WordPress/wp-includes/compat.php

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<?php
/**
* WordPress implementation for PHP functions either missing from older PHP versions or not included by default.
*
* @package PHP
* @access private
*/
// If gettext isn't available
if ( !function_exists('_') ) {
function _($string) {
return $string;
}
}
/**
* Returns whether PCRE/u (PCRE_UTF8 modifier) is available for use.
*
* @ignore
* @since 4.2.2
* @access private
*
* @param bool $set - Used for testing only
* null : default - get PCRE/u capability
* false : Used for testing - return false for future calls to this function
* 'reset': Used for testing - restore default behavior of this function
*/
function _wp_can_use_pcre_u( $set = null ) {
static $utf8_pcre = 'reset';
if ( null !== $set ) {
$utf8_pcre = $set;
}
if ( 'reset' === $utf8_pcre ) {
$utf8_pcre = @preg_match( '/^./u', 'a' );
}
return $utf8_pcre;
}
if ( ! function_exists( 'mb_substr' ) ) :
function mb_substr( $str, $start, $length = null, $encoding = null ) {
return _mb_substr( $str, $start, $length, $encoding );
}
endif;
/*
* Only understands UTF-8 and 8bit. All other character sets will be treated as 8bit.
* For $encoding === UTF-8, the $str input is expected to be a valid UTF-8 byte sequence.
* The behavior of this function for invalid inputs is undefined.
*/
function _mb_substr( $str, $start, $length = null, $encoding = null ) {
if ( null === $encoding ) {
$encoding = get_option( 'blog_charset' );
}
// The solution below works only for UTF-8,
// so in case of a different charset just use built-in substr()
if ( ! in_array( $encoding, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ) ) ) {
return is_null( $length ) ? substr( $str, $start ) : substr( $str, $start, $length );
}
if ( _wp_can_use_pcre_u() ) {
// Use the regex unicode support to separate the UTF-8 characters into an array
preg_match_all( '/./us', $str, $match );
$chars = is_null( $length ) ? array_slice( $match[0], $start ) : array_slice( $match[0], $start, $length );
return implode( '', $chars );
}
$regex = '/(
[\x00-\x7F] # single-byte sequences 0xxxxxxx
| [\xC2-\xDF][\x80-\xBF] # double-byte sequences 110xxxxx 10xxxxxx
| \xE0[\xA0-\xBF][\x80-\xBF] # triple-byte sequences 1110xxxx 10xxxxxx * 2
| [\xE1-\xEC][\x80-\xBF]{2}
| \xED[\x80-\x9F][\x80-\xBF]
| [\xEE-\xEF][\x80-\xBF]{2}
| \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences 11110xxx 10xxxxxx * 3
| [\xF1-\xF3][\x80-\xBF]{3}
| \xF4[\x80-\x8F][\x80-\xBF]{2}
)/x';
$chars = array( '' ); // Start with 1 element instead of 0 since the first thing we do is pop
do {
// We had some string left over from the last round, but we counted it in that last round.
array_pop( $chars );
// Split by UTF-8 character, limit to 1000 characters (last array element will contain the rest of the string)
$pieces = preg_split( $regex, $str, 1000, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );
$chars = array_merge( $chars, $pieces );
} while ( count( $pieces ) > 1 && $str = array_pop( $pieces ) ); // If there's anything left over, repeat the loop.
return join( '', array_slice( $chars, $start, $length ) );
}
if ( ! function_exists( 'mb_strlen' ) ) :
function mb_strlen( $str, $encoding = null ) {
return _mb_strlen( $str, $encoding );
}
endif;
/*
* Only understands UTF-8 and 8bit. All other character sets will be treated as 8bit.
* For $encoding === UTF-8, the $str input is expected to be a valid UTF-8 byte sequence.
* The behavior of this function for invalid inputs is undefined.
*/
function _mb_strlen( $str, $encoding = null ) {
if ( null === $encoding ) {
$encoding = get_option( 'blog_charset' );
}
// The solution below works only for UTF-8,
// so in case of a different charset just use built-in strlen()
if ( ! in_array( $encoding, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ) ) ) {
return strlen( $str );
}
if ( _wp_can_use_pcre_u() ) {
// Use the regex unicode support to separate the UTF-8 characters into an array
preg_match_all( '/./us', $str, $match );
return count( $match[0] );
}
$regex = '/(?:
[\x00-\x7F] # single-byte sequences 0xxxxxxx
| [\xC2-\xDF][\x80-\xBF] # double-byte sequences 110xxxxx 10xxxxxx
| \xE0[\xA0-\xBF][\x80-\xBF] # triple-byte sequences 1110xxxx 10xxxxxx * 2
| [\xE1-\xEC][\x80-\xBF]{2}
| \xED[\x80-\x9F][\x80-\xBF]
| [\xEE-\xEF][\x80-\xBF]{2}
| \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences 11110xxx 10xxxxxx * 3
| [\xF1-\xF3][\x80-\xBF]{3}
| \xF4[\x80-\x8F][\x80-\xBF]{2}
)/x';
$count = 1; // Start at 1 instead of 0 since the first thing we do is decrement
do {
// We had some string left over from the last round, but we counted it in that last round.
$count--;
// Split by UTF-8 character, limit to 1000 characters (last array element will contain the rest of the string)
$pieces = preg_split( $regex, $str, 1000 );
// Increment
$count += count( $pieces );
} while ( $str = array_pop( $pieces ) ); // If there's anything left over, repeat the loop.
// Fencepost: preg_split() always returns one extra item in the array
return --$count;
}
if ( !function_exists('hash_hmac') ):
function hash_hmac($algo, $data, $key, $raw_output = false) {
return _hash_hmac($algo, $data, $key, $raw_output);
}
endif;
function _hash_hmac($algo, $data, $key, $raw_output = false) {
$packs = array('md5' => 'H32', 'sha1' => 'H40');
if ( !isset($packs[$algo]) )
return false;
$pack = $packs[$algo];
if (strlen($key) > 64)
$key = pack($pack, $algo($key));
$key = str_pad($key, 64, chr(0));
$ipad = (substr($key, 0, 64) ^ str_repeat(chr(0x36), 64));
$opad = (substr($key, 0, 64) ^ str_repeat(chr(0x5C), 64));
$hmac = $algo($opad . pack($pack, $algo($ipad . $data)));
if ( $raw_output )
return pack( $pack, $hmac );
return $hmac;
}
if ( !function_exists('json_encode') ) {
function json_encode( $string ) {
global $wp_json;
if ( ! ( $wp_json instanceof Services_JSON ) ) {
require_once( ABSPATH . WPINC . '/class-json.php' );
$wp_json = new Services_JSON();
}
return $wp_json->encodeUnsafe( $string );
}
}
if ( !function_exists('json_decode') ) {
function json_decode( $string, $assoc_array = false ) {
global $wp_json;
if ( ! ($wp_json instanceof Services_JSON ) ) {
require_once( ABSPATH . WPINC . '/class-json.php' );
$wp_json = new Services_JSON();
}
$res = $wp_json->decode( $string );
if ( $assoc_array )
$res = _json_decode_object_helper( $res );
return $res;
}
function _json_decode_object_helper($data) {
if ( is_object($data) )
$data = get_object_vars($data);
return is_array($data) ? array_map(__FUNCTION__, $data) : $data;
}
}
if ( ! function_exists( 'hash_equals' ) ) :
/**
* Compare two strings in constant time.
*
* This function was added in PHP 5.6.
* It can leak the length of a string.
*
* @since 3.9.2
*
* @param string $a Expected string.
* @param string $b Actual string.
* @return bool Whether strings are equal.
*/
function hash_equals( $a, $b ) {
$a_length = strlen( $a );
if ( $a_length !== strlen( $b ) ) {
return false;
}
$result = 0;
// Do not attempt to "optimize" this.
for ( $i = 0; $i < $a_length; $i++ ) {
$result |= ord( $a[ $i ] ) ^ ord( $b[ $i ] );
}
return $result === 0;
}
endif;
// JSON_PRETTY_PRINT was introduced in PHP 5.4
// Defined here to prevent a notice when using it with wp_json_encode()
if ( ! defined( 'JSON_PRETTY_PRINT' ) ) {
define( 'JSON_PRETTY_PRINT', 128 );
}