|
1
|
|
|
<?php |
|
2
|
|
|
|
|
3
|
|
|
namespace Hexogen\KDTree; |
|
4
|
|
|
|
|
5
|
|
|
class FSTreePersister implements TreePersisterInterface |
|
6
|
|
|
{ |
|
7
|
|
|
/** |
|
8
|
|
|
* @var string path to the file |
|
9
|
|
|
*/ |
|
10
|
|
|
private $path; |
|
11
|
|
|
|
|
12
|
|
|
/** |
|
13
|
|
|
* @var resource file handler |
|
14
|
|
|
*/ |
|
15
|
|
|
private $handler; |
|
16
|
|
|
|
|
17
|
|
|
/** |
|
18
|
|
|
* @var int |
|
19
|
|
|
*/ |
|
20
|
|
|
private $dimensions; |
|
21
|
|
|
|
|
22
|
|
|
/** |
|
23
|
|
|
* @var int |
|
24
|
|
|
*/ |
|
25
|
|
|
private $nodeMemorySize; |
|
26
|
|
|
|
|
27
|
3 |
|
public function __construct(string $path) |
|
28
|
|
|
{ |
|
29
|
3 |
|
$this->path = $path; |
|
30
|
3 |
|
} |
|
31
|
|
|
|
|
32
|
|
|
/** |
|
33
|
|
|
* @param KDTreeInterface $tree |
|
34
|
|
|
* @param string $identifier that identifies persisted tree(may be a filename, database name etc.) |
|
35
|
|
|
* @return mixed |
|
36
|
|
|
*/ |
|
37
|
3 |
|
public function convert(KDTreeInterface $tree, string $identifier) |
|
38
|
|
|
{ |
|
39
|
3 |
|
$this->initTree($identifier); |
|
40
|
|
|
|
|
41
|
3 |
|
$this->dimensions = $tree->getDimensionCount(); |
|
42
|
|
|
|
|
43
|
3 |
|
$this->calculateNodeSize(); |
|
44
|
|
|
|
|
45
|
3 |
|
$this->specifyNumberOfDimensions(); |
|
46
|
|
|
|
|
47
|
3 |
|
$this->specifyNumberOfItems($tree); |
|
48
|
|
|
|
|
49
|
3 |
|
$upperBound = $tree->getMaxBoundary(); |
|
50
|
3 |
|
$this->writeCoordinate($upperBound); |
|
51
|
|
|
|
|
52
|
3 |
|
$lowerBound = $tree->getMinBoundary(); |
|
53
|
3 |
|
$this->writeCoordinate($lowerBound); |
|
54
|
|
|
|
|
55
|
3 |
|
$root = $tree->getRoot(); |
|
56
|
3 |
|
if ($root) { |
|
57
|
|
|
$this->writeNode($root); |
|
58
|
|
|
} |
|
59
|
3 |
|
fclose($this->handler); |
|
60
|
3 |
|
} |
|
61
|
|
|
|
|
62
|
|
|
/** |
|
63
|
|
|
* @param NodeInterface $node |
|
64
|
|
|
*/ |
|
65
|
|
|
private function writeNode(NodeInterface $node) |
|
66
|
|
|
{ |
|
67
|
|
|
$position = ftell($this->handler); |
|
68
|
|
|
$item = $node->getItem(); |
|
69
|
|
|
|
|
70
|
|
|
$this->writeItemId($item); |
|
71
|
|
|
|
|
72
|
|
|
$dataChunk = pack('V', 0); // left position currently unknown so it equal 0/null |
|
73
|
|
|
fwrite($this->handler, $dataChunk); |
|
74
|
|
|
|
|
75
|
|
|
$rightNode = $node->getRight(); |
|
76
|
|
|
|
|
77
|
|
|
$rightPosition = 0; |
|
78
|
|
|
if ($rightNode) { |
|
79
|
|
|
$rightPosition = $position + $this->nodeMemorySize; |
|
80
|
|
|
} |
|
81
|
|
|
$dataChunk = pack('V', $rightPosition); |
|
82
|
|
|
fwrite($this->handler, $dataChunk); |
|
83
|
|
|
|
|
84
|
|
|
$this->saveItemCoordinate($item); |
|
85
|
|
|
|
|
86
|
|
|
if ($rightNode) { |
|
87
|
|
|
$this->writeNode($rightNode); |
|
88
|
|
|
} |
|
89
|
|
|
|
|
90
|
|
|
$leftNode = $node->getLeft(); |
|
91
|
|
|
|
|
92
|
|
|
if ($leftNode == null) { |
|
93
|
|
|
return; |
|
94
|
|
|
} |
|
95
|
|
|
$this->persistLeftLink($position); |
|
96
|
|
|
$this->writeNode($leftNode); |
|
97
|
|
|
} |
|
98
|
|
|
|
|
99
|
|
|
/** |
|
100
|
|
|
* @param array $coordinate |
|
101
|
|
|
*/ |
|
102
|
3 |
|
private function writeCoordinate(array $coordinate) |
|
103
|
|
|
{ |
|
104
|
3 |
|
$dataChunk = pack('d'.$this->dimensions, ...$coordinate); |
|
105
|
3 |
|
fwrite($this->handler, $dataChunk); |
|
106
|
3 |
|
} |
|
107
|
|
|
|
|
108
|
|
|
/** |
|
109
|
|
|
* @param string $identifier |
|
110
|
|
|
*/ |
|
111
|
3 |
|
private function initTree(string $identifier) |
|
112
|
|
|
{ |
|
113
|
3 |
|
$this->handler = fopen($this->path . '/' . $identifier, 'wb'); |
|
114
|
3 |
|
} |
|
115
|
|
|
|
|
116
|
|
|
/** |
|
117
|
|
|
* Calculate memory size in file needed for single node |
|
118
|
|
|
*/ |
|
119
|
3 |
|
private function calculateNodeSize() |
|
120
|
|
|
{ |
|
121
|
3 |
|
$this->nodeMemorySize = $this->dimensions * 8 + 3 * 4; |
|
122
|
3 |
|
} |
|
123
|
|
|
|
|
124
|
|
|
/** |
|
125
|
|
|
* Specify number of dimensions according to file format |
|
126
|
|
|
*/ |
|
127
|
3 |
|
private function specifyNumberOfDimensions() |
|
128
|
|
|
{ |
|
129
|
3 |
|
$dataChunk = pack('V', $this->dimensions); |
|
130
|
3 |
|
fwrite($this->handler, $dataChunk); |
|
131
|
3 |
|
} |
|
132
|
|
|
|
|
133
|
|
|
/** |
|
134
|
|
|
* @param KDTreeInterface $tree |
|
135
|
|
|
*/ |
|
136
|
3 |
|
private function specifyNumberOfItems(KDTreeInterface $tree) |
|
137
|
|
|
{ |
|
138
|
3 |
|
$itemCount = $tree->getItemCount(); |
|
139
|
3 |
|
$dataChunk = pack('V', $itemCount); |
|
140
|
3 |
|
fwrite($this->handler, $dataChunk); |
|
141
|
3 |
|
} |
|
142
|
|
|
|
|
143
|
|
|
/** |
|
144
|
|
|
* @param $item |
|
145
|
|
|
*/ |
|
146
|
|
|
private function saveItemCoordinate(ItemInterface $item) |
|
147
|
|
|
{ |
|
148
|
|
|
$coordinate = []; |
|
149
|
|
|
for ($i = 0; $i < $this->dimensions; $i++) { |
|
150
|
|
|
$coordinate[] = $item->getNthDimension($i); |
|
151
|
|
|
} |
|
152
|
|
|
$this->writeCoordinate($coordinate); |
|
153
|
|
|
} |
|
154
|
|
|
|
|
155
|
|
|
/** |
|
156
|
|
|
* Persist current position before writing left node |
|
157
|
|
|
* @param $position |
|
158
|
|
|
*/ |
|
159
|
|
|
private function persistLeftLink($position) |
|
160
|
|
|
{ |
|
161
|
|
|
$leftPosition = ftell($this->handler); |
|
162
|
|
|
fseek($this->handler, $position + 4); |
|
163
|
|
|
$dataChunk = pack('V', $leftPosition); |
|
164
|
|
|
fwrite($this->handler, $dataChunk); |
|
165
|
|
|
fseek($this->handler, $leftPosition); |
|
166
|
|
|
} |
|
167
|
|
|
|
|
168
|
|
|
/** |
|
169
|
|
|
* @param $item |
|
170
|
|
|
*/ |
|
171
|
|
|
private function writeItemId(ItemInterface $item) |
|
172
|
|
|
{ |
|
173
|
|
|
$itemId = $item->getId(); |
|
174
|
|
|
$dataChunk = pack('V', $itemId); |
|
175
|
|
|
fwrite($this->handler, $dataChunk); |
|
176
|
|
|
} |
|
177
|
|
|
} |
|
178
|
|
|
|
hexogen /
kdtree
