From e0e0b7a68d19ccf597a7da7635869fccb4ca6caf Mon Sep 17 00:00:00 2001 From: luoyy Date: Sun, 22 Oct 2023 00:24:29 +0800 Subject: [PATCH] update: Add buffer test files and optimize code to improve readability. --- packet/type.go | 26 +- parser/type.go | 4 +- types/buffer_test.go | 730 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 746 insertions(+), 14 deletions(-) create mode 100644 types/buffer_test.go diff --git a/packet/type.go b/packet/type.go index f8764af..87324b1 100644 --- a/packet/type.go +++ b/packet/type.go @@ -6,7 +6,20 @@ import ( "github.com/zishang520/engine.io-go-parser/types" ) -type Type string +type ( + Type string + + Options struct { + Compress bool `json:"compress" mapstructure:"compress" msgpack:"compress"` + } + + Packet struct { + Type Type `json:"type" mapstructure:"type" msgpack:"type"` + Data io.Reader `json:"data,omitempty" mapstructure:"data,omitempty" msgpack:"data,omitempty"` + Options *Options `json:"options,omitempty" mapstructure:"options,omitempty" msgpack:"options,omitempty"` + WsPreEncoded types.BufferInterface `json:"wsPreEncoded,omitempty" mapstructure:"wsPreEncoded,omitempty" msgpack:"wsPreEncoded,omitempty"` + } +) // Packet types. const ( @@ -19,14 +32,3 @@ const ( NOOP Type = "noop" ERROR Type = "error" ) - -type Options struct { - Compress bool `json:"compress" mapstructure:"compress" msgpack:"compress"` -} - -type Packet struct { - Type Type `json:"type" mapstructure:"type" msgpack:"type"` - Data io.Reader `json:"data,omitempty" mapstructure:"data,omitempty" msgpack:"data,omitempty"` - Options *Options `json:"options,omitempty" mapstructure:"options,omitempty" msgpack:"options,omitempty"` - WsPreEncoded types.BufferInterface `json:"wsPreEncoded,omitempty" mapstructure:"wsPreEncoded,omitempty" msgpack:"wsPreEncoded,omitempty"` -} diff --git a/parser/type.go b/parser/type.go index 1854995..23576ab 100644 --- a/parser/type.go +++ b/parser/type.go @@ -13,6 +13,8 @@ type Parser interface { DecodePayload(types.BufferInterface) ([]*packet.Packet, error) } +const SEPARATOR byte = 0x1E + // Packet types. var ( PACKET_TYPES map[packet.Type]byte = map[packet.Type]byte{ @@ -38,5 +40,3 @@ var ( // Premade error packet. ERROR_PACKET = &packet.Packet{Type: packet.ERROR, Data: types.NewStringBufferString(`parser error`)} ) - -const SEPARATOR = byte(0x1E) diff --git a/types/buffer_test.go b/types/buffer_test.go new file mode 100644 index 0000000..aea446f --- /dev/null +++ b/types/buffer_test.go @@ -0,0 +1,730 @@ +// 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 types + +import ( + "bytes" + "fmt" + "io" + "math/rand" + "strconv" + "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() != "" { + t.Errorf("expected ; 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("oops") + } + 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 TestWriteAppend(t *testing.T) { + var got Buffer + var want []byte + for i := 0; i < 1000; i++ { + b := got.AvailableBuffer() + b = strconv.AppendInt(b, int64(i), 10) + want = strconv.AppendInt(want, int64(i), 10) + got.Write(b) + } + if !bytes.Equal(got.Bytes(), want) { + t.Fatalf("Bytes() = %q, want %q", got, want) + } + + // With a sufficiently sized buffer, there should be no allocations. + n := testing.AllocsPerRun(100, func() { + got.Reset() + for i := 0; i < 1000; i++ { + b := got.AvailableBuffer() + b = strconv.AppendInt(b, int64(i), 10) + got.Write(b) + } + }) + if n > 0 { + t.Errorf("allocations occurred while appending") + } +} + +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 !bytes.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 TestWriteInvalidRune(t *testing.T) { + // Invalid runes, including negative ones, should be written as + // utf8.RuneError. + for _, r := range []rune{-1, utf8.MaxRune + 1} { + var buf Buffer + buf.WriteRune(r) + check(t, fmt.Sprintf("TestWriteInvalidRune (%d)", r), &buf, "\uFFFD") + } +} + +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 := bytes.Repeat(x, startLen) + + buf := NewBuffer(xBytes) + // If we read, this affects buf.off, which is good to test. + readBytes, _ := buf.Read(tmp) + yBytes := bytes.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 !bytes.Equal(buf.Bytes()[0:startLen-readBytes], xBytes[readBytes:]) { + t.Errorf("bad initial data at %d %d", startLen, growLen) + } + if !bytes.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]) + } + } +} + +func BenchmarkBufferWriteBlock(b *testing.B) { + block := make([]byte, 1024) + for _, n := range []int{1 << 12, 1 << 16, 1 << 20} { + b.Run(fmt.Sprintf("N%d", n), func(b *testing.B) { + b.ReportAllocs() + for i := 0; i < b.N; i++ { + var bb Buffer + for bb.Len() < n { + bb.Write(block) + } + } + }) + } +} + +func BenchmarkBufferAppendNoCopy(b *testing.B) { + var bb Buffer + bb.Grow(16 << 20) + b.SetBytes(int64(bb.Available())) + b.ReportAllocs() + for i := 0; i < b.N; i++ { + bb.Reset() + b := bb.AvailableBuffer() + b = b[:cap(b)] // use max capacity to simulate a large append operation + bb.Write(b) // should be nearly infinitely fast + } +}