精简版StringBuilder,提速字符串拼接 QuickStringWriter完整代码

using System;
using System.Collections.Generic;
using System.Text;

namespace blqw
{
public class QuickStringWriter : IDisposable
{
public QuickStringWriter() : this(2048) { }
/// <summary>
/// 实例化新的对象,并且指定初始容量
/// </summary>
/// <param name="capacity"></param>
public QuickStringWriter(int capacity)
{
NumberBuff = new Char[64];
Buff = new Char[capacity];
}

//设置缓冲区容量
void SetCapacity(int capacity)
{
if (capacity > Buff.Length)
{
if (capacity > 6000 * 10000)   //6000W
{
throw new OutOfMemoryException("QuickStringWriter容量不能超过6000万个字符");
}
}
var newbuff = new char[capacity];
Array.Copy(Buff, 0, newbuff, 0, Math.Min(Position, capacity));
Buff = newbuff;
Position = Math.Min(Position, Buff.Length);
}
//当容量不足的时候,尝试翻倍空间
void ToDouble()
{
SetCapacity(Math.Min(Buff.Length * 2, 10 * 10000));
}

Char[] NumberBuff;
Char[] Buff;
int Position;

public void Dispose()
{
NumberBuff = null;
Buff = null;
}

public QuickStringWriter Append(Boolean val)
{
if (val)
{
Check(4);
Buff[Position++] = 't';
Buff[Position++] = 'r';
Buff[Position++] = 'u';
Buff[Position++] = 'e';
}
else
{
Check(5);
Buff[Position++] = 'f';
Buff[Position++] = 'a';
Buff[Position++] = 'l';
Buff[Position++] = 's';
Buff[Position++] = 'e';
}
return this;
}
public QuickStringWriter Append(DateTime val)
{
Check(18);
if (val.Year < 1000)
{
Buff[Position++] = '0';
if (val.Year < 100)
{
Buff[Position++] = '0';
if (val.Year < 10)
{
Buff[Position++] = '0';
}
}
}
Append((long)val.Year);
Buff[Position++] = '-';

if (val.Month < 10)
{
Buff[Position++] = '0';
}
Append((long)val.Month);
Buff[Position++] = '-';

if (val.Day < 10)
{
Buff[Position++] = '0';
}
Append((long)val.Day);
Buff[Position++] = ' ';

if (val.Hour < 10)
{
Buff[Position++] = '0';
}
Append((long)val.Hour);
Buff[Position++] = ':';

if (val.Minute < 10)
{
Buff[Position++] = '0';
}
Append((long)val.Minute);
Buff[Position++] = ':';

if (val.Second < 10)
{
Buff[Position++] = '0';
}
Append((long)val.Minute);
return this;
}

public QuickStringWriter Append(Guid val)
{
Append(val.ToString());
return this;
}

public QuickStringWriter Append(DateTime val, string format)
{

Append(val.ToString(format));
return this;
}
public QuickStringWriter Append(Guid val, string format)
{
Append(val.ToString(format));
return this;
}

public QuickStringWriter Append(Decimal val)
{
Append(val.ToString());
return this;
}
public QuickStringWriter Append(Double val)
{
Append(Convert.ToString(val));
return this;
}
public QuickStringWriter Append(Single val)
{
Append(Convert.ToString(val));
return this;
}

public QuickStringWriter Append(SByte val)
{
Append((Int64)val);
return this;
}
public QuickStringWriter Append(Int16 val)
{
Append((Int64)val);
return this;
}
public QuickStringWriter Append(Int32 val)
{
Append((Int64)val);
return this;
}

public override string ToString()
{
return new string(Buff, 0, Position);
}

public QuickStringWriter Append(Int64 val)
{
if (val == 0)
{
Buff[Position++] = '0';
return this;
}

var pos = 63;
if (val < 0)
{
Buff[Position++] = '-';
NumberBuff[pos] = (char)(~(val % 10) + '1');
if (val < -10)
{
val = val / -10;
NumberBuff[--pos] = (char)(val % 10 + '0');
}
}
else
{
NumberBuff[pos] = (char)(val % 10 + '0');
}
while ((val = val / 10L) != 0L)
{
NumberBuff[--pos] = (char)(val % 10L + '0');
}
var length = 64 - pos;
Check(length);
Array.Copy(NumberBuff, pos, Buff, Position, length);
Position += length;
return this;
}
public QuickStringWriter Append(Char val)
{
Try();
Buff[Position++] = val;
return this;
}
public QuickStringWriter Append(String val)
{
if (val == null || val.Length == 0)
{
return this;
}
else if (val.Length <= 3)
{
Check(val.Length);
Buff[Position++] = val[0];
if (val.Length > 1)
{
Buff[Position++] = val[1];
if (val.Length > 2)
{
Buff[Position++] = val[2];
}
}
}
else
{
Check(val.Length);
val.CopyTo(0, Buff, Position, val.Length);
Position += val.Length;
}
return this;
}

public QuickStringWriter Append(Byte val)
{
Append((UInt64)val);
return this;
}
public QuickStringWriter Append(UInt16 val)
{
Append((UInt64)val);
return this;
}
public QuickStringWriter Append(UInt32 val)
{
Append((UInt64)val);
return this;
}
public QuickStringWriter Append(UInt64 val)
{
if (val == 0)
{
Buff[Position++] = '0';
return this;
}
var pos = 63;

NumberBuff[pos] = (char)(val % 10 + '0');

while ((val = val / 10L) != 0L)
{
NumberBuff[--pos] = (char)(val % 10L + '0');
}
var length = 64 - pos;
Check(length);
Array.Copy(NumberBuff, pos, Buff, Position, length);
Position += length;
return this;
}

public QuickStringWriter Clear()
{
Position = 0;
return this;
}

//当容量不足的时候,尝试翻倍空间
void Try()
{
if (Position >= Buff.Length)
{
ToDouble();
}
}
//测试剩余空间大小,如果不足,则扩展至可用大小后再翻倍
void Check(int count)
{
var pre = Position + count;
if (pre >= Buff.Length)
{
SetCapacity(pre * 2);
}
}

}
}