/// <summary>
/// Writes the character or surrogate pair for the given code point into the buffer.
/// </summary>
/// <param name="buffer">The buffer into which to write the character(s). This
/// may be reallocated if there is not enough space.</param>
/// <param name="position">The position in <paramref name="buffer"/> into which to
/// write the character(s). The number of characters written will be added.</param>
/// <param name="value">A Unicode code point value.</param>
private static void _writeCodePoint(ref char[] buffer, ref int position, int value)
{
if (buffer.Length - position < 2)
{
DataStructureUtil.expandArray(ref buffer, 2);
}
if (value > 0xFFFF)
{
// Split into surrogate pairs.
int offsetValue = value - 0x10000;
buffer[position] = (char)(0xD800 | (offsetValue >> 10));
buffer[position + 1] = (char)(0xDC00 | (offsetValue & 0x3FF));
position += 2;
}
else
{
buffer[position] = (char)value;
position++;
}
}
public static string escape(string str = "undefined")
{
if (str == null)
{
return("null");
}
int strlen = str.Length;
char[] buffer = new char[strlen];
int bufPos = 0, bufLen = 0;
for (int i = 0; i < str.Length; i++)
{
char ch = str[i];
bool noEncode =
((uint)(ch - '0') <= 9) ||
((uint)(ch - 'A') <= 25) ||
((uint)(ch - 'a') <= 25) ||
(ch <= 0x7F && ESCAPE_NO_ENCODE.Contains(ch));
if (noEncode)
{
// No percent encoding
if (bufPos == bufLen)
{
DataStructureUtil.expandArray(ref buffer);
bufLen = buffer.Length;
}
buffer[bufPos++] = ch;
continue;
}
if (ch > 0xFF)
{
if (bufLen - bufPos < 6)
{
DataStructureUtil.expandArray(ref buffer, 6);
bufLen = buffer.Length;
}
var bufferSpan = buffer.AsSpan(6);
bufferSpan[0] = '%';
bufferSpan[1] = 'u';
URIUtil.byteToHex((byte)(ch >> 8), bufferSpan.Slice(2));
URIUtil.byteToHex((byte)ch, bufferSpan.Slice(4));
bufPos += 6;
}
else
{
if (bufLen - bufPos < 3)
{
DataStructureUtil.expandArray(ref buffer, 3);
bufLen = buffer.Length;
}
buffer[bufPos] = '%';
URIUtil.byteToHex((byte)ch, buffer.AsSpan(bufPos + 1));
bufPos += 3;
}
}
return(new string(buffer, 0, bufPos));
}
