add hexdump.js

hexdump.js

@@ -0,0 +1,32 @@
+(function (exports) {
+'use strict';
+
+exports.hexdump = function hexdump(ab) {
+  var ui8 = new Uint8Array(ab);
+  var bytecount = 0;
+  var head = '        0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F';
+  var trail;
+  var str = [].slice.call(ui8).map(function (i) {
+    var h = i.toString(16);
+    if (h.length < 2) {
+      h = '0' + h;
+    }
+    return h;
+  }).join('').match(/.{1,2}/g).join(' ').match(/.{1,48}/g).map(function (str) {
+    var lead = bytecount.toString(16);
+    bytecount += 16;
+
+    while (lead.length < 7) {
+      lead = '0' + lead;
+    }
+
+    return lead + ' ' + str;
+  }).join('\n');
+  trail = ab.byteLength.toString(16);
+  while (trail.length < 7) {
+    trail = '0' + trail;
+  }
+  return head + '\n' + str + '\n' + trail;
+};
+
+}('undefined' !== typeof exports && exports || 'undefined' !== typeof window && window || global));