PHP Native Interface

PHP Native Interface

PHP Native Interface (PNI) is a php extension this enables PHP code to call and being called by Native applications (Programs Specific to a hardware and operating system platform) and libraries written in other languages such as C, C + + and ASSEMBL Y..

It resembles Java Native Interface (JNI).

Outline

• Outline
• Purpose & Features
• Pitfalls
• Tutorial & Examples
• Installation
• Develpment
• Other

Purpose & Featuressituations

PNI allows programmers to use native code when an application cannot is written entirely in the PHP language. The following is typical situations where you might decide to use native code:

• You want to implement time-critical code in a lower-level, faster programming language.
• You have legacy code or code libraries so want to access from PHP programs.
• You need platform-dependent features isn't supported in PHP.
• You want-to-call other language interface such as C + + assemble etc.

Compared with PHP Extension

As all phpers known, the It is a tranditional-on-the-call C + + so to write PHP extension. However, PNI has multiple virtues:

• Reduce Maintenance Cost

It's a risk of restarting the PHP service when install or update a new PHP extension, especially while operating the PHP C Luster. But with PNI, we just the local interface library.

• Reduce Development Cost

Compared with developing PHP extension, developing native interface just like write native C/C + +.

• Reduce Learning Cost

Developers have no need to learn the Php-api, ZEND-API or PHP extension framework any more. The Data types and PNI framework is more simple.

• Flexible

Php-api and Zend API is also available in native interface.

• Scalable

Increasing native interface have no effect on the current PHP service.

Pitfallstutorial & Examples1.write-C + + code

File pni_math.c#Include<math.h>#Include"Php.h"/** Double pow (double x, double y);*/zval *Pni_pow (Zval **args) {Every PNI function returns Zval (PHP variable), the paramters is in the argsdouble x, y, z; zval *tmp = null, zval *res = null; tmp = args[0]; × = z_dval_p (TMP); //Get the Double value via z_dval_p tmp = args[1]; y = z_dval_p (TMP); //Why do we write it like this instead of ' Y = z_dval_p (args[1]); '? It ' s a C Trap. z = pow (x, y); // Alloc_init_zval (res); //It ' s essential to init return value unless the return value is NULL. zval_double (res, z); //Use zval_double to assign the result of the return variable, the data type is DOUBLE. return res;}               

2.Create the shared library file and move it to the directory which $LD_LIBRARY_PATHContains.

Php-ni-lm-o libpnimath.so pni_math.c

3.Create PHP Code

File testpni.php<?Phptry { $pni=NewPNI (' Libpnimath.so‘); Var_dump ($pni->pni_pow (2.0,6.0));   $noPni = new  PNI ( '/unexisted/library.so var_dump ( $PNI ->undefinedfunction ( 2.0,6.0));  catch (pniexception  $e) { var_dump ( $e ->getmessage ());  var_dump ( $e ->gettraceasstring ());                /span>              

4.Run the PHP script

The output as below

"Dlopen/unexisted/library.so Error (/unexisted/library.so:cannot open shared object file:no such file or directory), 
     DL handle resource is not created.   "#0/root/pni.php (5): pni->__construct ('/unexisted/libr ... ')#1 {main}"  

How to get the data from Zval?

All the operator macros is defined in the Zend APIs.

Z_lval_p (zval_p)   //Get Long (no int) z_bval_p (zval_p)   //Get Booleanz_dval_p (zval_p)   //Get The length of a string/long  

How to assign a value to the return variable

Thus the PNI function return variable is zval,first for all, you need to initialise it by using ALLOC_INIT_ZVAL(res) . And then, assign the value to it.

ZVAL_NULL(z)      // assign NULLZVAL_LONG(z, l)    // assign LONGZVAL_STRING(z, s, duplicate)     //assign a string/char * . Duplicate ? allways be 1.ZVAL_STRINGL(z, s, l, duplicate) //assign a string with fixed length. Duplicate ? the same as above.ZVAL_FALSE(z)ZVAL_TRUE(z)ZVAL_BOOL(z, boolean)    // ZVAL_BOOL(z, 1) and ZVAL_TRUE(z) are the same.Likely, ZVAL_BOOL(z, 0) and ZVAL_FALSE(z) are the same.

It ' s unnecessary to know more about Zend APIs or PHP APIs. All referred above are ample to help us achieve the simple communication between PHP code and C code.

Requirements

• PHP 5.3 or higher, PHP 5.2 untested
• *nix Platform
• Windows untested.

Installation

• Download the Code source

git clone https://github.com/zuocheng-liu/pni.git

• Complie the PNI Extension code

<SRC-PNI&& make install

• Make PNI work

Add the line below to PHP.ini

Extension=pni.so;

• Restart PHP Service

Service PHP-FPM Restart  //CGI modeapachectl restart in   CLI mode

Developmentreporting Bugs and contributing code

Contributions to PNI is highly appreciated either in the form of pulling requests for new features, bug fixes, or just bug R Eports.

Otherrelated Links

• Source Code

Author

• Zuocheng Liu [email protected]

License

The code for PNI is distributed under the terms of version 3.01 of the PHP license. (See LICENSE)

PHP Native Interface