The page I am working on has a javascript function executed to print parts of the page. For some reason, printing in Safari, causes the window to somehow update. I say somehow, because it does not really refresh as in reload the page, but rather it starts the "rendering" of the page from start, i.e. scroll to top, flash animations start from 0, and so forth. The effect is reproduced by this fiddle: http://jsfiddle.net/fYmnB/ Clicking the print button and finishing or cancelling a print in Safari causes the screen to "go white" for a sec, which in my real website manifests itself as something "like" a reload. While running print button with, let's say, Firefox, just opens and closes the print dialogue without affecting the fiddle page in any way. Is there something with my way of calling the browsers print method that causes this, or how can it be explained - and preferably, avoided? P.S.: On my real site the same occurs with Chrome. In the ex
While PHP code needs to be interpreted on every call, bytecode is precompiled code that runs almost instantly.
ReplyDeleteMostly you will only really need it, if you are running a larger website.
The following tools can be used to compile scripts or run compiled scripts:
eAccelerator
Zend Optimizer
PHC (http://www.phpcompiler.org/)
Alternative PHP Cache (APC)
Unless you're after serious performance then compiling PHP using something like Facebook's HipHop is probably a bit excessive.
ReplyDeleteI'd just install/configure APC on your machine which will cache the compiled bytecode and should give you an instant performance boost.
Facebook use such things. Their product is hiphop, and it's free.
ReplyDeleteThe idea of a compiler, is to convert human readble code (C, PHP, Java etc), into machine readable code. When you execute your PHP scripts, they are interpreted (almost inline compilation), which means they are read a line by line, and the code is executed accordingly.
ReplyDeleteCompiled code, means that it is compiled at source, therefore is already in machine language (or byte code for VM languages like Java), and therefore, the server does not have to interpret the code each time. This makes it quicker.
Facebook created a PHP compiler to speed up their site. The idea of compiled code is that usually, once it is written, it doesn't change for a while, so there is an overhead in having to interpret it into machine language each time the code is executed. That is why your friend means by optimize.
It will therefore be converted into machine language or bytecode (not exe, but effecively the same concept).
The bigger your application the more sense this makes. PHP loads your whole program into memory and then compiles it on the fly: meaning as it needs to be used. So if you pre-compile it should skip that step. Facebook does something like this. The translate their php into C++ via something called hip hop. Not exactly the same thing but you get the idea.
ReplyDeleteI doubt this will show you much difference on smaller applications.