i am running multiple websites with high traffic , as a requirement , all images are downloaded via image.php?id=IMAGE_ID_HERE
.
If you ever done that before , you
Why dont you cache the image content with apc ?
if(!apc_exists('img_'.$id)){
apc_store('img_'.$id,file_get_content(...));
}
echo apc_fetch('img_'.$id);
this way image content will not be read from your disk more than once.
fopen and file_get_contents are nearly equivalent
to speed up with consistence the page load you can use
http://www.php.net/fpassthru
or, even better
http://www.php.net/readfile
with those functions, content of file is printed directly, byte per byte
as opposed to file_get_contents, for example, where you store the whole data inside a variable
$var = file_get_contents();
so, to make these work correctly you will need to disable output buffering (otherwise it would make readfile() pointless) in the page that serves the images
hope this helps!