PHP Without PHP—Confoo

PHP without PHP
The Philosophy of
Good Architecture
terry chay
2010-03-10T09:30+0500
Confoo
Montreal, Canada

Thursday, March 18, 2010
An obscure but ubiquitous design pattern in PHP development is known as Funky Caching. Using real architectural examples as a lens to look at this one simple
PHP design pattern, we see how we can design web architectures that are "organic, democratic, and lasting…"

Funky Caching
Prologue #1


Two prologues

aka


Often attributed to Rasmus, but actually invented by Stig First you create an ErrorDocument
line in your apache.conf. What this does is tell the webserver to redirect all missing ﬁles to a
PHP script called “error.php” in your directory root. You then create this handler:

Reference:
http://derickrethans.nl/errorhandling/rasmus-trick.html
http://lerdorf.com/tips.pdf

aka
ErrorDocument trick



Reference:

aka
ErrorDocument trick

Smarter Caching



Reference:

aka
ErrorDocument trick

Smarter Caching

… Rasmus’s Trick (Stig’s trick)



Reference:

aka
ErrorDocument trick

Smarter Caching

… Rasmus’s Trick (Stig’s trick)

Go into apache.conf (or .htaccess) and

ErrorDocument 404 /error.php



Reference:

Error.PHP
$filepath = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH); //or $_SERVER['REDIRECT_URL']
$basepath = dirname(__FILE__).DIR_SEP;

// Test to see if you can work with it
if (false) { //…EDIT…
    //output a 404 page
    include('404.html'); // see http://www.alistapart.com/articles/perfect404/ for tips
    return;
}

// Generate the file
// …EDIT…
$data = 'something';

// Don't send 404 back, send 200 OK because this is a pretty smart 404
// not a clueless one! http://www.urbandictionary.com/define.php?term=404
header(sprintf('%s 200', $_SERVER['SERVER_PROTOCOL']));
//Show the file
echo $data;

//Store the page to bypass PHP on the next request. Use a temp file with a
// link trick in order to avoid race conditions between concurrent PHP
// processes.
$tmpfile = tempnam($basepath.'tmp','fc');
$fp = fopen($tmpfile,'w'); //remove the "_" this is crashing my blog syntax hilighter
fputs($fp, $data);
fclose($fp);
@link($basepath.$filepath, $tmpfile); //suppress errors due to losing race
unlink($tmpfile);


What does this trick do? Basically, when a ﬁle doesn’t exist, it gives an opportunity for PHP to
create the data and return it instead of a 404 error page.

The code above is pretty canonical, the only exceptions are where you branch to show the
default error page…

syntax highlighting code:
php_value highlight.string '#b02c04'
php_value highlight.comment '#8e98a6'
php_value highlight.keyword '#96ad53'
#php_value highlight.bg '#f1f7d7'
php_value highlight.default '#524e37'
php_value highlight.html '#95ad53'

Error.PHP

    //output a 404 page
    return; Ceheck
}

// …EDIT…

//Show the file
echo $data;

// processes.
fputs($fp, $data);
fclose($fp);
unlink($tmpfile);


…and where you generate the actual data to render to the user.

Error.PHP

    //output a 404 page
    return;
}

// …EDIT…

//Show the file
echo $data;

// processes.
fputs($fp, $data);
fclose($fp);
unlink($tmpfile);


At the bottom is where the magic happens. It places the generated file directly into the web
server path. What this means is that the next request to the same web resource goes directly
for that resource without starting up this code and regenerating the data.

Reference:
404 defined: http://en.wikipedia.org/wiki/HTTP_404
404 discussion: http://www.alistapart.com/articles/perfect404/
404 examples: http://www.plinko.net/404/
HTTP codes: http://www.urbandictionary.com/define.php?term=404

PHP without PHP


PHP never gets instantiated after the ﬁrst request!

At that point it truly becomes PHP without PHP.

Paradigms
Prologue #2


Code Complete
The metaphor of Code as
construction comes from this
book…

We now know this is
fundamentally wrong…

About the book and the metaphor.

The foundation of Steve McConnell’s seminal text, Code Complete, was that software development should be based around the paradigm
of construction. But that was fundamentally ﬂawed because of the mythical man-month—the “man-month” term itself originally coming
from construction work. We now know McConnell was wrong and software isn’t construction, it is engineering. And we’re called “software
engineers,” not “software workers” for this reason: we’re engineers, not construction workers.

Mythical Man Month
reorganize notes
too much text

“man-month” is a term from
construction work

The premise is that man and
months are interchangeable.

This means that in order to
reach a deadline I simply add
more people to the project.


Rhe foundation of Steve McConnell’s seminal text, Code Complete, was that software
development should be based around the paradigm of construction. But that was
fundamentally ﬂawed because of the mythical man-month—the “man-month” term itself
originally coming from construction work. We now know McConnell was wrong and software
isn’t construction, it is engineering. And we’re called “software engineers,” not “software
workers” for this reason: we’re engineers, not construction workers.

too much text


paritionable
with training
traning + communication
unpartitionable

20

Time to COmplete Title
too much text 15

10

5

Number of People


paritionable
with training
unpartitionable

20

First consider something like
p a i n t i n g a f e n c e : e v e r y t h i n g much text
too i s 15

partionable (man-month).

10

5

Number of People


paritionable
with training
unpartitionable

20

too i s 15


…add a constant time for training. 10

5

Number of People


paritionable
with training
unpartitionable

20

too i s 15



…add communication cost: n(n-1)/2.
5

Number of People


paritionable
with training
unpartitionable

20

too i s 15



5

Compare to the unpartitionable
(single man)

Number of People


paritionable
with training
unpartitionable

20

too i s 15



5

Compare to the unpartitionable
(single man)

Adding people to a late project
makes it later! Number of People


Engineer and
graphics

Architect


Software as Engineering vs. other. My title at Tagged is currently “software architect.” And I
have a “radical” idea that maybe titles are that way because they mean something. Meaning
that if I’m hired as a software architect then I should think like an architect and ﬁnd my
inspiration from architecture.

1 Fallingwater
organic, democratic, plasticity, continuity


So lets ﬁnd our inspiration from architecture and see how it explains the Funky Caching
pattern through three buildings. the ﬁrst is one known as Fallingwater.

References:
Fallingwater logo from: http://www.fallingwater.org/


In Eastern mountain range of the United States there is a house that is CANTILEVERed 40 feet
above a waterfall. This is one of the most famous buildings by American architect, FRANK
LLOYD WRIGHT. In 1991 it was voted as the best all-time work of American architecture by
the American Institute of Architects. Even though it is OVER 80KM from the nearest city
people over a MILLION PEOPLE have traveled to see it.

Reference:
Image from http://commons.wikimedia.org/wiki/File:Falling_Water_01.jpg
Wikipedia: http://en.wikipedia.org/wiki/Fallingwater
Frank Lloyd Wright: http://franklloydwright.org/Home.html

…including me

Yes, including me as a kid. The day it was built, TIME MAGAZINE wrote about it. Because it
was a quintessential example of ORGANIC ARCHITECTURE of FLW.

References:
Der Spiegel: http://en.wikipedia.org/wiki/Der_Spiegel

Hatchway Staircase View at the main (living room) level, from the
bridge (from east)


A staircase connects the house directly to the stream below. The stream and waterfall,
although not seen, can be heard in all parts of the house. The HATCHWAY that consists of
SLIDING GLASS DOORS and the bottom step has no support from below. (FLOAT above like
the water ﬂoats)

References:
http://wright-house.com/frank-lloyd-wright/fallingwater-pictures/06E-hatchway-
fallingwater.html

Beyond the glass Fallingwater: Living room terraces and glass
walls (from east).


WINDOWS WRAP AROUND THE ENTIRE BUILDING so that the building MERGES with the
surrounding GREENERY. Similarly the TUNGSTEN LIGHTING and the glasses compliments the
FALL FOLIAGE of the region…

Fall Foliage View from lookout, downstream.


This is the VIEW that FLW planned for the house.

References:
http://wright-house.com/frank-lloyd-wright/fallingwater-pictures/F1SW-fallingwater-in-
fall.html

Fall Foliage View from lookout, downstream.


No barriers Detail: corner window at the guest house,
from southeast.


Panes of glass are caulked directly to each other and to the steel frame or stone walls to
further symbolize the lack of barriers between the construction and the surrounding nature.

References:
http://wright-house.com/frank-lloyd-wright/fallingwater-pictures/34SE-guest-house-
window.html

Existing tree The trellis over the driveway is built to
accommodate a tree.


The driveway trellis has a semi-circular cutaway to accommodate an existing tree.

References:
http://wright-house.com/frank-lloyd-wright/fallingwater-pictures/15-tree-in-trellis-
fallingwater.html

Local quarry Living room, west (downstream) side, from
southeast


The stone ﬂoor in the living room, quarried from local rocks

http://wright-house.com/frank-lloyd-wright/fallingwater-pictures/livingroom-
fallingwater.html

Existing boulder Living room fireplace and hearth, looking
from kitchen door to south windows


The rock in the foreground is is an original boulder not disturbed from it’s original position.

References:
http://wright-house.com/frank-lloyd-wright/fallingwater-pictures/7-living-room-ﬁreplace-
hearth.php


From details like these to the whole view taken in at once, one gets a feeling that, in spite of
the SHARP HORIZONTAL AND VERTICAL LINES of the building, the whole lives in harmony with
its environment "instead of lording above [it] in an isolated spot as a man-made imposition.”
Why is this building as recognizable as any NATURAL WONDER?

Philosophy
organic,

democratic,

plasticity,

continuity.


Surveyed the grounds before building. Organic: "form follows function." Wright argued that
"form and function are one." Democratic “design should accommodate needs” Plasticity:
“physical element should remove barriers.” Continuity “element should be part of nature”

Why on PHP?


How prevalent is funky caching? Every time you visit PHP.NET, you use it (need to get the
order of needle-haystack by typing http://php.net/strstr). A cynic would say, because PHP is
so SLOW TO EXECUTE, it needs solutions like this to perform well. The problem with this
argument is that NO WEB LANGUAGE OUTPERFORMS STATIC SERVERS. Becase it trades off
speed of execution with SPEED FOR EASE OF DEVELOPMENT. As Andrei mentioned earlier, that
is fundamental to its design. In fact, all dynamically-typed scripting languages make this
tradeoff.

Harmony with Environment


The ubiquity of this trick in the PHP world is because it—like Frank Lloyd Wright's Fallingwater
—lives in harmony with its environment. The environment is an APACHE WEB SERVER,
persistent data store in the form of a RELATIONAL DATABASE, and the demands of large-
scale, CONSUMER-CENTRIC web sites. Would this solution exist without an ErrorDocument
handler built into Apache? Would this solution exist if we didn't persist content on a
(relatively) slow data store like a database? Would this solution exist if the consumer didn't
demand millisecond response time for dynamic content?


Apache web server: ErrorDocument





Customer-centric: Performance
paramount





paramount

Relational Database: Slow
persistence





paramount

Relational Database: Slow
persistence

Harmony with PHP itself…



write text to talk about
it

Architecture of PHP Modern web architecture


The language itself. PHP is a component of A WHOLE SYSTEM. It’s glue code.

PHP is “Cheap”
graphcis money
shorten quote

“A project done in Java will cost 5 times
as much, take twice as long, and be
harder to maintain than a project done
in a scripting language such as PHP or
Perl.”

—Phillip Greenspun


developer time and resources

PHP is “Scalable”
“That a Java servlet performs better
graphics notes?
shortne quote
than a PHP script, under optimal
conditions [has] nothing to do with
scalability. The point is can your
application continue to deliver
consistent performance as volume
increases. PHP delegates all the ‘hard
stuff’ to other systems.”

—Harry Fuecks


shared-nothing architecture

PHP is “Pragmatic”
“PHP is not about purity in CS
graphics
shorten quote
principles or architecture; it is about
solving the ugly web problem with an
admittedly ugly, but extremely
functional and convenient solution. If
you are looking for purity, you are in
the wrong boat. Get out now before
you get hit by a wet cat!”

—Rasmus Lerdorf


designed to solve the web problem

Could this "ugly, but extremely functional and convenient" web language have been built to
solve anything other than the ugly web problem?

2 Bellefield Towers
Design Hubris


One block from where my mother used to work, on the corner of Fifth Avenue and Belleﬁeld
in Pittsburgh, stands a strange sight…

make video of wpaking
towards?

If you weren’t in PITTSBURGH IN THE LATE 1980’s you wouldn’t have understood how his could have happened. On this ground
once stood the original Belleﬁeld church built in the 1880’s. Since its CONGREGATION HAD BEEN MOVED further down Fifth
Avenue, the building was sold a century later to developers trying to exploit the new business attracted by the PITTSBURGH
SUPERCOMPUTING CENTER. They wanted to level it and build a new building, but were blocked when people mobilized to SAVE
THE OLD TOWER. The developer then proceeded to honor this by DEMOLISH EVERYTHING BUT THE TOWER and building the
ironically-named “Belleﬁeld Towers” next to it.

Gothic Romanesque architecture The current Bellefield Church (two blocks
away)


This is the current Belleﬁeld Church and an example of city architecture of which the tower is
one of them…

Other city towers Allegheny Courthouse Main Tower & Four
Tower Types at Jail (and other towers)


The center is the county courthouse and jail, the top right is the local Korean church, and the
bottom right is a private residence in the same neighborhood.

Tower of
Learning
Within spitting distance of
Bellefield Towers


redo builds
break out slides
quots

Carnegie Library Most iconic moment in baseball history


The photo at the top is was taken from the Cathedral of learning (previous slide).

Why is Bellefield
Towers so Ugly?


When faced with a gorgeous 100-year old example of the area’s architecture, INSTEAD OF WORKING
WITH THE ENVIRONMENT like Frank Lloyd Wright did with Fallingwater—in the same area of
Pennsylvania no less!—the developer simply sawed it off! The CURVED MODERN ARCHITECTURE of the
TOWERS of the latter serves only to emphasize how it was built with no consideration of the
surrounding environment. I GREW UP WATCHING THIS HAPPEN and it is a LIFE LESSON IN
ARCHITECTURAL HUBRIS.

Design Hubris?
break out slides, graphics


“I’m a developer, I can make the software conform to my needs.”
Oh really? That sounds a lot like trying to “lord over the environment with an isolated man-made
imposition.” “But what I mean is it’s all man-made in software, there is no environment.”

Design Hubris?
Frameworks (almost by definition)



Design Hubris?
Develop in the PHP community?



Design Hubris?

Take over an existing project?



Design Hubris?


Limitations of Site Operations?
Hosting? or Virtual hosting?



Design Hubris?



Business needs trump programmer
desire?



Design Hubris?



Business needs trump programmer
desire?

Dealt with a user request?



add slideshow

…at Tagged

cover cube story, (where cubes are good- Yahoo, sales, user QA), cover waterfall process

…at Tagged break out slides

When I joined my current company, they had a couple services written in Java, only Zend Accelerator could code cache their PHP 4 installation,
Oracle RAC powered the back-end and development occurred by engineers working in cubes with a relatively heavyweight waterfall development
process.
Even though I prefer Python to Java for services, we’ve increased our Java development to around 40% of our code base! Even though I prefer
MySQL to Oracle, we still use Oracle as our back-end. Even the transition to the open office occurred after it became apparent the company had
outgrown the cube-space.


Cubes

process.


Cubes
Waterfall process

process.


Cubes
Waterfall process
Oracle RAC

process.


Cubes
Waterfall process
Oracle RAC
Java

process.


Cubes
Waterfall process
Oracle RAC
Java
PHP4

process.


Cubes
Waterfall process
Oracle RAC
Java
PHP4
Zend Accelerator

process.

Rework

Book on management by the founders of 37 Signals. Their last book was “Getting Real” about web business.

Rework
From the Founders of 37
Signals


Rework
From the Founders of 37
Signals

Last Book: “Getting Real”


Rework

- cliche ridden with few examples “Hannah Montanta” reach for you dreams
- “would rather be celebrities than businesspeople.”
- 'Meetings are toxic.' In reality, good meetings are good and bad meetings are not good (generalization)
- “Planning, they say, is not recommended” - only applies to their business
- “They need to stop behaving like children.”
- “Outside money is plan”, about why you should never take on third-party investors.37signals reveals that it took money from Bezos Expeditions,
the VC company that invests on behalf of the Amazon founder, Jeff Bezos, in 2006.

Rework
“Not Just Bad,
but dangerous”


Rework
“Not Just Bad,
but dangerous”
—John Vincent, Leon
Restaurants


Solutions Consider
Environment

Why? Because that is the environment and your solutions have to work within that environment. Anything else is architectural hubris.
Let’s say it is the early days of social networking and you join a company that is using Java/J2EE instead of PHP, or Oracle instead of MySQL, or they’re using Perl/Mason instead of your
favorite (PHP) framework, as Marco mentioned earlier—there are so many to choose from that the number is second only to Java.
Do you go in and say your experience building a CMS or e-store trumps their experience working on a nascent social network? Do you replace all the Java engineers with PHP ones? Do you
replace MySQL with Oracle? Do you rewrite the site from scratch using your favorite framework?
I’m not saying that in all these instances these architects shouldn’t have made the decisions they did. I am not qualiﬁed to answer that since I didn’t work at these places.
But what I do know was that in the vast majority of cases, people went in without considering the existing environment. I do know the dynamics of a Facebook.com is different from the
dynamics of Gamespot.com or Amazon.com. I do know a social network is different from a CMS or e-store. And all these solutions are very different from ones in enterprise.
Like building Fallingwater without getting an adequate survey done, every day people make the mistake of not looking before acting. They try to make PHP look like Java with dollar signs,
as Luke mentioned earlier. They expected the environment to conform to their reality so they can lord over it with “some isolated man-made imposition.”

3 Golden Gate Bridge
The Design Pattern


I’ve long since moved from the woods of Western Pennsylvania to the San Francisco
Peninsula. I am fortunate that my weekly run passes with a near-constant view of the most
recognizable architecture in the American West:

References:
Image licensed from: http://www.istockphoto.com/ﬁle_closeup.php?id=6091847

design build
quote of goldne gate
bridge


my weekend run

quote from emperor
norton

the other bridge

What’s interesting is that there are much longer spans in the country and the world. Even in
the same city, there exists a beautiful bridge that is both longer and of more utility. And yet
this bridge represents the icon of San Francisco and of the state as a whole.

quotes of sf


Same problem,
different pattern
Original design was hybrid
cantilever-suspension.
Replaced by purse
suspension


The original design was for a hybrid cantilever and suspension structure. But it was replaced
with a pure suspension design because the former was deemed too ugly. A pure suspension
of this length had never been attempted before.

Art Deco quote of art deco
movemebnt

Bridge Tower, Lighting,
pedestrial walkway

Irving Morrow designed the bridge tower, lighting, and pedestrian walkways with an entirely Art Deco decorative inﬂuence.

International
Orange
Rust colored like the
environment it lives in … and
safe.


The bridge was painted in a specially formulated anti-rust paint in International Orange on demand
from locals. The War Department, and others. The Navy alone originally demanded it be painted black
with yellow stripes to assure visibility with passing ships. The rust-colored paint evokes the hills of
Marin to the north as well as the setting sun. It is natural and visible enough to be safe.

Part of the
whole

rust-colored suspension-only art deco structure It becomes an icon. Every week I pass by it and am inspired and
thankful I can live in so beautiful a city.

Design Patterns
Defined shorten quote


This quote is the origin of “design pattern.”

Design Patterns
Defined shorten quote

“Each pattern describes a
problem which occurs over
and over again in our
environment, and then
describes the core of the
solution to that problem, in
such a way that you can use
this solution a million times
over, without ever doing it
the same way twice.”


This quote is the origin of “design pattern.”

Certainly iconic Me in front of both icons


But how are we to know which way to do it? Or even if it is the right pattern to be using in our
situation? The answer is found in how both a house in Pennsylvania and a bridge in San Francisco
represent ultimate expressions of architecture. They are wholly appropriate for the environment
in which they stand.

blend transition in
stages

Never the same way twice How do you know which one?
How do you know which way?


A cantilever is wholly appropriate to create the ﬂoating look of Fallingwater, but that same
pattern would disrupted the naturalness of the Golden Gate Bridge. When choosing between a
singleton and a global variable, which pattern to use is determined by the environment.

Funky Caching again

“search for the closest matching valid
URL and redirect, and use attempted
url text as a DB keyword lookup”

—Rasmus Lerdorf


the ﬁrst is in Rasmus’s talk and you can see PHP.NET in others.

cleanup text

At my previous company, we had the problem where images are stored on the database but need to be generated in multiple sizes and thumbnails
and streamed fast to the user. Previews and thumbnails can be dynamically and instantly generated from border parts, primary graphics, colors,
and sample font and text and then stored statically on a server using this method. Stuff may be stored in normal form on the database, but
representations built dynamically and served statically

Address complaint about storing in database…Not all images are stored in the database. In fact, at Tagged, not a single image is stored on a database. However, at Plaxo, the admin tool
to manage ecard content requires the assets be done by a non-developer but the only way of pushing out ﬁlesystem changes is through change control and there is little need of user
generated content. In fact, outside e-cards, the entire Plaxo address book database (including the thumbnail photo of yourself) is stored in a database. I’m not the architect of that, nor do
I see much a problem with it.
What I point out you CAN now get away with putting image content on the database again with this trick. That’s pretty impressive because different assets on a site (statics, javascripts,
web pages, user data, application, back-end, corporate site, customer support, etc) are usually managed on an ad hoc basis optimized for the task at hand. Not all of them can resort to
using a ﬁlesystem push or web tier restart.

Javascript and CSS
put a graphic or some
text

compiling & caching


Recently, Tagged has run across the very same performance (size and number) issues in
Javascript. The solution: Funky caching hooked up to a javascript compressor powered by a
Java service back-end to dynamically catenate and compress javascripts into a unique URL on
demand.

We recently imported 1/64th of our production data over to the staging environment for testing, but the user’s images would
take too much time and disk space to import. We could just link the images, but then tester’s didn’t know which ones they
uploaded and which ones were proxied from the live website. The solution was to spend an hour writing a Funky Caching Proxy.
If the image was missing, the ErrorDocument handler would try to grav the image from the production website and add a
watermark.


Since this is only for testing, there is no need to waste disk space by storing the created ﬁle.
The performance hit of real-time generation of redundant requests is unnoticeable to Quality
Assurance.

<?php

$watermark = '3129080702_c4e76f71d7_o.png';
$dead_url = 'http://example.com/dead_image.png';

// {{{ start_image($filename, &$data)
/**
* Creates a gd handle for a valid file
* @param $filename string the file to get
* @param $data array the imagesize
* @return resource GD handle
*/
function start_image($filename, &$data) {
    $data = @getimagesize($filename);
    if (empty($data)) { return null; }
    $data['ratio'] = $data[0]/$data[1]; expand callouts
    switch($data[2]) {
        case IMG_GIF: return imagecreatefromgif($filename);
        case 3: //problem where IMG_PNG is not bound correctly for my install
        case IMG_PNG: return imagecreatefrompng($filename);
        case IMG_JPG: return imagecreatefromjpeg($filename);
        case IMG_WBMP: return imagecreatefromwbmp($filename);
        case IMG_XPM: return imagecreatefromxbm($filename);
    }
    return null;
}
// }}}
$requestimg = $_SERVER['REDIRECT_URL'];
if (!$_SERVER['QUERY_STRING']) {
    // redirect user to invalid image
    tag_http::redirect($dead_url);
    return '';
}
// grab image to temp {{{
$ch = curl_init($_SERVER['QUERY_STRING']);
$tempfile = tempnam('/tmp', 'prod_remote_');
$fp = f_open($tempfile, 'w'); //again delete the "_"
curl_setopt($ch, CURLOPT_FILE, $fp);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_exec_($ch); //delete the final "_"
curl_close($ch);
fclose($fp);
// }}}

<?php

$watermark = '3129080702_c4e76f71d7_o.png';
$dead_url = 'http://example.com/dead_image.png';

// {{{ start_image($filename, &$data)
/**
* Creates a gd handle for a valid file
* @param $filename string the file to get
* @param $data array the imagesize
* @return resource GD handle
*/
function start_image($filename, &$data) {
    $data = @getimagesize($filename);
    if (empty($data)) { return null; }
    $data['ratio'] = $data[0]/$data[1];
    switch($data[2]) {
        case IMG_GIF: return imagecreatefromgif($filename);
        case 3: //problem where IMG_PNG is not bound correctly for my install
        case IMG_PNG: return imagecreatefrompng($filename);
        case IMG_JPG: return imagecreatefromjpeg($filename);
        case IMG_WBMP: return imagecreatefromwbmp($filename);
        case IMG_XPM: return imagecreatefromxbm($filename);
    }
    return null;
}
// }}}
$requestimg = $_SERVER['REDIRECT_URL'];
if (!$_SERVER['QUERY_STRING']) {
    // redirect user to invalid image
    return '';
}
// grab image to temp {{{
$ch = curl_init($_SERVER['QUERY_STRING']);
$tempfile = tempnam('/tmp', 'prod_remote_');
$fp = f_open($tempfile, 'w'); //again delete the "_"
curl_setopt($ch, CURLOPT_FILE, $fp);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_exec_($ch); //delete the final "_"
curl_close($ch);
fclose($fp);
// }}}

// configure image and dimensions {{{
$size_data = array();
$im = start_image($tempfile, $size_data);
if (!$im) {
    unlink($tempfile);
    return;
}
// }}}
// get watermark information {{{
$wm_data = array();
$wm = start_image($watermark, $wm_data);
if (!$wm) {
    unlink ($tempfile);
    return;
}
// }}}
// add watermark {{{
if ($size_data['ratio']> $wm_data['ratio']) {
    // image is wider format than the watermark
    $new_smaller_dim = $wm_data[0] * ($size_data[1]/$wm_data[1]);
    $dst_x = ($size_data[0] - $new_smaller_dim)/2;
    $dst_y = 0;
    $dst_w = $new_smaller_dim;
    $dst_h = $size_data[1];
} else {
    // image is taller format than the watermark
    $new_smaller_dim = $wm_data[1] * ($size_data[0]/$wm_data[0]);
    $dst_x = 0;
    $dst_y = ($size_data[1] - $new_smaller_dim)/2;
    $dst_w = $size_data[0];
    $dst_h = $new_smaller_dim;;
}
imagecopyresized($im, $wm, $dst_x, $dst_y, 0, 0, $dst_w, $dst_h, $wm_data[0], $wm_data[1]);
header(sprintf('Content-type: %s',$size_data['mime']));
// }}}
switch ($size_data[2]) {
    case IMG_GIF: imagegif($im); break;
    case 3: case IMG_PNG: imagepng($im); break;
    case IMG_JPG: imagejpeg($im); break;
    case IMG_WBMP: imagewbmp($im); break;
    case IMG_XPM: imagexbm($im); break;
}
imagedestroy($wm);
imagedestroy($im);
unlink($tempfile);

Beyond Funky
Caching


With a bit of creativity this concept can apply to modern applications where instead of
caching on the ﬁlesystem, you cache in memcache; instead of bypassing the application
server, you bypass the web servers themselves with a content distribution network; instead of
serving static content from the edge, you serve dynamic pages.
Whether to use it and how to use it is always determined by the environment.

San Francisco quotes of san francisco?

Looking around you for
inspiration

I hope this tour helps you see software development in a different way—that finding solutions are about using the right solution in a manner that fits with the environment.
Even then I realize that we can’t architect structures that work as harmoniously together as a city such as San Francisco. Story of Rounded Rectangles…

Bill Atkinson worked mostly at home, but whenever he made significant progress he rushed in to Apple to show it off to anyone who would appreciate it. This time, he
visited the Macintosh offices at Texaco Towers to show off his brand new oval routines, which were implemented using a really clever algorithm. Bill had added new code to
QuickDraw (which was still called LisaGraf at this point) to draw circles and ovals very quickly. That was a bit hard to do on the Macintosh, since the math for circles usually
involved taking square roots, and the 68000 processor in the Lisa and Macintosh didn't support floating point operations. But Bill had come up with a clever way to do the
circle calculation that only used addition and subtraction, not even multiplication or division, which the 68000 could do, but was kind of slow at.

Bill's technique used the fact the sum of a sequence of odd numbers is always the next perfect square (For example, 1 + 3 = 4, 1 + 3 + 5 = 9, 1 + 3 + 5 + 7 = 16, etc). So
he could figure out when to bump the dependent coordinate value by iterating in a loop until a threshold was exceeded. This allowed QuickDraw to draw ovals very quickly.

Bill fired up his demo and it quickly filled the Lisa screen with randomly-sized ovals, faster than you thought was possible. But something was bothering Steve Jobs. "Well,
circles and ovals are good, but how about drawing rectangles with rounded corners? Can we do that now, too?"

"No, there's no way to do that. In fact it would be really hard to do, and I don't think we really need it". I think Bill was a little miffed that Steve wasn't raving over the fast
ovals and still wanted more.

Steve suddenly got more intense. "Rectangles with rounded corners are everywhere! Just look around this room!". And sure enough, there were lots of them, like the
whiteboard and some of the desks and tables. Then he pointed out the window. "And look outside, there's even more, practically everywhere you look!". He even persuaded

Thanks!
resize

tychay@php.net
terrychay.com/blog


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