csharp-sdk-upm/Libs/Newtonsoft.Json/Utilities/StringBuffer.cs

116 lines
3.5 KiB
C#

#region License
// Copyright (c) 2007 James Newton-King
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#endregion
using System;
namespace LC.Newtonsoft.Json.Utilities
{
/// <summary>
/// Builds a string. Unlike <see cref="System.Text.StringBuilder"/> this class lets you reuse its internal buffer.
/// </summary>
internal struct StringBuffer
{
private char[] _buffer;
private int _position;
public int Position
{
get => _position;
set => _position = value;
}
public bool IsEmpty => _buffer == null;
public StringBuffer(IArrayPool<char> bufferPool, int initalSize) : this(BufferUtils.RentBuffer(bufferPool, initalSize))
{
}
private StringBuffer(char[] buffer)
{
_buffer = buffer;
_position = 0;
}
public void Append(IArrayPool<char> bufferPool, char value)
{
// test if the buffer array is large enough to take the value
if (_position == _buffer.Length)
{
EnsureSize(bufferPool, 1);
}
// set value and increment poisition
_buffer[_position++] = value;
}
public void Append(IArrayPool<char> bufferPool, char[] buffer, int startIndex, int count)
{
if (_position + count >= _buffer.Length)
{
EnsureSize(bufferPool, count);
}
Array.Copy(buffer, startIndex, _buffer, _position, count);
_position += count;
}
public void Clear(IArrayPool<char> bufferPool)
{
if (_buffer != null)
{
BufferUtils.ReturnBuffer(bufferPool, _buffer);
_buffer = null;
}
_position = 0;
}
private void EnsureSize(IArrayPool<char> bufferPool, int appendLength)
{
char[] newBuffer = BufferUtils.RentBuffer(bufferPool, (_position + appendLength) * 2);
if (_buffer != null)
{
Array.Copy(_buffer, newBuffer, _position);
BufferUtils.ReturnBuffer(bufferPool, _buffer);
}
_buffer = newBuffer;
}
public override string ToString()
{
return ToString(0, _position);
}
public string ToString(int start, int length)
{
// TODO: validation
return new string(_buffer, start, length);
}
public char[] InternalBuffer => _buffer;
}
}