Completed
Push — master ( e77b1c...2d8cf3 )
by Doug
07:16
created

VolumePacker   B

Coupling/Cohesion

Components 1
Dependencies 8

Complexity

Total Complexity 36

Size/Duplication

Total Lines 221
Duplicated Lines 0 %

Test Coverage

Coverage 99.03%

Importance

Changes 0
Metric Value
wmc 36
c 0
b 0
f 0
lcom 1
cbo 8
dl 0
loc 221
ccs 102
cts 103
cp 0.9903
rs 8.8

6 Methods

Rating   Name   Duplication   Size   Complexity  
A __construct() 0 6 1
C pack() 0 78 13
D findBestOrientation() 0 36 9
B findPossibleOrientations() 0 28 6
A canStackItemInLayer() 0 7 4
A isLayerStarted() 0 3 3
1
<?php
2
/**
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 * Box packing (3D bin packing, knapsack problem)
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 * @package BoxPacker
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 * @author Doug Wright
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 */
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namespace DVDoug\BoxPacker;
8
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use Psr\Log\LoggerAwareInterface;
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use Psr\Log\LoggerAwareTrait;
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use Psr\Log\NullLogger;
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/**
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 * Actual packer
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 * @author Doug Wright
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 * @package BoxPacker
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 */
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class VolumePacker implements LoggerAwareInterface
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{
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    use LoggerAwareTrait;
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22
    /**
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     * Box to pack items into
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     * @var Box
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     */
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    protected $box;
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    /**
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     * List of items to be packed
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     * @var ItemList
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     */
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    protected $items;
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    /**
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     * Constructor
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     */
37 26
    public function __construct(Box $box, ItemList $items)
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    {
39 26
        $this->box = $box;
40 26
        $this->items = $items;
41 26
        $this->logger = new NullLogger();
42 26
    }
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    /**
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     * Pack as many items as possible into specific given box
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     * @return PackedBox packed box
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     */
48 26
    public function pack()
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    {
50 26
        $this->logger->debug("[EVALUATING BOX] {$this->box->getReference()}");
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52 26
        $packedItems = new ItemList;
53 26
        $depthLeft = $this->box->getInnerDepth();
54 26
        $remainingWeight = $this->box->getMaxWeight() - $this->box->getEmptyWeight();
55 26
        $widthLeft = $this->box->getInnerWidth();
56 26
        $lengthLeft = $this->box->getInnerLength();
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58 26
        $layerWidth = $layerLength = $layerDepth = 0;
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60 26
        $prevItem = null;
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62 26
        while (!$this->items->isEmpty()) {
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            $itemToPack = $this->items->extract();
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            //skip items that are simply too heavy
67 26
            if ($itemToPack->getWeight() > $remainingWeight) {
68 4
                continue;
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            }
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            $this->logger->debug("evaluating item {$itemToPack->getDescription()}");
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            $this->logger->debug("remaining width: {$widthLeft}, length: {$lengthLeft}, depth: {$depthLeft}");
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            $this->logger->debug("layerWidth: {$layerWidth}, layerLength: {$layerLength}, layerDepth: {$layerDepth}");
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75 26
            $nextItem = !$this->items->isEmpty() ? $this->items->top() : null;
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            $orientatedItem = $this->findBestOrientation($itemToPack, $prevItem, $nextItem, $widthLeft, $lengthLeft, $depthLeft);
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78 26
            if ($orientatedItem) {
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80 26
                $packedItems->insert($orientatedItem->getItem());
81 26
                $remainingWeight -= $itemToPack->getWeight();
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83 26
                $lengthLeft -= $orientatedItem->getLength();
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                $layerLength += $orientatedItem->getLength();
85 26
                $layerWidth = max($orientatedItem->getWidth(), $layerWidth);
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87 26
                $layerDepth = max($layerDepth, $orientatedItem->getDepth()); //greater than 0, items will always be less deep
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                //allow items to be stacked in place within the same footprint up to current layerdepth
90 26
                $maxStackDepth = $layerDepth - $orientatedItem->getDepth();
91 26
                while (!$this->items->isEmpty() && $this->canStackItemInLayer($itemToPack, $this->items->top(), $maxStackDepth, $remainingWeight)) {
92 1
                    $remainingWeight -= $this->items->top()->getWeight();
93 1
                    $maxStackDepth -= $this->items->top()->getDepth(); // XXX no attempt at best fit
94 1
                    $packedItems->insert($this->items->extract());
95 1
                }
96
97 26
                $prevItem = $orientatedItem;
98 26
            } else {
99
100 23
                $prevItem = null;
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102 23
                if ($widthLeft >= min($itemToPack->getWidth(), $itemToPack->getLength()) && $this->isLayerStarted($layerWidth, $layerLength, $layerDepth)) {
103 22
                    $this->logger->debug("No more fit in lengthwise, resetting for new row");
104 22
                    $lengthLeft += $layerLength;
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                    $widthLeft -= $layerWidth;
106 22
                    $layerWidth = $layerLength = 0;
107 22
                    $this->items->insert($itemToPack);
108 22
                    continue;
109 18
                } elseif ($lengthLeft < min($itemToPack->getWidth(), $itemToPack->getLength()) || $layerDepth == 0) {
110 7
                    $this->logger->debug("doesn't fit on layer even when empty");
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                    continue;
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                }
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114 17
                $widthLeft = $layerWidth ? min(floor($layerWidth * 1.1), $this->box->getInnerWidth()) : $this->box->getInnerWidth();
115 17
                $lengthLeft = $layerLength ? min(floor($layerLength * 1.1), $this->box->getInnerLength()) : $this->box->getInnerLength();
116 17
                $depthLeft -= $layerDepth;
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118 17
                $layerWidth = $layerLength = $layerDepth = 0;
119 17
                $this->logger->debug("doesn't fit, so starting next vertical layer");
120 17
                $this->items->insert($itemToPack);
121
            }
122 26
        }
123 26
        $this->logger->debug("done with this box");
124 26
        return new PackedBox($this->box, $packedItems, $widthLeft, $lengthLeft, $depthLeft, $remainingWeight);
125
    }
126
127
    /**
128
     * Get the best orientation for an item
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     * @param Item $item
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     * @param OrientatedItem|null $prevItem
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     * @param Item|null $nextItem
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     * @param int $widthLeft
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     * @param int $lengthLeft
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     * @param int $depthLeft
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     * @return OrientatedItem|false
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     */
137 26
    protected function findBestOrientation(Item $item, OrientatedItem $prevItem = null, Item $nextItem = null, $widthLeft, $lengthLeft, $depthLeft) {
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139 26
        $orientations = $this->findPossibleOrientations($item, $prevItem, $widthLeft, $lengthLeft, $depthLeft);
140
141 26
        if (empty($orientations)) {
142 23
            return false;
143
        }
144
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        // special casing based on next item
146 26
        if (isset($orientations[0]) && $nextItem == $item && $lengthLeft >= 2 * $item->getLength()) {
147 5
            $this->logger->debug("not rotating based on next item");
148 5
            return $orientations[0]; // XXX this is tied to the ordering from ->findPossibleOrientations()
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        }
150
151 26
        $orientationFits = [];
152
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        /** @var OrientatedItem $orientation */
154 26
        foreach ($orientations as $o => $orientation) {
155 26
            $orientationFit = min($widthLeft   - $orientation->getWidth(),
156 26
                                  $lengthLeft  - $orientation->getLength());
157
158 26
            if ($orientationFit >= 0 && $depthLeft - $orientation->getDepth() >= 0) {
159 26
                $orientationFits[$o] = $orientationFit;
160 26
            }
161 26
        }
162
163 26
        if ($orientationFits) {
0 ignored issues
show
Bug Best Practice introduced by Doug Wright
The expression $orientationFits of type array is implicitly converted to a boolean; are you sure this is intended? If so, consider using ! empty($expr) instead to make it clear that you intend to check for an array without elements.

This check marks implicit conversions of arrays to boolean values in a comparison. While in PHP an empty array is considered to be equal (but not identical) to false, this is not always apparent.

Consider making the comparison explicit by using empty(..) or ! empty(...) instead.

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164 26
            asort($orientationFits);
165 26
            reset($orientationFits);
166 26
            $bestFit = key($orientationFits);
167 26
            $this->logger->debug("Using orientation #{$bestFit}");
168 26
            return $orientations[$bestFit];
169
        } else {
170
            return false;
171
        }
172
    }
173
174
    /**
175
     * Find all possible orientations for an item
176
     * @param Item $item
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     * @param OrientatedItem|null $prevItem
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     * @param int $widthLeft
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     * @param int $lengthLeft
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     * @param int $depthLeft
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     * @return OrientatedItem[]
182
     */
183 26
    protected function findPossibleOrientations(Item $item, OrientatedItem $prevItem = null, $widthLeft, $lengthLeft, $depthLeft) {
184
185 26
        $orientations = [];
186
187
        //Special case items that are the same as what we just packed - keep orientation
188 26
        if ($prevItem && $prevItem->getItem() == $item) {
189 9
            $orientations[] = new OrientatedItem($item, $prevItem->getWidth(), $prevItem->getLength(), $prevItem->getDepth());
190 9
        } else {
191
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            //simple 2D rotation
193 26
            $orientations[] = new OrientatedItem($item, $item->getWidth(), $item->getLength(), $item->getDepth());
194 26
            $orientations[] = new OrientatedItem($item, $item->getLength(), $item->getWidth(), $item->getDepth());
195
196
            //add 3D rotation if we're allowed
197 26
            if (!$item->getKeepFlat()) {
198 10
                $orientations[] = new OrientatedItem($item, $item->getWidth(), $item->getDepth(), $item->getLength());
199 10
                $orientations[] = new OrientatedItem($item, $item->getLength(), $item->getDepth(), $item->getWidth());
200 10
                $orientations[] = new OrientatedItem($item, $item->getDepth(), $item->getWidth(), $item->getLength());
201 10
                $orientations[] = new OrientatedItem($item, $item->getDepth(), $item->getLength(), $item->getWidth());
202 10
            }
203
        }
204
205
        //remove any that simply don't fit
206 26
        return array_filter($orientations, function (OrientatedItem $i) use ($widthLeft, $lengthLeft, $depthLeft) {
207 26
            return $i->getWidth() <= $widthLeft && $i->getLength() <= $lengthLeft && $i->getDepth() <= $depthLeft;
208 26
        });
209
210
    }
211
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    /**
213
     * Figure out if we can stack the next item vertically on top of this rather than side by side
214
     * Used when we've packed a tall item, and have just put a shorter one next to it
215
     * @param Item $item
216
     * @param Item $nextItem
217
     * @param $maxStackDepth
218
     * @param $remainingWeight
219
     * @return bool
220
     */
221 24
    protected function canStackItemInLayer(Item $item, Item $nextItem, $maxStackDepth, $remainingWeight)
222
    {
223 24
        return $nextItem->getDepth() <= $maxStackDepth &&
224 24
               $nextItem->getWeight() <= $remainingWeight &&
225 24
               $nextItem->getWidth() <= $item->getWidth() &&
226 24
               $nextItem->getLength() <= $item->getLength();
227
    }
228
229
    /**
230
     * @param $layerWidth
231
     * @param $layerLength
232
     * @param $layerDepth
233
     * @return bool
234
     */
235 23
    protected function isLayerStarted($layerWidth, $layerLength, $layerDepth) {
236 23
        return $layerWidth > 0 && $layerLength > 0 && $layerDepth > 0;
237
    }
238
}
239