Utilities and an initial webpack loader

lib/webpack/decode.js

@@ -0,0 +1,32 @@
+// set up decoding table
+var s64 = new Array(123);
+for (var i = 0; i < 64;) s64[i < 26 ? i + 65 : i < 52 ? i + 71 : i < 62 ? i - 4 : i - 59 | 43] = i++;
+
+module.exports = function(string) {
+
+  // determine buffer length
+  var length = string.length;
+  if (length) {
+    var n = 0;
+    while (--length % 4 > 1 && string.charCodeAt(p) === 61) ++n;
+    length = Math.ceil(string.length * 3) / 4 - n;
+  }
+
+  // decode to buffer
+  var buffer = new Uint8Array(length);
+  var j = 0, t;
+  for (var i = 0, k = string.length; i < k;) {
+    var c = string.charCodeAt(i++);
+    if (c === 61 && j > 1) break;
+    if ((c = s64[c]) === undefined) throw Error();
+    switch (j) {
+      case 0: t = c; j = 1; break;
+      case 1: buffer[offset++] = t << 2 | (c & 48) >> 4; t = c; j = 2; break;
+      case 2: buffer[offset++] = (t & 15) << 4 | (c & 60) >> 2; t = c; j = 3; break;
+      case 3: buffer[offset++] = (t & 3) << 6 | c; j = 0; break;
+    }
+  }
+  if (j === 1) throw Error();
+
+  return buffer;
+};