Jason Mayfield October 31st, 2007

43 Ways to Optimize your PHP Code

List from: http://reinholdweber.com/?p=3 , just to give credit where credit is due. This information is great, so thanks to the author at http://reinholdweber. 
  1. If a method can be static, declare it static. Speed improvement is by a factor of 4.
  2. echo is faster than print.
  3. Use echo's multiple parameters instead of string concatenation.
  4. Set the maxvalue for your for-loops before and not in the loop.
  5. Unset your variables to free memory, especially large arrays.
  6. Avoid magic like __get, __set, __autoload
  7. require_once() is expensive
  8. Use full paths in includes and requires, less time spent on resolving the OS paths.
  9. If you need to find out the time when the script started executing, $_SERVER[’REQUEST_TIME’] is preferred to time()
  10. See if you can use strncasecmp, strpbrk and stripos instead of regex
  11. str_replace is faster than preg_replace, but strtr is faster than str_replace by a factor of 4
  12. If the function, such as string replacement function, accepts both arrays and single characters as arguments, and if your argument list is not too long, consider writing a few redundant replacement statements, passing one character at a time, instead of one line of code that accepts arrays as search and replace arguments.
  13. It's better to use select statements than multi if, else if, statements.
  14. Error suppression with @ is very slow.
  15. Turn on apache's mod_deflate
  16. Close your database connections when you're done with them
  17. $row[’id’] is 7 times faster than $row[id]
  18. Error messages are expensive
  19. Do not use functions inside of for loop, such as for ($x=0; $x < count($array); $x) The count() function gets called each time.
  20. Incrementing a local variable in a method is the fastest. Nearly the same as calling a local variable in a function.
  21. Incrementing a global variable is 2 times slow than a local var.
  22. Incrementing an object property (eg. $this->prop++) is 3 times slower than a local variable.
  23. Incrementing an undefined local variable is 9-10 times slower than a pre-initialized one.
  24. Just declaring a global variable without using it in a function also slows things down (by about the same amount as incrementing a local var). PHP probably does a check to see if the global exists.
  25. Method invocation appears to be independent of the number of methods defined in the class because I added 10 more methods to the test class (before and after the test method) with no change in performance.
  26. Methods in derived classes run faster than ones defined in the base class.
  27. A function call with one parameter and an empty function body takes about the same time as doing 7-8 $localvar++ operations. A similar method call is of course about 15 $localvar++ operations.
  28. Surrounding your string by ' instead of " will make things interpret a little faster since php looks for variables inside "…" but not inside '…'. Of course you can only do this when you don't need to have variables in the string.
  29. When echoing strings it's faster to separate them by comma instead of dot. Note: This only works with echo, which is a function that can take several strings as arguments.
  30. A PHP script will be served at least 2-10 times slower than a static HTML page by Apache. Try to use more static HTML pages and fewer scripts.
  31. Your PHP scripts are recompiled every time unless the scripts are cached. Install a PHP caching product to typically increase performance by 25-100% by removing compile times.
  32. Cache as much as possible. Use memcached – memcached is a high-performance memory object caching system intended to speed up dynamic web applications by alleviating database load. OP code caches are useful so that your script does not have to be compiled on every request
  33. When working with strings and you need to check that the string is either of a certain length you'd understandably would want to use the strlen() function. This function is pretty quick since it's operation does not perform any calculation but merely return the already known length of a string available in the zval structure (internal C struct used to store variables in PHP). However because strlen() is a function it is still somewhat slow because the function call requires several operations such as lowercase & hashtable lookup followed by the execution of said function. In some instance you can improve the speed of your code by using an isset() trick.

    Ex.
    if (strlen($foo) < 5) { echo "Foo is too short"; }
    vs.
    if (!isset($foo{5})) { echo "Foo is too short"; }

    Calling isset() happens to be faster then strlen() because unlike strlen(), isset() is a language construct and not a function meaning that it's execution does not require function lookups and lowercase. This means you have virtually no overhead on top of the actual code that determines the string's length.

  34. When incrementing or decrementing the value of the variable $i++ happens to be a tad slower then ++$i. This is something PHP specific and does not apply to other languages, so don't go modifying your C or Java code thinking it'll suddenly become faster, it won't. ++$i happens to be faster in PHP because instead of 4 opcodes used for $i++ you only need 3. Post incrementation actually causes in the creation of a temporary var that is then incremented. While pre-incrementation increases the original value directly. This is one of the optimization that opcode optimized like Zend's PHP optimizer. It is a still a good idea to keep in mind since not all opcode optimizers perform this optimization and there are plenty of ISPs and servers running without an opcode optimizer.
  35. Not everything has to be OOP, often it is too much overhead, each method and object call consumes a lot of memory.
  36. Do not implement every data structure as a class, arrays are useful, too
  37. Don't split methods too much, think, which code you will really re-use
  38. You can always split the code of a method later, when needed
  39. Make use of the countless predefined functions
  40. If you have very time consuming functions in your code, consider writing them as C extensions
  41. Profile your code. A profiler shows you, which parts of your code consumes how many time. The Xdebug debugger already contains a profiler. Profiling shows you the bottlenecks in overview
  42. mod_gzip which is available as an Apache module compresses your data on the fly and can reduce the data to transfer up to 80%
  43. Excellent Article about optimizing php by John Lim

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Comments

  1. http://reinholdweber.com/?p=3


    Ethan
    November 2nd, 2007

  2. Great source ethan!

    jason


    Jason
    November 2nd, 2007

  3. These seem to be a really good source for improvements that a lot of people miss!


    Chris Vincent
    November 3rd, 2007

  4. “…$row[’id’] is 7 times faster than $row[id]…” and also easer to read!!!!


    Master Employment
    November 15th, 2007

  5. Great Stuff! I have never even heard of strtr() wow do I feel like a noob. I am a str_replace() junkie, I use it too much :)


    MiramarDesign
    March 28th, 2008

  6. hey dude nice work.. i’ve learn lots of it.. good job.. ^^


    fordy87
    August 16th, 2008

  7. Sadly, I keep seeing this list of PHP optimisation tricks posted around the Internet. I’ve literally stumbled onto the same techniques like 30948320948 times now.

    Good job though.


    Dwayne from Probably Sucks Blog
    October 13th, 2008

  8. #33: Yes, but which is easier to read? Almost all of these tricks have a negligible effect on the performance of your code; you’re better off going with whichever is easier to understand.

    #34: What makes you think this doesn’t apply to other languages?

    ++$i does something like

    return $i+1;

    whereas

    $i++ does something like

    $j = $i;
    $i = $i+1;
    return $j;

    Which… is pretty much the same for every language. There’s no two ways around it??

    Most of these tips are good to be aware of, but don’t become wrapped up in stupid little performance tweaks.


    Mark
    December 15th, 2008

  9. err…

    ++$i does something like
    $i = $i+1;
    return $i;

    You know what I mean.


    Mark
    December 15th, 2008

  10. I am still learning PHP, so this will definitely come in handy.

    Good find and thanks for sharing.


    Geoserv
    January 29th, 2009

  11. While I agree with all of the things said in the article, I feel like it is unnecessary to focus on such tight optimization.

    Scripting languages will never be bare metal speed demons – object oriented scripting languages are *meant* to be quick to write, quick to read, and easier to maintain; at the price of being slower than their statically compiled parents.

    I personally think the number one thing anyone *should* do to speed up execution times of a script is to use an OP code cache or memcached (as you have mentioned). Not just for caching DB results, but, for caching the results of heavy computations – I built an adserver in PHP for the last company I worked for (don’t ever do it in PHP BTW) and memcached came to the rescue when doing GeoIP calculations for the regions that were hitting us the hardest – rarely anything to do with the DB, but everything to do with the *result*.

    In addition to caching, I think learning to use your DBMS is the second most important optimization trick – many a time I have seen people pull this out of their butt and wonder why it’s so slow: “SELECT * FROM users” where `users` had upwards of 10000 records, then they were whittling down the result set IN PHP for pagination, where this simple little query sped up their application ten fold: “SELECT * FROM users LIMIT 0,10″…

    Now that I have written this entire comment, it appears I am saying that intelligent programming will by default be ‘optimized’ – I, however, do not agree with sacrificing maintainability and/or usability for optimization when memcached/OP Code caches, etc… are perfectly suited for picking up the slack of a well-designed but slow(er) application.


    Parnell Springmeyer
    February 1st, 2009

  12. A question, what about file_exists?
    I have static html’s that are pre generated, but i have to check whether they really exist, şf not i dynamically serve the page and generate the static html on the fly.


    dodo
    February 20th, 2009

  13. [...] is the original post: 43 Ways to Optimize your PHP Code | OpenJason Share and [...]


    43 Ways to Optimize your PHP Code | OpenJason
    May 9th, 2009

  14. Great article, there are a few of these that I was unaware of. I will take these into consideration, thanks.


    matthew
    June 4th, 2009

  15. Unfortunately, some of these optimizations are dead wrong.

    Both ” and ‘ have to scan the string, because ‘ might have \’ and \\ in it. The iteration through the string is killer, not the fact that ” has to do an extra check for $foo.

    echo with . instead of , is often faster, due to buffer sizes and the way I/O is sent. You’d have to benchmark in your app, on your hardware. And it’s rarely the bottleneck.

    In fact, none of these optimizations are likely to make any significant difference in a real webapp.

    Code it as straight-forward as you can, then profile it to find unacceptable bottle-necks and fix those. Leave the rest of your code alone.


    Richard Lynch
    July 9th, 2009

  16. A lot of those are just plain wrong.

    https://groups.google.com/group/make-the-web-faster/browse_thread/thread/ddfbe82dd80408cc?pli=1


    Jason
    July 9th, 2009

  17. nice code very well explained thanks


    cmsnx
    July 16th, 2009

  18. Nice article, I am PHP programmer working for more than 3years, even I didn’t know many of them.


    Mayank
    July 16th, 2009

  19. “6. It’s better to use select statements than multi if, else if, statements.”

    Do you mean switch statements ? ;)


    Marcin
    October 5th, 2009

  20. Above comment should have “13. …” sorry. Please feel free to edit.


    Marcin
    October 5th, 2009

  21. Hi,

    thanks a lot for the great tips.. btw echo is a construct not a function.. right ?


    Mohd Atif
    October 12th, 2009

  22. Yes, echo is a language construct. Quite a few of these tips are completely idiotic. Number two, for instance? It really doesnt matter, unless youre printing a LOT of code.

    http://www.learnphponline.com/php-basics/php-echo-vs-print


    bundyxc
    December 21st, 2009

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