本文实例讲述了php实现encode64编码类。分享给大家供大家参考。具体如下:
encode64可以获得最短的由26个英文大小写字母数字加上"-_"两个符号编码的数据, 这个个字串可以在网络自由传输, 无需考虑被自动转码引起的混乱. 缺点: 对于大字串太慢了, 原因不明, 可能PHP脚本本身就是慢, 所以它内置 很多函数, 这些函数如果用脚本来实现是不可忍受的. 而JavaScript就没这个问题, 脚本的速度快的多.
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<?PHP //encode64编码可以同时取代encodeURI,encodeURIComponent,endode函数 //因为选取的这些字符都不会被编码. class Encode64{ function code( $str ) { $KEY = 'PaAwO65goUf7IK2vi9-xq8cFTEXLCDY1Hd3tV0ryzjbpN_BlnSs4mGRkQWMZJeuh' ; $a = StrToBytes( $str ); $len = count ( $a ); $res = $len % 3; $s = "" ; $i = 2; $v = 0; for (; $i < $len ; $i += 3) { $v = $a [ $i - 2] + ( $a [ $i - 1] << 8) + ( $a [ $i ] << 16); $s .= $KEY [ $v & 0x3f]; $s .= $KEY [( $v >> 6) & 0x3f]; $s .= $KEY [( $v >> 12) & 0x3f]; $s .= $KEY [( $v >> 18)]; } if ( $res == 1) { $v = $a [ $i - 2]; $s .= $KEY [ $v & 0x3f]; $s .= $KEY [( $v >> 6) & 0x3f]; } else if ( $res == 2) { $v = $a [ $i - 2] + ( $a [ $i - 1] << 8); $s .= $KEY [ $v & 0x3f]; $s .= $KEY [( $v >> 6) & 0x3f]; $s .= $KEY [( $v >> 12) & 0x3f]; } return $s ; } function decode( $codeStr ) { $KEY = 'PaAwO65goUf7IK2vi9-xq8cFTEXLCDY1Hd3tV0ryzjbpN_BlnSs4mGRkQWMZJeuh' ; $dic = array (); for ( $i = 0; $i < 64; $i ++) { $dic [ $KEY [ $i ]] = $i ; } $len = strlen ( $codeStr ); $res = $len % 4; $cLen = floor ( $len /4)*3; if ( $res ==2) $clen += 1; elseif ( $res ==3) $clen += 2; $code = range(0, $clen ); $i = 3; $v = 0; $j = 0; for (; $i < $len ; $i += 4) { $v = $dic [ $codeStr [ $i - 3]]; $v += $dic [ $codeStr [ $i - 2]] << 6; $v += $dic [ $codeStr [ $i - 1]] << 12; $v += $dic [ $codeStr [ $i ]] << 18; $code [ $j ] = $v & 0xff; $code [ $j +1] = ( $v >> 8) & 0xff; $code [ $j +2] = ( $v >> 16) & 0xff; $j += 3; } if ( $res == 2) { //正确的字节数肯定是余2或3, 没有1的情况, 如果出现, 舍弃. $v = $dic [ $codeStr [ $i - 3]]; $v += $dic [ $codeStr [ $i - 2]] << 6; $code [ $j ] = $v & 0xff; } else if ( $res == 3) { $v = $dic [ $codeStr [ $i - 3]]; $v += $dic [ $codeStr [ $i - 2]] << 6; $v += $dic [ $codeStr [ $i - 1]] << 12; $code [ $j ] = $v & 0xff; $code [ $j +1] = ( $v >> 8) & 0xff; } return BytesToStr( $code ); } } function BytesToStr( $bytes ) { $str = '' ; foreach ( $bytes as $ch ) { $str .= chr ( $ch ); } return iconv( 'UTF-16BE' , 'utf-8' , $str ); } function StrToBytes( $str ) { $str = iconv( 'utf-8' , 'UTF-16BE' , $str ); $len = strlen ( $str ); $bytes = array (); for ( $i =0; $i < $len ; $i ++) { $bytes [] = ord( $str [ $i ]) ; } return $bytes ; } ?> |
希望本文所述对大家的php程序设计有所帮助。