Question

 private static void BuildDictionaryOfRequires(Regex exp, Dictionary<string, string> dictionary, DirectoryInfo dir)
    {
        var i = 0;
        var total = dir.EnumerateFiles("*.*", SearchOption.AllDirectories).
                                 Where(x => x.Extension == ".aspx" || x.Extension == ".ascx").Count();
        foreach (var item in dir.EnumerateFiles("*.*", SearchOption.AllDirectories).
                                 Where(x => x.Extension == ".aspx" || x.Extension == ".ascx"))
        {
 #if DEBUG
            Stopwatch sw = Stopwatch.StartNew();
 #endif

            var text = File.ReadAllText(item.FullName);

            MatchCollection matches = exp.Matches(text);
            foreach (Match match in matches)
            {
                var matchValue = match.Groups[0].Value;

                if (dictionary.ContainsKey(matchValue))
                {
                    dictionary[matchValue] = string.Format("{0},{1}", dictionary[matchValue], item.Name);
                }
                else
                {
                    dictionary.Add(matchValue, item.Name);
                }
            }

            Console.WriteLine(string.Format("Found matches in {0}.", item.Name));

 #if DEBUG
            sw.Stop();
            Console.WriteLine("Time used (float): {0} ms", sw.Elapsed.TotalMilliseconds);
 #endif


            Console.WriteLine(string.Format("{0} of {1}", (++i).ToString(), total));
        }
    }

there are about 232 files the lambda finds. It rips through 160 just fine then comes to a crawl. I’m profiling the code now but wondering if there is anything obvious i’m doing wrong.

the regex is

    Regex exp = new Regex(@"dojo\.require\([""'][\w\.]+['""]\);?", RegexOptions.IgnoreCase | RegexOptions.Compiled);

all of the files are similar length and similar structure.

most files take less than 30ms but some are 11251 ms.

with updated regex the whole process takes 1700ms now. phew!

Answer 1

Try simplifying your regex:

Regex exp = new Regex(@"dojo\.require\([""'][\w\.]+[""']\)", RegexOptions.IgnoreCase | RegexOptions.Compiled);

UPDATE: Then remove the semi-colon at the end if you want to match your example.