summaryrefslogtreecommitdiff
path: root/includes/api/ApiContinuationManager.php
blob: 354f4e7de10105003e5588a301b674501abbcf8d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
<?php
/**
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

/**
 * This manages continuation state.
 * @since 1.25 this is no longer a subclass of ApiBase
 * @ingroup API
 */
class ApiContinuationManager {
	private $source;

	private $allModules = array();
	private $generatedModules = array();

	private $continuationData = array();
	private $generatorContinuationData = array();

	private $generatorParams = array();
	private $generatorDone = false;

	/**
	 * @param ApiBase $module Module starting the continuation
	 * @param ApiBase[] $allModules Contains ApiBase instances that will be executed
	 * @param array $generatedModules Names of modules that depend on the generator
	 */
	public function __construct(
		ApiBase $module, array $allModules = array(), array $generatedModules = array()
	) {
		$this->source = get_class( $module );
		$request = $module->getRequest();

		$this->generatedModules = $generatedModules
			? array_combine( $generatedModules, $generatedModules )
			: array();

		$skip = array();
		$continue = $request->getVal( 'continue', '' );
		if ( $continue !== '' ) {
			$continue = explode( '||', $continue );
			if ( count( $continue ) !== 2 ) {
				throw new UsageException(
					'Invalid continue param. You should pass the original value returned by the previous query',
					'badcontinue'
				);
			}
			$this->generatorDone = ( $continue[0] === '-' );
			$skip = explode( '|', $continue[1] );
			if ( !$this->generatorDone ) {
				$params = explode( '|', $continue[0] );
				if ( $params ) {
					$this->generatorParams = array_intersect_key(
						$request->getValues(),
						array_flip( $params )
					);
				}
			} else {
				// When the generator is complete, don't run any modules that
				// depend on it.
				$skip += $this->generatedModules;
			}
		}

		foreach ( $allModules as $module ) {
			$name = $module->getModuleName();
			if ( in_array( $name, $skip, true ) ) {
				$this->allModules[$name] = false;
				// Prevent spurious "unused parameter" warnings
				$module->extractRequestParams();
			} else {
				$this->allModules[$name] = $module;
			}
		}
	}

	/**
	 * Get the class that created this manager
	 * @return string
	 */
	public function getSource() {
		return $this->source;
	}

	/**
	 * Is the generator done?
	 * @return bool
	 */
	public function isGeneratorDone() {
		return $this->generatorDone;
	}

	/**
	 * Get the list of modules that should actually be run
	 * @return ApiBase[]
	 */
	public function getRunModules() {
		return array_values( array_filter( $this->allModules ) );
	}

	/**
	 * Set the continuation parameter for a module
	 * @param ApiBase $module
	 * @param string $paramName
	 * @param string|array $paramValue
	 * @throws UnexpectedValueException
	 */
	public function addContinueParam( ApiBase $module, $paramName, $paramValue ) {
		$name = $module->getModuleName();
		if ( !isset( $this->allModules[$name] ) ) {
			throw new UnexpectedValueException(
				"Module '$name' called " . __METHOD__ .
					' but was not passed to ' . __CLASS__ . '::__construct'
			);
		}
		if ( !$this->allModules[$name] ) {
			throw new UnexpectedValueException(
				"Module '$name' was not supposed to have been executed, but " .
					'it was executed anyway'
			);
		}
		$paramName = $module->encodeParamName( $paramName );
		if ( is_array( $paramValue ) ) {
			$paramValue = join( '|', $paramValue );
		}
		$this->continuationData[$name][$paramName] = $paramValue;
	}

	/**
	 * Set the continuation parameter for the generator module
	 * @param ApiBase $module
	 * @param string $paramName
	 * @param string|array $paramValue
	 */
	public function addGeneratorContinueParam( ApiBase $module, $paramName, $paramValue ) {
		$name = $module->getModuleName();
		$paramName = $module->encodeParamName( $paramName );
		if ( is_array( $paramValue ) ) {
			$paramValue = join( '|', $paramValue );
		}
		$this->generatorContinuationData[$name][$paramName] = $paramValue;
	}

	/**
	 * Fetch raw continuation data
	 * @return array
	 */
	public function getRawContinuation() {
		return array_merge_recursive( $this->continuationData, $this->generatorContinuationData );
	}

	/**
	 * Fetch continuation result data
	 * @return array Array( (array)$data, (bool)$batchcomplete )
	 */
	public function getContinuation() {
		$data = array();
		$batchcomplete = false;

		$finishedModules = array_diff(
			array_keys( $this->allModules ),
			array_keys( $this->continuationData )
		);

		// First, grab the non-generator-using continuation data
		$continuationData = array_diff_key( $this->continuationData, $this->generatedModules );
		foreach ( $continuationData as $module => $kvp ) {
			$data += $kvp;
		}

		// Next, handle the generator-using continuation data
		$continuationData = array_intersect_key( $this->continuationData, $this->generatedModules );
		if ( $continuationData ) {
			// Some modules are unfinished: include those params, and copy
			// the generator params.
			foreach ( $continuationData as $module => $kvp ) {
				$data += $kvp;
			}
			$data += $this->generatorParams;
			$generatorKeys = join( '|', array_keys( $this->generatorParams ) );
		} elseif ( $this->generatorContinuationData ) {
			// All the generator-using modules are complete, but the
			// generator isn't. Continue the generator and restart the
			// generator-using modules
			$generatorParams = array();
			foreach ( $this->generatorContinuationData as $kvp ) {
				$generatorParams += $kvp;
			}
			$data += $generatorParams;
			$finishedModules = array_diff( $finishedModules, $this->generatedModules );
			$generatorKeys = join( '|', array_keys( $generatorParams ) );
			$batchcomplete = true;
		} else {
			// Generator and prop modules are all done. Mark it so.
			$generatorKeys = '-';
			$batchcomplete = true;
		}

		// Set 'continue' if any continuation data is set or if the generator
		// still needs to run
		if ( $data || $generatorKeys !== '-' ) {
			$data['continue'] = $generatorKeys . '||' . join( '|', $finishedModules );
		}

		return array( $data, $batchcomplete );
	}

	/**
	 * Store the continuation data into the result
	 * @param ApiResult $result
	 */
	public function setContinuationIntoResult( ApiResult $result ) {
		list( $data, $batchcomplete ) = $this->getContinuation();
		if ( $data ) {
			$result->addValue( null, 'continue', $data,
				ApiResult::ADD_ON_TOP | ApiResult::NO_SIZE_CHECK );
		}
		if ( $batchcomplete ) {
			$result->addValue( null, 'batchcomplete', true,
				ApiResult::ADD_ON_TOP | ApiResult::NO_SIZE_CHECK );
		}
	}
}