Federico Cargnelutti

Simple is better than complex. Complex is better than complicated. | @fedecarg

Archive for the ‘Programming’ Category

Increase speed and reduce bandwidth usage with ZF and Apache

with 17 comments

Apache’s mod_deflate module provides the DEFLATE output filter that allows output from your server to be compressed before being sent to the client over the network.

There are two ways of enabling gzip compression:

  1. Using Apache’s mod_deflate
  2. Using PHP’s built-in functions

Encoding the output and setting the appropriate headers manually makes the code more portable. Keep in mind that there are hundreds of Linux distributions, each slightly different to significantly different. To allow portability the application should not make assumptions about the OS or config involved.

Using Apache

1. Enable mod_deflate

Debian/Ubuntu:

$ a2enmod deflate
$ /etc/init.d/apache2 force-reload

2. Configure mode_deflate

$ nano /etc/apache2/mods-enabled/deflate.conf

#
# mod_deflate configuration
#
<IfModule mod_deflate.c>
 AddOutputFilterByType DEFLATE text/plain
 AddOutputFilterByType DEFLATE text/html
 AddOutputFilterByType DEFLATE text/xml
 AddOutputFilterByType DEFLATE text/css
 AddOutputFilterByType DEFLATE application/xml
 AddOutputFilterByType DEFLATE application/xhtml+xml
 AddOutputFilterByType DEFLATE application/rss+xml
 AddOutputFilterByType DEFLATE application/javascript
 AddOutputFilterByType DEFLATE application/x-javascript

 DeflateCompressionLevel 9

 BrowserMatch ^Mozilla/4 gzip-only-text/html
 BrowserMatch ^Mozilla/4\.0[678] no-gzip
 BrowserMatch \bMSIE !no-gzip !gzip-only-text/html

 DeflateFilterNote Input instream
 DeflateFilterNote Output outstream
 DeflateFilterNote Ratio ratio
</IfModule>

Using PHP

Create a gzip compressed string in your bootstrap file:

try {
    $frontController = Zend_Controller_Front::getInstance();
    if (@strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== false) {
        ob_start();
        $frontController->dispatch();
        $output = gzencode(ob_get_contents(), 9);
        ob_end_clean();
        header('Content-Encoding: gzip');
        echo $output;
    } else {
        $frontController->dispatch();
    }
} catch (Exeption $e) {
    if (Zend_Registry::isRegistered('Zend_Log')) {
        Zend_Registry::get('Zend_Log')->err($e->getMessage());
    }
    $message = $e->getMessage() . "\n\n" . $e->getTraceAsString();
    /* trigger event */
}

Reference

Use mod_deflate to compress Web content delivered by Apache

Written by Federico

July 6, 2009 at 11:09 am

Format a time interval with the requested granularity

with 8 comments

This class, a refactored version of Drupal’s format_interval function, makes it relatively easy to format an interval value. The format will automatically format as compactly as possible. For example: if the difference between the two dates is only a few hours and both dates occur on the same day, the year, month, and day parts of the date will be omitted.

class DateIntervalFormat
{
    /**
     * Format an interval value with the requested granularity.
     *
     * @param integer $timestamp The length of the interval in seconds.
     * @param integer $granularity How many different units to display in the string.
     * @return string A string representation of the interval.
     */
    public function getInterval($timestamp, $granularity = 2)
    {
        $seconds = time() - $timestamp;
        $units = array(
            '1 year|:count years' => 31536000,
            '1 week|:count weeks' => 604800,
            '1 day|:count days' => 86400,
            '1 hour|:count hours' => 3600,
            '1 min|:count min' => 60,
            '1 sec|:count sec' => 1);
        $output = '';
        foreach ($units as $key => $value) {
            $key = explode('|', $key);
            if ($seconds >= $value) {
                $count = floor($seconds / $value);
                $output .= ($output ? ' ' : '');
                $output .= ($count == 1) ? $key[0] : str_replace(':count', $count, $key[1]);
                $seconds %= $value;
                $granularity--;
            }
            if ($granularity == 0) {
                break;
            }
        }

        return $output ? $output : '0 sec';
    }
}

Usage:

$dateFormat = new DateIntervalFormat();
$timestamp = strtotime('2009-06-21 20:46:11');
print sprintf('Submitted %s ago',  $dateFormat->getInterval($timestamp));

Outputs:

Submitted 3 days 4 hours ago

Written by Federico

June 25, 2009 at 12:49 am

Java, C, Python and nested loops

with 3 comments

Java has no goto statement, to break or continue multiple-nested loop or switch constructs, Java programmers place labels on loop and switch constructs, and then break out of or continue to the block named by the label. The following example shows how to use java break statement to terminate the labeled loop:

public class BreakLabel
{
    public static void main(String[] args)
    {
        int[][] array = new int[][]{{1,2,3,4},{10,20,30,40}};
        boolean found = false;
        System.out.println("Searching 30 in two dimensional int array");

        Outer:
        for (int intOuter = 0; intOuter < array.length ; intOuter++) {
            Inner:
            for (int intInner = 0; intInner < array[intOuter].length; intInner++) {
                if (array[intOuter][intInner] == 30) {
                    found = true;
                    break Outer;
                }
            }
        }

        if (found == true) {
            System.out.println("30 found in the array");
        } else {
            System.out.println("30 not found in the array");
        }
    }
}

Use of labeled blocks in Java leads to considerable simplification in programming effort and a major reduction in maintenance.

On the other hand, the C continue statement can only continue the immediately enclosing block; to continue or exit outer blocks, programmers have traditionally either used auxiliary Boolean variables whose only purpose is to determine if the outer block is to be continued or exited; alternatively, programmers have misused the goto statement to exit out of nested blocks.

What’s interesting is that Python rejected the labeled break and continue proposal a while ago. And here’s why:

Guido van Rossum wrote:

I’m rejecting it on the basis that code so complicated to require this feature is very rare. While I’m sure there are some (rare) real cases where clarity of the code would suffer from a refactoring that makes it possible to use return, this is offset by two issues:

1. The complexity added to the language, permanently.

2. My expectation that the feature will be abused more than it will be used right, leading to a net decrease in code clarity (measured across all Python code written henceforth). Lazy programmers are everywhere, and before you know it you have an incredible mess on your hands of unintelligible code.

But what’s more interesting is that the idea of adding a goto statement was never ever mentioned.

Common sense perhaps?

Written by Federico

June 16, 2009 at 9:19 pm

Google Page Speed: Web Performance Best Practices

with one comment

When you profile a web page with Page Speed, it evaluates the page’s conformance to a number of different rules. These rules are general front-end best practices you can apply at any stage of web development. Google provides documentation of each of the rules, so whether or not you run the Page Speed tool, you can refer to these pages at any time.

The best practices are grouped into five categories that cover different aspects of page load optimization:

  • Optimizing caching: Keeping your application’s data and logic off the network altogether
  • Minimizing round-trip times: Reducing the number of serial request-response cycles
  • Minimizing request size: Reducing upload size
  • Minimizing payload size: Reducing the size of responses, downloads, and cached pages
  • Optimizing browser rendering: Improving the browser’s layout of a page

Web Performance Best Practices

Written by Federico

June 8, 2009 at 9:40 pm

Posted in Programming, Tools

The Little Manual of API Design

without comments

This manual gathers together the key insights into API design that were discovered through many years of software development on the Qt application development framework at Trolltech (now part of Nokia). When designing and implementing a library, you should also keep other factors in mind, such as efficiency and ease of implementation, in addition to pure API considerations. And although the focus is on public APIs, there is no harm in applying the principles described here when writing application code or internal library code.

The Little Manual of API Design (PDF)

Written by Federico

May 13, 2009 at 8:21 pm

E-Books Directory: More than 300 free programming books

with 2 comments

Here is a categorized list of online programming books available for free download. The books cover all major programming languages: Ada, Assembly, Basic, C, C#, C++, CGI, JavaScript, Perl, Delphi, Pascal, Haskell, Java, Lisp, PHP, Prolog, Python, Ruby, as well as some other languages, game programming, and software engineering. The books are in various formats for online reading or downloading.

Free Programming Books

Written by Federico

May 12, 2009 at 7:47 pm

Posted in Programming

New Zend Framework Book Published

with one comment

This book shows you how to build websites fast using PHP and MySQL. What’s more, it shows you how to supercharge your use of these technologies by taking advantage of a powerful, free web development solution known as the Zend Framework, which helps developers build websites with speed and efficiency.

This book embraces a teaching strategy of learning by doing, showing you how to build website features you’ll actually want to use within your own websites. Among other things you’ll learn how to manage data submitted through web forms, send unformatted and HTML e-mails through your website, manage user registrations, logins, and recover forgotten passwords, and even create the structure for a simple social network.

Along the way, you’ll learn how to take advantage of popular online services such as Google Maps, Amazon Web Services, the Facebook Platform, and PayPal to create even more compelling websites.

Easy PHP Websites with the Zend Framework

Written by Federico

May 11, 2009 at 7:26 pm

Posted in Frameworks, PHP, Programming

Yahoo Open Hack 2009 London

with one comment

Come and join Yahoo! on the 9th and 10th of May in London for 24 hours of learning, hacking, networking and fun.

It’s a two-day event on Saturday 9th of May with a morning of Tech Talks covering a wide range of topics led by some of the Web’s most respected developers. Yahoo will showcase the newest platforms and developer tools for you to play around with, and there will be plenty of experts on hand to answer questions.

Sign Up Now

Written by Federico

May 6, 2009 at 10:34 pm

PHP Support in Google App Engine

with 6 comments

Google App Engine now supports Java, this means that you can write PHP applications using Quercus: Demo script

The App Engine SDK for Java includes:

  • A Web application and Web server (Jetty) that emulates all App Engine services on your local development machine.
  • All the APIs and libraries available on App Engine.
  • Support to upload your application to App Engine.

Learn how to run PHP with Quercus in Jetty Web Server.

Written by Federico

April 13, 2009 at 10:43 pm

Posted in Java, PHP, Programming

Write, share and sell your own books

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As commercial book publishing crashes, personal book publishing is booming. Blurb is an online application which can be used to design and print your books in professional looking formats. Blurb makes it easier for you to write, share, promote and sell your own books.

Blurb BookSmart software is the most straightforward and easy to use software available. Multiple demos and tutorials are available, showcasing the potential that each Blurb book offers. Some of the books you buy on Amazon are manufactured with this same technology. You just can’t tell the difference!

From their site:

Holding a finished book with your name on the cover is a truly amazing feeling; it’s one of those experiences everyone should have. As software people, designers and publishing professionals at the top of our game, we realized something both incredible and obvious: there’s no good reason why it should take tons of time, technical skills, big bucks or friends in high places to publish a book. Or a zillion books, for that matter.

Blurb Features

  • Design your book with free software
  • Print your book by ordering online (as few as 1 book needs ordering)
  • Books created are of bookstore quality
  • Free to register and design books
  • Use the site to promote your books
  • Print your books with or without the Blurb Logo

Time to write some books :)

Links

Written by Federico

April 3, 2009 at 8:50 pm

Posted in Programming, Tools, Web, Web Apps