Roku Developer Program

[renojim]

I just noticed that a really long regular expression ReplaceAll can make the box look like it's screwed up. I was using an roRegEx to replace all the >'s with ">" in a string and I didn't notice that the string I was receiving from my server was something like 267k bytes long. I thought the box was locked up, but I could press Home and get back to the main menu and I could move the selection to different channels, but selecting a channel just made the sound and nothing happened. I rebooted the box before I figured out what the real problem was (don't try to ReplaceAll on a string that long, it takes quite a while). Anyway, I guess pressing Home doesn't really kill off everything the way I thought it did.

-JT

[kbenson]

What was your match regex and replace string? If it was non-trivial (or even it it was only sort of trivial), it can be easy to create a regex that uses exponentially increasing time/operations for each extra character. Those can usually be refactored into a cleaner implementation.

I'm not sure about PCRE, but I know just using a matching group "()" compared to a non-matching group "(?:)" utilizes more resources.

P.S. No, PCRE is not really the same as the Perl regex engine, just MOSTLY Perl compatible, so I can't be sure about how it's functioning unless I really look into it, even if I know how it works in Perl.

[kbenson]

"kbenson" wrote:

I'm not sure about PCRE, but I know just using a matching group "()" compared to a non-matching group "(?:)" utilizes more resources.

Whoops, meant to say that I'm not sure about PCRE, but I know in Perl...

[renojim]

I was just trying to replace ">" with ">".

 r = CreateObject("roRegEx",">",""
str2 = r.ReplaceAll(str1,">")

I wasn't really commenting on the amount of time it took. I think if you're trying to process a 267 kbyte string all at once you're probably doing something wrong. I was commenting on the fact that it looks like a ReplaceAll is not interrupted by pressing Home. I've been going on the assumption that pressing Home kills off everything, but I suppose there are some things that can't be canceled/aborted. It looked like my box was sort of locked up, but I suppose if I had just waited for the ReplaceAll to finish everything would have been ok.

For what it's worth, I only discovered this because I was reviving my attempt at a PlayOn channel after I saw scyber's effort. I wasn't having much luck with his channel, so I went back to try my own. PlayOn returns something that is basically xml, except that "<" and ">" are replaced with "&lt;" and "&gt;". I never thought I'd get a "directory" that was 267k long, so it looked like the box was locked up when it was just processing the regular expression. I'm starting to realize that PlayOn requires a faster connection than what I have. I really hate to shell out more money, so I may have to live without it.

-JT

[kbenson]

Ah, I get it. Yeah, I've seen instances where pressing home doesn't take for a few seconds. I think it may have something to do with whether a component is busy or BightScript itself is. It may have problems interrupting components that are blocking.