Skip to content

Binary writer fix #107369

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
koszeggy wants to merge 12 commits into
base: main
Choose a base branch
from
Open

Binary writer fix #107369

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
12 commits
Select commit Hold shift + click to select a range
5c1a3ec
BinaryWriter: fixing Write(string) for derived types. Fixes #107265
koszeggy Sep 4, 2024
80333be
Merge branch 'dotnet:main' into BinaryWriterFix
koszeggy Sep 4, 2024
3f93285
Fixing build
koszeggy Sep 4, 2024
d97391b
Merge branch 'BinaryWriterFix' of https://github.com/koszeggy/runtime…
koszeggy Sep 4, 2024
440f0be
Merge branch 'main' into BinaryWriterFix
koszeggy Sep 4, 2024
3d21d94
Apply suggestion from code review
jeffhandley Mar 23, 2025
c6a4f61
Merge branch 'main' into BinaryWriterFix
jeffhandley Mar 23, 2025
7fafa6e
Merge branch 'dotnet:main' into BinaryWriterFix
koszeggy Mar 26, 2025
ba1b351
BinaryWriter tests: checking derived reader/writer behavior (#107265)
koszeggy Mar 26, 2025
05284b2
Merge branch 'main' into BinaryWriterFix
jeffhandley Jan 5, 2026
a98ed01
Apply suggestions from code review
jeffhandley Feb 16, 2026
9dab275
Merge branch 'main' into BinaryWriterFix
jeffhandley Feb 16, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 4 additions & 1 deletion src/libraries/System.Private.CoreLib/src/System/IO/BinaryWriter.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -353,7 +353,10 @@ public virtual void Write(string value)

if (_useFastUtf8)
{
if (value.Length <= 127 / 3)
// If this is a non-derived BinaryWriter, then we can bypass the Write7BitEncodedInt call.
// But when this is a derived instance, call must not bypass it for compatibility reasons
// as it calls the virtual Write(byte) overload.
if (GetType() == typeof(BinaryWriter) && value.Length <= 127 / 3)
{
// Max expansion: each char -> 3 bytes, so 127 bytes max of data, +1 for length prefix
Span<byte> buffer = stackalloc byte[128];
Expand Down
363 changes: 348 additions & 15 deletions src/libraries/System.Runtime/tests/System.IO.Tests/BinaryWriter/BinaryWriter.WriteTests.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
// Licensed to the .NET Foundation under one or more agreements.
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Text;
Expand Down Expand Up @@ -188,26 +188,359 @@ protected virtual Stream CreateStream()

private void WriteTest<T>(T[] testElements, Action<BinaryWriter, T> write, Func<BinaryReader, T> read)
{
// Non-derived BinaryWriter/BinaryReader, UTF-8 encoding
using (Stream memStream = CreateStream())
using (BinaryWriter writer = new BinaryWriter(memStream))
using (BinaryReader reader = new BinaryReader(memStream))
using (var writer = new BinaryWriter(memStream))
using (var reader = new BinaryReader(memStream))
{
for (int i = 0; i < testElements.Length; i++)
{
write(writer, testElements[i]);
}
WriteTest(memStream, writer, reader, testElements, write, read);
}

// Derived BinaryWriter/BinaryReader, UTF-8 encoding
using (Stream memStream = CreateStream())
using (var writer = new TestWriter(memStream))
using (var reader = new TestReader(memStream))
{
WriteTest(memStream, writer, reader, testElements, write, read);
}

// Non-derived BinaryWriter/BinaryReader, UTF-16 encoding
using (Stream memStream = CreateStream())
using (var writer = new BinaryWriter(memStream, Encoding.Unicode))
using (var reader = new BinaryReader(memStream, Encoding.Unicode))
{
WriteTest(memStream, writer, reader, testElements, write, read);
}

// Derived BinaryWriter/BinaryReader, UTF-16 encoding
using (Stream memStream = CreateStream())
using (var writer = new TestWriter(memStream, Encoding.Unicode))
using (var reader = new TestReader(memStream, Encoding.Unicode))
{
WriteTest(memStream, writer, reader, testElements, write, read);
}
}

private void WriteTest<T>(Stream stream, BinaryWriter writer, BinaryReader reader, T[] testElements, Action<BinaryWriter, T> write, Func<BinaryReader, T> read)
{
for (int i = 0; i < testElements.Length; i++)
{
write(writer, testElements[i]);
}

writer.Flush();
stream.Position = 0;

for (int i = 0; i < testElements.Length; i++)
{
Assert.Equal(testElements[i], read(reader));
}

if (writer is TestWriter derivedWriter && reader is TestReader derivedReader)
{
// Checking if the internally tracked positions of a derived reader/writer are in sync (#107265)
Assert.Equal(derivedReader.Position, derivedWriter.Position);
}

// We've reached the end of the stream. Check for expected EndOfStreamException
Assert.Throws<EndOfStreamException>(() => read(reader));
}


private class TestWriter : BinaryWriter
{
private readonly Encoding _encoding;
public long Position { get; private set; }

public TestWriter(Stream stream, Encoding? encoding = null)
: base(stream, encoding ?? Encoding.UTF8)
{
_encoding = encoding ?? Encoding.UTF8;
}

public override void Write(bool value)
{
Advance(sizeof(byte));
base.Write(value);
}

public override void Write(byte value)
{
Advance(sizeof(byte));
base.Write(value);
}

public override void Write(byte[] buffer)
{
Advance(buffer.Length);
base.Write(buffer);
}

public override void Write(byte[] buffer, int index, int count)
{
Advance(count);
base.Write(buffer, index, count);
}

public override void Write(char ch)
{
Advance(_encoding.GetBytes([ch]).Length);
base.Write(ch);
}

public override void Write(char[] chars)
{
Advance(_encoding.GetBytes(chars).Length);
base.Write(chars);
}

public override void Write(char[] chars, int index, int count)
{
Advance(_encoding.GetBytes(chars, index, count).Length);
base.Write(chars, index, count);
}

public override void Write(decimal value)
{
Advance(sizeof(decimal));
base.Write(value);
}

public override void Write(double value)
{
Advance(sizeof(double));
base.Write(value);
}

public override void Write(float value)
{
Advance(sizeof(float));
base.Write(value);
}

public override void Write(int value)
{
Advance(sizeof(int));
base.Write(value);
}

public override void Write(long value)
{
Advance(sizeof(long));
base.Write(value);
}

public override void Write(sbyte value)
{
Advance(sizeof(sbyte));
base.Write(value);
}

public override void Write(short value)
{
Advance(sizeof(short));
base.Write(value);
}

public override void Write(string value)
{
Advance(_encoding.GetBytes(value).Length);
base.Write(value);
}

public override void Write(uint value)
{
Advance(sizeof(uint));
base.Write(value);
}

public override void Write(ulong value)
{
Advance(sizeof(ulong));
base.Write(value);
}

public override void Write(ushort value)
{
Advance(sizeof(ushort));
base.Write(value);
}

public override unsafe void Write(Half value)
{
Advance(sizeof(Half));
base.Write(value);
}

public override void Write(ReadOnlySpan<byte> buffer)
{
Advance(buffer.Length);
base.Write(buffer);
}

public override void Write(ReadOnlySpan<char> chars)
{
Advance(_encoding.GetBytes(chars.ToArray()).Length);
base.Write(chars);
}

private void Advance(int offset) => Position += offset;
}

private class TestReader : BinaryReader
{
private readonly Encoding _encoding;
public long Position { get; private set; }

public TestReader(Stream s, Encoding? encoding = null)
: base(s, encoding ?? Encoding.UTF8)
{
_encoding = encoding ?? Encoding.UTF8;
}

public override int Read()
{
var current = BaseStream.Position;
var result = base.Read();
Advance(BaseStream.Position - current);
return result;
}

writer.Flush();
memStream.Position = 0;
public override int Read(byte[] buffer, int index, int count)
{
var result = base.Read(buffer, index, count);
Advance(result);
return result;
}

for (int i = 0; i < testElements.Length; i++)
{
Assert.Equal(testElements[i], read(reader));
}
public override int Read(char[] buffer, int index, int count)
{
var result = base.Read(buffer, index, count);
Advance(_encoding.GetBytes(buffer, 0, result).Length);
return result;
}

// We've reached the end of the stream. Check for expected EndOfStreamException
Assert.Throws<EndOfStreamException>(() => read(reader));
public override bool ReadBoolean()
{
Advance(sizeof(bool));
return base.ReadBoolean();
}

public override byte ReadByte()
{
Advance(sizeof(byte));
return base.ReadByte();
}

public override byte[] ReadBytes(int count)
{
var result = base.ReadBytes(count);
Advance(result.Length);
return result;
}

public override char ReadChar()
{
var result = base.ReadChar();
Advance(_encoding.GetBytes([result]).Length);
return result;
}

public override char[] ReadChars(int count)
{
var result = base.ReadChars(count);
Advance(_encoding.GetBytes(result).Length);
return result;
}

public override decimal ReadDecimal()
{
Advance(sizeof(decimal));
return base.ReadDecimal();
}

public override double ReadDouble()
{
Advance(sizeof(double));
return base.ReadDouble();
}

public override short ReadInt16()
{
Advance(sizeof(short));
return base.ReadInt16();
}

public override int ReadInt32()
{
Advance(sizeof(int));
return base.ReadInt32();
}

public override long ReadInt64()
{
Advance(sizeof(long));
return base.ReadInt64();
}

public override sbyte ReadSByte()
{
Advance(sizeof(sbyte));
return base.ReadSByte();
}

public override float ReadSingle()
{
Advance(sizeof(float));
return base.ReadSingle();
}

public override string ReadString()
{
var result = base.ReadString();
Advance(_encoding.GetBytes(result).Length);
return result;
}

public override ushort ReadUInt16()
{
Advance(sizeof(ushort));
return base.ReadUInt16();
}

public override uint ReadUInt32()
{
Advance(sizeof(uint));
return base.ReadUInt32();
}

public override ulong ReadUInt64()
{
Advance(sizeof(ulong));
return base.ReadUInt64();
}

public override unsafe Half ReadHalf()
{
Advance(sizeof(Half));
return base.ReadHalf();
}

public override int Read(Span<byte> buffer)
{
var result = base.Read(buffer);
Advance(result);
return result;
}

public override int Read(Span<char> buffer)
{
var result = base.Read(buffer);
Advance(_encoding.GetBytes(buffer[..result].ToArray()).Length);
return result;
}

private void Advance(long offset) => Position += offset;
}
}
}
Loading