public unsafe static void WriteNumeric(ref WritableBufferWriter buffer, ulong number)
{
const byte AsciiDigitStart = (byte)'0';
var span = buffer.Span;
var bytesLeftInBlock = span.Length;
// Fast path, try copying to the available memory directly
var simpleWrite = true;
fixed(byte *output = &span.DangerousGetPinnableReference())
{
var start = output;
if (number < 10 && bytesLeftInBlock >= 1)
{
*(start) = (byte)(((uint)number) + AsciiDigitStart);
buffer.Advance(1);
}
else if (number < 100 && bytesLeftInBlock >= 2)
{
var val = (uint)number;
var tens = (byte)((val * 205u) >> 11); // div10, valid to 1028
*(start) = (byte)(tens + AsciiDigitStart);
*(start + 1) = (byte)(val - (tens * 10) + AsciiDigitStart);
buffer.Advance(2);
}
else if (number < 1000 && bytesLeftInBlock >= 3)
{
var val = (uint)number;
var digit0 = (byte)((val * 41u) >> 12); // div100, valid to 1098
var digits01 = (byte)((val * 205u) >> 11); // div10, valid to 1028
*(start) = (byte)(digit0 + AsciiDigitStart);
*(start + 1) = (byte)(digits01 - (digit0 * 10) + AsciiDigitStart);
*(start + 2) = (byte)(val - (digits01 * 10) + AsciiDigitStart);
buffer.Advance(3);
}
else
{
simpleWrite = false;
}
}
if (!simpleWrite)
{
WriteNumericMultiWrite(ref buffer, number);
}
}
public unsafe static void WriteAsciiNoValidation(ref WritableBufferWriter buffer, string data)
{
if (string.IsNullOrEmpty(data))
{
return;
}
var dest = buffer.Span;
var destLength = dest.Length;
var sourceLength = data.Length;
// Fast path, try copying to the available memory directly
if (sourceLength <= destLength)
{
fixed(char *input = data)
fixed(byte *output = &dest.DangerousGetPinnableReference())
{
EncodeAsciiCharsToBytes(input, output, sourceLength);
}
buffer.Advance(sourceLength);
}
else
{
WriteAsciiMultiWrite(ref buffer, data);
}
}
private unsafe static void WriteAsciiMultiWrite(ref WritableBufferWriter buffer, string data)
{
var remaining = data.Length;
fixed(char *input = data)
{
var inputSlice = input;
while (remaining > 0)
{
var writable = Math.Min(remaining, buffer.Span.Length);
if (writable == 0)
{
buffer.Ensure();
continue;
}
fixed(byte *output = &buffer.Span.DangerousGetPinnableReference())
{
EncodeAsciiCharsToBytes(inputSlice, output, writable);
}
inputSlice += writable;
remaining -= writable;
buffer.Advance(writable);
}
}
}
