static internal Tuple <double, double> time_it_ns <T>(string[] lines, ParsingFunc sut, long repeat)
{
double average = 0;
double min_value = double.MaxValue;
// warmup
for (int i = 0; i != 100; i++)
{
sut(lines);
}
Stopwatch sw = new Stopwatch();
for (int i = 0; i != repeat; i++)
{
// ...;
sw.Restart();
sut(lines);
sw.Stop();
var dif = sw.ElapsedMilliseconds * 1000000;
average += dif;
min_value = min_value < dif ? min_value : dif;
}
average /= repeat;
return(new Tuple <double, double>(min_value, average));
}
public IEnumerable <T> ParseFile <T>(string path, ParsingFunc <T> lineParser)
{
using (var fileStream = new FileStream(FilePath, FileMode.Open, FileAccess.Read))
{
byte[] buffer = new byte[16000 * 8]; // 128 KB
int bytesRead = 0;
while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) > 0)
{
var slice = new ReadOnlySpan <byte>(buffer, start: 0, length: bytesRead); // bytesRead can be != buffer.Length
int newLineLength = 0;
while ((newLineLength = slice.IndexOf((byte)0x0A)) > 0) // 0x0A = new line
{
ReadOnlySpan <byte> utf8Line = slice.Slice(0, newLineLength);
yield return(lineParser(utf8Line));
slice = slice.Slice(start: newLineLength + 1);
}
fileStream.Seek(-1 * slice.Length, SeekOrigin.Current); // we go back to the line end
}
}
}
private static bool IsParseable <T>(string s, ParsingFunc <T> parsingFunc) where T : struct
{
T result = default(T);
if (parsingFunc(s, out result))
{
return(true);
}
return(false);
}
// Métodos auxiliares
private static T TryParse <T>(string s, ParsingFunc <T> parsingFunc, T defaultValue) where T : struct
{
T result = defaultValue;
if (parsingFunc(s, out result))
{
return(result);
}
return(defaultValue);
}
static internal Tuple <double, double, double> time_it_ns <T>(string[] lines, ParsingFunc sut, long repeat)
{
double average = 0;
double average_tpr = 0; // tick per run
double min_value = double.MaxValue;
// warmup
for (int i = 0; i != 250; i++)
{
sut(lines);
}
Stopwatch sw = new Stopwatch();
for (int i = 0; i != repeat; i++)
{
// ...;
sw.Restart();
sut(lines);
sw.Stop();
// NOTE : Elapsed.TotalMilliseconds (double) returns the total number of whole and fractional milliseconds elapsed since inception
// Elapsed.Milliseconds (int) returns the number of whole milliseconds in the current second => this is absolutely not what we need !
var dif = sw.Elapsed.TotalMilliseconds * 1000000;
average += dif;
average_tpr += sw.ElapsedTicks;
min_value = min_value < dif ? min_value : dif;
}
average /= repeat;
average_tpr /= repeat;
return(new Tuple <double, double, double>(min_value, average, average_tpr));
}
