From 32070efcc1985b4419bd41b1ba92948379f545b8 Mon Sep 17 00:00:00 2001
From: juliandescottes <julian.descottes@gmail.com>
Date: Wed, 21 Dec 2016 12:22:50 +0100
Subject: [PATCH] save split: add comments and cleanup

---
 src/js/utils/Array.js                    | 27 +++++++++++++++---------
 src/js/utils/serialization/Serializer.js | 11 ++++++++++
 test/js/utils/ArrayTest.js               |  2 +-
 3 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/src/js/utils/Array.js b/src/js/utils/Array.js
index bfa08536..4e2753d0 100644
--- a/src/js/utils/Array.js
+++ b/src/js/utils/Array.js
@@ -12,22 +12,29 @@
       return match;
     },
 
-    chunk : function (array, chunks) {
-      var chunked = [];
+    /**
+     * Split a provided array in a given amount of chunks.
+     * For instance [1,2,3,4] chunked in 2 parts will be [1,2] & [3,4].
+     * @param  {Array} array the array to chunk
+     * @param  {Number} chunksCount the number of chunks to create
+     * @return {Array<Array>} array of arrays containing the items of the original array
+     */
+    chunk : function (array, chunksCount) {
+      var chunks = [];
 
       // We cannot have more chunks than array items.
-      chunks = Math.min(chunks, array.length);
+      chunksCount = Math.min(chunksCount, array.length);
 
-      // chunks should be at least 1
-      chunks = Math.max(1, chunks);
+      // chunksCount should be at least 1
+      chunksCount = Math.max(1, chunksCount);
 
-      var step = Math.round(array.length / chunks);
-      for (var i = 0 ; i < chunks ; i++) {
-        var isLast = i == chunks - 1;
+      var step = Math.round(array.length / chunksCount);
+      for (var i = 0 ; i < chunksCount ; i++) {
+        var isLast = i == chunksCount - 1;
         var end = isLast ? array.length : (i + 1) * step;
-        chunked.push(array.slice(i * step, end));
+        chunks.push(array.slice(i * step, end));
       }
-      return chunked;
+      return chunks;
     }
   };
 
diff --git a/src/js/utils/serialization/Serializer.js b/src/js/utils/serialization/Serializer.js
index b160c210..7cea3131 100644
--- a/src/js/utils/serialization/Serializer.js
+++ b/src/js/utils/serialization/Serializer.js
@@ -42,8 +42,19 @@
         frameCount : frames.length
       };
 
+      // A layer spritesheet data can be chunked in case the spritesheet PNG is to big to be
+      // converted to a dataURL.
+      // Frames are divided equally amongst chunks and each chunk is converted to a spritesheet
+      // PNG. If any chunk contains an invalid base64 PNG, we increase the number of chunks and
+      // retry.
       var chunks = [];
       while (!areChunksValid(chunks)) {
+        if (chunks.length > frames.length) {
+          // Something went horribly wrong.
+          chunks = [];
+          break;
+        }
+
         // Chunks are invalid, increase the number of chunks by one, and chunk the frames array.
         var frameChunks = pskl.utils.Array.chunk(frames, chunks.length + 1);
 
diff --git a/test/js/utils/ArrayTest.js b/test/js/utils/ArrayTest.js
index bded97b6..c52d422c 100644
--- a/test/js/utils/ArrayTest.js
+++ b/test/js/utils/ArrayTest.js
@@ -65,4 +65,4 @@ describe("Array utils", function() {
     expect(chunks.length).toBe(1);
     expect(chunks[0]).toEqual([1, 2, 3, 4]);
   });
-});
\ No newline at end of file
+});