Question

I have the following function.

private boolean codeContains(String name, String code) {
    if (name == null || code == null) {
        return false;
    }

    Pattern pattern = Pattern.compile("\\b" + Pattern.quote(name) + "\\b");
    Matcher matcher = pattern.matcher(code);

    return matcher.find();
}

It is called many thousand times in my code, and is the function in which my program spends the most amount of time in. Is there any way to make this function go faster, or is it already as fast as it can be?

Answer 1

If you don’t need to check word boundaries, you might do this :

private boolean codeContains(String name, String code) {
    return name != null && code != null && code.indexOf(name)>=0;
}

If you need to check word boundaries but, as I suppose is your case, you have a big code in which you often search, you could “compile” the code once by

• splitting the code string using the split method
• putting the tokens in a HashSet (checking if a token is in a hashset is reasonably fast).

Of course, if you have more than one code, it’s easy to store them in a structure adapted to your program, for example in a map having as key the file name.