A page is sending AJAX call to server and should get item info in response. The array to look-up/return is a rather big one and I can’t hold it in the PHP file to accept the request. So, as far as my knowledge and experience tell, there are 2 methods:
Access database for each request.
Store items in files (e.g. “item12.txt”) and send contents to the user.
My C experience says that opening and closing a file takes much more system time than the rest of the program. How is it in PHP? What is the preferred method (most importantly, resource-wise) – file system or database? Is there any other way you would recommend (e.g. JavaScript directly loading the file with variable array from the server for each request)? Maybe there’s some innovative method lying around you’re aware of?
P.S. On the server-side a number only will be accepted, so no worries regarding someone trying to access files in the server or trying to do some fancy stuff on database.
Sockets
Depending on how many requests you will be handling, you could look into socket connections.
Sockets gives you 2 way communication between the client and the server, which would allow you to do interactive things, as needed.
Socket tutorial 1
Socket tutorial 2
Node.js
node.js is the new kid on the block. You write your own socket webserver, and use javascript to communicate with it. This is a great alternative to Ajax, as it's much more efficient and reliabe.
node.js can be run alongside PHP, and only be used for ajax-like calls.
node.js
node.js socket turotial
There are nothing innovative. If you have low frequency calls to data and you want super simple access to data then use files. But today is much better to use any database (SQL lite) is ok i think. IF you need more performance then use MySQL or NoSQL solutions. Tools made to solve things. Use the right tool for your purpose.
Related
I'm working on feeding the client realtime events using event-streams and HTML5 SSEs client-side.
But some of my events will actually come from form submissions by other clients.
What's the best method for detecting these form submissions (so as to append them to the event-stream script) ASAP (after they occur)?
So essentially, I need realtime cross-script messaging between multiple instances of different scripts instantiated by different clients, analagous to X-doc messaging in JS, but for PHP.
The best I can come up with is to repeatedly poll a subdir of /tmp for notification files, which is a terrible solution.
Often you can use MYSQL to play the role of the tmp dir you were talking about. This is more portable because they don't have to be on the same server to do this and the data is separate. However the scripts will have to manually check the mysql location to see if the other one has taken care of this. The other option is to open sockets and write back and forth in real time or to use some prebuilt tool for just this purpose which I'm pretty sure might exist.
If you want the events to be triggered near to realtime, then you need to handle them synchronously - which means running a daemon. And the simplest way to implement a daemon which can synchronize data across client connections is to use an event based server. There's a nice implementation of the latter using php here - there are plenty of examples of how to daemonize a PHP process on the interent. Then just open a blocking connection to the server from your PHP code / access this via comet.
Is it possible to send data from C++ to PHP? I have wrote a server in C++ that connects to a database, and I was wondering if it is possible at all to use the socket library built into PHP to connect to the socket server written in C++. Would it just be PHP itself? I mean, would I not use JavaScript (AJAX) to call a PHP script that might do the socket work?
Basically, how do Google do this? I know some of their applications use C++/Java as their back-end, but is there any performance at all?
For those wondering why I am asking this question, then the answer is I don't want to rely on PHP to handle data as I am writing a game. I would like PHP to handle the web part, but not necessarily the game client so-to-speak; and I just think C++ would be a lot efficient at sending and receiving data to store in the database.
Has anyone done something like this and if so did you run into problems; and is this a practical solution at all?
Thanks.
Google use protocol buffers for data exchange between different services. Facebook has Thrift. Etc, etc. There's a plenty of protocols and libraries for you to choose from, but I'm afraid you'll have to do the research yourself.
Last time we had such a task (connecting C++ backends with PHP frontend), we wrote our own, very simple protocol. It's not that hard, in fact, it might be easier than implementing some abstraction on both sides.
I want to create a live, checkers-like app, which will work like this: There will be multiple icons/avatars displayed on this checkerboard like surface. I want to have a command prompt beneath this board, or some other sort of interface, that will allow them to control a certain avatar, and get it to preform actions. Multiple users will be using it at one time, and I will all be able to view the other user's changes/actions to the checkerboard.
What I'm wondering is: what's the best way to do this? I've got my HTML, CSS, and JS approach down, but not my data storage method. I know that, using PHP, I've got the choices to use either: file-based storage, MYSQL, or some other method. I need to know which is better, because I don't want to have server-lag, poor-response time, or some other issue, especially in this case since actions will be preformed every other second 2 or so, by these multiple users.
I've done similar stuff before, but I'm wanting to hear how others would handle it (advice, etc.) from more experienced programmers.
Sounds like a great project for node.js!
To clarify, node.js is a server-side implementation of javascript. What you'll want is a comet based application (a web-based client application that receives server side pushes instead of the client constantly polling the server), which is exactly what node.js is good at.
Traditional ajax calls for your clients to poll the server for data. This creates enormous overhead for both the client and the server. Allowing the server to push requests directly to the client without the client repeatedly asking solves the overhead issue and creates a more responsive interface. This is accomplished by holding asynchronous client connections on the server and only returning when the server has something to respond with. Once the server responds with data, another connection is immediately created and held by the server again until data is ready to be sent.
You may be able to accomplish the same thing with PHP, but I'm not that familiar with PHP and Comet type applications.
Number of users and hosting costs will play into your file vs DB options. If you're planning on more than a couple of users, I'd stick to the database. There are some NoSQL options available out there, but in my experience MySQL is much faster and more reliable than those options.
Good luck with your project!
http://en.wikipedia.org/wiki/Comet_%28programming%29
http://www.nodejs.org/
http://zenmachine.wordpress.com/2010/01/31/node-js-and-comet/
http://socket.io/ - abstracts away the communication layer with your clients based on their capability (LongPolling, WebSockets, etc.)
MySQL and XCache !!!!
Make sure you use predefined statements so MySQL does not need to compile the SQL again. Also memtables could be used to use memory storage
Of course make use of indexes appropriately.
If the 'gamestate' is not that important you can even store everything in XCache.
Remember that XCache does not store data persistently (after Apache restart)
I am developing a non-real time browser RPG game (think Kingdom of Loathing) which would be played from within a Flash app. At first I just wanted to make the communication with server using simply URLLoader to tell PHP what I am doing, and using $_SESSION to store data needed in-between request.
I wonder if it wouldn't be better to base it on a socket connection, an app residing on a server written in Java or Python. The problem is I have never ever written such an app so I have no idea how much I'd have to "shift" my thoughts from simple responding do request (like PHP) to continuously working application. I won't hide I am also concerned about the memory and CPU usage of such Server app, when for example there would be hundreds of users connected. I've done some research.
I have tried to do some research, but thanks to my nil knowledge on the sockets subject I haven't found anything helpful. So, considering the fact I don't need real time data exchange, will it be wise to develop the server side part as socket server, not in plain ol' PHP?
Since your game isn't something that's working in realtime you probably don't need to go down the socket route, though it's certainly a viable option. The nice thing about sockets is that updates would be instant without requiring page refresh (or server poll), so you're right to at least consider it.
If you do want to do a more real-time server setup, you might consider using something like Electroserver - this abstracts out much of the setup for you so you don't have to write your own server from scratch, plus it's free up to a certain number of concurrent users if I recall correctly.
Finally, a third option you have is a modified POST approach using AMF. Look into AMFPHP, it lets you call methods on a PHP back-end directly from your flash application. A little bit faster and easier than simply using POST stuff, but not quite as seamless as a socket connection or a specifically built gaming server.
Lots of options out there, it sounds like you are aware of this and kudos for trying to come up with the best approach rather than just rolling with what you know! I hope this helps, let me know if you have any questions.
Here's a link to Electroserver - http://www.electro-server.com/
I've been scouring Google to find out how I can make Flash bring at least two users together in an environment. What I've been trying to do is, for example: both users load http://example.com/myflashenvironment.html, and on that page is the same flashenv.swf file that they both see from two different computers. In the flashenv.swf there is a movieclip object that is draggable. I want to make it so if user 1 drags the movieclip then user 2 can see it being dragged, over the Internet in some kind of online type of deal. I've been trying to do it at runtime, like an online game.
I've been searching google and I've found things about sockets, but it's very hard to just jump right in when you are me. I've tried to figure out so far that I need a PHP file that creates a connects to my server with fsockopen, and then I need to create a socket? But then I don't know how to have user 1 write the (x, y) coordinates of the movieclip when he drags it and have user 2 automatically pick up those same coordinates.
And please believe me, I used this as a last resort to see if anyone knew what I am talking about. Google just isn't cutting it tonight.
It sounds to me like you need to read up on how to actually use sockets. Once you understand how they work, how you should structure your program should become very clear. You could serialize a small object with whatever you want the other user to see (like a coordinate change, for example).
But nevermind that, PHP is not what you want. PHP is not made for this sort of thing. What you need is some kind of standalone server - you would have to roll your own using C++ or Java, for example. PHP is made for short requests - you can't run it as a server. Yes, it does have sockets, but they're also made for quick one-shot connections. You need something that is always running, I'm assuming.
You should check out some of the flash multiuser servers that are already made if you don't want to roll your own. Red5 is a free one, and SmartFoxServer is a more fully featured server, but it is not free (they do have a free version, but it only supports a few concurrent users).
It is questionable (but not without precedence) to write and run a server in PHP.
The suggested Java based solution fits better for your needs.
If you are totally new to multi-user Flash, I recommend using SmartFox Server. It is very easy to use and there are many tutorials.
it is possible to create the socket server you want in php, but i don't really recommend it.
the difference to traditional php scripts is, you wouldn't run it like it's called over the browser, but a long-running (think infinite loop) cli-server-application (more like java)
simplified it works like this:
php: the script starts and listens for incoming request
flash: the flash app is started and connects to the server
php: the connection (from 2) is stored in an array
flash: now if the user moves his movieclip, the coordinates are sent to the script
php: data arrives (the coordinates from 4). now you loop through all connections and ...
... send the data to all the other movieclips
flash: if data (from 6) arrives, update the mc position accordingly
if the flash connection is terminated, remove it from the array
the problems:
- php is not really well suited for this
- you still have to learn about sockets. there are lots of tutorials on this topic, but most of them cover only single connections.
- depending on where you host it, your provider might not support long-running php-cli apps
No need to write your own server, use sockets or other complicated and time-consuming techniques.
Adobe has created the shared object class for exactly that purpose. You need to have a server running Flash Media Server (or equivalent) and use remote shared objects.