Re: Improving IO Speed

[flamencofantasy via Digitalmars-d-learn]

Try this;

import std.mmfile;
scope mmFile = new MmFile("T201212A.IDX");

TaqIdx* arr = cast(TaqIdx*)mmFile[0..mmFile.length].ptr;

for (ulong i = 0; i < mmFile.length/TaqIdx.sizeof; ++i)
{
    // do something...
    writeln(arr[i].symbol);
}


On Friday, 14 March 2014 at 18:00:58 UTC, TJB wrote:

I have a program in C++ that I am translating to D as a way to investigate and learn D. The program is used to process potentially hundreds of TB's of financial transactions data so it is crucial that it be performant. Right now the C++ version is orders of magnitude faster.

Here is a simple example of what I am doing in D:

import std.stdio : writefln;
import std.stream;

align(1) struct TaqIdx
{
  align(1) char[10] symbol;
  align(1) int tdate;
  align(1) int begrec;
  align(1) int endrec;
}

void main()
{
  auto input = new File("T201212A.IDX");
  TaqIdx tmp;
  int count;

  while(!input.eof())
  {
    input.readExact(&tmp, TaqIdx.sizeof);
   // Do something with the data
  }
}

Do you have any suggestions for improving the speed in this situation?

Thank you!

TJB