Create your own PHP extension, step by step - phpDay 2012 Verona

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Ever been interested by contributing to the PHP core team?
In this workshop you will not only learn how (easy it is) to create your own PHP extension from scratch but you will also strengthen your knowledge of PHP by disecting its internals.
After this workshop, you will be able to create an extension on your own, whether it is to optimize the most CPU intensive parts of your code, to create new bindings to C libraries or just to leverage your PHP knowledge.
And what if PHP was a web framework for the C developer?
This workshop requires a bit of C knowledge and preferably a *nix system.

Published in: Technology

Create your own PHP extension, step by step - phpDay 2012 Verona

  1. 1. Create your own PHP extension, step by stepPatrick Allaert, Derick Rethans, Rasmus Lerdorf phpDay 2012 Verona, Italy
  2. 2. Patrick Allaert● Founder of Libereco● Playing with PHP/Linux for +10 years● eZ Publish core developer● Author of the APM PHP extension● @patrick_allaert● patrickallaert@php.net● http://github.com/patrickallaert/● http://patrickallaert.blogspot.com/
  3. 3. Derick Rethans● Dutchman living in London● PHP Engineer/Evangelist for 10gen (the MongoDB people), where I also work on the MongoDB PHP driver.● Author of Xdebug● Author of the mcrypt, input_filter, dbus, translit and date/time extensions
  4. 4. Workshop overview● Brief reminders about PHP architecture● Configure your environment● Grab the example extension● Do some exercises while seeing a bit of theory
  5. 5. PHP architecture
  6. 6. Configuring your environment● Debian-like:$ sudo apt-get install php5-dev
  7. 7. Download the sample extensiona) Using git:$ git clonegit://github.com/patrickallaert/PHP_Extension_Workshop.gitb) Download archive at:https://github.com/patrickallaert/PHP_Extension_Workshop/downloads
  8. 8. Minimal C code (myext.c)#ifdef HAVE_CONFIG_H#include "config.h"#endif#include "php.h"#include "php_ini.h"#include "ext/standard/info.h"#include "php_myext.h"zend_module_entry myext_module_entry = { STANDARD_MODULE_HEADER, "myext", NULL, /* Function entries */ NULL, /* Module init */ NULL, /* Module shutdown */ NULL, /* Request init */ NULL, /* Request shutdown */ NULL, /* Module information */ "0.1", /* Replace with version number for your extension */ STANDARD_MODULE_PROPERTIES};#ifdef COMPILE_DL_MYEXTZEND_GET_MODULE(myext)#endif
  9. 9. CompilationPrepare build environment:1. $ phpizeConfigure the extension:2. $ ./configureCompile it:3. $ makeInstall it (may require root):4. $ make install
  10. 10. Verify installation$ php -d extension=myext.so -mYou should see “myext” as part of the loadedextensions.
  11. 11. Minimal config.m4dnl config.m4 for myextPHP_ARG_ENABLE(myext, whether to enable myextsupport,[ --enable-myext Enable myext support])if test "$PHP_MYEXT" != "no"; then PHP_NEW_EXTENSION(myext, myext.c,$ext_shared)fi
  12. 12. Exercise one: fibonacci (1/7)● F(n) = F(n-1) + F(n-2) with F(0) = 0 and F(1) = 1
  13. 13. Exercise one: fibonacci (2/7)function fibo($n) { switch ($n) { case 0: case 1: return $n; } return fibo($n-2) + fibo($n-1);}
  14. 14. Exercise one: fibonacci (3/7)
  15. 15. Exercise one: fibonacci (4/7)
  16. 16. Exercise one: fibonacci (5/7)
  17. 17. Exercise one: fibonacci (6/7)
  18. 18. Exercise one: fibonacci (7/7)Compile:$ makeInstall:$ make installTest:$ php -d extension=myext.so -r echo fibonacci(35), “n”;9227465
  19. 19. Exercise one: fibonacci solutionThe full changes required to implement the fibonaccifunction are available at:http://tinyurl.com/PHP-ext-fibonacci
  20. 20. zend_parse_parameters● Handles the conversion of PHP userspace variables into C ones.● Generate errors in the case of missing parameters or if the type is wrong.
  21. 21. zend_parse_parameters● Second parameter describes Type Cod Variable type e the type of the parameter(s) Boolean b zend_bool as a string composed of Long l long characters having all a Double d double special meaning. String s char *, int (length) Path p char *, int (length)● To mark the start of optional Class C zend_class_entry* name parameter(s), a pipe (“|”) Resource r zval* character is used. Array a zval* Object o zval* zval z zval* Zval Z zval** pointer Callback f zend_fcall_info, zend_fcall_info_cache
  22. 22. zend_parse_parameters examples● sleep(), usleep(), func_get_arg(): zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "l", &long)● bin2hex(), quotemeta(), ord(), ucfirst(): zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s", &str, &str_len)● str*pos(): zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "sz|l", &haystack, &haystack_len, &needle, &offset)● var_dump(): zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "+", &args, &argc)● file_put_contents() zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "pz/| lr!", &filename, &filename_len, &data, &flags, &zcontext)
  23. 23. OpenGrok (1/2)● Your best friend to browse PHPs source code: http://lxr.php.net/
  24. 24. OpenGrok (2/2)
  25. 25. zval (=== _zval_struct)struct _zval_struct { /* Variable information */ zvalue_value value; /* value */ zend_uint refcount__gc; zend_uchar type; /* active type */ zend_uchar is_ref__gc;};typedef union _zvalue_value { long lval; /* long value */ double dval; /* double value */ struct { char *val; int len; } str; HashTable *ht; /* hash table value */ zend_object_value obj;} zvalue_value;
  26. 26. Types● IS_NULL● IS_LONG● IS_DOUBLE● IS_BOOL● IS_ARRAY● IS_OBJECT● IS_STRING● IS_RESOURCE● IS_CONSTANT● IS_CONSTANT_ARRAY● IS_CALLABLE● http://lxr.php.net/xref/PHP_TRUNK/Zend/zend.h#IS_NULL
  27. 27. Access macrosZ_TYPE(zval) (zval).typeZ_LVAL(zval) (zval).value.lvalZ_BVAL(zval) ((zend_bool)(zval).value.lval)Z_DVAL(zval) (zval).value.dvalZ_STRVAL(zval) (zval).value.str.valZ_STRLEN(zval) (zval).value.str.lenZ_ARRVAL(zval) (zval).value.htZ_OBJVAL(zval) (zval).value.objZ_OBJ_HANDLE(zval) Z_OBJVAL(zval).handleZ_OBJ_HT(zval) Z_OBJVAL(zval).handlersZ_RESVAL(zval) (zval).value.lvalZ_TYPE_P(zval_p) Z_TYPE(*zval_p)Z_LVAL_P(zval_p) Z_LVAL(*zval_p)Z_BVAL_P(zval_p) Z_BVAL(*zval_p)Z_DVAL_P(zval_p) Z_DVAL(*zval_p)Z_STRVAL_P(zval_p) Z_STRVAL(*zval_p)Z_STRLEN_P(zval_p) Z_STRLEN(*zval_p)Z_ARRVAL_P(zval_p) Z_ARRVAL(*zval_p)Z_RESVAL_P(zval_p) Z_RESVAL(*zval_p)Z_OBJVAL_P(zval_p) Z_OBJVAL(*zval_p)Z_OBJ_HANDLE_P(zval_p) Z_OBJ_HANDLE(*zval_p)Z_OBJ_HT_P(zval_p) Z_OBJ_HT(*zval_p)http://lxr.php.net/xref/PHP_TRUNK/Zend/zend_operators.h#Z_LVAL
  28. 28. Exercise two: my_dump($val) (1/2)● Create a very simple my_dump($val) function:● my_dump(null); // null value!● my_dump(42); // Long: 42● my_dump(123.456); // Double: 123.456● my_dump(true); // Boolean: true● my_dump(“hello”); // String: hello
  29. 29. Exercise two: my_dump($val) (2/2)● Hints:● Define a pointer to a zval: zval *val;● Use “z” with zend_parse_parameters()● Switch/case based on the type of val (Z_TYPE_P(uservar))● Use php_printf() to print, except for strings from zval, since they may contain NULL characters: PHPWRITE(const char *, size_t);
  30. 30. Exercise two: solutionPHP_FUNCTION(my_dump) { zval *val; if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "z", val) ==FAILURE) { return; } switch (Z_TYPE_P(val)) { case IS_NULL: php_printf("NULL"); break; case IS_BOOL: php_printf("Boolean: %s", Z_LVAL_P(val) ? "true" : "false"); break; case IS_LONG: php_printf("Long: %ld", Z_LVAL_P(val)); break; case IS_DOUBLE: php_printf("Double: %f", Z_DVAL_P(val)); break; case IS_STRING: php_printf("String: "); PHPWRITE(Z_STRVAL_P(val), Z_STRLEN_P(val)); break; default: php_printf("Not supported"); }}
  31. 31. PHP life cycles● 4 functions (2 initializations, 2 shutdowns ones) let you do stuff at specific moments of the PHP life cycles: ● PHP_MINIT_FUNCTION ● PHP_MSHUTDOWN_FUNCTION ● PHP_RINIT_FUNCTION ● PHP_RSHUTDOWN_FUNCTION
  32. 32. PHP life cycles - CLI● Credits: Extending and Embedding PHP by Sara Golemon (2006 June 9th)
  33. 33. PHP life cycles – Web server (prefork)● Credits: Extending and Embedding PHP by Sara Golemon (2006 June 9th)
  34. 34. PHP life cycles - Web server (multi thread)● Credits: Extending and Embedding PHP by Sara Golemon (2006 June 9th)
  35. 35. Exercise three: MyClass (1/10)● Steps: ● Create a class named “MyClass” ● Create a class constant ● Add some properties with various visibilities/modifiers ● Add some methods
  36. 36. Exercise three: MyClass (2/10)
  37. 37. Exercise three: MyClass (3/10)● http://tinyurl.com/PHP-ext-MyClass-1
  38. 38. Exercise three: MyClass (4/10)● Declaring a class constant can be made from a C type: ● zend_declare_class_constant_null(); ● zend_declare_class_constant_long(); ● zend_declare_class_constant_bool(); ● zend_declare_class_constant_double(); ● zend_declare_class_constant_stringl(); ● zend_declare_class_constant_string();● Or from a zval: ● zend_declare_class_constant();
  39. 39. Exercise three: MyClass (5/10)● http://tinyurl.com/PHP-ext-MyClass-2
  40. 40. Exercise three: MyClass (6/10)● Creating class properties can be made from a C type: ● zend_declare_property_long(); ● zend_declare_property_bool(); ● zend_declare_property_double(); ● zend_declare_property_stringl(); ● zend_declare_property_string();● Or from a zval: ● zend_declare_property();● Visibility: ● ZEND_ACC_PUBLIC, ZEND_ACC_PROTECTED, ZEND_ACC_PRIVATE● Modifiers: ● ZEND_ACC_STATIC, ZEND_ACC_ABSTRACT, ZEND_ACC_FINAL
  41. 41. Exercise three: MyClass (7/10)● http://tinyurl.com/PHP-ext-MyClass-3
  42. 42. Exercise three: MyClass (8/10)
  43. 43. Exercise three: MyClass (9/10)
  44. 44. Exercise three: MyClass (10/10)● http://tinyurl.com/PHP-ext-MyClass-4
  45. 45. Questions?
  46. 46. Thanks● Dont forget to rate this workshop on https://joind.in/6386

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