From bc0d5e20e874802f1fe73eeb2ab50d116ac30cee Mon Sep 17 00:00:00 2001
From: Doug Wright <github@dougweb.org>
Date: Mon, 12 Nov 2018 23:17:50 +0000
Subject: [PATCH] Cap lookahead recursion

---
 src/ItemList.php              | 20 ++++++++++++++++++++
 src/OrientatedItemFactory.php |  2 +-
 tests/data/expected.csv       | 12 ++++++------
 3 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/src/ItemList.php b/src/ItemList.php
index c2a99e1d..a0047eca 100644
--- a/src/ItemList.php
+++ b/src/ItemList.php
@@ -14,6 +14,7 @@
 use Traversable;
 use function array_pop;
 use function array_reverse;
+use function array_slice;
 use function count;
 use function end;
 use function usort;
@@ -107,6 +108,25 @@ public function top(): Item
         return end($temp);
     }
 
+    /**
+     * @internal
+     *
+     * @param  int      $n
+     * @return ItemList
+     */
+    public function topN(int $n): self
+    {
+        if (!$this->isSorted) {
+            usort($this->list, [$this, 'compare']);
+            $this->isSorted = true;
+        }
+
+        $topNList = new self();
+        $topNList->insertFromArray(array_slice($this->list, 0, $n));
+
+        return $topNList;
+    }
+
     /**
      * @return Traversable
      */
diff --git a/src/OrientatedItemFactory.php b/src/OrientatedItemFactory.php
index c2d12a55..d296dde6 100644
--- a/src/OrientatedItemFactory.php
+++ b/src/OrientatedItemFactory.php
@@ -294,7 +294,7 @@ protected function calculateAdditionalItemsPackedWithThisOrientation(
         $packedCount = 0;
 
         // first try packing into current row
-        $currentRowWorkingSetItems = clone $nextItems;
+        $currentRowWorkingSetItems = $nextItems->topN(8); // cap lookahead as this gets recursive and slow
         $nextRowWorkingSetItems = new ItemList();
         $widthLeft = $originalWidthLeft - $prevItem->getWidth();
         $lengthLeft = $originalLengthLeft;
diff --git a/tests/data/expected.csv b/tests/data/expected.csv
index ce65109c..64dddc9f 100644
--- a/tests/data/expected.csv
+++ b/tests/data/expected.csv
@@ -393,7 +393,7 @@
 1672e9897bfb16f7f644365da8d6992c,1,0,26.4,1,0,26.4
 167db38fa514a30e70f167f70d19f214,1,0,16.2,1,0,16.2
 168065302d10d2f4b683e3d5e7475594,2,536556.3,32.7,1,0,19.8
-1680b70ba864c313d28c9386ce54ac25,3,12592978.7,44,3,203349.6,49.5
+1680b70ba864c313d28c9386ce54ac25,3,12592978.7,44,3,64070.2,38.5
 1694662b95ac32661ee2b45826bb54f6,1,0,42.4,1,0,42.4
 16a2283358cddda00bf2e47e5ad746d3,1,0,24,1,0,24
 16a59c72d05be053c19e4b32ceafaef0,1,0,29.2,1,0,29.2
@@ -868,7 +868,7 @@
 3223ff53874ff3768881db6e163c96a3,2,99856,31.5,1,0,19.1
 323d3a61ac8f60761edc56c34b339a1d,1,0,40.8,1,0,40.8
 3242e661790ad530e5a8419a5c7c0b5b,1,0,22.8,1,0,22.8
-3247e39c4bfd94e9f525f7ef5c179317,2,366025,36.9,2,3721,29.2
+3247e39c4bfd94e9f525f7ef5c179317,2,366025,36.9,2,1,21.2
 326b6af0e5d3ac4f72622ce744ee4b27,1,0,32.4,1,0,32.4
 3276e0aa9afede0f2e5b0d5e3dcf7426,2,14884,23.9,1,0,7.2
 328f28aadcd871aa3ade0646fda55b85,1,0,25.2,1,0,25.2
@@ -1466,7 +1466,7 @@
 547b3c46daded352fbf63c857d87921c,6,8937399.5,61.4,2,167690.3,50.8
 548c715873b6223fe988a0f94c932b05,1,0,57.2,1,0,57.2
 549e072fe0adbf86a9cdf96456702e6b,2,58806.3,26.5,1,0,8
-54aa5358f035a72d895437e03cf3393c,1,0,51.2,1,0,51.2
+54aa5358f035a72d895437e03cf3393c,2,121,35.2,1,0,51.2
 54d00e9d39e00973e74abb7d463509df,2,3782.3,43.7,1,0,13.1
 54d7241c191e5c5d30f55f86f3c2a1e2,2,25600,37.6,1,0,11.3
 54ebd8d18b8e5eed18b5f0e263dc6449,2,9,36.5,1,0,10.9
@@ -2076,7 +2076,7 @@
 77ee435e81a6ed974d2d23d5ad92d758,1,0,43.8,1,0,43.8
 77f36d03b8b0972966f784ede18df036,1,0,31.8,1,0,31.8
 7803029edad1118c42361b90838021ff,1,0,15.5,1,0,15.5
-7808268fc06dc358047e06d04131dae6,2,121,40,2,121,40
+7808268fc06dc358047e06d04131dae6,2,34225,55,2,121,40
 780e3fcb605b33a5293dc71d295e4f38,1,0,34.7,1,0,34.7
 7818ebbfce480f11d9c91b9fdfeae9d7,1,0,33.9,1,0,33.9
 78202b56af66040afa4b19d23164168b,1,0,18.9,1,0,18.9
@@ -2227,7 +2227,7 @@
 808255961bd2cd69ada085757150b913,1,0,38,1,0,38
 808b82b9297c4ab6bbd366c4e189962c,1,0,33.3,1,0,33.3
 80ad76b20162a20c96fd28c1a0fd1554,1,0,57.8,1,0,57.8
-80b35862e48198d457d850237619a1be,1,0,73.1,1,0,33.3
+80b35862e48198d457d850237619a1be,1,0,33.3,1,0,33.3
 80bfcbb8cabb6d518bd218a09f72d280,1,0,26.1,1,0,26.1
 80d45c7ecee2bf6045d135f0b149a218,1,0,56.3,1,0,56.3
 80f0a1007c7e471ed1bfff1373ba6b53,2,756.3,47.1,2,36290.3,12.3
@@ -3553,7 +3553,7 @@ d0efe6d5522001320a4372da93769920,1,0,33.1,1,0,33.1
 d10e78eff303de831aff0a556a536a0f,1,0,48.7,1,0,48.7
 d11076dc6cd4720a1fe9add55d2281aa,1,0,14.9,1,0,14.9
 d1239d721e49347c9804bed0a6db56ab,1,0,39.3,1,0,39.3
-d12f9cb4e8c278ab3286ae03ea30313a,2,90000,23.3,1,0,7
+d12f9cb4e8c278ab3286ae03ea30313a,2,39204,11.5,1,0,7
 d130d596db644f016ca8529c8abf46cc,1,0,37.8,1,0,37.8
 d138dfe2bd5abdd66b951e505e6ce634,1,0,21.3,1,0,21.3
 d144251f58433c0af02fa1a09ce64d30,1,0,74.6,1,0,74.6