Optimized chunks flatten

lib/deflate.js

@@ -126,26 +126,8 @@ function deflate(input, options) {
   };
 
   deflator.onEnd = function(error) {
-    var i, l, len, pos, chunk;
-
     if (error) { throw error; }
-
-    // calculate data length
-    len = 0;
-    for (i=0, l=chunks.length; i<l; i++) {
-      len += chunks[i].length;
-    }
-
-    // join chunks
-    result = utils.arrayCreate(len);
-    pos = 0;
-
-    for (i=0, l=chunks.length; i<l; i++) {
-      chunk = chunks[i];
-      len = chunk.length;
-      utils.arraySet(result, chunk, 0, len, pos);
-      pos += len;
-    }
+    result = utils.flattenChunks(chunks);
   };
 
   deflator.push(input);

lib/zlib/utils.js

@@ -84,6 +84,8 @@ exports.array16Create = function (length) {
 };
 
 
+// Fill Array || Typed Array with constant
+//
 exports.fill = function (buf, val) {
   var len = buf.length;
 
@@ -92,3 +94,33 @@ exports.fill = function (buf, val) {
   // fastest for untyped Array
   while (--len) { buf[len] = val; }
 };
+
+
+// Join array of chunks to single array.
+// Expect Array of (Array(Bytes) || Uint8Array).
+//
+exports.flattenChunks = function(chunks) {
+  var i, l, len, pos, chunk, result;
+
+  if (typedOk()) {
+    // calculate data length
+    len = 0;
+    for (i=0, l=chunks.length; i<l; i++) {
+      len += chunks[i].length;
+    }
+
+    // join chunks
+    result = new Uint8Array(len);
+    pos = 0;
+    for (i=0, l=chunks.length; i<l; i++) {
+      chunk = chunks[i];
+      result.set(chunk, pos);
+      pos += chunk.length;
+    }
+
+    return result;
+  }
+
+  // Fallback for untyped arrays
+  return [].concat.apply([], chunks);
+};