The why and how of moving to php 7
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The document discusses the importance and methods of upgrading to PHP 7.x, highlighting both the reasons to upgrade and the challenges involved in the process. It outlines the significant changes in PHP 7, such as performance improvements, new features, and deprecated functions, along with statistics on PHP version usage. Additionally, it emphasizes the need for automated tools like PHP_CodeSniffer and PHPCompatibility to assist in the upgrade process and ensure compatibility across different PHP versions.
The why and how of moving to php 7
- 1. The Why and How of moving to PHP 7.x
- 2. Join the chat http://www.midwestphp.org/chat Channel #everyday-php
- 3. Who am I ? Wim Godden (@wimgtr)
- 10. My town
- 11. My town
- 12. Belgium – the traffic
- 13. Who am I ? Wim Godden (@wimgtr) Founder of Cu.be Solutions (http://cu.be) Open Source developer since 1997 Developer of PHPCompatibility, OpenX, ... Speaker at Open Source conferences
- 14. Why vs How Part 1 : why upgrade ? Bad reasons : It's cool to have the latest version Annoy sysadmins Oh cool, a new toy ! Part 2 : how to upgrade ? The nightmare of compatibility The joy of automation No miracles here !
- 15. Show of hands 3 / 4 5.0 5.1 5.2 5.3 5.4 5.5 5.6 6.0 7.0 7.1 7.2 7.3 7.4 8.0
- 16. The numbers W3Techs (http://w3techs.com/technologies/details/pl-php/all/all) Now Oct 2018 Jan 2015 PHP 4 : 0.4% 0.8% 1.8% PHP 5 : 50.0% 87.2% 98.2% 5.0 : < 0.1% < 0.1% 0.1% 5.1 : 0.3% 0.5% 1.2% 5.2 : 6.1% 7.8% 19.2% 5.3 : 14.8% 19.7% 45.5% 5.4 : 17.7% 21.2% 26.9% 5.5 : 10.0% 15.4% 6.3% 5.6 : 51.0% 35.3% 0.5% PHP 7 : 49.6% 12.0% 7.0 : 19.4% 66.8% 7.1 : 17.8% 31.2% 7.2 : 35.3% 2.1% 7.3 : 24.8% 7.4 : 2.7%
- 17. 5.3 – 5.6 quick recap Namespaces () Late static binding Closures Better garbage collection Goto Mysqlnd Performance gain Short array syntax Traits Built-in webserver Binary notation No more register_globals, magic_quotes_gpc and safe_mode Generators (yield keyword) password_hash() function Built-in opcache
- 18. PHP 7.x – what's changed ? New features Performance and memory usage Improved consistency Lots of things removed or deprecated
- 19. New things – Scalar type + return type declarations (7.0) New scalar types : int, float, bool and string Return type can be specified as well (and can be scalar type as well)
- 20. Weak and strong typing Weak : Default Parameters will be coerced (PHP 5 style) Strong/strict : At top of file : Strict typing is file-specific, so must be enabled in each file ! If wrong type is given, a TypeError is thrown : Fatal error: Uncaught TypeError: Return value of testFunction() must be of the type integer, string returned Returning null is also invalid → if you want an int, you will get an int or an error
- 21. Null coalescing operator (??) PHP 5 : PHP 7 : Can be chained :
- 23. Spaceship operator (<=>) Compares expressions Returns -1, 0 or 1 Examples :
- 24. Unicode codepoint escape syntax Converts hexadecimal Unicode codepoint to UTF8 double quoted string will output :
- 25. CSPRNG functions Cross platform functions to generate random data Cryptographically secure 2 functions : random_bytes($length) random_int($min, $max)
- 26. Deprecated in PHP 7.0 PHP 4 style constructors Static calls to non-static methods
- 27. Error handling in PHP 7 Most fatal errors in PHP 5 → Exceptions in PHP 7 New class : Error If your PHP 5 code has a class called Error, you will need to rename it All Error and Exception classes now implement Throwable Error Flow : Error is thrown Bubbles up through called functions/methods At first matching catch block, code is run No matching catch → default exception handler No default exception handler → Fatal error
- 29. Variable handling PHP 7 uses abstract syntax tree (AST) Can be detected automatically in some cases Requires manual fixing and testing
- 31. Other changes (1/2) Invalid octals now throw a ParseError PHP Parse error: Invalid numeric literal in octal.php Negative bitshifts throw an ArithmeticError Fatal error: Uncaught ArithmeticError: Bit shift by negative number Division by zero throws DivisionByZeroError Hexadecimal strings are no longer numeric In PHP 5 : bool(true) In PHP 7 : bool(false)
- 32. Other changes (2/2) New reserved keywords : bool, float, int, null, string, true, false Reserved for future use : mixed, number, object, resource, void (7.1), iterable (7.1) However, keyword usage inside classes is less restrictive. This is now allowed :
- 33. Performance and memory usage from 5.6 to 7.0 Performance : 200 – 300% increase How ? Core optimizations More direct approach Fewer memory allocations Smaller data structures across all data types … Reduced memory usage : up to 50% ! Big impact on large frameworks Even bigger impact on codebases such as Wordpress, Drupal, ...
- 34. PHP 7.0 → 7.1 (1/2) Nullable types Exception on passing too few function arguments Fatal error: Uncaught ArgumentCountError: Too few arguments to function test(), 0 passed in %s on line %d and exactly 1 expected in %s:%d
- 35. PHP 7.0 → 7.1 (2/2) DateTime constructor now uses microseconds SSLv2 stream support has been dropped
- 36. PHP 7.1 → 7.2 object type is available call parameter type and return type of any objects Sodium extension added : modern cryptographic library TLS version used is now 1.0, 1.1 or 1.2 (instead of 1.0 only) create_function() is deprecated __autoload() is deprecated each() is deprecated
- 37. PHP 7.2 → 7.3 (1/2) Flexible heredoc and nowdoc Trailing commas are allowed in function calls
- 38. PHP 7.2 → 7.3 (2/2) array_key_first() and array_key_last() Argon2 hashing algorithm continue in switch statement generates a warning Mysqli and PDO_Mysql now return fractional seconds for datetime, time and timestamp (!) Constants can no longer be defined as case-insensitive is_countable()
- 39. PHP 7.3 → 7.4 (1/2) Typed properties → Will be checked on read/write Null Coalesce Assignment operator : FFI (Foreign Function Interface) : Allows PHP to talk directly to C libraries Experimental Preloading Like Opcache on steroids Will preload all files and opcache them Requires restart of web server / PHP-FPM to reload any changed files
- 40. PHP 7.3 → 7.4 (2/2) Operator precedence deprecation : In PHP 7.4 : Deprecated: The behavior of unparenthesized expressions containing both '.' and '+'/'-' will change in PHP 8: '+'/'-' will take a higher precedence in test.php on line 4 Deprecated curly brace syntax for accessing array elements : Output : 3 !!!
- 41. So... Should you upgrade today ?
- 42. Postponing upgrades - End-Of-Life In the past : we'll see Now : 2 years after initial release Critical security patches : 1 extra year (but no regular bugfixes) In practice 7.1 was released Dec 2016 → already EOL (Nov 30 2019) 7.2 was released Nov 2017 → already EOL (Nov 2019) 7.3 was released Dec 2018 → EOL Dec 2020 7.4 was released Nov 28 → EOL Nov 2021 If you’re on PHP 7.0 - 7.2 → start upgrading !
- 43. Postponing upgrades Security Performance Framework support Symfony 5 : PHP 7.2.5+ Zend Framework 3 : PHP 5.6+ Laravel 6 : PHP 7.2+ Developer motivation
- 44. Upgrade paths 1 upgrade every 5 years Knowledge of upgrade steps will be forgotten Documentation is not very useful (for example : SysvInit → Systemd) Massive task to upgrade all apps, all environments, all servers Upgrade every release Upgrade steps can be automated Can be integrated with continuous integration and continuous deployment Documentation is in the automation flow
- 45. So you want to upgrade... Option 1 : run your unit tests Option 2 : visit each page (good luck !) + check error_log Or : record visits, then replay log on test environment Or : proxy requests to 2 environments Option 3 : automated static analysis
- 46. Back in 2010... PHP Architect @ Belgian Railways 8 years of legacy code (4.x and 5.x) 40+ different developers 40+ projects Challenge : migrate all projects from PHP 5.1.x (on Solaris) to PHP 5.3.x (on Linux)
- 47. The idea Automate it How ? → Use the CI environment Which tool ? → PHP_CodeSniffer
- 48. PHP_CodeSniffer Originally PEAR package (pear install PHP_CodeSniffer) Also on Composer now Detects coding standard violations Supports multiple standards Static analysis tool → Runs without executing code → Splits code in tokens Ex. : T_OPEN_CURLY_BRACKET T_FALSE T_SEMICOLON → Parses each file separately
- 49. PHP_CodeSniffer Let's see what it looks like
- 50. PHP_CodeSniffer options -i Show available standards -p Show progress -s Show real error/warning sniff names -n Ignore warnings -v Verbose --parallel=x (since PHP_CodeSniffer 3)
- 51. PHPCompatibility PHP_CodeSniffer standard Only purpose : find compatibility issues Detects : Deprecated functions Deprecated extensions Deprecated php.ini settings and ini_set() calls Prohibited function names, class names, … … Works for PHP 5.0 5.3 and above (5.4 for PHP_CodeSniffer 3 support)
- 52. PHPCompatibility – making it work - Composer In require-dev : phpcompatibility/php-compatibility If PHPCompatibility is the only PHP CodeSniffer standard : "scripts": { "post-install-cmd": ""vendor/bin/phpcs" --config-set installed_paths vendor/wimg/php-compatibility/PHPCompatibility", "post-update-cmd" : ""vendor/bin/phpcs" --config-set installed_paths vendor/wimg/php-compatibility/PHPCompatibility" } Otherwise use one of these : DealerDirect/phpcodesniffer-composer-installer higidi/composer-phpcodesniffer-standards-plugin
- 53. PHPCompatibility – making it work - Github Download PHP CodeSniffer Download from http://github.com/phpcompatibility/PHPCompatibility Run phpcs --config-set installed_paths /path/to/PHPCompatibility
- 54. PHPCompatibility – making it work – testing and running Check if coding standard is available : phpcs -i Should output something similar to : The installed coding standards are MySource, PEAR, PHPCompatibility, PHPCS, PSR1, PSR2, Squiz and Zend To run : phpcs --standard=PHPCompatibility /path/of/your/code
- 55. Important notes Large directories → can be slow ! Use --extensions=php No point scanning .js files Test PHP x.x compatibility → needs PHP x.x on the system Static analysis Doesn't actually run the code Can not detect every single incompatibility → some things only happen on runtime Provides filename and line number
- 56. Checking for specific versions Default : latest PHP version Check for single version : phpcs --standard=PHPCompatibility --runtime-set testVersion 7.0 srcdir Check for multiple specific versions : phpcs --standard=PHPCompatibility --runtime-set testVersion 7.0-7.1 srcdir Check for minimum version : phpcs --standard=PHPCompatibility --runtime-set testVersion 7.0- srcdir Checking for older version : phpcs --standard=PHPCompatibility --runtime-set testVersion 5.0 srcdir
- 57. Extra rulesets
- 58. Other tools For Wordpress : PHP Compatibility Checker (uses PHPCompatibility)
- 59. Other tools For Wordpress : PHP Compatibility Checker (uses PHPCompatibility) PhpStorm 10+ : PHP 7 Compatibility Inspection sstalle/php7cc : similar functionality, slightly less up-to-date phan/phan : general static analyzer, compatibility checks are mostly useful for type checking adamculp/php-compatibility-check : docker image that uses PHPCompatibility, php7cc and phan
- 60. Conclusion No 100% detection But : 95% automation = lots of time saved ! First : PHPCompatibility on local machine Then : use your CI environment Start upgrading !
- 61. Big thanks to... Juliette Reinders Folmer Has been the main contributor (95%+ of all commits) in last 3 years PHP_CodeSniffer wizard
- 62. Questions ?
- 63. Questions ?
- 64. Thanks !