PHP

EXTENSIONSFor Dummies

But I don’t know C!1.compiled

2.strictly typed

3.php internals do “hard” stuff

4.copy and paste!

5.cairo, pecl_http, date, imagick, dio

lxr.php.net

Quick Setup Needs1.compiler

2.sdk (on win, put this on FIRST)

3.tools

4.dependencies

5.code

phpize is your friend!

How to Compile1.phpize

2../configure

3.make

4.make install

5.make test

configure might require –with-php-config

How to Play alonghttps://github.com/auroraeosrose/php-extensions-code.git

git://github.com/auroraeosrose/php-extensions-code.git

1. Set up configuration2. Write a module definition3. Learn about the PHP lifecycle4. Learn about zvals5. Add functions6. ???7. Profit!

Every Other Extensions Talk

DO

IN IT R

ON

G

Which do YOU want?

Please be the solution, not the problemWe need no more painful APIs in PHP

1. Do something you can’t do in userland2. Utilize a C library3. Make slow code faster

Maybe you should just use ffi!

Step 1. What, When, Why

FFI

1. Think about what the API should be2. Look at the C APIs but don’t mimic them3. Write an example of how you WANT it to

work4. Write more then one example!

Step 2. How

1. This is copy and paste1. config.m4 & config.w322. macros for version api changes if

necessary3. main module file (php_{$ext}.c)4. main header file (php_{$ext}.h)

2. Compile it and test!

Step 3. Scaffolding

Configure files

Module struct

Scaffolding rules

1. make sure you name your files in a standard way2. document! use a license header, proto statements3. read the coding standards http://

lxr.php.net/xref/PHP_5_4/CODING_STANDARDS 4. FOLLOW THE CODING STANDARDS5. use version control early on – github is easy!

php –d extension=myext.so –m

The scaffold extension should show up in the list

Make sure to 1. define a version constant2. read and use PHP code standards

Check if it works

1. run-test.php2. make test will magically have output

more at http://qa.php.net/write-test.php and docs at http://qa.php.net/phpt_details.php

Step 4. Write the test

PHPT tests

1. add functions2. get data3. return data

Step 5. Actually do something

long any numeric

double numeric with decimal

char* + int

(length)strings, binary

Hashtabledictionaries,

arrays,structs

object any complicated type

Anatomy of a Function

zval

getting data OUTZ_LVAL(zval) Z_LVAL_P(zval_p) Z_LVAL_PP(zval_pp)

Z_BVAL(zval) Z_BVAL_P(zval_p) Z_BVAL_PP(zval_pp)

Z_DVAL(zval) Z_DVAL_P(zval_p) Z_DVAL_PP(zval_pp)

Z_STRVAL(zval) Z_STRVAL_P(zval_p) Z_STRVAL_PP(zval_pp)

Z_STRLEN(zval) Z_STRLEN_P(zval_p) Z_STRLEN_PP(zval_pp)

Z_ARRVAL(zval) Z_ARRVAL_P(zval_p) Z_ARRVAL_PP(zval_pp)

Z_OBJVAL(zval) Z_OBJVAL_P(zval_p) Z_OBJVAL_PP(zval_pp)

Z_OBJ_HANDLE(zval)

Z_OBJ_HANDLE_P(zval_p)

Z_OBJ_HANDLE_PP(zval_pp)

Z_OBJ_HT(zval) Z_OBJ_HT_P(zval_p) Z_OBJ_HT_PP(zval_pp)

Z_OBJCE(zval) Z_OBJCE_P(zval_p) Z_OBJCE_PP(zval_pp)

Z_OBJPROP(zval) Z_OBJPROP_P(zval_p) Z_OBJPROP_PP(zval_pp)

Z_TYPE(zval) Z_TYPE_P(zval_p) Z_TYPE_PP(zval_pp)

zend_parse_parametersphp type cod

e c type

array or object a zval *

boolean b zend_bool

class C zend_class_entry *

double d double

callable f zend_fcall_info andzend_fcall_info_cache

array or HASH_OF(object) H HashTable*

array h HashTable*

integer l long (NOT INT)

integer L long with LONG_MAX, LONG_MIN limits

object o zval *

object of specific type O zval *, zend_class_entry

string (no null bytes) p char*, int

resource r zval *

string (possible null bytes)

s char*, int

actual zval z zval *

actual zval Z zval**

zend_parse_parameterstype code

variable args (any) * int, zval***

variable args (1 or more) + int, zval***

| anything after is optional, use defaults

/ use SEPARATE_ZVAL_IF_NOT_REF

doesn’t apply to b, l, and d ! C NULL for zval null

Returning Data with return_valueRETURN_RESOURCE(l)

RETURN_BOOL(b)

RETURN_NULL()

RETURN_LONG(l)

RETURN_DOUBLE(d)

RETURN_STRING(s, duplicate)

RETURN_STRINGL(s, l, duplicate)

RETURN_EMPTY_STRING()

RETURN_ZVAL(zv, copy, dtor)

RETURN_FALSE

RETURN_TRUE

RETVAL_RESOURCE(l)

RETVAL_BOOL(b)

RETVAL_NULL()

RETVAL_LONG(l)

RETVAL_DOUBLE(d)

RETVAL_STRING(s, duplicate)

RETVAL_STRINGL(s, l, duplicate)

RETVAL_EMPTY_STRING()

RETVAL_ZVAL(zv, copy, dtor)

RETURN_FALSE

RETURN_TRUE

Complex Data

array_init()

add_(index|assoc)_long()

add_(index|assoc)_bool()

add_(index|assoc)_string()

object_init()

add_property_long()

add_property_bool()

add_property_string()

1. namespaces2. classes3. methods4. constants

Step 6. Make it shiny

Classes

1. name, parent, and flags2. hashtables of methods, default methods,

static methods3. hashtables of static properties, default

properties, and properties4. object handlers 5. union of either file information, or

internal structures (for internal classes)

Lifecycle

PHP stops

MSHUTDOWN – for each extension

RSHUTDOWN – for each request

GSHUTDOWN – for each thread

GINIT – for each thread

RINIT – for each request

MINIT – for each extension

PHP starts

Class Properties

Class Constants

Class Methods

Alter $this

Abstract, Interface, TraitClass Method

ZEND_ACC_IMPLICIT_ABSTRACT_CLASS ZEND_ACC_STATIC

ZEND_ACC_EXPLICIT_ABSTRACT_CLASS ZEND_ACC_ABSTRACT

ZEND_ACC_FINAL_CLASS ZEND_ACC_FINAL

ZEND_ACC_INTERFACE ZEND_ACC_PUBLIC

ZEND_ACC_TRAIT ZEND_ACC_PROTECTED

ZEND_ACC_PRIVATE

ZEND_ACC_CTOR

ZEND_ACC_DTOR

ZEND_ACC_CLONE

spl_ce_FilterIterator->ce_flags |= ZEND_ACC_EXPLICIT_ABSTRACT_CLASS;PHP_ME(DateTime, __construct, arginfo_date_create, ZEND_ACC_CTOR|ZEND_ACC_PUBLIC)

1. globals2. memory management3. custom objects4. object handlers5. thread safety

Step 7. Advanced topics

1. in your header – use ZEND_BEGIN|END_MODULE_GLOBALS

2. create the global access macro in your header (copy and paste)

3. ZEND_DECLARE_MODULE_GLOBALS in every file where you will use them

4. use the macro to access COUNTER_G(basic_counter_value)); }

5. Create ginit/gshutdown functions if your globals need initializing , etc

Global Variables (threads = evil)

emalloc( )• allocates the specified number of bytes

safe_emalloc()• like emalloc but adds a special protection against overflows

efree( )• releases the specified block of memory back to the system

estrdup( )• allocate a buffer and copy the string into that buffer

estrndup( )• same as estrdup when you already know the length of the string

ecalloc( )• allocates the number of bytes and initializes them to zero

erealloc( )• resizes the specified block of memory

https://wiki.php.net/internals/zend_mm

1. clean up what you emalloc (C level destructor)2. read wiki on how to make them extendable!

Object Handlers (black magic)

https://wiki.php.net/internals/engine/objects

TSRMthread safe resource

managerZTS

zend thread safety• tsrm_lsTSRMLS_C

• void ***tsrm_lsTSRMLS_D

• , tsrm_lsTSRMLS_CC

• , void ***tsrm_ls

TSRMLS_DC

1. http://edit.php.net 2. http://svn.php.net/viewvc/phpdoc/en/trunk/referenc

e/

3. PhD is awesomesauce• http://doc.php.net/phd/

4. email pecl-dev@lists.php.net 1. who you are2. what you wrote (with links to your code!)3. why you think it should be in pecl

5. poke me (or other devs)

Step 7. Document, PECL, release

Stuff I didn’t talk about

1. resources (use custom objects instead)2. ini entries (just DON’T)3. threading and parallel processing4. engine hooking

About Me

http://emsmith.net

https://joind.in/6337

auroraeosrose@gmail.com

IRC – freenode – auroraeosrose

#php-gtk #coapp and others

Questions?

HELP WITH DOCS!http://edit.php.nethttp://wiki.php.net/internals

lonestar

12Free codez 4 u!

Resources:http://devzone.zend.com/303/extension-writing-part-i-introduction-to-php-and-zend/ http://blog.golemon.com/2006/06/what-heck-is-tsrmlscc-anyway.html http://www.kchodorow.com/blog/2011/08/11/php-extensions-made-eldrich-installing-php/ http://php.net/manual/en/internals2.phphttps://wiki.php.net/internals http://conf.phpquebec.com/slides/2009/PHP_Extension_Writing-phpquebec_2009.pdf http://devzone.zend.com/1435/wrapping-c-classes-in-a-php-extension/http://lxr.php.net http://www.amazon.com/Extending-Embedding-PHP-Sara-Golemon/dp/067232704X