Image Caching with PHP Does Not Work

[godius]

Hi guys, i run a small image hosting site, and i have a problem with caching my images.

 

I want to make the URL as short as possible, so i have a script which fakes the location of the images.

 

http://img.cx/RZVB.jpg is an image for example, but really the image is in a different location /uploads/blabla/secret/bla/RZVB.jpg (for example). My index.php script fakes this location, which works great, but browsers will not cache the image now, which is annoying for the users. Everytime I re-load an image, it gets all the data fresh from the server, instead of from the browsers cache.

 

In my index.php i read out the image like this.

 

$image_location = 'uploads/full/'.$result->image_folder.'/'.$image_id.'.'.$image_type.'';
$expires = 60*60*24*14;
header("Pragma: public");
header("Cache-Control: maxage=".$expires);
header('Expires: ' . gmdate('D, d M Y H:i:s', time()+$expires) . ' GMT');
header('Content-Length: '.filesize($image_location).'');
header('Content-Type: image/'.$image_mime.'');
readfile($image_location); 
exit;	

 

I have also tried caching .jpg/.gif/.png files via .htaccess file, but that also did not work.

 

Im running php 5.2.8, on Cent OS 5, and apache 2.

 

Please how do I enable caching for this image forwarding that im doing?

[dreamwest]

<FilesMatch "\.(jpg|jpeg|gif|ico|png)$">
Header set Cache-Control "max-age=604800, public"
</FilesMatch>

[godius]

I have tried that before, was no go.

 

Ive have added them to my .htaccess files again. It does not work.

 

Caching DOES work when I link to the full path of the image, eg: http://img.cx/uploads/full/20090922/RZVB.jpg

 

But when i get the image via my index.php script, it always completely reloads the image.

 

Any ideas?

[ILMV]

Is there a way to check the headers? Just to make sure they are being set correctly :-)

 

Especially Content-type

[dreamwest]

Using headers for image caching is a waste of your time - you only need htaccess.

 

Anyway i loaded the image and it is cached, so it is working.

 

If you refreah the page the images WILL of course reload - simple

[godius]

Its not working yet, its probably because the image is not found on that location... the header is 404, as the real image is hosted elsewhere.

 

 

http://img.cx/RZVB.jpg =

Date: Fri, 25 Sep 2009 08:36:50 GMT

Server: Apache/2.0.63 (Unix) mod_ssl/2.0.63 OpenSSL/0.9.8e-fips-rhel5 mod_auth_passthrough/2.1 mod_bwlimited/1.4 FrontPage/5.0.2.2635 PHP/5.2.8

X-Powered-By: PHP/5.2.8

Pragma: public

Cache-Control: max-age=604800, public

Content-Length: 3429601

Keep-Alive: timeout=15, max=97

Connection: Keep-Alive

Content-Type: image/jpeg

 

404 Not Found

 

 

http://img.cx/uploads/full/20090922/RZVB.jpg =

Date: Fri, 25 Sep 2009 08:33:37 GMT

Server: Apache/2.0.63 (Unix) mod_ssl/2.0.63 OpenSSL/0.9.8e-fips-rhel5 mod_auth_passthrough/2.1 mod_bwlimited/1.4 FrontPage/5.0.2.2635 PHP/5.2.8

Last-Modified: Tue, 22 Sep 2009 10:50:09 GMT

Etag: "2279be-3454e1-474285ca9fa40"

Accept-Ranges: bytes

Content-Length: 3429601

Cache-Control: max-age=604800, public

Content-Type: image/jpeg

 

200 OK

 

Cache probably does not work because of the 404 error, even though it does display the image correctly. But does not cache it...

 

 

Any idea what i can do now to get it working?

[ILMV]

Are you using .htaccess to redirect your URL to your index.php script?

[godius]

No im not. Dont think that is possible with the REAL path vs FAKE path.

 

http://img.cx/RZVB.jpg = FAKE path

http://img.cx/uploads/full/20090922/RZVB.jpg = REAL path

 

The '20090922' a directory with the date of the day the image was uploaded. This is done to prevent 1 directory from getting overloaded with images.

 

Or am i wrong and is it possible with mod_rewrite?

 

 

my current .htaccess

 

Options Indexes FollowSymLinks MultiViews All
php_flag register_globals on
ErrorDocument 404 /index.php

<FilesMatch "\.(jpg|jpeg|gif|ico|png)$">
Header set Cache-Control "max-age=604800, public"
</FilesMatch>

[ILMV]

Ah! That's your problem, because it cannot find your fake directory and you haven't mod_rewrite it correctly, you are firing a 404 error and your index is picking it up, you then handle the URL that the error handle has provided. No matter what happens the browser will receive a 404 and will not cache the image.

 

You need to use mod_rewrite to convert your fake path to your index, like this --> index.php?file=RZVB,jpg

 

That way you can handle the script without a 404, and the browser should cache the image.

 

I'm not an expert on mod_rewrite, but there is a forum here to help

 

 

ILMV

[godius]

Ok thanks, at least i know what im doing wrong now

 

So i wrote a little something, but it does not work.

 

 

.htaccess

Options Indexes FollowSymLinks MultiViews All
php_flag register_globals on
RewriteEngine On
RewriteRule  ^/([A-Z]+)\.jpg$  /pic.php?id=$1  [PT,L]

 

Shows..

 

Not Found

The requested URL /RZVB.jpg was not found on this server.

 

http://img.cx/pic.php?i=RZVB does show the image, but maybe my mod_rewrite code isnt correct.

 

Does anybody know?

[godius]

Never mind... i found it

 

Options Indexes FollowSymLinks MultiViews All
php_flag register_globals on


RewriteEngine on
RewriteRule RZVB(.*)\.jpg$ /index.php?i=$1

 

Thanks for all your help guys!! caching works perfect now.

[ILMV]

You're welcome,

 

I used to do exactly the same, causing an error to handle funny URLs, when I learnt about mod-rewrite it made things sooo much more efficient.

 

 

ILMV

[godius]

Seems my code is still buggy.

 

The regex problem i have posted elsewhere: http://www.phpfreaks.com/forums/index.php/topic,270675.0.html