Finding the first file in a dir, fast, for message queue

I have a file based msg queue, and msgs are stored five folders down.

When a request for the next msg is received, I need to grab the first
file I can find, as fast as I can.

I’ve tried Dir.glob, and only selecting the first file. This however is
an awful way of doing it as it loads every file into memory, before
selecting the first.

A bit better is Find.find, which finds files incrementally. However,
this still takes about 0.005 seconds (I presume since it’s also
‘finding’ directories’).

Is there a faster way to do this?

2008/1/8, Alex M. [email protected]:

this still takes about 0.005 seconds (I presume since it’s also
‘finding’ directories’).

Is there a faster way to do this?

You find 5ms when accessing the file system long? I’d say that’s
pretty fast considering what you do (recursive search). I doubt you
will get much improvement as long as you always access the file system
for your search. If you know the change frequency of files then you
could store file system contents in memory and only update every n
seconds / minutes or whatever or have a background thread that
continuously updates your in memory representation.

Kind regards

robert

You find 5ms when accessing the file system long? I’d say that’s
pretty fast considering what you do (recursive search). I doubt you
will get much improvement as long as you always access the file system
for your search. If you know the change frequency of files then you
could store file system contents in memory and only update every n
seconds / minutes or whatever or have a background thread that
continuously updates your in memory representation.

Well, it’s long compared to generating folder names, a guid, and writing
files. It means that I can publish about 1000 msgs per second on to my
queue, but only pull of 243 msgs per second.

2008/1/8, Alex M. [email protected]:

files. It means that I can publish about 1000 msgs per second on to my
queue, but only pull of 243 msgs per second.

Here’s another option: find all files and put them in a queue. Only
redo search when the queue is empty. This might pay off over all.

robert

Robert K. wrote:

2008/1/8, Alex M. [email protected]:

files. It means that I can publish about 1000 msgs per second on to my
queue, but only pull of 243 msgs per second.

Here’s another option: find all files and put them in a queue. Only
redo search when the queue is empty. This might pay off over all.

robert

Yes, that’s what I’ve done. Message polling is now the same speed as
publishing (so the overall speed is about 10000 msg per second). If you
interested, here’s the queue:

http://code.google.com/p/sparrow

This forum is not affiliated to the Ruby language, Ruby on Rails framework, nor any Ruby applications discussed here.

| Privacy Policy | Terms of Service | Remote Ruby Jobs