Tuning and Securing PHP Applications CHAPTER 21 Speeding Up PHP Applications CHAPTER 22 Securing PHP Applications Part VI 27 549669 PP06.qxd 4/4/03 9:27 AM Page 711 27 549669 PP06.qxd 4/4/03 9:27 AM Page 712 Chapter 21 Speeding Up PHP Applications IN THIS CHAPTER ◆ Benchmarking your PHP application ◆ Stress-testing your PHP application ◆ Compressing your PHP application output ◆ Using output caching using jpcache ◆ Using output caching using the PEAR cache ◆ Using function caching using the PEAR cache ◆ Using PHP opcode caching techniques THIS CHAPTER DESCRIBES HOW YOU can speed up your PHP applications using vari- ous techniques, including fine-tuning code, output buffering, output compression, output caching, and code caching. These techniques will enable you to turbocharge your application for the high-volume access scenarios usually present in heavy- traffic Web sites with PHP applications. Optimization isn’t a task that should be undertaken on every piece of code. You must ask yourself, before starting to optimize code, “is this code fast enough?” If the answer is “yes,” optimization probably isn’t necessary. Spending time optimizing existing code could be time wasted if you neglect other tasks for the optimization time. The best advice is to use good tech- niques while constructing the code in the first place and only optimize code that actually needs it. 713 28 549669 ch21.qxd 4/4/03 9:27 AM Page 713 Benchmarking Your PHP Application Most Web programming is done quickly, and often carelessly. When someone needs a new Web application, notifying the developers is often the last priority. Once the developers are notified, the application gets the “was needed yesterday” status. Therefore, developers design quick-and-dirty applications, and lack the necessary time to fine-tune the code. When you plan to develop a new application, try to allocate one-third of your project time to fine-tuning your code. The first step in fine-tuning your code is identifying the most commonly used code segments. You can easily do this by adding spurious print statements to your code or enabling logging/debugging for critical segments of your applications. Once you have identified the segments of code that are most commonly required to service a request, you need to identify any elements that are not operating at optimal speed. To identify slow code, you should review your code as frequently as possible, using the benchmarking techniques described in the following section. Note that optimizing code won’t always improve performance. It’s impor- tant to consider the whole picture when you are experiencing performance problems — if your database is maxed out, your bandwidth not adequate for your traffic, or hardware not keeping up with the demand, optimizing code won’t improve a thing. Benchmarking your code The PEAR package discussed in Chapter 4 includes a set of benchmark classes that you can use to benchmark your code without writing a lot of new code. For exam- ple, Listing 21-1 shows a PHP script that benchmarks a function called myFunction. Listing 21-1: bench1.php <?php // If you have installed PEAR packages in // a different directory than %DocumentRoot%/pear // change the setting below. $PEAR_DIR = $_SERVER[‘DOCUMENT_ROOT’] . ‘/pear’ ; $PATH = $PEAR_DIR; 714 Part VI: Tuning and Securing PHP Applications 28 549669 ch21.qxd 4/4/03 9:27 AM Page 714 ini_set( ‘include_path’, ‘:’ . $PATH . ‘:’ . ini_get(‘include_path’)); require_once ‘Benchmark/Iterate.php’; $benchmark = new Benchmark_Iterate; $benchmark->run(10, ‘myFunction’, $argument); $result = $benchmark->get(); echo “<pre>”; print_r($result); echo “</pre>”; exit; function myFunction($var) { // do something echo ‘x ‘; } ?> The $PEAR_DIR variable points to the PEAR directory, which in this case is installed in %DocumentRoot%/pear. The $PEAR_DIR variable is included in the include_path using the ini_set() call. Then the Benchmark/Iterate.php class is loaded into the application. A benchmark Iterate object called $benchmark is created. This object is used to run the myFunction function 10 times. The $argument variable is passed to myFunction each time it is called. The profiling result of the multiple execution, $result, is retrieved using the get() method of the benchmark object. The result is output to the screen using the print_r() function. A sample of typical output looks as follows: x x x x x x x x x x Array ( [1] => 0.00074100494384766 [2] => 0.00013399124145508 [3] => 0.00013101100921631 [4] => 0.0001380443572998 [5] => 0.00014901161193848 [6] => 0.00013506412506104 [7] => 0.00013101100921631 [8] => 0.00013399124145508 Chapter 21: Speeding Up PHP Applications 715 28 549669 ch21.qxd 4/4/03 9:27 AM Page 715 . Page 712 Chapter 21 Speeding Up PHP Applications IN THIS CHAPTER ◆ Benchmarking your PHP application ◆ Stress-testing your PHP application ◆ Compressing your PHP application output ◆ Using output. Tuning and Securing PHP Applications CHAPTER 21 Speeding Up PHP Applications CHAPTER 22 Securing PHP Applications Part VI 27 549669 PP06.qxd 4/4/03 9:27 AM. lot of new code. For exam- ple, Listing 21-1 shows a PHP script that benchmarks a function called myFunction. Listing 21-1: bench1 .php < ?php // If you have installed PEAR packages in // a