add hw2

node_modules/pako/lib/utils/common.js

@@ -0,0 +1,48 @@
+'use strict';
+
+
+const _has = (obj, key) => {
+  return Object.prototype.hasOwnProperty.call(obj, key);
+};
+
+module.exports.assign = function (obj /*from1, from2, from3, ...*/) {
+  const sources = Array.prototype.slice.call(arguments, 1);
+  while (sources.length) {
+    const source = sources.shift();
+    if (!source) { continue; }
+
+    if (typeof source !== 'object') {
+      throw new TypeError(source + 'must be non-object');
+    }
+
+    for (const p in source) {
+      if (_has(source, p)) {
+        obj[p] = source[p];
+      }
+    }
+  }
+
+  return obj;
+};
+
+
+// Join array of chunks to single array.
+module.exports.flattenChunks = (chunks) => {
+  // calculate data length
+  let len = 0;
+
+  for (let i = 0, l = chunks.length; i < l; i++) {
+    len += chunks[i].length;
+  }
+
+  // join chunks
+  const result = new Uint8Array(len);
+
+  for (let i = 0, pos = 0, l = chunks.length; i < l; i++) {
+    let chunk = chunks[i];
+    result.set(chunk, pos);
+    pos += chunk.length;
+  }
+
+  return result;
+};