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 BaseDatabaseFrontend implements DatabaseFrontendInterface {
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 // "Connect" to the database
93 $databaseInstance->connectToDatabase();
95 // Return database instance
96 return $databaseInstance;
100 * Setter for the last read file
102 * @param $fqfn The FQFN of the last read file
105 private final function setLastFile ($fqfn) {
106 // Cast string and set it
107 $this->lastFile = (string) $fqfn;
111 * Getter for last read file
113 * @return $lastFile The last read file's name with full path
115 public final function getLastFile () {
116 return $this->lastFile;
120 * Setter for contents of the last read file
122 * @param $contents An array with header and data elements
125 private final function setLastFileContents (array $contents) {
127 $this->lastContents = $contents;
131 * Getter for last read file's content as an array
133 * @return $lastContent The array with elements 'header' and 'data'.
135 public final function getLastContents () {
136 return $this->lastContents;
140 * Getter for file extension
142 * @return $fileExtension The array with elements 'header' and 'data'.
144 public final function getFileExtension () {
145 return $this->fileExtension;
149 * Getter for index key
151 * @return $indexKey Index key
153 public final function getIndexKey () {
154 return $this->indexKey;
158 * Reads a local data file and returns it's contents in an array
160 * @param $fqfn The FQFN for the requested file
163 private function getDataArrayFromFile ($fqfn) {
164 // Get a file pointer
165 $fileInstance = FrameworkFileInputPointer::createFrameworkFileInputPointer($fqfn);
167 // Get the raw data and BASE64-decode it
168 $compressedData = base64_decode($fileInstance->readLinesFromFile());
170 // Close the file and throw the instance away
171 $fileInstance->closeFile();
172 unset($fileInstance);
175 $serializedData = $this->getCompressorChannel()->getCompressor()->decompressStream($compressedData);
178 $dataArray = unserialize($serializedData);
185 * Writes data array to local file
187 * @param $fqfn The FQFN of the local file
188 * @param $dataArray An array with all the data we shall write
191 private function writeDataArrayToFqfn ($fqfn, array $dataArray) {
193 /* NOISY-DEBUG: */ $this->debugOutput('DATABASE: Flushing ' . count($dataArray) . ' elements to database file ' . $fqfn . ' ...');
195 // Get a file pointer instance
196 $fileInstance = FrameworkFileOutputPointer::createFrameworkFileOutputPointer($fqfn, 'w');
198 // Serialize and compress it
199 $compressedData = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($dataArray));
201 // Write this data BASE64 encoded to the file
202 $fileInstance->writeToFile(base64_encode($compressedData));
204 // Close the file pointer
205 $fileInstance->closeFile();
208 /* NOISY-DEBUG: */ $this->debugOutput('DATABASE: Flushing ' . count($dataArray) . ' elements to database file completed.');
212 * Getter for table information file contents or an empty if info file was not created
214 * @param $dataSetInstance An instance of a database set class
215 * @return $infoArray An array with all table informations
217 private function getContentsFromTableInfoFile (StoreableCriteria $dataSetInstance) {
218 // Default content is no data
219 $infoArray = array();
221 // Create FQFN for getting the table information file
222 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
224 // Get the file contents
226 $infoArray = $this->getDataArrayFromFile($fqfn);
227 } catch (FileIoException $e) {
228 // Not found, so ignore it here
236 * Generates an FQFN from given dataset instance and string
238 * @param $dataSetInstance An instance of a database set class
239 * @param $rowName Name of the row
240 * @return $fqfn The FQFN for this row
242 private function generateFqfnFromDataSet (Criteria $dataSetInstance, $rowName) {
244 $fqfn = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/' . $rowName . '.' . $this->getFileExtension();
251 * Creates the table info file from given dataset instance
253 * @param $dataSetInstance An instance of a database set class
256 private function createTableInfoFile (StoreableCriteria $dataSetInstance) {
257 // Create FQFN for creating the table information file
258 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
260 // Get the data out from dataset in a local array
261 $this->tableInfo[$dataSetInstance->getTableName()] = array(
262 'primary' => $dataSetInstance->getPrimaryKey(),
264 'last_updated' => time()
267 // Write the data to the file
268 $this->writeDataArrayToFqfn($fqfn, $this->tableInfo[$dataSetInstance->getTableName()]);
272 * Updates the primary key information or creates the table info file if not found
274 * @param $dataSetInstance An instance of a database set class
277 private function updatePrimaryKey (StoreableCriteria $dataSetInstance) {
278 // Get the information array from lower method
279 $infoArray = $this->getContentsFromTableInfoFile($dataSetInstance);
281 // Is the primary key there?
282 if (!isset($this->tableInfo['primary'])) {
283 // Then create the info file
284 $this->createTableInfoFile($dataSetInstance);
285 } elseif (($this->getConfigInstance()->getConfigEntry('db_update_primary_forced') == 'Y') && ($dataSetInstance->getPrimaryKey() != $this->tableInfo['primary'])) {
286 // Set the array element
287 $this->tableInfo[$dataSetInstance->getTableName()]['primary'] = $dataSetInstance->getPrimaryKey();
290 $this->updateTableInfoFile($dataSetInstance);
295 * Makes sure that the database connection is alive
298 * @todo Do some checks on the database directory and files here
300 public function connectToDatabase () {
304 * Starts a SELECT query on the database by given return type, table name
305 * and search criteria
307 * @param $tableName Name of the database table
308 * @param $criteria Local search criteria class
309 * @return $resultData Result data of the query
310 * @throws UnsupportedCriteriaException If the criteria is unsupported
311 * @throws SqlException If an 'SQL error' occurs
313 public function querySelect ($tableName, LocalSearchCriteria $criteriaInstance) {
314 // The result is null by any errors
317 // Create full path name
318 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $tableName . '/';
320 // A 'select' query is not that easy on local files, so first try to
321 // find the 'table' which is in fact a directory on the server
323 // Get a directory pointer instance
324 $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
326 // Initialize the result data, this need to be rewritten e.g. if a local file cannot be read
328 BaseDatabaseFrontend::RESULT_INDEX_STATUS => LocalfileDatabase::RESULT_OKAY,
329 BaseDatabaseFrontend::RESULT_INDEX_ROWS => array()
332 // Initialize limit/skip
337 // Read the directory with some exceptions
338 while (($dataFile = $directoryInstance->readDirectoryExcept(array('.', '..', '.htaccess', '.svn', 'info.' . $this->getFileExtension()))) && (($limitFound < $criteriaInstance->getLimit()) || ($criteriaInstance->getLimit() == 0))) {
339 // Does the extension match?
340 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
346 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
349 if (is_array($dataArray)) {
350 // Search in the criteria with FMFW (First Matches, First Wins)
351 foreach ($dataArray as $key => $value) {
352 // Get criteria element
353 $criteria = $criteriaInstance->getCriteriaElemnent($key);
355 // Is the criteria met?
356 //* NOISY-DEBUG: */ $this->debugOutput('DATABASE: criteria[' . gettype($criteria) . ']=' . $criteria . ',()=' . strlen($criteria) . ',value=' . $value . ',()=' . strlen($value));
357 if ((!is_null($criteria)) && ($criteria == $value)) {
358 // Shall we skip this entry?
359 if ($criteriaInstance->getSkip() > 0) {
360 // We shall skip some entries
361 if ($skipFound < $criteriaInstance->getSkip()) {
369 $dataArray[$this->getIndexKey()] = $idx;
372 //* NOISY-DEBUG: */ $this->debugOutput('DATABASE: indexKey=' . $this->getIndexKey() . ',idx=' . $idx . ',dataArray=' . print_r($dataArray, true));
373 $resultData[BaseDatabaseFrontend::RESULT_INDEX_ROWS][] = $dataArray;
375 // Count found entries up
381 // Throw an exception here
382 throw new SqlException(array($this, sprintf("File '%s' contains invalid data.", $dataFile), self::DB_CODE_DATA_FILE_CORRUPT), self::EXCEPTION_SQL_QUERY);
389 // Close directory and throw the instance away
390 $directoryInstance->closeDirectory();
391 unset($directoryInstance);
393 // Reset last exception
394 $this->resetLastException();
395 } catch (PathIsNoDirectoryException $e) {
396 // Path not found means "table not found" for real databases...
397 $this->setLastException($e);
399 // So throw an SqlException here with faked error message
400 throw new SqlException (array($this, sprintf("Table '%s' not found", $tableName), self::DB_CODE_TABLE_MISSING), self::EXCEPTION_SQL_QUERY);
401 } catch (FrameworkException $e) {
402 // Catch all exceptions and store them in last error
403 $this->setLastException($e);
406 // Return the gathered result
411 * "Inserts" a data set instance into a local file database folder
413 * @param $dataSetInstance A storeable data set
415 * @throws SqlException If an SQL error occurs
417 public function queryInsertDataSet (StoreableCriteria $dataSetInstance) {
418 // Create full path name
419 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, md5($dataSetInstance->getUniqueValue()));
421 // Try to save the request away
423 // Write the data away
424 $this->writeDataArrayToFqfn($fqfn, $dataSetInstance->getCriteriaArray());
426 // Update the primary key
427 $this->updatePrimaryKey($dataSetInstance);
429 // Reset last exception
430 $this->resetLastException();
431 } catch (FrameworkException $e) {
432 // Catch all exceptions and store them in last error
433 $this->setLastException($e);
435 // Throw an SQL exception
436 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);
441 * "Updates" a data set instance with a database layer
443 * @param $dataSetInstance A storeable data set
445 * @throws SqlException If an SQL error occurs
447 public function queryUpdateDataSet (StoreableCriteria $dataSetInstance) {
448 // Create full path name
449 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/';
451 // Try all the requests
453 // Get a file pointer instance
454 $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
456 // Initialize limit/skip
460 // Get the criteria array from the dataset
461 $criteriaArray = $dataSetInstance->getCriteriaArray();
463 // Get search criteria
464 $searchInstance = $dataSetInstance->getSearchInstance();
466 // Read the directory with some exceptions
467 while (($dataFile = $directoryInstance->readDirectoryExcept(array('.', '..', '.htaccess', '.svn', 'info.' . $this->getFileExtension()))) && ($limitFound < $searchInstance->getLimit())) {
468 // Does the extension match?
469 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
474 // Open this file for reading
475 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
478 if (is_array($dataArray)) {
479 // Search in the criteria with FMFW (First Matches, First Wins)
480 foreach ($dataArray as $key => $value) {
481 // Get criteria element
482 $criteria = $searchInstance->getCriteriaElemnent($key);
484 // Is the criteria met?
485 if ((!is_null($criteria)) && ($criteria == $value)) {
486 // Shall we skip this entry?
487 if ($searchInstance->getSkip() > 0) {
488 // We shall skip some entries
489 if ($skipFound < $searchInstance->getSkip()) {
496 // Entry found, so update it
497 foreach ($criteriaArray as $criteriaKey => $criteriaValue) {
498 $dataArray[$criteriaKey] = $criteriaValue;
501 // Write the data to a local file
502 $this->writeDataArrayToFqfn($pathName . $dataFile, $dataArray);
512 // Close the file pointer
513 $directoryInstance->closeDirectory();
515 // Update the primary key
516 $this->updatePrimaryKey($dataSetInstance);
518 // Reset last exception
519 $this->resetLastException();
520 } catch (FrameworkException $e) {
521 // Catch all exceptions and store them in last error
522 $this->setLastException($e);
524 // Throw an SQL exception
525 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);
530 * Getter for primary key of specified table or if not found null will be
531 * returned. This must be database-specific.
533 * @param $tableName Name of the table we need the primary key from
534 * @return $primaryKey Primary key column of the given table
536 public function getPrimaryKeyOfTable ($tableName) {
537 // Default key is null
540 // Does the table information exist?
541 if (isset($this->tableInfo[$tableName])) {
542 // Then return the primary key
543 $primaryKey = $this->tableInfo[$tableName]['primary'];