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sys/db/Id.hx

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+/*
+ * Copyright (c)2012 Nicolas Cannasse
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package sys.db;
+
+class Id {
+
+	public static function encode( id : String ) : Int {
+		var l = id.length;
+		if( l > 6 )
+			throw "Invalid identifier '"+id+"'";
+		var k = 0;
+		var p = l;
+		while( p > 0 ) {
+			var c = id.charCodeAt(--p) - 96;
+			if( c < 1 || c > 26 ) {
+				c = c + 96 - 48;
+				if( c >= 1 && c <= 5 )
+					c += 26;
+				else
+					throw "Invalid character "+id.charCodeAt(p)+" in "+id;
+			}
+			k <<= 5;
+			k += c;
+		}
+		return k;
+	}
+
+	public static function decode( id : Int ) : String {
+		var s = new StringBuf();
+		if( id < 1 ) {
+			if( id == 0 ) return "";
+			throw "Invalid ID "+id;
+		}
+		while( id > 0 ) {
+			var k = id & 31;
+			if( k < 27 )
+				s.addChar(k + 96);
+			else
+				s.addChar(k + 22);
+			id >>= 5;
+		}
+		return s.toString();
+	}
+
+}