Ascii Bytes Array To Int32 or Double
- by Michael Covelli
I'm re-writing alibrary with a mandate to make it totally allocation free. The goal is to have 0 collections after the app's startup phase is done.
Previously, there were a lot of calls like this:
Int32 foo = Int32.Parse(ASCIIEncoding.ASCII.GetString(bytes, start, length));
Which I believe is allocating a string. I couldn't find a C# library function that would do the same thing automatically. I looked at the BitConverter class, but it looks like that is only if your Int32 is encoded with the actual bytes that represent it. Here, I have an array of bytes representing Ascii characters that represent an Int32.
Here's what I did
public static Int32 AsciiBytesToInt32(byte[] bytes, int start, int length)
{
Int32 Temp = 0;
Int32 Result = 0;
Int32 j = 1;
for (int i = start + length - 1; i >= start; i--)
{
Temp = ((Int32)bytes[i]) - 48;
if (Temp < 0 || Temp > 9)
{
throw new Exception("Bytes In AsciiBytesToInt32 Are Not An Int32");
}
Result += Temp * j;
j *= 10;
}
return Result;
}
Does anyone know of a C# library function that already does this in a more optimal way? Or an improvement to make the above run faster (its going to be called millions of times during the day probably). Thanks!
