Re: efficiency of include()

Larry Garfield wrote: > On Sunday 20 December 2009 10:45:45 am Daniel Kolbo wrote: >> Hello PHPers, >> >> This is a two part question: >> >> 1) Is it faster to include one file with lots of code, or many separate >> smaller individual files? Assume the one massive file is merely the >> concatenation of all the smaller individual files. (I am assuming the >> one massive file would be faster..., but i wanted to get confirmation). > > Conventional wisdom is that the one big file is faster, since it requires one > disk I/O hit instead of several. HOWEVER, if you're only using a small > portion of that code then it could be faster to load only the code you really > need. Where the trade off is varies with your architecture, the amount of > code, ad how good the disk caching of your OS is. > >> 2) Suppose php has to invoke the include function 100 times. Suppose >> all files are on average the same size and contain the same number of >> instructions. Would it be faster to include the same exact file 100 >> times as opposed to 100 different file names? Basically, does the >> engine/parser take any shortcuts if it notices that the file name has >> already been included once? > > I'm pretty sure that PHP will recognize that it's already parsed that file and > keep the opcode caches in memory, so it needn't hit disk again. I've not > checked into that part of the engine, though, so I may be wrong there. > Thanks for the reply. For 2): I've often searched for php parsing documentation. I love the php.net documentation. However, i have yet to find an excellent source documenting the php parser/engine. My searches always yield the zend website, but it doesn't seem like i can get very far from that page. Any suggestions on where i could learn more of the nitty gritty details of the php/zend behaviours? Thanks, dK `