1])
+ c, err := buf.ReadByte()
+ if want := testString[1]; err != nil || c != want {
+ t.Errorf("ReadByte: got (%q, %v), want (%q, %v)", c, err, want, nil)
+ }
+ c, err = buf.ReadByte()
+ if err != io.EOF {
+ t.Errorf("ReadByte: got (%q, %v), want (%q, %v)", c, err, byte(0), io.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, testString)
+ empty(t, "TestLargeStringWrites (2)", &buf, s, make([]byte, len(testString)/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(testString)/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, testString[0:len(testString)/i])
+ empty(t, "TestLargeReads (2)", &buf, s, make([]byte, len(testString)))
+ }
+ 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(testString)))
+ }
+ check(t, "TestLargeByteReads (3)", &buf, "")
+}
+
+func TestMixedReadsAndWrites(t *testing.T) {
+ var buf Buffer
+ s := ""
+ for i := 0; i < 50; i++ {
+ wlen := rand.Intn(len(testString))
+ if i%2 == 0 {
+ s = fillString(t, "TestMixedReadsAndWrites (1)", &buf, s, 1, testString[0:wlen])
+ } else {
+ s = fillBytes(t, "TestMixedReadsAndWrites (1)", &buf, s, 1, testBytes[0:wlen])
+ }
+
+ rlen := rand.Intn(len(testString))
+ 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(testString)))
+ }
+}
+
+type panicReader struct{ panic bool }
+
+func (r panicReader) Read(p []byte) (int, error) {
+ if r.panic {
+ panic(nil)
+ }
+ return 0, io.EOF
+}
+
+// Make sure that an empty Buffer remains empty when
+// it is "grown" before a Read that panics
+func TestReadFromPanicReader(t *testing.T) {
+
+ // First verify non-panic behaviour
+ var buf Buffer
+ i, err := buf.ReadFrom(panicReader{})
+ if err != nil {
+ t.Fatal(err)
+ }
+ if i != 0 {
+ t.Fatalf("unexpected return from bytes.ReadFrom (1): got: %d, want %d", i, 0)
+ }
+ check(t, "TestReadFromPanicReader (1)", &buf, "")
+
+ // Confirm that when Reader panics, the empty buffer remains empty
+ var buf2 Buffer
+ defer func() {
+ recover()
+ check(t, "TestReadFromPanicReader (2)", &buf2, "")
+ }()
+ buf2.ReadFrom(panicReader{panic: true})
+}
+
+func TestReadFromNegativeReader(t *testing.T) {
+ var b Buffer
+ defer func() {
+ switch err := recover().(type) {
+ case nil:
+ t.Fatal("bytes.Buffer.ReadFrom didn't panic")
+ case error:
+ // this is the error string of errNegativeRead
+ wantError := "bytes.Buffer: reader returned negative count from Read"
+ if err.Error() != wantError {
+ t.Fatalf("recovered panic: got %v, want %v", err.Error(), wantError)
+ }
+ default:
+ t.Fatalf("unexpected panic value: %#v", err)
+ }
+ }()
+
+ b.ReadFrom(new(negativeReader))
+}
+
+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(testString)))
+ }
+}
+
+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()
+
+ // check at EOF
+ if err := buf.UnreadRune(); err == nil {
+ t.Fatal("UnreadRune at EOF: got no error")
+ }
+ if _, _, err := buf.ReadRune(); err == nil {
+ t.Fatal("ReadRune at EOF: got no error")
+ }
+ if err := buf.UnreadRune(); err == nil {
+ t.Fatal("UnreadRune after ReadRune at EOF: got no error")
+ }
+
+ // check not at EOF
+ 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 _, growLen := range []int{0, 100, 1000, 10000, 100000} {
+ for _, startLen := range []int{0, 100, 1000, 10000, 100000} {
+ xBytes := Repeat(x, startLen)
+
+ buf := NewBuffer(xBytes)
+ // If we read, this affects buf.off, which is good to test.
+ readBytes, _ := buf.Read(tmp)
+ yBytes := Repeat(y, growLen)
+ allocs := testing.AllocsPerRun(100, func() {
+ buf.Grow(growLen)
+ buf.Write(yBytes)
+ })
+ // Check no allocation occurs in write, as long as we're single-threaded.
+ if allocs != 0 {
+ 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)
+ }
+ }
+ }
+}
+
+func TestGrowOverflow(t *testing.T) {
+ defer func() {
+ if err := recover(); err != ErrTooLarge {
+ t.Errorf("after too-large Grow, recover() = %v; want %v", err, ErrTooLarge)
+ }
+ }()
+
+ buf := NewBuffer(make([]byte, 1))
+ const maxInt = int(^uint(0) >> 1)
+ buf.Grow(maxInt)
+}
+
+// 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)
+
+ // check at EOF
+ if err := b.UnreadByte(); err == nil {
+ t.Fatal("UnreadByte at EOF: got no error")
+ }
+ if _, err := b.ReadByte(); err == nil {
+ t.Fatal("ReadByte at EOF: got no error")
+ }
+ if err := b.UnreadByte(); err == nil {
+ t.Fatal("UnreadByte after ReadByte at EOF: got no error")
+ }
+
+ // check not at EOF
+ b.WriteString("abcdefghijklmnopqrstuvwxyz")
+
+ // after unsuccessful read
+ if n, err := b.Read(nil); n != 0 || err != nil {
+ t.Fatalf("Read(nil) = %d,%v; want 0,nil", n, err)
+ }
+ if err := b.UnreadByte(); err == nil {
+ t.Fatal("UnreadByte after Read(nil): got no error")
+ }
+
+ // after successful read
+ if _, err := b.ReadBytes('m'); err != nil {
+ t.Fatalf("ReadBytes: %v", err)
+ }
+ if err := b.UnreadByte(); 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 BenchmarkWriteByte(b *testing.B) {
+ const n = 4 << 10
+ b.SetBytes(n)
+ buf := NewBuffer(make([]byte, n))
+ for i := 0; i < b.N; i++ {
+ buf.Reset()
+ for i := 0; i < n; i++ {
+ buf.WriteByte('x')
+ }
+ }
+}
+
+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])
+ }
+ }
+}
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