Zein’s place on the net

Once upon a time, the options available to Linux users interested in managing their book collections were limited. The situation was so bleak that I attempted to create my own web-based application. That app was fine until I tried to host it on my 64MB VPS and failed (RoR had a footprint of 60MB all by itself)!

Lately, I have been missing the ability to browse through my books. I started thinking about having another attempt at a book collection manger. Maybe this time I would try and write a desktop application. I could use python or even try out mono. So today I did a bit of googling and stumbled upon Alexandria, a book collection manager for GNOME.

This application is brilliant! It is almost the perfect application. All I needed to do was get a list of books in my old app:

echo "select isbn from books;" | sqlite3 mybooklist_production.sqlite > import-list.txt

I was then able to import all my old books into Alexandria using the import ISBN list feature. I would like to recommend this app to anyone who is looking for a book collection manger for Linux. The site also has deb packages for those who use Debian or Ubuntu.

In my “mybooklist” application I deal with lots of images! My current method has been to store the uploaded book covers in public/images/bookcovers/isbnnumber.png” and creating thumbnails on the fly in the list and grid views!

Of course this is a very bad thing to do! The load on my server was going crazy with all the CPU intensive image manipulation going on! I had to do something.

The task required to different solutions. The first was client side caching to prevent the browser downloading the image multiple times! to achieve this I modified the show browser function like so:

# 2. we see if we need to send the file or not
        lastmod = File.stat(filepath).mtime
        minTime = Time.rfc2822(@request.env["HTTP_IF_MODIFIED_SINCE"]) rescue nil
        if minTime and lastmod < = minTime
            # use cached version
            render_text '', '304 Not Modified'
        else
            # send image

now I only send the image to the client only in I need to!

The second area of improvement was the thumbnail creation on the fly! I first tried the rails

caches_page :show_cover

but I found myself in a situation where I was sending the image to the client every time because rails was sending the cached image without ever running the show_cover function (and my browser cache code)!

I guess I am just going to generate the thumbnails in the create and update functions. The app should feel a lot different and the load on the server should stay low!