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) {
165 //* NOISY-DEBUG: */ $this->debugOutput('DATABASE: Reading elements from database file ' . $fqfn . ' ...');
167 // Get a file pointer
168 $fileInstance = FrameworkFileInputPointer::createFrameworkFileInputPointer($fqfn);
170 // Get the raw data and BASE64-decode it
171 $compressedData = base64_decode($fileInstance->readLinesFromFile());
173 // Close the file and throw the instance away
174 $fileInstance->closeFile();
175 unset($fileInstance);
178 $serializedData = $this->getCompressorChannel()->getCompressor()->decompressStream($compressedData);
181 $dataArray = unserialize($serializedData);
184 //* NOISY-DEBUG: */ $this->debugOutput('DATABASE: Read ' . count($dataArray) . ' elements from database file ' . $fqfn . '.');
191 * Writes data array to local file
193 * @param $fqfn The FQFN of the local file
194 * @param $dataArray An array with all the data we shall write
197 private function writeDataArrayToFqfn ($fqfn, array $dataArray) {
199 //* NOISY-DEBUG: */ $this->debugOutput('DATABASE: Flushing ' . count($dataArray) . ' elements to database file ' . $fqfn . ' ...');
201 // Get a file pointer instance
202 $fileInstance = FrameworkFileOutputPointer::createFrameworkFileOutputPointer($fqfn, 'w');
204 // Serialize and compress it
205 $compressedData = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($dataArray));
207 // Write this data BASE64 encoded to the file
208 $fileInstance->writeToFile(base64_encode($compressedData));
210 // Close the file pointer
211 $fileInstance->closeFile();
214 //* NOISY-DEBUG: */ $this->debugOutput('DATABASE: Flushing ' . count($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 BaseDatabaseFrontend::RESULT_INDEX_STATUS => LocalfileDatabase::RESULT_OKAY,
335 BaseDatabaseFrontend::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 . $dataFile);
355 if (is_array($dataArray)) {
356 // Search in the criteria with FMFW (First Matches, First Wins)
357 foreach ($dataArray as $key => $value) {
358 // Get criteria element
359 $criteria = $criteriaInstance->getCriteriaElemnent($key);
361 // Is the criteria met or none set?
362 //* NOISY-DEBUG: */ $this->debugOutput('DATABASE: criteria[' . gettype($criteria) . ']=' . $criteria . ';()=' . strlen($criteria) . ',criteriaInstance()=' . $criteriaInstance->count() . ',value(' . strlen($value) . ')=' . $value);
363 if (((!is_null($criteria)) && ($criteria == $value)) || ($criteriaInstance->count() == 0)) {
364 // Shall we skip this entry?
365 if ($criteriaInstance->getSkip() > 0) {
366 // We shall skip some entries
367 if ($skipFound < $criteriaInstance->getSkip()) {
375 $dataArray[$this->getIndexKey()] = $idx;
378 //* NOISY-DEBUG: */ $this->debugOutput('DATABASE: indexKey=' . $this->getIndexKey() . ',idx=' . $idx . ',dataArray=' . print_r($dataArray, true));
379 $resultData[BaseDatabaseFrontend::RESULT_INDEX_ROWS][] = $dataArray;
381 // Count found entries up
387 // Throw an exception here
388 throw new SqlException(array($this, sprintf("File '%s' contains invalid data.", $dataFile), self::DB_CODE_DATA_FILE_CORRUPT), self::EXCEPTION_SQL_QUERY);
395 // Close directory and throw the instance away
396 $directoryInstance->closeDirectory();
397 unset($directoryInstance);
399 // Reset last exception
400 $this->resetLastException();
401 } catch (PathIsNoDirectoryException $e) {
402 // Path not found means "table not found" for real databases...
403 $this->setLastException($e);
405 // So throw an SqlException here with faked error message
406 throw new SqlException (array($this, sprintf("Table '%s' not found", $tableName), self::DB_CODE_TABLE_MISSING), self::EXCEPTION_SQL_QUERY);
407 } catch (FrameworkException $e) {
408 // Catch all exceptions and store them in last error
409 $this->setLastException($e);
412 // Return the gathered result
417 * "Inserts" a data set instance into a local file database folder
419 * @param $dataSetInstance A storeable data set
421 * @throws SqlException If an SQL error occurs
423 public function queryInsertDataSet (StoreableCriteria $dataSetInstance) {
424 // Create full path name
425 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, md5($dataSetInstance->getUniqueValue()));
427 // Try to save the request away
429 // Write the data away
430 $this->writeDataArrayToFqfn($fqfn, $dataSetInstance->getCriteriaArray());
432 // Update the primary key
433 $this->updatePrimaryKey($dataSetInstance);
435 // Reset last exception
436 $this->resetLastException();
437 } catch (FrameworkException $e) {
438 // Catch all exceptions and store them in last error
439 $this->setLastException($e);
441 // Throw an SQL exception
442 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);
447 * "Updates" a data set instance with a database layer
449 * @param $dataSetInstance A storeable data set
451 * @throws SqlException If an SQL error occurs
453 public function queryUpdateDataSet (StoreableCriteria $dataSetInstance) {
454 // Create full path name
455 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/';
457 // Try all the requests
459 // Get a file pointer instance
460 $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
462 // Initialize limit/skip
466 // Get the criteria array from the dataset
467 $criteriaArray = $dataSetInstance->getCriteriaArray();
469 // Get search criteria
470 $searchInstance = $dataSetInstance->getSearchInstance();
472 // Read the directory with some exceptions
473 while (($dataFile = $directoryInstance->readDirectoryExcept(array('.', '..', '.htaccess', '.svn', 'info.' . $this->getFileExtension()))) && ($limitFound < $searchInstance->getLimit())) {
474 // Does the extension match?
475 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
477 /* NOISY-DEBUG: */ $this->debugOutput('DATABASE: dataFile=' . $dataFile . ',getFileExtension()=' . $this->getFileExtension());
482 // Open this file for reading
483 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
486 if (is_array($dataArray)) {
487 // Search in the criteria with FMFW (First Matches, First Wins)
488 foreach ($dataArray as $key => $value) {
489 // Get criteria element
490 $criteria = $searchInstance->getCriteriaElemnent($key);
492 // Is the criteria met?
493 if ((!is_null($criteria)) && ($criteria == $value)) {
494 // Shall we skip this entry?
495 if ($searchInstance->getSkip() > 0) {
496 // We shall skip some entries
497 if ($skipFound < $searchInstance->getSkip()) {
504 // Entry found, so update it
505 foreach ($criteriaArray as $criteriaKey => $criteriaValue) {
506 $dataArray[$criteriaKey] = $criteriaValue;
509 // Write the data to a local file
510 $this->writeDataArrayToFqfn($pathName . $dataFile, $dataArray);
520 // Close the file pointer
521 $directoryInstance->closeDirectory();
523 // Update the primary key
524 $this->updatePrimaryKey($dataSetInstance);
526 // Reset last exception
527 $this->resetLastException();
528 } catch (FrameworkException $e) {
529 // Catch all exceptions and store them in last error
530 $this->setLastException($e);
532 // Throw an SQL exception
533 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);
538 * Getter for primary key of specified table or if not found null will be
539 * returned. This must be database-specific.
541 * @param $tableName Name of the table we need the primary key from
542 * @return $primaryKey Primary key column of the given table
544 public function getPrimaryKeyOfTable ($tableName) {
545 // Default key is null
548 // Does the table information exist?
549 if (isset($this->tableInfo[$tableName])) {
550 // Then return the primary key
551 $primaryKey = $this->tableInfo[$tableName]['primary'];