[PHP] Modularity--Optimizing Includes and Libs
Hi; I have a question regarding includes and writing library modules in PHP. In one of the replies to my previous e-mail,I was told that PHP parses/compiles pages everytime a new request comes in. So, does this mean we have to minimize the amount of code per page (which also means to minimize number of includes) to improve response time? I mean, usually in many programming languages, it is a common practice to gather shared functions in a library and include/import them from individual scripts. But, in case of PHP, given that this library will also be parsed/compiled per every request, is this a bad practice? What is the alternative to this? Replicate functions that are used in scripts in every page? Thanks, Baho __ Terrorist Attacks on U.S. - How can you help? Donate cash, emergency relief information http://dailynews.yahoo.com/fc/US/Emergency_Information/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] To contact the list administrators, e-mail: [EMAIL PROTECTED]
[PHP] PHP vs. PERL (Functional Comparison)??
Hi; I am planning to implement a new site which will be using mysql db heavily, and I am in the middle of (and stuck:) deciding what I should use for implementation. I would definitely prefer Java Servlets, but it is very expensive to host servlets, so I am only comparing PHP vs. Perl. I have been hearing very good things about PHP for a long time, and I started reading the manual/tutorial posted on php.net. To be honest, I didn't see much difference from perl. It is almost identical (I have to admit, there are some practical advantages, but not a huge difference), even the syntax is almost same to perl. Comparing basic functional stuff: 1.Speed: If you use mod_perl or fastcgi kind of deals (which are based on threadding instead of forking), I don't think PHP is considerably faster than perl? Is that the case? 2.Database Connection: What is the BIG advantage of PHP here? Using DBI packages for perl, and fastcgi for db connection pooling, you can achieve the same thing, I guess. It just looks like PHP has some of these libraries embedded in the core language, but the idea is same--implementing the native db protocol over sockets? 3.Shared Memory, global variables, etc: I was expecting a better interface for this in PHP, and I was really disappointed to see that developers have to use O/S level shared memory. First of all, this is not available on Windows And, it is kind of messy and hard to use, especially when you compare this to Java's static variables. 4.Session Management: If you use files to manage sessions, same thing can be achieved in perl. Regarding in memory session management, as far as I know, FastCGI can share variables among sessions, so it shouldn't be hard to write a session manager in perl as well. 5.Architecture: I couldn't find any doc about how PHP works. And any answer to important questions, like -How does compilation process work? Does the PHP engine compile htmls first time a request is made to that html and use that compiled code later on(just like JSPs), or does it compile everytime? Is PHP engine an interpreter, jvm-like byte-code generator/executer or a compiler? -How does threadding work? How can you cache stuff, etc.? -What is the generic lifecycle of a request/response? 6. Embedding scripts in HTML: Well, I mean, this is similar to JSP, but what the hell, you can use AA . AA; syntax and embed any string you want at any point by mixing and matching HTML and perl code. I mean, yeah PHP is easier, but it is not considerably easier, I believe. I have been searching the internet to find some serious comparisons, but all I found was a stupid page which compares the syntax rather than functionality. As I said, I really need to start developing soon, and I would appreciate comments regarding this issue. Thanks in advance, Baho. __ Terrorist Attacks on U.S. - How can you help? Donate cash, emergency relief information http://dailynews.yahoo.com/fc/US/Emergency_Information/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] To contact the list administrators, e-mail: [EMAIL PROTECTED]
Re: [PHP] PHP vs. PERL (Functional Comparison)??
Why on earth would you prefer java servlets? Hmm... Let's see;Java is a full-fledge, totally OOP and awesome programming language but not a scripting language. Speed (will be mentioning this later), having total control over whatever you want (exception handling, db pooling, caching, syncrhonization, threadding, etc. etc.), ease of use, etc. etc. I mean, come on;) veins as well), therefore its imho much easier to do web programming with php. That is what I saw, but as I said, I didn't see a lot of difference between perl and php, I mean, C++ and perl are very different, likewise java and perl or other languages, but PHP has a very similar syntax. FYI, JSP is the slowest to my knowledge. The first request is slow since JSPs are compiled into servlets (java classes)... But, then it is not bad... In fact, I saw some comparisons showing that servlets are kicking ass! But, again, I mean, this all depends on how you design/configure the system, one simple example:java used to crap out (before 1.2, don't know the latest situation, but heard that it is better) after 40-50 threads per jvm, so if you have more than 40-50 concurrent requests, starting couple of servlet engines on different jvms and using apache dispatching improves the speed a lot! Likewise, tricks like using caching, staying away from classic traps (i.e. using StringBuffers instead of Strings when needed), minimizing garbage collection, etc. etc. Also, with the introduction of JIT and hotspot capable JREs, java is doing pretty well these days...You can check comparisons at rasin servlet engine page. No, its not available on Windows, but then again, why on earth would you want to use Windows? ;) Same here;) I am supposed to implement this sytem on windows 2000...But I totally agree! I would definitely prefer linux or other unix systems over windows... If you really need shm on windows, submit a patch, hint, its just a mmap() :) Well, what I meant was something like ease of sharing data in java (using static variables) and dealing with synchronization is extremely easy in java... Also, FastCGI is not that hard as far as I could see, but I am not an expert in that area;) You can use Files or SHM management, or write your own custom session backend using for example MySQL. Using a database in the backhand is what huge sites are doing, but they have huge boxes to run these databases and very fast network infrastructure. Do you think overhead of serializing/de-serializing session for every request via the database is a lot? Files again is??? I don't know... As you specified SHM is not very nice either (dealing with synchronization might be messy). No. Its compile and execute everytime ??? Don't you think using perl and printing out html from the code is faster than this? I mean, parsing the whole html doesn't seem very good???Actually, this is what I was scared of. I mean, for example say you have an html that consists of blocks... Making every block an include is clean, but this time, php engine has to read all of these includes, and parse the html+php and compile/run php everytime a request is made??? I am not sure about this? Yes, but do you want your web designer going through your perl code Hmmm, good point, hehehehe... Thanks a lot for your time and I appreciate your comments. Baho... __ Terrorist Attacks on U.S. - How can you help? Donate cash, emergency relief information http://dailynews.yahoo.com/fc/US/Emergency_Information/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] To contact the list administrators, e-mail: [EMAIL PROTECTED]
Re: [PHP] PHP vs. PERL (Functional Comparison)??
Threading instead of forking? None of these do either. Apache is a pre-forking multi-process server and both PHP and mod_perl are part of these pre-forked processes. Neither mod_perl nor PHP do any threading nor forking. ??? I didn't get this? Aren't these pre-forked processes handle requests using threads internally? Say you configure apache to pre-fork 5 server processes, what you are saying implies that you can only handle 5 concurrent requests?? can you please explain this more? Again, the architectural difference makes this a lot easier to do in a single-process JVM scenario. Note that such a single-process JVM architecture which maintains static objects is very hard to scale cleanly. Actually, as far as I know, you can configure tomcat or other servlet engines to start multiple servlet engines (JVMs) and the dispatcher code makes sure that every user goes to the same JVM for subsequent requests. So, you can scale with this architecture... The lifecycle of a request/response matches the lifecycle of an HTTP request/response. Actually, I was asking the low-level information, I mean something like web server receives the request, hands this over to mod_php, that requests a thread from the worker threads, so on so forth... Anyways, once again, thanks for your time... Baho. __ Terrorist Attacks on U.S. - How can you help? Donate cash, emergency relief information http://dailynews.yahoo.com/fc/US/Emergency_Information/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] To contact the list administrators, e-mail: [EMAIL PROTECTED]
