// Licensed to the .NET Foundation under one or more agreements. // The .NET Foundation licenses this file to you under the MIT license. // See the LICENSE file in the project root for more information. /*============================================================ ** ** ** ** ** Purpose: Provides a way to write primitives types in ** binary from a Stream, while also supporting writing Strings ** in a particular encoding. ** ** ===========================================================*/ using System; using System.Runtime; using System.Runtime.Serialization; using System.Text; using System.Diagnostics; using System.Diagnostics.Contracts; namespace System.IO { // This abstract base class represents a writer that can write // primitives to an arbitrary stream. A subclass can override methods to // give unique encodings. // [Serializable] public class BinaryWriter : IDisposable { public static readonly BinaryWriter Null = new BinaryWriter(); protected Stream OutStream; private byte[] _buffer; // temp space for writing primitives to. private Encoding _encoding; private Encoder _encoder; [OptionalField] // New in .NET FX 4.5. False is the right default value. private bool _leaveOpen; // Perf optimization stuff private byte[] _largeByteBuffer; // temp space for writing chars. private int _maxChars; // max # of chars we can put in _largeByteBuffer // Size should be around the max number of chars/string * Encoding's max bytes/char private const int LargeByteBufferSize = 256; // Protected default constructor that sets the output stream // to a null stream (a bit bucket). protected BinaryWriter() { OutStream = Stream.Null; _buffer = new byte[16]; _encoding = EncodingCache.UTF8NoBOM; _encoder = _encoding.GetEncoder(); } public BinaryWriter(Stream output) : this(output, EncodingCache.UTF8NoBOM, false) { } public BinaryWriter(Stream output, Encoding encoding) : this(output, encoding, false) { } public BinaryWriter(Stream output, Encoding encoding, bool leaveOpen) { if (output==null) throw new ArgumentNullException(nameof(output)); if (encoding==null) throw new ArgumentNullException(nameof(encoding)); if (!output.CanWrite) throw new ArgumentException(Environment.GetResourceString("Argument_StreamNotWritable")); Contract.EndContractBlock(); OutStream = output; _buffer = new byte[16]; _encoding = encoding; _encoder = _encoding.GetEncoder(); _leaveOpen = leaveOpen; } // Closes this writer and releases any system resources associated with the // writer. Following a call to Close, any operations on the writer // may raise exceptions. public virtual void Close() { Dispose(true); } protected virtual void Dispose(bool disposing) { if (disposing) { if (_leaveOpen) OutStream.Flush(); else OutStream.Close(); } } public void Dispose() { Dispose(true); } /* * Returns the stream associate with the writer. It flushes all pending * writes before returning. All subclasses should override Flush to * ensure that all buffered data is sent to the stream. */ public virtual Stream BaseStream { get { Flush(); return OutStream; } } // Clears all buffers for this writer and causes any buffered data to be // written to the underlying device. public virtual void Flush() { OutStream.Flush(); } public virtual long Seek(int offset, SeekOrigin origin) { return OutStream.Seek(offset, origin); } // Writes a boolean to this stream. A single byte is written to the stream // with the value 0 representing false or the value 1 representing true. // public virtual void Write(bool value) { _buffer[0] = (byte) (value ? 1 : 0); OutStream.Write(_buffer, 0, 1); } // Writes a byte to this stream. The current position of the stream is // advanced by one. // public virtual void Write(byte value) { OutStream.WriteByte(value); } // Writes a signed byte to this stream. The current position of the stream // is advanced by one. // [CLSCompliant(false)] public virtual void Write(sbyte value) { OutStream.WriteByte((byte) value); } // Writes a byte array to this stream. // // This default implementation calls the Write(Object, int, int) // method to write the byte array. // public virtual void Write(byte[] buffer) { if (buffer == null) throw new ArgumentNullException(nameof(buffer)); Contract.EndContractBlock(); OutStream.Write(buffer, 0, buffer.Length); } // Writes a section of a byte array to this stream. // // This default implementation calls the Write(Object, int, int) // method to write the byte array. // public virtual void Write(byte[] buffer, int index, int count) { OutStream.Write(buffer, index, count); } // Writes a character to this stream. The current position of the stream is // advanced by two. // Note this method cannot handle surrogates properly in UTF-8. // public unsafe virtual void Write(char ch) { if (Char.IsSurrogate(ch)) throw new ArgumentException(Environment.GetResourceString("Arg_SurrogatesNotAllowedAsSingleChar")); Contract.EndContractBlock(); Debug.Assert(_encoding.GetMaxByteCount(1) <= 16, "_encoding.GetMaxByteCount(1) <= 16)"); int numBytes = 0; fixed(byte * pBytes = &_buffer[0]) { numBytes = _encoder.GetBytes(&ch, 1, pBytes, _buffer.Length, flush: true); } OutStream.Write(_buffer, 0, numBytes); } // Writes a character array to this stream. // // This default implementation calls the Write(Object, int, int) // method to write the character array. // public virtual void Write(char[] chars) { if (chars == null) throw new ArgumentNullException(nameof(chars)); Contract.EndContractBlock(); byte[] bytes = _encoding.GetBytes(chars, 0, chars.Length); OutStream.Write(bytes, 0, bytes.Length); } // Writes a section of a character array to this stream. // // This default implementation calls the Write(Object, int, int) // method to write the character array. // public virtual void Write(char[] chars, int index, int count) { byte[] bytes = _encoding.GetBytes(chars, index, count); OutStream.Write(bytes, 0, bytes.Length); } // Writes a double to this stream. The current position of the stream is // advanced by eight. // public unsafe virtual void Write(double value) { ulong TmpValue = *(ulong *)&value; _buffer[0] = (byte) TmpValue; _buffer[1] = (byte) (TmpValue >> 8); _buffer[2] = (byte) (TmpValue >> 16); _buffer[3] = (byte) (TmpValue >> 24); _buffer[4] = (byte) (TmpValue >> 32); _buffer[5] = (byte) (TmpValue >> 40); _buffer[6] = (byte) (TmpValue >> 48); _buffer[7] = (byte) (TmpValue >> 56); OutStream.Write(_buffer, 0, 8); } public virtual void Write(decimal value) { Decimal.GetBytes(value,_buffer); OutStream.Write(_buffer, 0, 16); } // Writes a two-byte signed integer to this stream. The current position of // the stream is advanced by two. // public virtual void Write(short value) { _buffer[0] = (byte) value; _buffer[1] = (byte) (value >> 8); OutStream.Write(_buffer, 0, 2); } // Writes a two-byte unsigned integer to this stream. The current position // of the stream is advanced by two. // [CLSCompliant(false)] public virtual void Write(ushort value) { _buffer[0] = (byte) value; _buffer[1] = (byte) (value >> 8); OutStream.Write(_buffer, 0, 2); } // Writes a four-byte signed integer to this stream. The current position // of the stream is advanced by four. // public virtual void Write(int value) { _buffer[0] = (byte) value; _buffer[1] = (byte) (value >> 8); _buffer[2] = (byte) (value >> 16); _buffer[3] = (byte) (value >> 24); OutStream.Write(_buffer, 0, 4); } // Writes a four-byte unsigned integer to this stream. The current position // of the stream is advanced by four. // [CLSCompliant(false)] public virtual void Write(uint value) { _buffer[0] = (byte) value; _buffer[1] = (byte) (value >> 8); _buffer[2] = (byte) (value >> 16); _buffer[3] = (byte) (value >> 24); OutStream.Write(_buffer, 0, 4); } // Writes an eight-byte signed integer to this stream. The current position // of the stream is advanced by eight. // public virtual void Write(long value) { _buffer[0] = (byte) value; _buffer[1] = (byte) (value >> 8); _buffer[2] = (byte) (value >> 16); _buffer[3] = (byte) (value >> 24); _buffer[4] = (byte) (value >> 32); _buffer[5] = (byte) (value >> 40); _buffer[6] = (byte) (value >> 48); _buffer[7] = (byte) (value >> 56); OutStream.Write(_buffer, 0, 8); } // Writes an eight-byte unsigned integer to this stream. The current // position of the stream is advanced by eight. // [CLSCompliant(false)] public virtual void Write(ulong value) { _buffer[0] = (byte) value; _buffer[1] = (byte) (value >> 8); _buffer[2] = (byte) (value >> 16); _buffer[3] = (byte) (value >> 24); _buffer[4] = (byte) (value >> 32); _buffer[5] = (byte) (value >> 40); _buffer[6] = (byte) (value >> 48); _buffer[7] = (byte) (value >> 56); OutStream.Write(_buffer, 0, 8); } // Writes a float to this stream. The current position of the stream is // advanced by four. // public unsafe virtual void Write(float value) { uint TmpValue = *(uint *)&value; _buffer[0] = (byte) TmpValue; _buffer[1] = (byte) (TmpValue >> 8); _buffer[2] = (byte) (TmpValue >> 16); _buffer[3] = (byte) (TmpValue >> 24); OutStream.Write(_buffer, 0, 4); } // Writes a length-prefixed string to this stream in the BinaryWriter's // current Encoding. This method first writes the length of the string as // a four-byte unsigned integer, and then writes that many characters // to the stream. // public unsafe virtual void Write(String value) { if (value==null) throw new ArgumentNullException(nameof(value)); Contract.EndContractBlock(); int len = _encoding.GetByteCount(value); Write7BitEncodedInt(len); if (_largeByteBuffer == null) { _largeByteBuffer = new byte[LargeByteBufferSize]; _maxChars = _largeByteBuffer.Length / _encoding.GetMaxByteCount(1); } if (len <= _largeByteBuffer.Length) { //Debug.Assert(len == _encoding.GetBytes(chars, 0, chars.Length, _largeByteBuffer, 0), "encoding's GetByteCount & GetBytes gave different answers! encoding type: "+_encoding.GetType().Name); _encoding.GetBytes(value, 0, value.Length, _largeByteBuffer, 0); OutStream.Write(_largeByteBuffer, 0, len); } else { // Aggressively try to not allocate memory in this loop for // runtime performance reasons. Use an Encoder to write out // the string correctly (handling surrogates crossing buffer // boundaries properly). int charStart = 0; int numLeft = value.Length; #if _DEBUG int totalBytes = 0; #endif while (numLeft > 0) { // Figure out how many chars to process this round. int charCount = (numLeft > _maxChars) ? _maxChars : numLeft; int byteLen; checked { if (charStart < 0 || charCount < 0 || charStart > value.Length - charCount) { throw new ArgumentOutOfRangeException(nameof(charCount)); } fixed (char* pChars = value) { fixed (byte* pBytes = &_largeByteBuffer[0]) { byteLen = _encoder.GetBytes(pChars + charStart, charCount, pBytes, _largeByteBuffer.Length, charCount == numLeft); } } } #if _DEBUG totalBytes += byteLen; Debug.Assert (totalBytes <= len && byteLen <= _largeByteBuffer.Length, "BinaryWriter::Write(String) - More bytes encoded than expected!"); #endif OutStream.Write(_largeByteBuffer, 0, byteLen); charStart += charCount; numLeft -= charCount; } #if _DEBUG Debug.Assert(totalBytes == len, "BinaryWriter::Write(String) - Didn't write out all the bytes!"); #endif } } protected void Write7BitEncodedInt(int value) { // Write out an int 7 bits at a time. The high bit of the byte, // when on, tells reader to continue reading more bytes. uint v = (uint) value; // support negative numbers while (v >= 0x80) { Write((byte) (v | 0x80)); v >>= 7; } Write((byte)v); } } }