summaryrefslogtreecommitdiffstats
path: root/lib/private/Search/SearchComposer.php
blob: dd4edfc5f40c5d6106f9817d00a4fbd146f6ac8e (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
<?php

declare(strict_types=1);

/**
 * @copyright 2020 Christoph Wurst <christoph@winzerhof-wurst.at>
 *
 * @author 2020 Christoph Wurst <christoph@winzerhof-wurst.at>
 *
 * @license GNU AGPL version 3 or any later version
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

namespace OC\Search;

use InvalidArgumentException;
use OC\AppFramework\Bootstrap\Coordinator;
use OCP\AppFramework\QueryException;
use OCP\ILogger;
use OCP\IServerContainer;
use OCP\IUser;
use OCP\Search\IProvider;
use OCP\Search\ISearchQuery;
use OCP\Search\SearchResult;
use function array_map;

/**
 * Queries individual \OCP\Search\IProvider implementations and composes a
 * unified search result for the user's search term
 *
 * The search process is generally split into two steps
 *
 *   1. Get a list of provider (`getProviders`)
 *   2. Get search results of each provider (`search`)
 *
 * The reasoning behind this is that the runtime complexity of a combined search
 * result would be O(n) and linearly grow with each provider added. This comes
 * from the nature of php where we can't concurrently fetch the search results.
 * So we offload the concurrency the client application (e.g. JavaScript in the
 * browser) and let it first get the list of providers to then fetch all results
 * concurrently. The client is free to decide whether all concurrent search
 * results are awaited or shown as they come in.
 *
 * @see IProvider::search() for the arguments of the individual search requests
 */
class SearchComposer {

	/** @var IProvider[] */
	private $providers = [];

	/** @var Coordinator */
	private $bootstrapCoordinator;

	/** @var IServerContainer */
	private $container;

	/** @var ILogger */
	private $logger;

	public function __construct(Coordinator $bootstrapCoordinator,
								IServerContainer $container,
								ILogger $logger) {
		$this->container = $container;
		$this->logger = $logger;
		$this->bootstrapCoordinator = $bootstrapCoordinator;
	}

	/**
	 * Load all providers dynamically that were registered through `registerProvider`
	 *
	 * If a provider can't be loaded we log it but the operation continues nevertheless
	 */
	private function loadLazyProviders(): void {
		$context = $this->bootstrapCoordinator->getRegistrationContext();
		if ($context === null) {
			// Too early, nothing registered yet
			return;
		}

		$registrations = $context->getSearchProviders();
		foreach ($registrations as $registration) {
			try {
				/** @var IProvider $provider */
				$provider = $this->container->query($registration['class']);
				$this->providers[$provider->getId()] = $provider;
			} catch (QueryException $e) {
				// Log an continue. We can be fault tolerant here.
				$this->logger->logException($e, [
					'message' => 'Could not load search provider dynamically: ' . $e->getMessage(),
					'level' => ILogger::ERROR,
				]);
			}
		}
	}

	/**
	 * Get a list of all provider IDs & Names for the consecutive calls to `search`
	 *
	 * @return array
	 */
	public function getProviders(): array {
		$this->loadLazyProviders();

		/**
		 * Return an array with the IDs, but strip the associative keys
		 */
		return array_values(
			array_map(function (IProvider $provider) {
				return [
					'id' => $provider->getId(),
					'name' => $provider->getName()
				];
			}, $this->providers));
	}

	/**
	 * Query an individual search provider for results
	 *
	 * @param IUser $user
	 * @param string $providerId one of the IDs received by `getProviders`
	 * @param ISearchQuery $query
	 *
	 * @return SearchResult
	 * @throws InvalidArgumentException when the $providerId does not correspond to a registered provider
	 */
	public function search(IUser $user,
						   string $providerId,
						   ISearchQuery $query): SearchResult {
		$this->loadLazyProviders();

		$provider = $this->providers[$providerId] ?? null;
		if ($provider === null) {
			throw new InvalidArgumentException("Provider $providerId is unknown");
		}
		return $provider->search($user, $query);
	}
}