3 * Database backend class for storing objects in locally created files.
5 * This class serializes objects and saves them to local files.
7 * @author Roland Haeder <webmaster@ship-simu.org>
9 * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2012 Core Developer Team
10 * @license GNU GPL 3.0 or any newer version
11 * @link http://www.ship-simu.org
13 * This program is free software: you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation, either version 3 of the License, or
16 * (at your option) any later version.
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program. If not, see <http://www.gnu.org/licenses/>.
26 class LocalFileDatabase extends BaseDatabaseBackend implements DatabaseBackendInterface {
27 // Constants for MySQL backward-compatiblity (PLEASE FIX THEM!)
28 const DB_CODE_TABLE_MISSING = 0x100;
29 const DB_CODE_TABLE_UNWRITEABLE = 0x101;
30 const DB_CODE_DATA_FILE_CORRUPT = 0x102;
33 const RESULT_OKAY = 'ok';
36 * The file's extension
38 private $fileExtension = 'serialized';
41 * The last read file's name
43 private $lastFile = '';
46 * The last read file's content including header information
48 private $lastContents = array();
51 * Whether the "connection is already up
53 private $alreadyConnected = false;
56 * Table information array
58 private $tableInfo = array();
63 private $indexKey = '__idx';
66 * The protected constructor. Do never instance from outside! You need to
67 * set a local file path. The class will then validate it.
71 protected function __construct () {
72 // Call parent constructor
73 parent::__construct(__CLASS__);
77 * Create an object of LocalFileDatabase and set the save path from
78 * configuration for local files.
80 * @return $databaseInstance An instance of LocalFileDatabase
82 public static final function createLocalFileDatabase () {
84 $databaseInstance = new LocalFileDatabase();
86 // Get a new compressor channel instance
87 $compressorInstance = ObjectFactory::createObjectByConfiguredName('compressor_channel_class');
89 // Set the compressor channel
90 $databaseInstance->setCompressorChannel($compressorInstance);
92 // Get a file IO handler
93 $fileIoInstance = ObjectFactory::createObjectByConfiguredName('file_io_class');
96 $databaseInstance->setFileIoInstance($fileIoInstance);
98 // "Connect" to the database
99 $databaseInstance->connectToDatabase();
101 // Return database instance
102 return $databaseInstance;
106 * Setter for the last read file
108 * @param $fqfn The FQFN of the last read file
111 private final function setLastFile ($fqfn) {
112 // Cast string and set it
113 $this->lastFile = (string) $fqfn;
117 * Getter for last read file
119 * @return $lastFile The last read file's name with full path
121 public final function getLastFile () {
122 return $this->lastFile;
126 * Setter for contents of the last read file
128 * @param $contents An array with header and data elements
131 private final function setLastFileContents (array $contents) {
133 $this->lastContents = $contents;
137 * Getter for last read file's content as an array
139 * @return $lastContent The array with elements 'header' and 'data'.
141 public final function getLastContents () {
142 return $this->lastContents;
146 * Getter for file extension
148 * @return $fileExtension The array with elements 'header' and 'data'.
150 public final function getFileExtension () {
151 return $this->fileExtension;
155 * Getter for index key
157 * @return $indexKey Index key
159 public final function getIndexKey () {
160 return $this->indexKey;
164 * Reads a local data file and returns it's contents in an array
166 * @param $fqfn The FQFN for the requested file
169 private function getDataArrayFromFile ($fqfn) {
171 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Reading elements from database file ' . $fqfn . ' ...');
173 // Init compressed data
174 $compressedData = $this->getFileIoInstance()->loadFileContents($fqfn);
175 $compressedData = $compressedData['data'];
177 // Close the file and throw the instance away
178 unset($fileInstance);
181 $serializedData = $this->getCompressorChannel()->getCompressor()->decompressStream($compressedData);
184 $dataArray = unserialize($serializedData);
187 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Read ' . count($dataArray) . ' elements from database file ' . $fqfn . '.');
194 * Writes data array to local file
196 * @param $fqfn The FQFN of the local file
197 * @param $dataArray An array with all the data we shall write
200 private function writeDataArrayToFqfn ($fqfn, array $dataArray) {
202 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Flushing ' . count($dataArray) . ' elements to database file ' . $fqfn . ' ...');
204 // Serialize and compress it
205 $compressedData = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($dataArray));
208 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Writing ' . strlen($compressedData) . ' bytes ...');
210 // Write this data BASE64 encoded to the file
211 $this->getFileIoInstance()->saveFile($fqfn, $compressedData);
214 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Flushing ' . count($dataArray) . ' elements to database file completed.');
218 * Getter for table information file contents or an empty if info file was not created
220 * @param $dataSetInstance An instance of a database set class
221 * @return $infoArray An array with all table informations
223 private function getContentsFromTableInfoFile (StoreableCriteria $dataSetInstance) {
224 // Default content is no data
225 $infoArray = array();
227 // Create FQFN for getting the table information file
228 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
230 // Get the file contents
232 $infoArray = $this->getDataArrayFromFile($fqfn);
233 } catch (FileIoException $e) {
234 // Not found, so ignore it here
242 * Generates an FQFN from given dataset instance and string
244 * @param $dataSetInstance An instance of a database set class
245 * @param $rowName Name of the row
246 * @return $fqfn The FQFN for this row
248 private function generateFqfnFromDataSet (Criteria $dataSetInstance, $rowName) {
250 $fqfn = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/' . $rowName . '.' . $this->getFileExtension();
257 * Creates the table info file from given dataset instance
259 * @param $dataSetInstance An instance of a database set class
262 private function createTableInfoFile (StoreableCriteria $dataSetInstance) {
263 // Create FQFN for creating the table information file
264 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
266 // Get the data out from dataset in a local array
267 $this->tableInfo[$dataSetInstance->getTableName()] = array(
268 'primary' => $dataSetInstance->getPrimaryKey(),
270 'last_updated' => time()
273 // Write the data to the file
274 $this->writeDataArrayToFqfn($fqfn, $this->tableInfo[$dataSetInstance->getTableName()]);
278 * Updates the primary key information or creates the table info file if not found
280 * @param $dataSetInstance An instance of a database set class
283 private function updatePrimaryKey (StoreableCriteria $dataSetInstance) {
284 // Get the information array from lower method
285 $infoArray = $this->getContentsFromTableInfoFile($dataSetInstance);
287 // Is the primary key there?
288 if (!isset($this->tableInfo['primary'])) {
289 // Then create the info file
290 $this->createTableInfoFile($dataSetInstance);
291 } elseif (($this->getConfigInstance()->getConfigEntry('db_update_primary_forced') == 'Y') && ($dataSetInstance->getPrimaryKey() != $this->tableInfo['primary'])) {
292 // Set the array element
293 $this->tableInfo[$dataSetInstance->getTableName()]['primary'] = $dataSetInstance->getPrimaryKey();
296 $this->updateTableInfoFile($dataSetInstance);
301 * Makes sure that the database connection is alive
304 * @todo Do some checks on the database directory and files here
306 public function connectToDatabase () {
310 * Starts a SELECT query on the database by given return type, table name
311 * and search criteria
313 * @param $tableName Name of the database table
314 * @param $criteria Local search criteria class
315 * @return $resultData Result data of the query
316 * @throws UnsupportedCriteriaException If the criteria is unsupported
317 * @throws SqlException If an 'SQL error' occurs
319 public function querySelect ($tableName, LocalSearchCriteria $criteriaInstance) {
320 // The result is null by any errors
323 // Create full path name
324 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $tableName . '/';
326 // A 'select' query is not that easy on local files, so first try to
327 // find the 'table' which is in fact a directory on the server
329 // Get a directory pointer instance
330 $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
332 // Initialize the result data, this need to be rewritten e.g. if a local file cannot be read
334 BaseDatabaseBackend::RESULT_INDEX_STATUS => LocalfileDatabase::RESULT_OKAY,
335 BaseDatabaseBackend::RESULT_INDEX_ROWS => array()
338 // Initialize limit/skip
343 // Read the directory with some exceptions
344 while (($dataFile = $directoryInstance->readDirectoryExcept(array('.', '..', '.htaccess', '.svn', 'info.' . $this->getFileExtension()))) && (($limitFound < $criteriaInstance->getLimit()) || ($criteriaInstance->getLimit() == 0))) {
345 // Does the extension match?
346 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
352 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
353 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataFile=' . $dataFile . ',dataArray='.print_r($dataArray,true));
356 if (is_array($dataArray)) {
357 // Search in the criteria with FMFW (First Matches, First Wins)
358 foreach ($dataArray as $key => $value) {
359 // Get criteria element
360 $criteria = $criteriaInstance->getCriteriaElemnent($key);
362 // Is the criteria met or none set?
363 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: criteria[' . gettype($criteria) . ']=' . $criteria . ';()=' . strlen($criteria) . ',criteriaInstance()=' . $criteriaInstance->count() . ',value(' . strlen($value) . ')=' . $value);
364 if (((!is_null($criteria)) && ($criteria == $value)) || ($criteriaInstance->count() == 0)) {
365 // Shall we skip this entry?
366 if ($criteriaInstance->getSkip() > 0) {
367 // We shall skip some entries
368 if ($skipFound < $criteriaInstance->getSkip()) {
376 $dataArray[$this->getIndexKey()] = $idx;
379 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: indexKey=' . $this->getIndexKey() . ',idx=' . $idx . ',dataArray=' . print_r($dataArray, true));
380 $resultData[BaseDatabaseBackend::RESULT_INDEX_ROWS][] = $dataArray;
382 // Count found entries up
388 // Throw an exception here
389 throw new SqlException(array($this, sprintf("File '%s' contains invalid data.", $dataFile), self::DB_CODE_DATA_FILE_CORRUPT), self::EXCEPTION_SQL_QUERY);
396 // Close directory and throw the instance away
397 $directoryInstance->closeDirectory();
398 unset($directoryInstance);
400 // Reset last exception
401 $this->resetLastException();
402 } catch (PathIsNoDirectoryException $e) {
403 // Path not found means "table not found" for real databases...
404 $this->setLastException($e);
406 // So throw an SqlException here with faked error message
407 throw new SqlException (array($this, sprintf("Table '%s' not found", $tableName), self::DB_CODE_TABLE_MISSING), self::EXCEPTION_SQL_QUERY);
408 } catch (FrameworkException $e) {
409 // Catch all exceptions and store them in last error
410 $this->setLastException($e);
413 // Return the gathered result
418 * "Inserts" a data set instance into a local file database folder
420 * @param $dataSetInstance A storeable data set
422 * @throws SqlException If an SQL error occurs
424 public function queryInsertDataSet (StoreableCriteria $dataSetInstance) {
425 // Create full path name
426 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, md5($dataSetInstance->getUniqueValue()));
428 // Try to save the request away
430 // Write the data away
431 $this->writeDataArrayToFqfn($fqfn, $dataSetInstance->getCriteriaArray());
433 // Update the primary key
434 $this->updatePrimaryKey($dataSetInstance);
436 // Reset last exception
437 $this->resetLastException();
438 } catch (FrameworkException $e) {
439 // Catch all exceptions and store them in last error
440 $this->setLastException($e);
442 // Throw an SQL exception
443 throw new SqlException(array($this, sprintf("Cannot write data to table '%s', is the table created?", $dataSetInstance->getTableName()), self::DB_CODE_TABLE_UNWRITEABLE), self::EXCEPTION_SQL_QUERY);
448 * "Updates" a data set instance with a database layer
450 * @param $dataSetInstance A storeable data set
452 * @throws SqlException If an SQL error occurs
454 public function queryUpdateDataSet (StoreableCriteria $dataSetInstance) {
455 // Create full path name
456 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/';
458 // Try all the requests
460 // Get a file pointer instance
461 $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
463 // Initialize limit/skip
467 // Get the criteria array from the dataset
468 $criteriaArray = $dataSetInstance->getCriteriaArray();
470 // Get search criteria
471 $searchInstance = $dataSetInstance->getSearchInstance();
473 // Read the directory with some exceptions
474 while (($dataFile = $directoryInstance->readDirectoryExcept(array('.', '..', '.htaccess', '.svn', 'info.' . $this->getFileExtension()))) && ($limitFound < $searchInstance->getLimit())) {
475 // Does the extension match?
476 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
478 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataFile=' . $dataFile . ',getFileExtension()=' . $this->getFileExtension() . ' - SKIPPED!');
483 // Open this file for reading
484 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
485 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataFile=' . $dataFile . ',dataArray='.print_r($dataArray,true));
488 if (is_array($dataArray)) {
489 // Search in the criteria with FMFW (First Matches, First Wins)
490 foreach ($dataArray as $key => $value) {
491 // Get criteria element
492 $criteria = $searchInstance->getCriteriaElemnent($key);
493 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataFile=' . $dataFile . ',key=' . $key . ',criteria=' . $criteria);
495 // Is the criteria met?
496 if (((!is_null($criteria)) && ($criteria == $value)) || ($searchInstance->count() == 0)) {
497 // Shall we skip this entry?
498 if ($searchInstance->getSkip() > 0) {
499 // We shall skip some entries
500 if ($skipFound < $searchInstance->getSkip()) {
507 // Entry found, so update it
508 foreach ($criteriaArray as $criteriaKey => $criteriaValue) {
509 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: criteriaKey=' . $criteriaKey . ',criteriaValue=' . $criteriaValue);
510 $dataArray[$criteriaKey] = $criteriaValue;
513 // Write the data to a local file
514 $this->writeDataArrayToFqfn($pathName . $dataFile, $dataArray);
524 // Close the file pointer
525 $directoryInstance->closeDirectory();
527 // Update the primary key
528 $this->updatePrimaryKey($dataSetInstance);
530 // Reset last exception
531 $this->resetLastException();
532 } catch (FrameworkException $e) {
533 // Catch all exceptions and store them in last error
534 $this->setLastException($e);
536 // Throw an SQL exception
537 throw new SqlException(array($this, sprintf("Cannot write data to table '%s', is the table created?", $dataSetInstance->getTableName()), self::DB_CODE_TABLE_UNWRITEABLE), self::EXCEPTION_SQL_QUERY);
542 * Getter for primary key of specified table or if not found null will be
543 * returned. This must be database-specific.
545 * @param $tableName Name of the table we need the primary key from
546 * @return $primaryKey Primary key column of the given table
548 public function getPrimaryKeyOfTable ($tableName) {
549 // Default key is null
552 // Does the table information exist?
553 if (isset($this->tableInfo[$tableName])) {
554 // Then return the primary key
555 $primaryKey = $this->tableInfo[$tableName]['primary'];