#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.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>
public sealed partial class CodedOutputStream : IDisposable
{
// "Local" copy of Encoding.UTF8, for efficiency. (Yes, it makes a difference.)
internal static readonly Encoding Utf8Encoding = Encoding.UTF8;
/// <summary>
/// The buffer size used by CreateInstance(Stream).
/// </summary>
public static readonly int DefaultBufferSize = 4096;
private readonly bool leaveOpen;
private readonly byte[] buffer;
private readonly int limit;
private int position;
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 = buffer;
this.position = offset;
this.limit = offset + length;
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.position = 0;
this.limit = buffer.Length;
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 + position;
}
return 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)
{
WriteRawLittleEndian64((ulong)BitConverter.DoubleToInt64Bits(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)
{
byte[] rawBytes = BitConverter.GetBytes(value);
if (!BitConverter.IsLittleEndian)
{
ByteArray.Reverse(rawBytes);
}
if (limit - position >= 4)
{
buffer[position++] = rawBytes[0];
buffer[position++] = rawBytes[1];
buffer[position++] = rawBytes[2];
buffer[position++] = rawBytes[3];
}
else
{
WriteRawBytes(rawBytes, 0, 4);
}
}
/// <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)
{
WriteRawVarint64(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)
{
WriteRawVarint64((ulong) 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)
{
if (value >= 0)
{
WriteRawVarint32((uint) value);
}
else
{
// Must sign-extend.
WriteRawVarint64((ulong) 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)
{
WriteRawLittleEndian64(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)
{
WriteRawLittleEndian32(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)
{
WriteRawByte(value ? (byte) 1 : (byte) 0);
}
/// <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)
{
// Optimise the case where we have enough space to write
// the string directly to the buffer, which should be common.
int length = Utf8Encoding.GetByteCount(value);
WriteLength(length);
if (limit - position >= length)
{
if (length == value.Length) // Must be all ASCII...
{
for (int i = 0; i < length; i++)
{
buffer[position + i] = (byte)value[i];
}
}
else
{
Utf8Encoding.GetBytes(value, 0, value.Length, buffer, position);
}
position += length;
}
else
{
byte[] bytes = Utf8Encoding.GetBytes(value);
WriteRawBytes(bytes);
}
}
/// <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)
{
WriteLength(value.CalculateSize());
value.WriteTo(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)
{
WriteLength(value.Length);
value.WriteRawBytesTo(this);
}
/// <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)
{
WriteRawVarint32(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)
{
WriteInt32(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)
{
WriteRawLittleEndian32((uint) 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)
{
WriteRawLittleEndian64((ulong) 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)
{
WriteRawVarint32(EncodeZigZag32(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)
{
WriteRawVarint64(EncodeZigZag64(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)
{
WriteRawVarint32((uint) 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)
{
WriteRawVarint32(WireFormat.MakeTag(fieldNumber, type));
}
/// <summary>
/// Writes an already-encoded tag.
/// </summary>
/// <param name="tag">The encoded tag</param>
public void WriteTag(uint tag)
{
WriteRawVarint32(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)
{
WriteRawByte(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)
{
WriteRawByte(b1);
WriteRawByte(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)
{
WriteRawByte(b1);
WriteRawByte(b2);
WriteRawByte(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)
{
WriteRawByte(b1);
WriteRawByte(b2);
WriteRawByte(b3);
WriteRawByte(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)
{
WriteRawByte(b1);
WriteRawByte(b2);
WriteRawByte(b3);
WriteRawByte(b4);
WriteRawByte(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)
{
// Optimize for the common case of a single byte value
if (value < 128 && position < limit)
{
buffer[position++] = (byte)value;
return;
}
while (value > 127 && position < limit)
{
buffer[position++] = (byte) ((value & 0x7F) | 0x80);
value >>= 7;
}
while (value > 127)
{
WriteRawByte((byte) ((value & 0x7F) | 0x80));
value >>= 7;
}
if (position < limit)
{
buffer[position++] = (byte) value;
}
else
{
WriteRawByte((byte) value);
}
}
internal void WriteRawVarint64(ulong value)
{
while (value > 127 && position < limit)
{
buffer[position++] = (byte) ((value & 0x7F) | 0x80);
value >>= 7;
}
while (value > 127)
{
WriteRawByte((byte) ((value & 0x7F) | 0x80));
value >>= 7;
}
if (position < limit)
{
buffer[position++] = (byte) value;
}
else
{
WriteRawByte((byte) value);
}
}
internal void WriteRawLittleEndian32(uint value)
{
if (position + 4 > limit)
{
WriteRawByte((byte) value);
WriteRawByte((byte) (value >> 8));
WriteRawByte((byte) (value >> 16));
WriteRawByte((byte) (value >> 24));
}
else
{
buffer[position++] = ((byte) value);
buffer[position++] = ((byte) (value >> 8));
buffer[position++] = ((byte) (value >> 16));
buffer[position++] = ((byte) (value >> 24));
}
}
internal void WriteRawLittleEndian64(ulong value)
{
if (position + 8 > limit)
{
WriteRawByte((byte) value);
WriteRawByte((byte) (value >> 8));
WriteRawByte((byte) (value >> 16));
WriteRawByte((byte) (value >> 24));
WriteRawByte((byte) (value >> 32));
WriteRawByte((byte) (value >> 40));
WriteRawByte((byte) (value >> 48));
WriteRawByte((byte) (value >> 56));
}
else
{
buffer[position++] = ((byte) value);
buffer[position++] = ((byte) (value >> 8));
buffer[position++] = ((byte) (value >> 16));
buffer[position++] = ((byte) (value >> 24));
buffer[position++] = ((byte) (value >> 32));
buffer[position++] = ((byte) (value >> 40));
buffer[position++] = ((byte) (value >> 48));
buffer[position++] = ((byte) (value >> 56));
}
}
internal void WriteRawByte(byte value)
{
if (position == limit)
{
RefreshBuffer();
}
buffer[position++] = value;
}
internal void WriteRawByte(uint value)
{
WriteRawByte((byte) 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)
{
if (limit - position >= length)
{
ByteArray.Copy(value, offset, buffer, position, length);
// We have room in the current buffer.
position += length;
}
else
{
// Write extends past current buffer. Fill the rest of this buffer and
// flush.
int bytesWritten = limit - position;
ByteArray.Copy(value, offset, buffer, position, bytesWritten);
offset += bytesWritten;
length -= bytesWritten;
position = limit;
RefreshBuffer();
// Now deal with the rest.
// Since we have an output stream, this is our buffer
// and buffer offset == 0
if (length <= limit)
{
// Fits in new buffer.
ByteArray.Copy(value, offset, buffer, 0, length);
position = length;
}
else
{
// Write is very big. Let's do it all at once.
output.Write(value, offset, length);
}
}
}
#endregion
/// <summary>
/// Encode a 32-bit value with ZigZag encoding.
/// </summary>
/// <remarks>
/// ZigZag encodes signed integers into values that can be efficiently
/// encoded with varint. (Otherwise, negative values must be
/// sign-extended to 64 bits to be varint encoded, thus always taking
/// 10 bytes on the wire.)
/// </remarks>
internal static uint EncodeZigZag32(int n)
{
// Note: the right-shift must be arithmetic
return (uint) ((n << 1) ^ (n >> 31));
}
/// <summary>
/// Encode a 64-bit value with ZigZag encoding.
/// </summary>
/// <remarks>
/// ZigZag encodes signed integers into values that can be efficiently
/// encoded with varint. (Otherwise, negative values must be
/// sign-extended to 64 bits to be varint encoded, thus always taking
/// 10 bytes on the wire.)
/// </remarks>
internal static ulong EncodeZigZag64(long n)
{
return (ulong) ((n << 1) ^ (n >> 63));
}
private void RefreshBuffer()
{
if (output == null)
{
// We're writing to a single buffer.
throw new OutOfSpaceException();
}
// Since we have an output stream, this is our buffer
// and buffer offset == 0
output.Write(buffer, 0, position);
position = 0;
}
/// <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()
{
if (output != null)
{
RefreshBuffer();
}
}
/// <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 bugs.
/// </summary>
public void CheckNoSpaceLeft()
{
if (SpaceLeft != 0)
{
throw new InvalidOperationException("Did not write as much data as expected.");
}
}
/// <summary>
/// If writing to a flat array, returns the space left in the array. Otherwise,
/// throws an InvalidOperationException.
/// </summary>
public int SpaceLeft
{
get
{
if (output == null)
{
return limit - position;
}
else
{
throw new InvalidOperationException(
"SpaceLeft can only be called on CodedOutputStreams that are " +
"writing to a flat array.");
}
}
}
}
}