PHP implementation ENCODE64 Encoding class instance, ENCODE64 encoding _php Tutorial

PHP implements ENCODE64 encoding class instance, ENCODE64 encoding

This paper describes the PHP implementation encode64 encoding class. Share to everyone for your reference. Specific as follows:

Encode64 can obtain the shortest 26 English-size alphanumeric plus "-_" two symbols encoded data, the string can be transmitted freely in the network, without regard to the confusion caused by automatic transcoding. Cons: For large strings too slow, the reason is unclear, maybe the php script itself is slow, so it built a lot of functions, these functions if the implementation of the script is intolerable. JavaScript does not have this problem, the script is much faster.

<? PHP//ENCODE64 encoding can replace the Encodeuri,encodeuricomponent,endode function at the same time//because the selected characters are not encoded. 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 >>) & 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 >>) & 0x3f]; } return $s;  } function decode ($codeStr) {$KEY = ' paawo65gouf7ik2vi9-xq8cftexlcdy1hd3tv0ryzjbpn_blnss4mgrkqwmzjeuh ';  $dic = Array (); for ($i = 0; $i < $i + +) {$dic[$KEY [$i]] = $i;  } $len = strlen ($CODESTR);  $res = $len% 4;  $cLen = Floor ($len/4)  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 >>) & 0xFF;  $j + = 3;   if ($res = = 2) {//The correct number of bytes is definitely more than 2 or 3, No 1 case, if present, discard.   $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;}? >

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