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Diffstat (limited to 'includes/normal/UtfNormal.php')
-rw-r--r-- | includes/normal/UtfNormal.php | 792 |
1 files changed, 792 insertions, 0 deletions
diff --git a/includes/normal/UtfNormal.php b/includes/normal/UtfNormal.php new file mode 100644 index 00000000..d8641993 --- /dev/null +++ b/includes/normal/UtfNormal.php @@ -0,0 +1,792 @@ +<?php +# Copyright (C) 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 + +/** + * 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 deterimine is already normalized. + * + * All functions can be called static. + * + * See description of forms at http://www.unicode.org/reports/tr15/ + * + * @package UtfNormal + */ + +/** */ +require_once 'UtfNormalUtil.php'; + +global $utfCombiningClass, $utfCanonicalComp, $utfCanonicalDecomp; +$utfCombiningClass = NULL; +$utfCanonicalComp = NULL; +$utfCanonicalDecomp = NULL; + +# Load compatibility decompositions on demand if they are needed. +global $utfCompatibilityDecomp; +$utfCompatibilityDecomp = NULL; + +define( 'UNICODE_HANGUL_FIRST', 0xac00 ); +define( 'UNICODE_HANGUL_LAST', 0xd7a3 ); + +define( 'UNICODE_HANGUL_LBASE', 0x1100 ); +define( 'UNICODE_HANGUL_VBASE', 0x1161 ); +define( 'UNICODE_HANGUL_TBASE', 0x11a7 ); + +define( 'UNICODE_HANGUL_LCOUNT', 19 ); +define( 'UNICODE_HANGUL_VCOUNT', 21 ); +define( 'UNICODE_HANGUL_TCOUNT', 28 ); +define( 'UNICODE_HANGUL_NCOUNT', UNICODE_HANGUL_VCOUNT * UNICODE_HANGUL_TCOUNT ); + +define( 'UNICODE_HANGUL_LEND', UNICODE_HANGUL_LBASE + UNICODE_HANGUL_LCOUNT - 1 ); +define( 'UNICODE_HANGUL_VEND', UNICODE_HANGUL_VBASE + UNICODE_HANGUL_VCOUNT - 1 ); +define( 'UNICODE_HANGUL_TEND', UNICODE_HANGUL_TBASE + UNICODE_HANGUL_TCOUNT - 1 ); + +define( 'UNICODE_SURROGATE_FIRST', 0xd800 ); +define( 'UNICODE_SURROGATE_LAST', 0xdfff ); +define( 'UNICODE_MAX', 0x10ffff ); +define( 'UNICODE_REPLACEMENT', 0xfffd ); + + +define( 'UTF8_HANGUL_FIRST', "\xea\xb0\x80" /*codepointToUtf8( UNICODE_HANGUL_FIRST )*/ ); +define( 'UTF8_HANGUL_LAST', "\xed\x9e\xa3" /*codepointToUtf8( UNICODE_HANGUL_LAST )*/ ); + +define( 'UTF8_HANGUL_LBASE', "\xe1\x84\x80" /*codepointToUtf8( UNICODE_HANGUL_LBASE )*/ ); +define( 'UTF8_HANGUL_VBASE', "\xe1\x85\xa1" /*codepointToUtf8( UNICODE_HANGUL_VBASE )*/ ); +define( 'UTF8_HANGUL_TBASE', "\xe1\x86\xa7" /*codepointToUtf8( UNICODE_HANGUL_TBASE )*/ ); + +define( 'UTF8_HANGUL_LEND', "\xe1\x84\x92" /*codepointToUtf8( UNICODE_HANGUL_LEND )*/ ); +define( 'UTF8_HANGUL_VEND', "\xe1\x85\xb5" /*codepointToUtf8( UNICODE_HANGUL_VEND )*/ ); +define( 'UTF8_HANGUL_TEND', "\xe1\x87\x82" /*codepointToUtf8( UNICODE_HANGUL_TEND )*/ ); + +define( 'UTF8_SURROGATE_FIRST', "\xed\xa0\x80" /*codepointToUtf8( UNICODE_SURROGATE_FIRST )*/ ); +define( 'UTF8_SURROGATE_LAST', "\xed\xbf\xbf" /*codepointToUtf8( UNICODE_SURROGATE_LAST )*/ ); +define( 'UTF8_MAX', "\xf4\x8f\xbf\xbf" /*codepointToUtf8( UNICODE_MAX )*/ ); +define( 'UTF8_REPLACEMENT', "\xef\xbf\xbd" /*codepointToUtf8( UNICODE_REPLACEMENT )*/ ); +#define( 'UTF8_REPLACEMENT', '!' ); + +define( 'UTF8_OVERLONG_A', "\xc1\xbf" ); +define( 'UTF8_OVERLONG_B', "\xe0\x9f\xbf" ); +define( 'UTF8_OVERLONG_C', "\xf0\x8f\xbf\xbf" ); + +# These two ranges are illegal +define( 'UTF8_FDD0', "\xef\xb7\x90" /*codepointToUtf8( 0xfdd0 )*/ ); +define( 'UTF8_FDEF', "\xef\xb7\xaf" /*codepointToUtf8( 0xfdef )*/ ); +define( 'UTF8_FFFE', "\xef\xbf\xbe" /*codepointToUtf8( 0xfffe )*/ ); +define( 'UTF8_FFFF', "\xef\xbf\xbf" /*codepointToUtf8( 0xffff )*/ ); + +define( 'UTF8_HEAD', false ); +define( 'UTF8_TAIL', true ); + + +/** + * For using the ICU wrapper + */ +define( 'UNORM_NONE', 1 ); +define( 'UNORM_NFD', 2 ); +define( 'UNORM_NFKD', 3 ); +define( 'UNORM_NFC', 4 ); +define( 'UNORM_DEFAULT', UNORM_NFC ); +define( 'UNORM_NFKC', 5 ); +define( 'UNORM_FCD', 6 ); + +define( 'NORMALIZE_ICU', function_exists( 'utf8_normalize' ) ); + +/** + * + * @package MediaWiki + */ +class UtfNormal { + /** + * 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 + */ + function cleanUp( $string ) { + if( NORMALIZE_ICU ) { + # We exclude a few chars that ICU would not. + $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 ); + + # 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", UNORM_NFC ), "\x01" ); + } 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 + */ + function toNFC( $string ) { + if( NORMALIZE_ICU ) + return utf8_normalize( $string, 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 + */ + function toNFD( $string ) { + if( NORMALIZE_ICU ) + return utf8_normalize( $string, 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 + */ + function toNFKC( $string ) { + if( NORMALIZE_ICU ) + return utf8_normalize( $string, 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 + */ + function toNFKD( $string ) { + if( NORMALIZE_ICU ) + return utf8_normalize( $string, UNORM_NFKD ); + elseif( preg_match( '/[\x80-\xff]/', $string ) ) + return UtfNormal::NFKD( $string ); + else + return $string; + } + + /** + * Load the basic composition data if necessary + * @private + */ + function loadData() { + # fixme : are $utfCanonicalComp, $utfCanonicalDecomp really used? + global $utfCombiningClass, $utfCanonicalComp, $utfCanonicalDecomp; + if( !isset( $utfCombiningClass ) ) { + require_once( '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 + */ + 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(); + global $utfCheckNFC, $utfCombiningClass; + $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( $utfCheckNFC[$c] ) ) { + # If it's NO or MAYBE, bail and do the slow check. + return false; + } + if( isset( $utfCombiningClass[$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 $string a UTF-8 string, altered on output to be valid UTF-8 safe for XML. + */ + function quickIsNFCVerify( &$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(); + global $utfCheckNFC, $utfCombiningClass; + + $utfCheckOrCombining = array_merge( $utfCheckNFC, $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. + 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; ) { + if( $remaining = $tailBytes[$c = $str{++$i}] ) { + # 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 + */ + function NFC( $string ) { + return UtfNormal::fastCompose( UtfNormal::NFD( $string ) ); + } + + /** + * @param string $string + * @return string + * @private + */ + function NFD( $string ) { + UtfNormal::loadData(); + global $utfCanonicalDecomp; + return UtfNormal::fastCombiningSort( + UtfNormal::fastDecompose( $string, $utfCanonicalDecomp ) ); + } + + /** + * @param string $string + * @return string + * @private + */ + function NFKC( $string ) { + return UtfNormal::fastCompose( UtfNormal::NFKD( $string ) ); + } + + /** + * @param string $string + * @return string + * @private + */ + function NFKD( $string ) { + global $utfCompatibilityDecomp; + if( !isset( $utfCompatibilityDecomp ) ) { + require_once( 'UtfNormalDataK.inc' ); + } + return UtfNormal::fastCombiningSort( + UtfNormal::fastDecompose( $string, $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) + */ + 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 + */ + function fastCombiningSort( $string ) { + UtfNormal::loadData(); + global $utfCombiningClass; + $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( $utfCombiningClass[$c] ) ) { + $lastClass = $utfCombiningClass[$c]; + @$combiners[$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 + */ + function fastCompose( $string ) { + UtfNormal::loadData(); + global $utfCanonicalComp, $utfCombiningClass; + $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( $utfCombiningClass[$c] ) ) { + # A combining char; see what we can do with it + $class = $utfCombiningClass[$c]; + if( !empty( $startChar ) && + $lastClass < $class && + $class > 0 && + isset( $utfCanonicalComp[$pair] ) ) { + $startChar = $utfCanonicalComp[$pair]; + $class = 0; + } else { + $combining .= $c; + } + $lastClass = $class; + $lastHangul = 0; + continue; + } + } + # New start char + if( $lastClass == 0 ) { + if( isset( $utfCanonicalComp[$pair] ) ) { + $startChar = $utfCanonicalComp[$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 + */ + function placebo( $string ) { + $len = strlen( $string ); + $out = ''; + for( $i = 0; $i < $len; $i++ ) { + $out .= $string{$i}; + } + return $out; + } +} + +?> |