Encode64 encoding class instance implemented by php

This article mainly introduces the php encode64 encoding class. The example analyzes php's skills for implementing encode64 encoding, which has some reference value, for more information about php encode64 coding, see the following example. Share it with you for your reference. The details are as follows:

Encode64 can obtain the minimum data encoded by 26 uppercase/lowercase letters and numbers plus the "-_" symbol. this string can be freely transmitted over the network, there is no need to consider the confusion caused by automatic transcoding. disadvantage: it is too slow for a large string for unknown reasons. maybe the PHP script itself is slow, so it has many built-in functions, which are intolerable if implemented using scripts. javaScript does not have this problem, and the script speed is much faster.

<? PHP // encode64 encoding can replace encodeURI, encodeURIComponent, and endode functions at the same time. // The selected characters are not encoded. class Encode64 {function code ($ str) {$ KEY = 'paawo65gouf7ik2vi9-callback'; $ a = StrToBytes ($ str); $ len = count ($ ); $ 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) & 0x 3f]; $ 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-example KQWMZJeuh '; $ 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; (; $ 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) {// The correct number of bytes must be 2 or 3. if no value is 1, discard it. $ 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;}?>

I hope this article will help you with php programming.