db0d582eef67f52237aead05631e04b4b7329a12
[core.git] / inc / main / classes / index / file_stack / class_FileStackIndex.php
1 <?php
2 /**
3  * A FileStack index class
4  *
5  * @author              Roland Haeder <webmaster@ship-simu.org>
6  * @version             0.0.0
7  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
8  * @license             GNU GPL 3.0 or any newer version
9  * @link                http://www.ship-simu.org
10  *
11  * This program is free software: you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation, either version 3 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program. If not, see <http://www.gnu.org/licenses/>.
23  */
24 class FileStackIndex extends BaseIndex implements IndexableStack, Registerable {
25         /**
26          * Protected constructor
27          *
28          * @return      void
29          */
30         protected function __construct () {
31                 // Call parent constructor
32                 parent::__construct(__CLASS__);
33         }
34
35         /**
36          * Creates an instance of this Index class and prepares it for usage
37          *
38          * @param       $fileName               Name of the file stack to create an index file for
39          * @return      $indexInstance  An instance of this Index class
40          */
41         public final static function createFileStackIndex ($fileName) {
42                 // Get a new instance
43                 $indexInstance = new FileStackIndex();
44
45                 // Initialize index
46                 $indexInstance->initIndex($fileName);
47
48                 // Return the prepared instance
49                 return $indexInstance;
50         }
51
52         /**
53          * Adds given hash to an index file
54          *
55          * @param       $groupId        Name of stack to add hash for
56          * @param       $data           Hash and gap position to be added to the index
57          * @return      void
58          */
59         public function addHashToIndex ($groupId, array $data) {
60                 // Debug message
61                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,gap=%d,length=%d - CALLED!', __METHOD__, __LINE__, $groupId, $data[BaseFileStack::ARRAY_INDEX_HASH], $data[BaseFileStack::ARRAY_INDEX_GAP_POSITION], $data[BaseFileStack::ARRAY_INDEX_DATA_LENGTH]));
62
63                 // Raw data been written to the file
64                 $rawData = sprintf('%s%s%s%s%s%s%s',
65                         $groupId,
66                         self::SEPARATOR_GROUP_HASH,
67                         hex2bin($data[BaseFileStack::ARRAY_INDEX_HASH]),
68                         self::SEPARATOR_HASH_GAP_POSITION,
69                         $data[BaseFileStack::ARRAY_INDEX_GAP_POSITION],
70                         self::SEPARATOR_GAP_LENGTH,
71                         $data[BaseFileStack::ARRAY_INDEX_DATA_LENGTH]
72                 );
73
74                 // Debug message
75                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,rawData()=%d', __METHOD__, __LINE__, $groupId, $data[BaseFileStack::ARRAY_INDEX_HASH], strlen($rawData)));
76
77                 // Search for next free gap
78                 $gapPosition = $this->getIteratorInstance()->searchNextGap(strlen($rawData));
79
80                 // Gap position cannot be smaller than header length + 1
81                 assert($gapPosition > $this->getIteratorInstance()->getHeaderSize());
82
83                 // Debug message
84                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,gapPosition=%s', __METHOD__, __LINE__, $groupId, $data[BaseFileStack::ARRAY_INDEX_HASH], $gapPosition));
85
86                 // Then write the data at that gap
87                 $this->getIteratorInstance()->writeData($gapPosition, $rawData);
88
89                 // Debug message
90                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,rawData()=%d - EXIT!', __METHOD__, __LINE__, $groupId, $data[BaseFileStack::ARRAY_INDEX_HASH], strlen($rawData)));
91         }
92
93         /**
94          * Searches for next suitable gap the given length of data can fit in
95          * including padding bytes.
96          *
97          * @param       $length                 Length of raw data
98          * @return      $seekPosition   Found next gap's seek position
99          */
100         public function searchNextGap ($length) {
101                 $this->partialStub('length=' . $length);
102         }
103 }
104
105 // [EOF]
106 ?>