<?php
/**
* Unicode normalization routines
*
* Copyright © 2004 Brion Vibber <brion@pobox.com>
* http://www.mediawiki.org/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
* @ingroup UtfNormal
*/
/**
* @defgroup UtfNormal UtfNormal
*/
define( 'NORMALIZE_ICU', function_exists( 'utf8_normalize' ) );
define( 'NORMALIZE_INTL', function_exists( 'normalizer_normalize' ) );
/**
* Unicode normalization routines for working with UTF-8 strings.
* Currently assumes that input strings are valid UTF-8!
*
* Not as fast as I'd like, but should be usable for most purposes.
* UtfNormal::toNFC() will bail early if given ASCII text or text
* it can quickly determine is already normalized.
*
* All functions can be called static.
*
* See description of forms at http://www.unicode.org/reports/tr15/
*
* @ingroup UtfNormal
*/
class UtfNormal {
/**
* For using the ICU wrapper
*/
const UNORM_NONE = 1;
const UNORM_NFD = 2;
const UNORM_NFKD = 3;
const UNORM_NFC = 4;
const UNORM_NFKC = 5;
const UNORM_FCD = 6;
const UNORM_DEFAULT = self::UNORM_NFC;
static $utfCombiningClass = null;
static $utfCanonicalComp = null;
static $utfCanonicalDecomp = null;
# Load compatibility decompositions on demand if they are needed.
static $utfCompatibilityDecomp = null;
static $utfCheckNFC;
/**
* The ultimate convenience function! Clean up invalid UTF-8 sequences,
* and convert to normal form C, canonical composition.
*
* Fast return for pure ASCII strings; some lesser optimizations for
* strings containing only known-good characters. Not as fast as toNFC().
*
* @param string $string a UTF-8 string
* @return string a clean, shiny, normalized UTF-8 string
*/
static function cleanUp( $string ) {
if( NORMALIZE_ICU ) {
$string = self::replaceForNativeNormalize( $string );
# UnicodeString constructor fails if the string ends with a
# head byte. Add a junk char at the end, we'll strip it off.
return rtrim( utf8_normalize( $string . "\x01", self::UNORM_NFC ), "\x01" );
} elseif( NORMALIZE_INTL ) {
$string = self::replaceForNativeNormalize( $string );
$norm = normalizer_normalize( $string, Normalizer::FORM_C );
if( $norm === null || $norm === false ) {
# normalizer_normalize will either return false or null
# (depending on which doc you read) if invalid utf8 string.
# quickIsNFCVerify cleans up invalid sequences.
if( UtfNormal::quickIsNFCVerify( $string ) ) {
# if that's true, the string is actually already normal.
return $string;
} else {
# Now we are valid but non-normal
return normalizer_normalize( $string, Normalizer::FORM_C );
}
} else {
return $norm;
}
} elseif( UtfNormal::quickIsNFCVerify( $string ) ) {
# Side effect -- $string has had UTF-8 errors cleaned up.
return $string;
} else {
return UtfNormal::NFC( $string );
}
}
/**
* Convert a UTF-8 string to normal form C, canonical composition.
* Fast return for pure ASCII strings; some lesser optimizations for
* strings containing only known-good characters.
*
* @param string $string a valid UTF-8 string. Input is not validated.
* @return string a UTF-8 string in normal form C
*/
static function toNFC( $string ) {
if( NORMALIZE_INTL )
return normalizer_normalize( $string, Normalizer::FORM_C );
elseif( NORMALIZE_ICU )
return utf8_normalize( $string, self::UNORM_NFC );
elseif( UtfNormal::quickIsNFC( $string ) )
return $string;
else
return UtfNormal::NFC( $string );
}
/**
* Convert a UTF-8 string to normal form D, canonical decomposition.
* Fast return for pure ASCII strings.
*
* @param string $string a valid UTF-8 string. Input is not validated.
* @return string a UTF-8 string in normal form D
*/
static function toNFD( $string ) {
if( NORMALIZE_INTL )
return normalizer_normalize( $string, Normalizer::FORM_D );
elseif( NORMALIZE_ICU )
return utf8_normalize( $string, self::UNORM_NFD );
elseif( preg_match( '/[\x80-\xff]/', $string ) )
return UtfNormal::NFD( $string );
else
return $string;
}
/**
* Convert a UTF-8 string to normal form KC, compatibility composition.
* This may cause irreversible information loss, use judiciously.
* Fast return for pure ASCII strings.
*
* @param string $string a valid UTF-8 string. Input is not validated.
* @return string a UTF-8 string in normal form KC
*/
static function toNFKC( $string ) {
if( NORMALIZE_INTL )
return normalizer_normalize( $string, Normalizer::FORM_KC );
elseif( NORMALIZE_ICU )
return utf8_normalize( $string, self::UNORM_NFKC );
elseif( preg_match( '/[\x80-\xff]/', $string ) )
return UtfNormal::NFKC( $string );
else
return $string;
}
/**
* Convert a UTF-8 string to normal form KD, compatibility decomposition.
* This may cause irreversible information loss, use judiciously.
* Fast return for pure ASCII strings.
*
* @param string $string a valid UTF-8 string. Input is not validated.
* @return string a UTF-8 string in normal form KD
*/
static function toNFKD( $string ) {
if( NORMALIZE_INTL )
return normalizer_normalize( $string, Normalizer::FORM_KD );
elseif( NORMALIZE_ICU )
return utf8_normalize( $string, self::UNORM_NFKD );
elseif( preg_match( '/[\x80-\xff]/', $string ) )
return UtfNormal::NFKD( $string );
else
return $string;
}
/**
* Load the basic composition data if necessary
* @private
*/
static function loadData() {
if( !isset( self::$utfCombiningClass ) ) {
require_once __DIR__ . '/UtfNormalData.inc';
}
}
/**
* Returns true if the string is _definitely_ in NFC.
* Returns false if not or uncertain.
* @param string $string a valid UTF-8 string. Input is not validated.
* @return bool
*/
static function quickIsNFC( $string ) {
# ASCII is always valid NFC!
# If it's pure ASCII, let it through.
if( !preg_match( '/[\x80-\xff]/', $string ) ) return true;
UtfNormal::loadData();
$len = strlen( $string );
for( $i = 0; $i < $len; $i++ ) {
$c = $string[$i];
$n = ord( $c );
if( $n < 0x80 ) {
continue;
} elseif( $n >= 0xf0 ) {
$c = substr( $string, $i, 4 );
$i += 3;
} elseif( $n >= 0xe0 ) {
$c = substr( $string, $i, 3 );
$i += 2;
} elseif( $n >= 0xc0 ) {
$c = substr( $string, $i, 2 );
$i++;
}
if( isset( self::$utfCheckNFC[$c] ) ) {
# If it's NO or MAYBE, bail and do the slow check.
return false;
}
if( isset( self::$utfCombiningClass[$c] ) ) {
# Combining character? We might have to do sorting, at least.
return false;
}
}
return true;
}
/**
* Returns true if the string is _definitely_ in NFC.
* Returns false if not or uncertain.
* @param string $string a UTF-8 string, altered on output to be valid UTF-8 safe for XML.
* @return bool
*/
static function quickIsNFCVerify( &$string ) {
# Screen out some characters that eg won't be allowed in XML
$string = preg_replace( '/[\x00-\x08\x0b\x0c\x0e-\x1f]/', UTF8_REPLACEMENT, $string );
# ASCII is always valid NFC!
# If we're only ever given plain ASCII, we can avoid the overhead
# of initializing the decomposition tables by skipping out early.
if( !preg_match( '/[\x80-\xff]/', $string ) ) return true;
static $checkit = null, $tailBytes = null, $utfCheckOrCombining = null;
if( !isset( $checkit ) ) {
# Load/build some scary lookup tables...
UtfNormal::loadData();
$utfCheckOrCombining = array_merge( self::$utfCheckNFC, self::$utfCombiningClass );
# Head bytes for sequences which we should do further validity checks
$checkit = array_flip( array_map( 'chr',
array( 0xc0, 0xc1, 0xe0, 0xed, 0xef,
0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff ) ) );
# Each UTF-8 head byte is followed by a certain
# number of tail bytes.
$tailBytes = array();
for( $n = 0; $n < 256; $n++ ) {
if( $n < 0xc0 ) {
$remaining = 0;
} elseif( $n < 0xe0 ) {
$remaining = 1;
} elseif( $n < 0xf0 ) {
$remaining = 2;
} elseif( $n < 0xf8 ) {
$remaining = 3;
} elseif( $n < 0xfc ) {
$remaining = 4;
} elseif( $n < 0xfe ) {
$remaining = 5;
} else {
$remaining = 0;
}
$tailBytes[chr($n)] = $remaining;
}
}
# Chop the text into pure-ASCII and non-ASCII areas;
# large ASCII parts can be handled much more quickly.
# Don't chop up Unicode areas for punctuation, though,
# that wastes energy.
$matches = array();
preg_match_all(
'/([\x00-\x7f]+|[\x80-\xff][\x00-\x40\x5b-\x5f\x7b-\xff]*)/',
$string, $matches );
$looksNormal = true;
$base = 0;
$replace = array();
foreach( $matches[1] as $str ) {
$chunk = strlen( $str );
if( $str[0] < "\x80" ) {
# ASCII chunk: guaranteed to be valid UTF-8
# and in normal form C, so skip over it.
$base += $chunk;
continue;
}
# We'll have to examine the chunk byte by byte to ensure
# that it consists of valid UTF-8 sequences, and to see
# if any of them might not be normalized.
#
# Since PHP is not the fastest language on earth, some of
# this code is a little ugly with inner loop optimizations.
$head = '';
$len = $chunk + 1; # Counting down is faster. I'm *so* sorry.
for( $i = -1; --$len; ) {
$remaining = $tailBytes[$c = $str[++$i]];
if( $remaining ) {
# UTF-8 head byte!
$sequence = $head = $c;
do {
# Look for the defined number of tail bytes...
if( --$len && ( $c = $str[++$i] ) >= "\x80" && $c < "\xc0" ) {
# Legal tail bytes are nice.
$sequence .= $c;
} else {
if( 0 == $len ) {
# Premature end of string!
# Drop a replacement character into output to
# represent the invalid UTF-8 sequence.
$replace[] = array( UTF8_REPLACEMENT,
$base + $i + 1 - strlen( $sequence ),
strlen( $sequence ) );
break 2;
} else {
# Illegal tail byte; abandon the sequence.
$replace[] = array( UTF8_REPLACEMENT,
$base + $i - strlen( $sequence ),
strlen( $sequence ) );
# Back up and reprocess this byte; it may itself
# be a legal ASCII or UTF-8 sequence head.
--$i;
++$len;
continue 2;
}
}
} while( --$remaining );
if( isset( $checkit[$head] ) ) {
# Do some more detailed validity checks, for
# invalid characters and illegal sequences.
if( $head == "\xed" ) {
# 0xed is relatively frequent in Korean, which
# abuts the surrogate area, so we're doing
# this check separately to speed things up.
if( $sequence >= UTF8_SURROGATE_FIRST ) {
# Surrogates are legal only in UTF-16 code.
# They are totally forbidden here in UTF-8
# utopia.
$replace[] = array( UTF8_REPLACEMENT,
$base + $i + 1 - strlen( $sequence ),
strlen( $sequence ) );
$head = '';
continue;
}
} else {
# Slower, but rarer checks...
$n = ord( $head );
if(
# "Overlong sequences" are those that are syntactically
# correct but use more UTF-8 bytes than are necessary to
# encode a character. Naïve string comparisons can be
# tricked into failing to see a match for an ASCII
# character, for instance, which can be a security hole
# if blacklist checks are being used.
($n < 0xc2 && $sequence <= UTF8_OVERLONG_A)
|| ($n == 0xe0 && $sequence <= UTF8_OVERLONG_B)
|| ($n == 0xf0 && $sequence <= UTF8_OVERLONG_C)
# U+FFFE and U+FFFF are explicitly forbidden in Unicode.
|| ($n == 0xef &&
($sequence == UTF8_FFFE)
|| ($sequence == UTF8_FFFF) )
# Unicode has been limited to 21 bits; longer
# sequences are not allowed.
|| ($n >= 0xf0 && $sequence > UTF8_MAX) ) {
$replace[] = array( UTF8_REPLACEMENT,
$base + $i + 1 - strlen( $sequence ),
strlen( $sequence ) );
$head = '';
continue;
}
}
}
if( isset( $utfCheckOrCombining[$sequence] ) ) {
# If it's NO or MAYBE, we'll have to rip
# the string apart and put it back together.
# That's going to be mighty slow.
$looksNormal = false;
}
# The sequence is legal!
$head = '';
} elseif( $c < "\x80" ) {
# ASCII byte.
$head = '';
} elseif( $c < "\xc0" ) {
# Illegal tail bytes
if( $head == '' ) {
# Out of the blue!
$replace[] = array( UTF8_REPLACEMENT, $base + $i, 1 );
} else {
# Don't add if we're continuing a broken sequence;
# we already put a replacement character when we looked
# at the broken sequence.
$replace[] = array( '', $base + $i, 1 );
}
} else {
# Miscellaneous freaks.
$replace[] = array( UTF8_REPLACEMENT, $base + $i, 1 );
$head = '';
}
}
$base += $chunk;
}
if( count( $replace ) ) {
# There were illegal UTF-8 sequences we need to fix up.
$out = '';
$last = 0;
foreach( $replace as $rep ) {
list( $replacement, $start, $length ) = $rep;
if( $last < $start ) {
$out .= substr( $string, $last, $start - $last );
}
$out .= $replacement;
$last = $start + $length;
}
if( $last < strlen( $string ) ) {
$out .= substr( $string, $last );
}
$string = $out;
}
return $looksNormal;
}
# These take a string and run the normalization on them, without
# checking for validity or any optimization etc. Input must be
# VALID UTF-8!
/**
* @param $string string
* @return string
* @private
*/
static function NFC( $string ) {
return UtfNormal::fastCompose( UtfNormal::NFD( $string ) );
}
/**
* @param $string string
* @return string
* @private
*/
static function NFD( $string ) {
UtfNormal::loadData();
return UtfNormal::fastCombiningSort(
UtfNormal::fastDecompose( $string, self::$utfCanonicalDecomp ) );
}
/**
* @param $string string
* @return string
* @private
*/
static function NFKC( $string ) {
return UtfNormal::fastCompose( UtfNormal::NFKD( $string ) );
}
/**
* @param $string string
* @return string
* @private
*/
static function NFKD( $string ) {
if( !isset( self::$utfCompatibilityDecomp ) ) {
require_once 'UtfNormalDataK.inc';
}
return self::fastCombiningSort(
self::fastDecompose( $string, self::$utfCompatibilityDecomp ) );
}
/**
* Perform decomposition of a UTF-8 string into either D or KD form
* (depending on which decomposition map is passed to us).
* Input is assumed to be *valid* UTF-8. Invalid code will break.
* @private
* @param string $string valid UTF-8 string
* @param array $map hash of expanded decomposition map
* @return string a UTF-8 string decomposed, not yet normalized (needs sorting)
*/
static function fastDecompose( $string, $map ) {
UtfNormal::loadData();
$len = strlen( $string );
$out = '';
for( $i = 0; $i < $len; $i++ ) {
$c = $string[$i];
$n = ord( $c );
if( $n < 0x80 ) {
# ASCII chars never decompose
# THEY ARE IMMORTAL
$out .= $c;
continue;
} elseif( $n >= 0xf0 ) {
$c = substr( $string, $i, 4 );
$i += 3;
} elseif( $n >= 0xe0 ) {
$c = substr( $string, $i, 3 );
$i += 2;
} elseif( $n >= 0xc0 ) {
$c = substr( $string, $i, 2 );
$i++;
}
if( isset( $map[$c] ) ) {
$out .= $map[$c];
continue;
} else {
if( $c >= UTF8_HANGUL_FIRST && $c <= UTF8_HANGUL_LAST ) {
# Decompose a hangul syllable into jamo;
# hardcoded for three-byte UTF-8 sequence.
# A lookup table would be slightly faster,
# but adds a lot of memory & disk needs.
#
$index = ( (ord( $c[0] ) & 0x0f) << 12
| (ord( $c[1] ) & 0x3f) << 6
| (ord( $c[2] ) & 0x3f) )
- UNICODE_HANGUL_FIRST;
$l = intval( $index / UNICODE_HANGUL_NCOUNT );
$v = intval( ($index % UNICODE_HANGUL_NCOUNT) / UNICODE_HANGUL_TCOUNT);
$t = $index % UNICODE_HANGUL_TCOUNT;
$out .= "\xe1\x84" . chr( 0x80 + $l ) . "\xe1\x85" . chr( 0xa1 + $v );
if( $t >= 25 ) {
$out .= "\xe1\x87" . chr( 0x80 + $t - 25 );
} elseif( $t ) {
$out .= "\xe1\x86" . chr( 0xa7 + $t );
}
continue;
}
}
$out .= $c;
}
return $out;
}
/**
* Sorts combining characters into canonical order. This is the
* final step in creating decomposed normal forms D and KD.
* @private
* @param string $string a valid, decomposed UTF-8 string. Input is not validated.
* @return string a UTF-8 string with combining characters sorted in canonical order
*/
static function fastCombiningSort( $string ) {
UtfNormal::loadData();
$len = strlen( $string );
$out = '';
$combiners = array();
$lastClass = -1;
for( $i = 0; $i < $len; $i++ ) {
$c = $string[$i];
$n = ord( $c );
if( $n >= 0x80 ) {
if( $n >= 0xf0 ) {
$c = substr( $string, $i, 4 );
$i += 3;
} elseif( $n >= 0xe0 ) {
$c = substr( $string, $i, 3 );
$i += 2;
} elseif( $n >= 0xc0 ) {
$c = substr( $string, $i, 2 );
$i++;
}
if( isset( self::$utfCombiningClass[$c] ) ) {
$lastClass = self::$utfCombiningClass[$c];
if( isset( $combiners[$lastClass] ) ) {
$combiners[$lastClass] .= $c;
} else {
$combiners[$lastClass] = $c;
}
continue;
}
}
if( $lastClass ) {
ksort( $combiners );
$out .= implode( '', $combiners );
$combiners = array();
}
$out .= $c;
$lastClass = 0;
}
if( $lastClass ) {
ksort( $combiners );
$out .= implode( '', $combiners );
}
return $out;
}
/**
* Produces canonically composed sequences, i.e. normal form C or KC.
*
* @private
* @param string $string a valid UTF-8 string in sorted normal form D or KD. Input is not validated.
* @return string a UTF-8 string with canonical precomposed characters used where possible
*/
static function fastCompose( $string ) {
UtfNormal::loadData();
$len = strlen( $string );
$out = '';
$lastClass = -1;
$lastHangul = 0;
$startChar = '';
$combining = '';
$x1 = ord(substr(UTF8_HANGUL_VBASE, 0, 1));
$x2 = ord(substr(UTF8_HANGUL_TEND, 0, 1));
for( $i = 0; $i < $len; $i++ ) {
$c = $string[$i];
$n = ord( $c );
if( $n < 0x80 ) {
# No combining characters here...
$out .= $startChar;
$out .= $combining;
$startChar = $c;
$combining = '';
$lastClass = 0;
continue;
} elseif( $n >= 0xf0 ) {
$c = substr( $string, $i, 4 );
$i += 3;
} elseif( $n >= 0xe0 ) {
$c = substr( $string, $i, 3 );
$i += 2;
} elseif( $n >= 0xc0 ) {
$c = substr( $string, $i, 2 );
$i++;
}
$pair = $startChar . $c;
if( $n > 0x80 ) {
if( isset( self::$utfCombiningClass[$c] ) ) {
# A combining char; see what we can do with it
$class = self::$utfCombiningClass[$c];
if( !empty( $startChar ) &&
$lastClass < $class &&
$class > 0 &&
isset( self::$utfCanonicalComp[$pair] ) ) {
$startChar = self::$utfCanonicalComp[$pair];
$class = 0;
} else {
$combining .= $c;
}
$lastClass = $class;
$lastHangul = 0;
continue;
}
}
# New start char
if( $lastClass == 0 ) {
if( isset( self::$utfCanonicalComp[$pair] ) ) {
$startChar = self::$utfCanonicalComp[$pair];
$lastHangul = 0;
continue;
}
if( $n >= $x1 && $n <= $x2 ) {
# WARNING: Hangul code is painfully slow.
# I apologize for this ugly, ugly code; however
# performance is even more teh suck if we call
# out to nice clean functions. Lookup tables are
# marginally faster, but require a lot of space.
#
if( $c >= UTF8_HANGUL_VBASE &&
$c <= UTF8_HANGUL_VEND &&
$startChar >= UTF8_HANGUL_LBASE &&
$startChar <= UTF8_HANGUL_LEND ) {
#
#$lIndex = utf8ToCodepoint( $startChar ) - UNICODE_HANGUL_LBASE;
#$vIndex = utf8ToCodepoint( $c ) - UNICODE_HANGUL_VBASE;
$lIndex = ord( $startChar[2] ) - 0x80;
$vIndex = ord( $c[2] ) - 0xa1;
$hangulPoint = UNICODE_HANGUL_FIRST +
UNICODE_HANGUL_TCOUNT *
(UNICODE_HANGUL_VCOUNT * $lIndex + $vIndex);
# Hardcode the limited-range UTF-8 conversion:
$startChar = chr( $hangulPoint >> 12 & 0x0f | 0xe0 ) .
chr( $hangulPoint >> 6 & 0x3f | 0x80 ) .
chr( $hangulPoint & 0x3f | 0x80 );
$lastHangul = 0;
continue;
} elseif( $c >= UTF8_HANGUL_TBASE &&
$c <= UTF8_HANGUL_TEND &&
$startChar >= UTF8_HANGUL_FIRST &&
$startChar <= UTF8_HANGUL_LAST &&
!$lastHangul ) {
# $tIndex = utf8ToCodepoint( $c ) - UNICODE_HANGUL_TBASE;
$tIndex = ord( $c[2] ) - 0xa7;
if( $tIndex < 0 ) $tIndex = ord( $c[2] ) - 0x80 + (0x11c0 - 0x11a7);
# Increment the code point by $tIndex, without
# the function overhead of decoding and recoding UTF-8
#
$tail = ord( $startChar[2] ) + $tIndex;
if( $tail > 0xbf ) {
$tail -= 0x40;
$mid = ord( $startChar[1] ) + 1;
if( $mid > 0xbf ) {
$startChar[0] = chr( ord( $startChar[0] ) + 1 );
$mid -= 0x40;
}
$startChar[1] = chr( $mid );
}
$startChar[2] = chr( $tail );
# If there's another jamo char after this, *don't* try to merge it.
$lastHangul = 1;
continue;
}
}
}
$out .= $startChar;
$out .= $combining;
$startChar = $c;
$combining = '';
$lastClass = 0;
$lastHangul = 0;
}
$out .= $startChar . $combining;
return $out;
}
/**
* This is just used for the benchmark, comparing how long it takes to
* interate through a string without really doing anything of substance.
* @param $string string
* @return string
*/
static function placebo( $string ) {
$len = strlen( $string );
$out = '';
for( $i = 0; $i < $len; $i++ ) {
$out .= $string[$i];
}
return $out;
}
/**
* Function to replace some characters that we don't want
* but most of the native normalize functions keep.
*
* @param string $string The string
* @return String String with the character codes replaced.
*/
private static function replaceForNativeNormalize( $string ) {
$string = preg_replace(
'/[\x00-\x08\x0b\x0c\x0e-\x1f]/',
UTF8_REPLACEMENT,
$string );
$string = str_replace( UTF8_FFFE, UTF8_REPLACEMENT, $string );
$string = str_replace( UTF8_FFFF, UTF8_REPLACEMENT, $string );
return $string;
}
}