csharp/src/Google.Protobuf/CodedOutputStream.cs - third_party/github/protocolbuffers/protobuf - Git at Google

 #region Copyright notice and license
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
 //     * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endregion

 using Google.Protobuf.Collections;
 using System;
 using System.IO;
 using System.Security;
 using System.Text;

 namespace Google.Protobuf
 {
     /// <summary>
     /// Encodes and writes protocol message fields.
     /// </summary>
     /// <remarks>
     /// <para>
     /// This class is generally used by generated code to write appropriate
     /// primitives to the stream. It effectively encapsulates the lowest
     /// levels of protocol buffer format. Unlike some other implementations,
     /// this does not include combined "write tag and value" methods. Generated
     /// code knows the exact byte representations of the tags they're going to write,
     /// so there's no need to re-encode them each time. Manually-written code calling
     /// this class should just call one of the <c>WriteTag</c> overloads before each value.
     /// </para>
     /// <para>
     /// Repeated fields and map fields are not handled by this class; use <c>RepeatedField&lt;T&gt;</c>
     /// and <c>MapField&lt;TKey, TValue&gt;</c> to serialize such fields.
     /// </para>
     /// </remarks>
     [SecuritySafeCritical]
     public sealed partial class CodedOutputStream : IDisposable
     {
         /// <summary>
         /// The buffer size used by CreateInstance(Stream).
         /// </summary>
         public static readonly int DefaultBufferSize = 4096;

         private readonly bool leaveOpen;
         private readonly byte[] buffer;
         private WriterInternalState state;

         private readonly Stream output;

         #region Construction
         /// <summary>
         /// Creates a new CodedOutputStream that writes directly to the given
         /// byte array. If more bytes are written than fit in the array,
         /// OutOfSpaceException will be thrown.
         /// </summary>
         public CodedOutputStream(byte[] flatArray) : this(flatArray, 0, flatArray.Length)
         {
         }

         /// <summary>
         /// Creates a new CodedOutputStream that writes directly to the given
         /// byte array slice. If more bytes are written than fit in the array,
         /// OutOfSpaceException will be thrown.
         /// </summary>
         private CodedOutputStream(byte[] buffer, int offset, int length)
         {
             this.output = null;
             this.buffer = ProtoPreconditions.CheckNotNull(buffer, nameof(buffer));
             this.state.position = offset;
             this.state.limit = offset + length;
             WriteBufferHelper.Initialize(this, out this.state.writeBufferHelper);
             leaveOpen = true; // Simple way of avoiding trying to dispose of a null reference
         }

         private CodedOutputStream(Stream output, byte[] buffer, bool leaveOpen)
         {
             this.output = ProtoPreconditions.CheckNotNull(output, nameof(output));
             this.buffer = buffer;
             this.state.position = 0;
             this.state.limit = buffer.Length;
             WriteBufferHelper.Initialize(this, out this.state.writeBufferHelper);
             this.leaveOpen = leaveOpen;
         }

         /// <summary>
         /// Creates a new <see cref="CodedOutputStream" /> which write to the given stream, and disposes of that
         /// stream when the returned <c>CodedOutputStream</c> is disposed.
         /// </summary>
         /// <param name="output">The stream to write to. It will be disposed when the returned <c>CodedOutputStream is disposed.</c></param>
         public CodedOutputStream(Stream output) : this(output, DefaultBufferSize, false)
         {
         }

         /// <summary>
         /// Creates a new CodedOutputStream which write to the given stream and uses
         /// the specified buffer size.
         /// </summary>
         /// <param name="output">The stream to write to. It will be disposed when the returned <c>CodedOutputStream is disposed.</c></param>
         /// <param name="bufferSize">The size of buffer to use internally.</param>
         public CodedOutputStream(Stream output, int bufferSize) : this(output, new byte[bufferSize], false)
         {
         }

         /// <summary>
         /// Creates a new CodedOutputStream which write to the given stream.
         /// </summary>
         /// <param name="output">The stream to write to.</param>
         /// <param name="leaveOpen">If <c>true</c>, <paramref name="output"/> is left open when the returned <c>CodedOutputStream</c> is disposed;
         /// if <c>false</c>, the provided stream is disposed as well.</param>
         public CodedOutputStream(Stream output, bool leaveOpen) : this(output, DefaultBufferSize, leaveOpen)
         {
         }

         /// <summary>
         /// Creates a new CodedOutputStream which write to the given stream and uses
         /// the specified buffer size.
         /// </summary>
         /// <param name="output">The stream to write to.</param>
         /// <param name="bufferSize">The size of buffer to use internally.</param>
         /// <param name="leaveOpen">If <c>true</c>, <paramref name="output"/> is left open when the returned <c>CodedOutputStream</c> is disposed;
         /// if <c>false</c>, the provided stream is disposed as well.</param>
         public CodedOutputStream(Stream output, int bufferSize, bool leaveOpen) : this(output, new byte[bufferSize], leaveOpen)
         {
         }
         #endregion

         /// <summary>
         /// Returns the current position in the stream, or the position in the output buffer
         /// </summary>
         public long Position
         {
             get
             {
                 if (output != null)
                 {
                     return output.Position + state.position;
                 }
                 return state.position;
             }
         }

         #region Writing of values (not including tags)

         /// <summary>
         /// Writes a double field value, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteDouble(double value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteDouble(ref span, ref state, value);
         }

         /// <summary>
         /// Writes a float field value, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteFloat(float value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteFloat(ref span, ref state, value);
         }

         /// <summary>
         /// Writes a uint64 field value, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteUInt64(ulong value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteUInt64(ref span, ref state, value);
         }

         /// <summary>
         /// Writes an int64 field value, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteInt64(long value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteInt64(ref span, ref state, value);
         }

         /// <summary>
         /// Writes an int32 field value, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteInt32(int value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteInt32(ref span, ref state, value);
         }

         /// <summary>
         /// Writes a fixed64 field value, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteFixed64(ulong value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteFixed64(ref span, ref state, value);
         }

         /// <summary>
         /// Writes a fixed32 field value, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteFixed32(uint value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteFixed32(ref span, ref state, value);
         }

         /// <summary>
         /// Writes a bool field value, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteBool(bool value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteBool(ref span, ref state, value);
         }

         /// <summary>
         /// Writes a string field value, without a tag, to the stream.
         /// The data is length-prefixed.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteString(string value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteString(ref span, ref state, value);
         }

         /// <summary>
         /// Writes a message, without a tag, to the stream.
         /// The data is length-prefixed.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteMessage(IMessage value)
         {
             // TODO(jtattermusch): if the message doesn't implement IBufferMessage (and thus does not provide the InternalWriteTo method),
             // what we're doing here works fine, but could be more efficient.
             // For now, this inefficiency is fine, considering this is only a backward-compatibility scenario (and regenerating the code fixes it).
             var span = new Span<byte>(buffer);
             WriteContext.Initialize(ref span, ref state, out WriteContext ctx);
             try
             {
                 WritingPrimitivesMessages.WriteMessage(ref ctx, value);
             }
             finally
             {
                 ctx.CopyStateTo(this);
             }
         }

         /// <summary>
         /// Writes a message, without a tag, to the stream.
         /// Only the message data is written, without a length-delimiter.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteRawMessage(IMessage value)
         {
             // TODO(jtattermusch): if the message doesn't implement IBufferMessage (and thus does not provide the InternalWriteTo method),
             // what we're doing here works fine, but could be more efficient.
             // For now, this inefficiency is fine, considering this is only a backward-compatibility scenario (and regenerating the code fixes it).
             var span = new Span<byte>(buffer);
             WriteContext.Initialize(ref span, ref state, out WriteContext ctx);
             try
             {
                 WritingPrimitivesMessages.WriteRawMessage(ref ctx, value);
             }
             finally
             {
                 ctx.CopyStateTo(this);
             }
         }

         /// <summary>
         /// Writes a group, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteGroup(IMessage value)
         {
             var span = new Span<byte>(buffer);
             WriteContext.Initialize(ref span, ref state, out WriteContext ctx);
             try
             {
                 WritingPrimitivesMessages.WriteGroup(ref ctx, value);
             }
             finally
             {
                 ctx.CopyStateTo(this);
             }
         }

         /// <summary>
         /// Write a byte string, without a tag, to the stream.
         /// The data is length-prefixed.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteBytes(ByteString value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteBytes(ref span, ref state, value);
         }

         /// <summary>
         /// Writes a uint32 value, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteUInt32(uint value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteUInt32(ref span, ref state, value);
         }

         /// <summary>
         /// Writes an enum value, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteEnum(int value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteEnum(ref span, ref state, value);
         }

         /// <summary>
         /// Writes an sfixed32 value, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write.</param>
         public void WriteSFixed32(int value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteSFixed32(ref span, ref state, value);
         }

         /// <summary>
         /// Writes an sfixed64 value, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteSFixed64(long value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteSFixed64(ref span, ref state, value);
         }

         /// <summary>
         /// Writes an sint32 value, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteSInt32(int value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteSInt32(ref span, ref state, value);
         }

         /// <summary>
         /// Writes an sint64 value, without a tag, to the stream.
         /// </summary>
         /// <param name="value">The value to write</param>
         public void WriteSInt64(long value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteSInt64(ref span, ref state, value);
         }

         /// <summary>
         /// Writes a length (in bytes) for length-delimited data.
         /// </summary>
         /// <remarks>
         /// This method simply writes a rawint, but exists for clarity in calling code.
         /// </remarks>
         /// <param name="length">Length value, in bytes.</param>
         public void WriteLength(int length)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteLength(ref span, ref state, length);
         }

         #endregion

         #region Raw tag writing
         /// <summary>
         /// Encodes and writes a tag.
         /// </summary>
         /// <param name="fieldNumber">The number of the field to write the tag for</param>
         /// <param name="type">The wire format type of the tag to write</param>
         public void WriteTag(int fieldNumber, WireFormat.WireType type)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteTag(ref span, ref state, fieldNumber, type);
         }

         /// <summary>
         /// Writes an already-encoded tag.
         /// </summary>
         /// <param name="tag">The encoded tag</param>
         public void WriteTag(uint tag)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteTag(ref span, ref state, tag);
         }

         /// <summary>
         /// Writes the given single-byte tag directly to the stream.
         /// </summary>
         /// <param name="b1">The encoded tag</param>
         public void WriteRawTag(byte b1)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteRawTag(ref span, ref state, b1);
         }

         /// <summary>
         /// Writes the given two-byte tag directly to the stream.
         /// </summary>
         /// <param name="b1">The first byte of the encoded tag</param>
         /// <param name="b2">The second byte of the encoded tag</param>
         public void WriteRawTag(byte b1, byte b2)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteRawTag(ref span, ref state, b1, b2);
         }

         /// <summary>
         /// Writes the given three-byte tag directly to the stream.
         /// </summary>
         /// <param name="b1">The first byte of the encoded tag</param>
         /// <param name="b2">The second byte of the encoded tag</param>
         /// <param name="b3">The third byte of the encoded tag</param>
         public void WriteRawTag(byte b1, byte b2, byte b3)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteRawTag(ref span, ref state, b1, b2, b3);
         }

         /// <summary>
         /// Writes the given four-byte tag directly to the stream.
         /// </summary>
         /// <param name="b1">The first byte of the encoded tag</param>
         /// <param name="b2">The second byte of the encoded tag</param>
         /// <param name="b3">The third byte of the encoded tag</param>
         /// <param name="b4">The fourth byte of the encoded tag</param>
         public void WriteRawTag(byte b1, byte b2, byte b3, byte b4)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteRawTag(ref span, ref state, b1, b2, b3, b4);
         }

         /// <summary>
         /// Writes the given five-byte tag directly to the stream.
         /// </summary>
         /// <param name="b1">The first byte of the encoded tag</param>
         /// <param name="b2">The second byte of the encoded tag</param>
         /// <param name="b3">The third byte of the encoded tag</param>
         /// <param name="b4">The fourth byte of the encoded tag</param>
         /// <param name="b5">The fifth byte of the encoded tag</param>
         public void WriteRawTag(byte b1, byte b2, byte b3, byte b4, byte b5)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteRawTag(ref span, ref state, b1, b2, b3, b4, b5);
         }
         #endregion

         #region Underlying writing primitives

         /// <summary>
         /// Writes a 32 bit value as a varint. The fast route is taken when
         /// there's enough buffer space left to whizz through without checking
         /// for each byte; otherwise, we resort to calling WriteRawByte each time.
         /// </summary>
         internal void WriteRawVarint32(uint value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteRawVarint32(ref span, ref state, value);
         }

         internal void WriteRawVarint64(ulong value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteRawVarint64(ref span, ref state, value);
         }

         internal void WriteRawLittleEndian32(uint value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteRawLittleEndian32(ref span, ref state, value);
         }

         internal void WriteRawLittleEndian64(ulong value)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteRawLittleEndian64(ref span, ref state, value);
         }

         /// <summary>
         /// Writes out an array of bytes.
         /// </summary>
         internal void WriteRawBytes(byte[] value)
         {
             WriteRawBytes(value, 0, value.Length);
         }

         /// <summary>
         /// Writes out part of an array of bytes.
         /// </summary>
         internal void WriteRawBytes(byte[] value, int offset, int length)
         {
             var span = new Span<byte>(buffer);
             WritingPrimitives.WriteRawBytes(ref span, ref state, value, offset, length);
         }

         #endregion

         /// <summary>
         /// Indicates that a CodedOutputStream wrapping a flat byte array
         /// ran out of space.
         /// </summary>
         public sealed class OutOfSpaceException : IOException
         {
             internal OutOfSpaceException()
                 : base("CodedOutputStream was writing to a flat byte array and ran out of space.")
             {
             }
         }

         /// <summary>
         /// Flushes any buffered data and optionally closes the underlying stream, if any.
         /// </summary>
         /// <remarks>
         /// <para>
         /// By default, any underlying stream is closed by this method. To configure this behaviour,
         /// use a constructor overload with a <c>leaveOpen</c> parameter. If this instance does not
         /// have an underlying stream, this method does nothing.
         /// </para>
         /// <para>
         /// For the sake of efficiency, calling this method does not prevent future write calls - but
         /// if a later write ends up writing to a stream which has been disposed, that is likely to
         /// fail. It is recommend that you not call any other methods after this.
         /// </para>
         /// </remarks>
         public void Dispose()
         {
             Flush();
             if (!leaveOpen)
             {
                 output.Dispose();
             }
         }

         /// <summary>
         /// Flushes any buffered data to the underlying stream (if there is one).
         /// </summary>
         public void Flush()
         {
             var span = new Span<byte>(buffer);
             WriteBufferHelper.Flush(ref span, ref state);
         }

         /// <summary>
         /// Verifies that SpaceLeft returns zero. It's common to create a byte array
         /// that is exactly big enough to hold a message, then write to it with
         /// a CodedOutputStream. Calling CheckNoSpaceLeft after writing verifies that
         /// the message was actually as big as expected, which can help finding bugs.
         /// </summary>
         public void CheckNoSpaceLeft()
         {
             WriteBufferHelper.CheckNoSpaceLeft(ref state);
         }

         /// <summary>
         /// If writing to a flat array, returns the space left in the array. Otherwise,
         /// throws an InvalidOperationException.
         /// </summary>
         public int SpaceLeft => WriteBufferHelper.GetSpaceLeft(ref state);

         internal byte[] InternalBuffer => buffer;

         internal Stream InternalOutputStream => output;

         internal ref WriterInternalState InternalState => ref state;
     }
 }
	#region Copyright notice and license
	// Protocol Buffers - Google's data interchange format
	// Copyright 2008 Google Inc. All rights reserved.
	// https://developers.google.com/protocol-buffers/
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions are
	// met:
	//
	// * Redistributions of source code must retain the above copyright
	// notice, this list of conditions and the following disclaimer.
	// * Redistributions in binary form must reproduce the above
	// copyright notice, this list of conditions and the following disclaimer
	// in the documentation and/or other materials provided with the
	// distribution.
	// * Neither the name of Google Inc. nor the names of its
	// contributors may be used to endorse or promote products derived from
	// this software without specific prior written permission.
	//
	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	#endregion

	using Google.Protobuf.Collections;
	using System;
	using System.IO;
	using System.Security;
	using System.Text;

	namespace Google.Protobuf
	{
	/// <summary>
	/// Encodes and writes protocol message fields.
	/// </summary>
	/// <remarks>
	/// <para>
	/// This class is generally used by generated code to write appropriate
	/// primitives to the stream. It effectively encapsulates the lowest
	/// levels of protocol buffer format. Unlike some other implementations,
	/// this does not include combined "write tag and value" methods. Generated
	/// code knows the exact byte representations of the tags they're going to write,
	/// so there's no need to re-encode them each time. Manually-written code calling
	/// this class should just call one of the <c>WriteTag</c> overloads before each value.
	/// </para>
	/// <para>
	/// Repeated fields and map fields are not handled by this class; use <c>RepeatedField<T></c>
	/// and <c>MapField<TKey, TValue></c> to serialize such fields.
	/// </para>
	/// </remarks>
	[SecuritySafeCritical]
	public sealed partial class CodedOutputStream : IDisposable
	{
	/// <summary>
	/// The buffer size used by CreateInstance(Stream).
	/// </summary>
	public static readonly int DefaultBufferSize = 4096;

	private readonly bool leaveOpen;
	private readonly byte[] buffer;
	private WriterInternalState state;

	private readonly Stream output;

	#region Construction
	/// <summary>
	/// Creates a new CodedOutputStream that writes directly to the given
	/// byte array. If more bytes are written than fit in the array,
	/// OutOfSpaceException will be thrown.
	/// </summary>
	public CodedOutputStream(byte[] flatArray) : this(flatArray, 0, flatArray.Length)
	{
	}

	/// <summary>
	/// Creates a new CodedOutputStream that writes directly to the given
	/// byte array slice. If more bytes are written than fit in the array,
	/// OutOfSpaceException will be thrown.
	/// </summary>
	private CodedOutputStream(byte[] buffer, int offset, int length)
	{
	this.output = null;
	this.buffer = ProtoPreconditions.CheckNotNull(buffer, nameof(buffer));
	this.state.position = offset;
	this.state.limit = offset + length;
	WriteBufferHelper.Initialize(this, out this.state.writeBufferHelper);
	leaveOpen = true; // Simple way of avoiding trying to dispose of a null reference
	}

	private CodedOutputStream(Stream output, byte[] buffer, bool leaveOpen)
	{
	this.output = ProtoPreconditions.CheckNotNull(output, nameof(output));
	this.buffer = buffer;
	this.state.position = 0;
	this.state.limit = buffer.Length;
	WriteBufferHelper.Initialize(this, out this.state.writeBufferHelper);
	this.leaveOpen = leaveOpen;
	}

	/// <summary>
	/// Creates a new <see cref="CodedOutputStream" /> which write to the given stream, and disposes of that
	/// stream when the returned <c>CodedOutputStream</c> is disposed.
	/// </summary>
	/// <param name="output">The stream to write to. It will be disposed when the returned <c>CodedOutputStream is disposed.</c></param>
	public CodedOutputStream(Stream output) : this(output, DefaultBufferSize, false)
	{
	}

	/// <summary>
	/// Creates a new CodedOutputStream which write to the given stream and uses
	/// the specified buffer size.
	/// </summary>
	/// <param name="output">The stream to write to. It will be disposed when the returned <c>CodedOutputStream is disposed.</c></param>
	/// <param name="bufferSize">The size of buffer to use internally.</param>
	public CodedOutputStream(Stream output, int bufferSize) : this(output, new byte[bufferSize], false)
	{
	}

	/// <summary>
	/// Creates a new CodedOutputStream which write to the given stream.
	/// </summary>
	/// <param name="output">The stream to write to.</param>
	/// <param name="leaveOpen">If <c>true</c>, <paramref name="output"/> is left open when the returned <c>CodedOutputStream</c> is disposed;
	/// if <c>false</c>, the provided stream is disposed as well.</param>
	public CodedOutputStream(Stream output, bool leaveOpen) : this(output, DefaultBufferSize, leaveOpen)
	{
	}

	/// <summary>
	/// Creates a new CodedOutputStream which write to the given stream and uses
	/// the specified buffer size.
	/// </summary>
	/// <param name="output">The stream to write to.</param>
	/// <param name="bufferSize">The size of buffer to use internally.</param>
	/// <param name="leaveOpen">If <c>true</c>, <paramref name="output"/> is left open when the returned <c>CodedOutputStream</c> is disposed;
	/// if <c>false</c>, the provided stream is disposed as well.</param>
	public CodedOutputStream(Stream output, int bufferSize, bool leaveOpen) : this(output, new byte[bufferSize], leaveOpen)
	{
	}
	#endregion

	/// <summary>
	/// Returns the current position in the stream, or the position in the output buffer
	/// </summary>
	public long Position
	{
	get
	{
	if (output != null)
	{
	return output.Position + state.position;
	}
	return state.position;
	}
	}

	#region Writing of values (not including tags)

	/// <summary>
	/// Writes a double field value, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteDouble(double value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteDouble(ref span, ref state, value);
	}

	/// <summary>
	/// Writes a float field value, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteFloat(float value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteFloat(ref span, ref state, value);
	}

	/// <summary>
	/// Writes a uint64 field value, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteUInt64(ulong value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteUInt64(ref span, ref state, value);
	}

	/// <summary>
	/// Writes an int64 field value, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteInt64(long value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteInt64(ref span, ref state, value);
	}

	/// <summary>
	/// Writes an int32 field value, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteInt32(int value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteInt32(ref span, ref state, value);
	}

	/// <summary>
	/// Writes a fixed64 field value, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteFixed64(ulong value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteFixed64(ref span, ref state, value);
	}

	/// <summary>
	/// Writes a fixed32 field value, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteFixed32(uint value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteFixed32(ref span, ref state, value);
	}

	/// <summary>
	/// Writes a bool field value, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteBool(bool value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteBool(ref span, ref state, value);
	}

	/// <summary>
	/// Writes a string field value, without a tag, to the stream.
	/// The data is length-prefixed.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteString(string value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteString(ref span, ref state, value);
	}

	/// <summary>
	/// Writes a message, without a tag, to the stream.
	/// The data is length-prefixed.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteMessage(IMessage value)
	{
	// TODO(jtattermusch): if the message doesn't implement IBufferMessage (and thus does not provide the InternalWriteTo method),
	// what we're doing here works fine, but could be more efficient.
	// For now, this inefficiency is fine, considering this is only a backward-compatibility scenario (and regenerating the code fixes it).
	var span = new Span<byte>(buffer);
	WriteContext.Initialize(ref span, ref state, out WriteContext ctx);
	try
	{
	WritingPrimitivesMessages.WriteMessage(ref ctx, value);
	}
	finally
	{
	ctx.CopyStateTo(this);
	}
	}

	/// <summary>
	/// Writes a message, without a tag, to the stream.
	/// Only the message data is written, without a length-delimiter.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteRawMessage(IMessage value)
	{
	// TODO(jtattermusch): if the message doesn't implement IBufferMessage (and thus does not provide the InternalWriteTo method),
	// what we're doing here works fine, but could be more efficient.
	// For now, this inefficiency is fine, considering this is only a backward-compatibility scenario (and regenerating the code fixes it).
	var span = new Span<byte>(buffer);
	WriteContext.Initialize(ref span, ref state, out WriteContext ctx);
	try
	{
	WritingPrimitivesMessages.WriteRawMessage(ref ctx, value);
	}
	finally
	{
	ctx.CopyStateTo(this);
	}
	}

	/// <summary>
	/// Writes a group, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteGroup(IMessage value)
	{
	var span = new Span<byte>(buffer);
	WriteContext.Initialize(ref span, ref state, out WriteContext ctx);
	try
	{
	WritingPrimitivesMessages.WriteGroup(ref ctx, value);
	}
	finally
	{
	ctx.CopyStateTo(this);
	}
	}

	/// <summary>
	/// Write a byte string, without a tag, to the stream.
	/// The data is length-prefixed.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteBytes(ByteString value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteBytes(ref span, ref state, value);
	}

	/// <summary>
	/// Writes a uint32 value, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteUInt32(uint value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteUInt32(ref span, ref state, value);
	}

	/// <summary>
	/// Writes an enum value, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteEnum(int value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteEnum(ref span, ref state, value);
	}

	/// <summary>
	/// Writes an sfixed32 value, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write.</param>
	public void WriteSFixed32(int value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteSFixed32(ref span, ref state, value);
	}

	/// <summary>
	/// Writes an sfixed64 value, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteSFixed64(long value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteSFixed64(ref span, ref state, value);
	}

	/// <summary>
	/// Writes an sint32 value, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteSInt32(int value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteSInt32(ref span, ref state, value);
	}

	/// <summary>
	/// Writes an sint64 value, without a tag, to the stream.
	/// </summary>
	/// <param name="value">The value to write</param>
	public void WriteSInt64(long value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteSInt64(ref span, ref state, value);
	}

	/// <summary>
	/// Writes a length (in bytes) for length-delimited data.
	/// </summary>
	/// <remarks>
	/// This method simply writes a rawint, but exists for clarity in calling code.
	/// </remarks>
	/// <param name="length">Length value, in bytes.</param>
	public void WriteLength(int length)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteLength(ref span, ref state, length);
	}

	#endregion

	#region Raw tag writing
	/// <summary>
	/// Encodes and writes a tag.
	/// </summary>
	/// <param name="fieldNumber">The number of the field to write the tag for</param>
	/// <param name="type">The wire format type of the tag to write</param>
	public void WriteTag(int fieldNumber, WireFormat.WireType type)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteTag(ref span, ref state, fieldNumber, type);
	}

	/// <summary>
	/// Writes an already-encoded tag.
	/// </summary>
	/// <param name="tag">The encoded tag</param>
	public void WriteTag(uint tag)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteTag(ref span, ref state, tag);
	}

	/// <summary>
	/// Writes the given single-byte tag directly to the stream.
	/// </summary>
	/// <param name="b1">The encoded tag</param>
	public void WriteRawTag(byte b1)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteRawTag(ref span, ref state, b1);
	}

	/// <summary>
	/// Writes the given two-byte tag directly to the stream.
	/// </summary>
	/// <param name="b1">The first byte of the encoded tag</param>
	/// <param name="b2">The second byte of the encoded tag</param>
	public void WriteRawTag(byte b1, byte b2)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteRawTag(ref span, ref state, b1, b2);
	}

	/// <summary>
	/// Writes the given three-byte tag directly to the stream.
	/// </summary>
	/// <param name="b1">The first byte of the encoded tag</param>
	/// <param name="b2">The second byte of the encoded tag</param>
	/// <param name="b3">The third byte of the encoded tag</param>
	public void WriteRawTag(byte b1, byte b2, byte b3)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteRawTag(ref span, ref state, b1, b2, b3);
	}

	/// <summary>
	/// Writes the given four-byte tag directly to the stream.
	/// </summary>
	/// <param name="b1">The first byte of the encoded tag</param>
	/// <param name="b2">The second byte of the encoded tag</param>
	/// <param name="b3">The third byte of the encoded tag</param>
	/// <param name="b4">The fourth byte of the encoded tag</param>
	public void WriteRawTag(byte b1, byte b2, byte b3, byte b4)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteRawTag(ref span, ref state, b1, b2, b3, b4);
	}

	/// <summary>
	/// Writes the given five-byte tag directly to the stream.
	/// </summary>
	/// <param name="b1">The first byte of the encoded tag</param>
	/// <param name="b2">The second byte of the encoded tag</param>
	/// <param name="b3">The third byte of the encoded tag</param>
	/// <param name="b4">The fourth byte of the encoded tag</param>
	/// <param name="b5">The fifth byte of the encoded tag</param>
	public void WriteRawTag(byte b1, byte b2, byte b3, byte b4, byte b5)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteRawTag(ref span, ref state, b1, b2, b3, b4, b5);
	}
	#endregion

	#region Underlying writing primitives

	/// <summary>
	/// Writes a 32 bit value as a varint. The fast route is taken when
	/// there's enough buffer space left to whizz through without checking
	/// for each byte; otherwise, we resort to calling WriteRawByte each time.
	/// </summary>
	internal void WriteRawVarint32(uint value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteRawVarint32(ref span, ref state, value);
	}

	internal void WriteRawVarint64(ulong value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteRawVarint64(ref span, ref state, value);
	}

	internal void WriteRawLittleEndian32(uint value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteRawLittleEndian32(ref span, ref state, value);
	}

	internal void WriteRawLittleEndian64(ulong value)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteRawLittleEndian64(ref span, ref state, value);
	}

	/// <summary>
	/// Writes out an array of bytes.
	/// </summary>
	internal void WriteRawBytes(byte[] value)
	{
	WriteRawBytes(value, 0, value.Length);
	}

	/// <summary>
	/// Writes out part of an array of bytes.
	/// </summary>
	internal void WriteRawBytes(byte[] value, int offset, int length)
	{
	var span = new Span<byte>(buffer);
	WritingPrimitives.WriteRawBytes(ref span, ref state, value, offset, length);
	}

	#endregion

	/// <summary>
	/// Indicates that a CodedOutputStream wrapping a flat byte array
	/// ran out of space.
	/// </summary>
	public sealed class OutOfSpaceException : IOException
	{
	internal OutOfSpaceException()
	: base("CodedOutputStream was writing to a flat byte array and ran out of space.")
	{
	}
	}

	/// <summary>
	/// Flushes any buffered data and optionally closes the underlying stream, if any.
	/// </summary>
	/// <remarks>
	/// <para>
	/// By default, any underlying stream is closed by this method. To configure this behaviour,
	/// use a constructor overload with a <c>leaveOpen</c> parameter. If this instance does not
	/// have an underlying stream, this method does nothing.
	/// </para>
	/// <para>
	/// For the sake of efficiency, calling this method does not prevent future write calls - but
	/// if a later write ends up writing to a stream which has been disposed, that is likely to
	/// fail. It is recommend that you not call any other methods after this.
	/// </para>
	/// </remarks>
	public void Dispose()
	{
	Flush();
	if (!leaveOpen)
	{
	output.Dispose();
	}
	}

	/// <summary>
	/// Flushes any buffered data to the underlying stream (if there is one).
	/// </summary>
	public void Flush()
	{
	var span = new Span<byte>(buffer);
	WriteBufferHelper.Flush(ref span, ref state);
	}

	/// <summary>
	/// Verifies that SpaceLeft returns zero. It's common to create a byte array
	/// that is exactly big enough to hold a message, then write to it with
	/// a CodedOutputStream. Calling CheckNoSpaceLeft after writing verifies that
	/// the message was actually as big as expected, which can help finding bugs.
	/// </summary>
	public void CheckNoSpaceLeft()
	{
	WriteBufferHelper.CheckNoSpaceLeft(ref state);
	}

	/// <summary>
	/// If writing to a flat array, returns the space left in the array. Otherwise,
	/// throws an InvalidOperationException.
	/// </summary>
	public int SpaceLeft => WriteBufferHelper.GetSpaceLeft(ref state);

	internal byte[] InternalBuffer => buffer;

	internal Stream InternalOutputStream => output;

	internal ref WriterInternalState InternalState => ref state;
	}
	}