PDF version of my slide deck for "PHP Without PHP" given at International PHP Conference in Berlin, Germany on May 2009 Abstract: 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."

1. PHP without PHP
The Philosophy of Good
Architecture
terry chay
2009-05-27T14:15+0200
International PHP Conference
Berlin, Germany

2. Funky Caching
Prologue #1

3. aka
ErrorDocument trick
Smarter Caching
… Rasmus’s Trick (Stig’s trick)
Go into apache.conf (or .htaccess) and
ErrorDocument 404 /error.php

4. 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 quot;_quot; this is crashing my blog syntax hilighter
fputs($fp, $data);
fclose($fp);
@link($basepath.$filepath, $tmpfile); //suppress errors due to losing race
unlink($tmpfile);

5. 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 quot;_quot; this is crashing my blog syntax hilighter
fputs($fp, $data);
fclose($fp);
@link($basepath.$filepath, $tmpfile); //suppress errors due to losing race
unlink($tmpfile);

6. 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 quot;_quot; this is crashing my blog syntax hilighter
fputs($fp, $data);
fclose($fp);
@link($basepath.$filepath, $tmpfile); //suppress errors due to losing race
unlink($tmpfile);

7. PHP without PHP

8. Paradigms
Prologue #2

9. Code Complete
The metaphor of Code as
construction comes from this
book…
We now know this is
fundamentally wrong…

10. Mythical Man Month
“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.

11. paritionable
with training
traning + communication
unpartitionable
20
Time to COmplete Title
First consider something like
painting a fence: everything is
15
partionable (man-month).
…add a constant time for training. 10
…add communication cost: n(n-1)/2.
5
Compare to the unpartitionable
(single man)
Adding people to a late project
makes it later! Number of People

12. Engineer and
Architect

13. 1 Fallingwater
organic, democratic, plasticity, continuity

15. …including me

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

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

18. Fall Foliage View from lookout, downstream.

19. Fall Foliage View from lookout, downstream.

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

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

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

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

25. Philosophy
organic,
democratic,
plasticity,
continuity.

26. Why on PHP?

27. Harmony with Environment
Apache web server: ErrorDocument
Customer-centric: Performance
paramount
Relational Database: Slow
persistence
Harmony with PHP itself…

28. Architecture of PHP Modern web architecture

29. PHP is “Cheap”
“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

30. PHP is “Scalable”
“That a Java servlet performs better
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

31. PHP is “Pragmatic”
“PHP is not about purity in CS
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

32. 2 Bellefield Towers
Design Hubris

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

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

36. Tower of
Learning
Within spitting distance of
Bellefield Towers

37. Carnegie Library Most iconic moment in baseball history

38. Why is Bellefield
Towers so Ugly?

39. Design Hubris?
Frameworks (almost by definition)
Develop in the PHP community?
Take over an existing project?
Limitations of Site Operations?
Hosting? or Virtual hosting?
Business needs trump programmer
desire?
Dealt with a user request?

40. add slideshow
…at Tagged

41. …at Tagged
Cubes
Waterfall process
Oracle RAC
Java
PHP4
Zend Accelerator

42. Solutions Consider
Environment

43. 3 Golden Gate Bridge
The Design Pattern

45. the other bridge

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

49. Art Deco
Bridge Tower, Lighting,
pedestrial walkway

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

51. Part of the
whole

52. Design Patterns
Defined
“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.”

53. Certainly iconic Me in front of both icons

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

55. Funky Caching again
“search for the closest matching valid
URL and redirect, and use attempted
url text as a DB keyword lookup”
—Rasmus Lerdorf

58. Javascript and CSS
compiling & caching

61. <?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
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 quot;_quot;
curl_setopt($ch, CURLOPT_FILE, $fp);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_exec_($ch); //delete the final quot;_quot;
curl_close($ch);
fclose($fp);
// }}}

62. <?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
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 quot;_quot;
curl_setopt($ch, CURLOPT_FILE, $fp);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_exec_($ch); //delete the final quot;_quot;
curl_close($ch);
fclose($fp);
// }}}

63. <?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
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 quot;_quot;
curl_setopt($ch, CURLOPT_FILE, $fp);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_exec_($ch); //delete the final quot;_quot;
curl_close($ch);
fclose($fp);
// }}}

64. <?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
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 quot;_quot;
curl_setopt($ch, CURLOPT_FILE, $fp);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_exec_($ch); //delete the final quot;_quot;
curl_close($ch);
fclose($fp);
// }}}

65. // configure image and dimensions {{{
$size_data = array();
$im = start_image($tempfile, $size_data);
if (!$im) {
unlink($tempfile);
tag_http::redirect($dead_url);
return;
}
// }}}
// get watermark information {{{
$wm_data = array();
$wm = start_image($watermark, $wm_data);
if (!$wm) {
unlink ($tempfile);
tag_http::redirect($dead_url);
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('%s 200', $_SERVER['SERVER_PROTOCOL']));
header(sprintf('Content-type: %s',$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);

66. // configure image and dimensions {{{
$size_data = array();
$im = start_image($tempfile, $size_data);
if (!$im) {
unlink($tempfile);
tag_http::redirect($dead_url);
return;
}
// }}}
// get watermark information {{{
$wm_data = array();
$wm = start_image($watermark, $wm_data);
if (!$wm) {
unlink ($tempfile);
tag_http::redirect($dead_url);
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('%s 200', $_SERVER['SERVER_PROTOCOL']));
header(sprintf('Content-type: %s',$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);

67. // configure image and dimensions {{{
$size_data = array();
$im = start_image($tempfile, $size_data);
if (!$im) {
unlink($tempfile);
tag_http::redirect($dead_url);
return;
}
// }}}
// get watermark information {{{
$wm_data = array();
$wm = start_image($watermark, $wm_data);
if (!$wm) {
unlink ($tempfile);
tag_http::redirect($dead_url);
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('%s 200', $_SERVER['SERVER_PROTOCOL']));
header(sprintf('Content-type: %s',$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);

68. Beyond Funky
Caching

69. San Francisco
Looking around you for
inspiration

70. Thanks!
tychay@php.net
terrychay.com/blog