Why is reading some text files with JS so darn slow?! (title changed to reflect answers)

Questions & Answers
1

Here's the relevant code:

var textAsset : TextAsset;

var lineCounter = 0;

function Start() {

    readHugeFile();
}

function readHugeFile() {

    var startTimer = Time.realtimeSinceStartup;

    if (textAsset == null) return;
    reader = new StringReader(textAsset.text);
    line = reader.ReadLine();
    while (line != null)
    {
        lineCounter++;
        line = reader.ReadLine();
    }

    var timeExpired = Time.realtimeSinceStartup - startTimer;

    print("Time Expired:");
    print(timeExpired);

    print("Number of Lines:");
    print(lineCounter);

}

Ok, by points.

  1. I'm not interested in alternatives to reading these files. Alternative/smarter code would be super welcome!

  2. This code is to darn SLOW when the number of lines grows.

  3. This thing scales weirdly. The length of time taken isn't linear with the number of lines in the file.

Some random sampling of text files of different sizes.

                                          (Edits after modification suggested)

Number of Lines   Lines Read / second  |  *Lines Read / second

57,012            251                     518,000
54,818            245                     550,000
41,239            359                     412,000
38,138            385                     545,000
32,305            447                     538,000
25,908            551                     518,000
21,098            681                     527,000
17,668            803                     589,000
16,038            891                     535,000
13,118           1161                     656,000
11,616           1263                     581,000
2,293            6551                     573,000

WTH?

Thanks for any answers, pointers, or directions for better code. Am I doing something silly here?

*Notes The large variance in the number in the far right column are a result of variances in actual line lengths in the files, rounding error, and poor use of significant digits by myself.

With the largest file tested here, the suggested change of code represents a 2000X speed increase!

2

How about

if (textAsset == null) return;
var lines = textAsset.text.Split("
"[0]);
var lineCounter = lines.Length;

Might have to be "\r" if that's how lines are delineated.