85 lines
2.4 KiB
PHP
85 lines
2.4 KiB
PHP
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<?php
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/*
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Analyzes UTF-8 characters.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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//@require 'Swift/CharacterReader.php';
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/**
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* Analyzes UTF-8 characters.
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* @package Swift
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* @subpackage Encoder
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* @author Chris Corbyn
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*/
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class Swift_CharacterReader_Utf8Reader
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implements Swift_CharacterReader
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{
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/** Pre-computed for optimization */
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private static $length_map=array(
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x0N
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x1N
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x2N
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x3N
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x4N
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x5N
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x6N
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, //0x7N
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, //0x8N
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, //0x9N
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, //0xAN
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, //0xBN
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2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, //0xCN
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2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, //0xDN
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3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, //0xEN
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4,4,4,4,4,4,4,4,5,5,5,5,6,6,0,0 //0xFN
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);
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/**
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* Returns an integer which specifies how many more bytes to read.
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* A positive integer indicates the number of more bytes to fetch before invoking
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* this method again.
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* A value of zero means this is already a valid character.
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* A value of -1 means this cannot possibly be a valid character.
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* @param string $bytes
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* @return int
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*/
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public function validateByteSequence($bytes, $size)
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{
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if ($size<1){
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return -1;
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}
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$needed = self::$length_map[$bytes[0]] - $size;
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return ($needed > -1)
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? $needed
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: -1
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;
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}
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/**
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* Returns the number of bytes which should be read to start each character.
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* @return int
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*/
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public function getInitialByteSize()
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{
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return 1;
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}
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}
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