|
1
|
|
|
<?php |
|
2
|
|
|
|
|
3
|
|
|
/** |
|
4
|
|
|
* @author Jared King <[email protected]> |
|
5
|
|
|
* |
|
6
|
|
|
* @see http://jaredtking.com |
|
7
|
|
|
* |
|
8
|
|
|
* @copyright 2015 Jared King |
|
9
|
|
|
* @license MIT |
|
10
|
|
|
*/ |
|
11
|
|
|
|
|
12
|
|
|
namespace Pulsar; |
|
13
|
|
|
|
|
14
|
|
|
final class Iterator implements \Iterator, \Countable, \ArrayAccess |
|
15
|
|
|
{ |
|
16
|
|
|
/** |
|
17
|
|
|
* @var Query |
|
18
|
|
|
*/ |
|
19
|
|
|
private $query; |
|
20
|
|
|
|
|
21
|
|
|
/** |
|
22
|
|
|
* @var int |
|
23
|
|
|
*/ |
|
24
|
|
|
private $start; |
|
25
|
|
|
|
|
26
|
|
|
/** |
|
27
|
|
|
* @var int |
|
28
|
|
|
*/ |
|
29
|
|
|
private $pointer; |
|
30
|
|
|
|
|
31
|
|
|
/** |
|
32
|
|
|
* @var int |
|
33
|
|
|
*/ |
|
34
|
|
|
private $limit; |
|
35
|
|
|
|
|
36
|
|
|
/** |
|
37
|
|
|
* @var int|bool |
|
38
|
|
|
*/ |
|
39
|
|
|
private $loadedStart; |
|
40
|
|
|
|
|
41
|
|
|
/** |
|
42
|
|
|
* @var array |
|
43
|
|
|
*/ |
|
44
|
|
|
private $models; |
|
45
|
|
|
|
|
46
|
|
|
/** |
|
47
|
|
|
* @var int|bool |
|
48
|
|
|
*/ |
|
49
|
|
|
private $count; |
|
50
|
|
|
|
|
51
|
|
|
public function __construct(Query $query) |
|
52
|
|
|
{ |
|
53
|
|
|
$this->query = $query; |
|
54
|
|
|
$this->models = []; |
|
55
|
|
|
$this->start = $query->getStart(); |
|
56
|
|
|
$this->limit = $query->getLimit(); |
|
57
|
|
|
$this->pointer = $this->start; |
|
58
|
|
|
|
|
59
|
|
|
$sort = $query->getSort(); |
|
60
|
|
|
if (empty($sort)) { |
|
61
|
|
|
$model = $query->getModel(); |
|
62
|
|
|
$idProperties = $model::getIDProperties(); |
|
63
|
|
|
foreach ($idProperties as &$property) { |
|
64
|
|
|
$property .= ' asc'; |
|
65
|
|
|
} |
|
66
|
|
|
|
|
67
|
|
|
$query->sort(implode(',', $idProperties)); |
|
68
|
|
|
} |
|
69
|
|
|
} |
|
70
|
|
|
|
|
71
|
|
|
public function getQuery(): Query |
|
72
|
|
|
{ |
|
73
|
|
|
return $this->query; |
|
74
|
|
|
} |
|
75
|
|
|
|
|
76
|
|
|
////////////////////////// |
|
77
|
|
|
// Iterator Interface |
|
78
|
|
|
////////////////////////// |
|
79
|
|
|
|
|
80
|
|
|
/** |
|
81
|
|
|
* Rewind the Iterator to the first element. |
|
82
|
|
|
*/ |
|
83
|
|
|
public function rewind() |
|
84
|
|
|
{ |
|
85
|
|
|
$this->pointer = $this->start; |
|
86
|
|
|
$this->loadedStart = false; |
|
87
|
|
|
$this->models = []; |
|
88
|
|
|
$this->count = false; |
|
89
|
|
|
} |
|
90
|
|
|
|
|
91
|
|
|
/** |
|
92
|
|
|
* Returns the current element. |
|
93
|
|
|
* |
|
94
|
|
|
* @return mixed |
|
95
|
|
|
*/ |
|
96
|
|
|
public function current() |
|
97
|
|
|
{ |
|
98
|
|
|
if ($this->pointer >= $this->count()) { |
|
99
|
|
|
return null; |
|
100
|
|
|
} |
|
101
|
|
|
|
|
102
|
|
|
$this->loadModels(); |
|
103
|
|
|
$k = $this->pointer % $this->limit; |
|
104
|
|
|
|
|
105
|
|
|
if (isset($this->models[$k])) { |
|
106
|
|
|
return $this->models[$k]; |
|
107
|
|
|
} |
|
108
|
|
|
|
|
109
|
|
|
return null; |
|
110
|
|
|
} |
|
111
|
|
|
|
|
112
|
|
|
/** |
|
113
|
|
|
* Return the key of the current element. |
|
114
|
|
|
* |
|
115
|
|
|
* @return int |
|
116
|
|
|
*/ |
|
117
|
|
|
public function key() |
|
118
|
|
|
{ |
|
119
|
|
|
return $this->pointer; |
|
120
|
|
|
} |
|
121
|
|
|
|
|
122
|
|
|
/** |
|
123
|
|
|
* Move forward to the next element. |
|
124
|
|
|
*/ |
|
125
|
|
|
public function next() |
|
126
|
|
|
{ |
|
127
|
|
|
++$this->pointer; |
|
128
|
|
|
} |
|
129
|
|
|
|
|
130
|
|
|
/** |
|
131
|
|
|
* Checks if current position is valid. |
|
132
|
|
|
* |
|
133
|
|
|
* @return bool |
|
134
|
|
|
*/ |
|
135
|
|
|
public function valid() |
|
136
|
|
|
{ |
|
137
|
|
|
return $this->pointer < $this->count(); |
|
138
|
|
|
} |
|
139
|
|
|
|
|
140
|
|
|
////////////////////////// |
|
141
|
|
|
// Countable Interface |
|
142
|
|
|
////////////////////////// |
|
143
|
|
|
|
|
144
|
|
|
/** |
|
145
|
|
|
* Get total number of models matching query. |
|
146
|
|
|
* |
|
147
|
|
|
* @return int |
|
148
|
|
|
*/ |
|
149
|
|
|
public function count() |
|
150
|
|
|
{ |
|
151
|
|
|
$this->updateCount(); |
|
152
|
|
|
|
|
153
|
|
|
return $this->count; |
|
|
|
|
|
|
154
|
|
|
} |
|
155
|
|
|
|
|
156
|
|
|
////////////////////////// |
|
157
|
|
|
// ArrayAccess Interface |
|
158
|
|
|
////////////////////////// |
|
159
|
|
|
|
|
160
|
|
|
public function offsetExists($offset) |
|
161
|
|
|
{ |
|
162
|
|
|
return is_numeric($offset) && $offset < $this->count(); |
|
163
|
|
|
} |
|
164
|
|
|
|
|
165
|
|
|
public function offsetGet($offset) |
|
166
|
|
|
{ |
|
167
|
|
|
if (!$this->offsetExists($offset)) { |
|
168
|
|
|
throw new \OutOfBoundsException("$offset does not exist on this Iterator"); |
|
169
|
|
|
} |
|
170
|
|
|
|
|
171
|
|
|
$this->pointer = $offset; |
|
172
|
|
|
|
|
173
|
|
|
return $this->current(); |
|
174
|
|
|
} |
|
175
|
|
|
|
|
176
|
|
|
public function offsetSet($offset, $value) |
|
177
|
|
|
{ |
|
178
|
|
|
// iterators are immutable |
|
179
|
|
|
throw new \Exception('Cannot perform set on immutable Iterator'); |
|
180
|
|
|
} |
|
181
|
|
|
|
|
182
|
|
|
public function offsetUnset($offset) |
|
183
|
|
|
{ |
|
184
|
|
|
// iterators are immutable |
|
185
|
|
|
throw new \Exception('Cannot perform unset on immutable Iterator'); |
|
186
|
|
|
} |
|
187
|
|
|
|
|
188
|
|
|
////////////////////////// |
|
189
|
|
|
// Private Methods |
|
190
|
|
|
////////////////////////// |
|
191
|
|
|
|
|
192
|
|
|
/** |
|
193
|
|
|
* Load the next round of models. |
|
194
|
|
|
*/ |
|
195
|
|
|
private function loadModels() |
|
196
|
|
|
{ |
|
197
|
|
|
$start = $this->rangeStart($this->pointer, $this->limit); |
|
198
|
|
|
if ($this->loadedStart !== $start) { |
|
199
|
|
|
$this->query->start($start); |
|
200
|
|
|
|
|
201
|
|
|
$this->models = $this->query->execute(); |
|
202
|
|
|
$this->loadedStart = $start; |
|
|
|
|
|
|
203
|
|
|
} |
|
204
|
|
|
} |
|
205
|
|
|
|
|
206
|
|
|
/** |
|
207
|
|
|
* Updates the total count of models. For better performance |
|
208
|
|
|
* the count is only updated on edges, which is when new models |
|
209
|
|
|
* need to be loaded. |
|
210
|
|
|
*/ |
|
211
|
|
|
private function updateCount() |
|
212
|
|
|
{ |
|
213
|
|
|
// The count only needs to be updated when the pointer is |
|
214
|
|
|
// on the edges |
|
215
|
|
|
if (0 != $this->pointer % $this->limit && |
|
216
|
|
|
$this->pointer < $this->count) { |
|
217
|
|
|
return; |
|
218
|
|
|
} |
|
219
|
|
|
|
|
220
|
|
|
$newCount = $this->query->count(); |
|
221
|
|
|
|
|
222
|
|
|
// It's possible when iterating over models that something |
|
223
|
|
|
// is modified or deleted that causes the model count |
|
224
|
|
|
// to decrease. If the count has decreased then we |
|
225
|
|
|
// shift the pointer to prevent overflow. |
|
226
|
|
|
// This calculation is based on the assumption that |
|
227
|
|
|
// the first N (count - count') models are deleted. |
|
228
|
|
|
if (0 != $this->count && $newCount < $this->count) { |
|
229
|
|
|
$this->pointer = max(0, $this->pointer - ($this->count - $newCount)); |
|
|
|
|
|
|
230
|
|
|
} |
|
231
|
|
|
|
|
232
|
|
|
// If the count has increased then the pointer is still |
|
233
|
|
|
// valid. Update the count to include the extra models. |
|
234
|
|
|
$this->count = $newCount; |
|
235
|
|
|
} |
|
236
|
|
|
|
|
237
|
|
|
/** |
|
238
|
|
|
* Generates the starting page given a pointer and limit. |
|
239
|
|
|
*/ |
|
240
|
|
|
private function rangeStart(int $pointer, int $limit) |
|
241
|
|
|
{ |
|
242
|
|
|
return floor($pointer / $limit) * $limit; |
|
243
|
|
|
} |
|
244
|
|
|
|
|
245
|
|
|
/** |
|
246
|
|
|
* Cast Iterator to array |
|
247
|
|
|
* @return array |
|
248
|
|
|
*/ |
|
249
|
|
|
public function toArray(): array |
|
250
|
|
|
{ |
|
251
|
|
|
return iterator_to_array($this); |
|
252
|
|
|
} |
|
253
|
|
|
} |
|
254
|
|
|
|