3 * A FileStack index class
5 * @author Roland Haeder <webmaster@ship-simu.org>
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
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.
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.
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/>.
24 class FileStackIndex extends BaseIndex implements IndexableStack, Registerable {
26 * Protected constructor
30 protected function __construct () {
31 // Call parent constructor
32 parent::__construct(__CLASS__);
36 * Creates an instance of this Index class and prepares it for usage
38 * @param $fileName Name of the file stack to create an index file for
39 * @return $indexInstance An instance of this Index class
41 public final static function createFileStackIndex ($fileName) {
43 $indexInstance = new FileStackIndex();
46 $indexInstance->initIndex($fileName);
48 // Return the prepared instance
49 return $indexInstance;
53 * Adds given hash to an index file
55 * @param $groupId Name of stack to add hash for
56 * @param $data Hash and gap position to be added to the index
59 public function addHashToIndex ($groupId, array $data) {
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]));
63 // Raw data been written to the file
64 $rawData = sprintf('%s%s%s%s%s%s%s',
66 self::SEPARATOR_GROUP_HASH,
67 hex2bin($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]
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)));
77 // Search for next free gap
78 $gapPosition = $this->getIteratorInstance()->searchNextGap(strlen($rawData));
80 // Gap position cannot be smaller than header length + 1
81 assert($gapPosition > $this->getIteratorInstance()->getHeaderSize());
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));
86 // Then write the data at that gap
87 $this->getIteratorInstance()->writeData($gapPosition, $rawData);
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)));
94 * Searches for next suitable gap the given length of data can fit in
95 * including padding bytes.
97 * @param $length Length of raw data
98 * @return $seekPosition Found next gap's seek position
100 public function searchNextGap ($length) {
101 $this->partialStub('length=' . $length);