Create Can.php

Author: pedra

php/Lib/Can.php

@@ -0,0 +1,135 @@
+<?php
+/*
+ * CAN - Código Alfa Numérico
+ * Classe para converter um valor numérico em CAN e de volta à numérico.
+ * @copyright   Bill Rocha - http://plus.google.com/+BillRocha
+ * @license     MIT & GLP2
+ * @author      Bill Rocha - prbr@ymail.com
+ * @version     0.0.1
+ * @package     Lib
+ * @access      public
+ * @since       0.0.4
+ * @date        2015/08/30-19:00:00
+
+
+    digitos      -      resolução
+
+    1  =                        64
+    2  =                     4.096
+    3  =                   262.144
+    4  =                16.777.216
+    5  =             1.073.741.824
+    6  =            68.719.476.736 ( 68 bilhões )
+    7  =         4.398.046.511.104
+    8  =       281.474.976.710.656
+    9  =    18.014.398.509.481.984
+    10 = 1.152.921.504.606.846.976 ( 1 quinquilhão )
+
+
+    Exemplo:
+
+    $can = new Can();
+    $can->encode(50000) => "ntW"
+    $can->decode("ntW") => 50000
+
+    Depende do arquivo com a chave aleatória (gerada na instalação da aplicação)
+    define('_CONFIG', 'path/to/config/file/');
+
+    Use "Lib" para gerar uma chave aleatória:
+    >> php Lib key:generate [enter]
+
+*/
+
+namespace Lib;
+
+class Can
+{
+
+    private $number = 0;
+    private $can = '';
+    private $resolution = 10;
+    private $useExtra = false;
+
+
+    static $base = ['I','u','h','5','B','A','r','i','7','9','z','d','n','t','F','2','W','X','f','e','x','v','_','8','m','T','N','R','L','c','6','P','k','Q','q','j','Y','M','4','S','G','o','0','$','K','s','g','H','E','b','a','J','U','Z','l','1','O','3','y','p','V','D','C','w'];
+
+    static $extra_base = ['$','!','#','%','&','*','+','-','?','@','(',')','/','\\','[',']','_','0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'];
+
+    /*
+     *
+     */
+
+    function __construct($resolution = 10, $extra = false){
+        if((0 + $resolution) > 0){
+            $this->resolution = 0 + $resolution;
+        }
+
+        if($extra) $this->useExtra = true;
+
+        //get "base" key OR use default
+        if(file_exists(_CONFIG.'Key/can.key')){
+            $base = file_get_contents(_CONFIG.'Key/can.key');
+            static::$base = [];
+            static::$extra_base = [];
+            $base = explode("\n", $base);
+
+            for($i = 0; $i < strlen($base[0]); $i ++){
+                static::$base[] = $base[0][$i];
+            }
+            for($i = 0; $i < strlen($base[1]); $i ++){
+                static::$extra_base[] = $base[1][$i];
+            }
+        }
+    }
+
+    /* Codifica um valor numérico em CAN ( ex.: 63.145 > GQT )
+     * Parametro forceWidth: true - completa com base[0] os campos com valor "0" à esquerda
+     *                       false - mostra somente os caracteres que fazem diferença.
+     * Ex.: encode(1)       => 'u'
+     *      encode(1, true) => 'IIIIIIIIIu';
+     *
+     */
+    function encode($num = null, $forceWidth = false){
+        if($num !== null && (0 + $num) >= 0) $this->number = 0 + $num;
+
+        //overflow...
+        if($this->number >= bcpow(64, $this->resolution)) return false;
+
+        $res = '';
+        $num = $this->number;
+        $himem = false;
+
+        for($i = $this->resolution; $i >= 1; $i--){
+            if($num <= 0) {
+                $res .= $this->useExtra ? static::$extra_base[0] : static::$base[0];
+                continue;
+            }
+            $ind = bcpow(64, $i-1);
+            $a = intval($num/$ind);
+            if($a > 0) $himem = true;
+            $num = $num - ($a*$ind);
+            if($himem || $forceWidth) $res .= $this->useExtra ? static::$extra_base[$a] : static::$base[$a];
+        }
+        $this->can = $res;
+        return $this->can;
+    }
+
+    //Decodifica uma string CAN para um valor numérico ( ex.: GQT > 63.145 )
+    function decode($can = null){
+        if($can != null && is_string($can)) $this->can = $can;
+
+        $len = strlen($this->can) -1;
+        $valor = 0;
+        for($i = $len; $i >= 0; $i--){
+            $peso = bcpow(64, $i);
+            $d = substr($this->can, $len-$i, 1);
+            $c = array_search($d, $this->useExtra ? static::$extra_base : static::$base);
+
+            if($c === false) return false;
+            $valor += $peso * $c;
+        }
+
+        $this->number = $valor;
+        return $this->number;
+    }
+}