3 * Database backend class for storing objects in locally created files.
5 * This class serializes arrays stored in the dataset instance and saves them
6 * to local files. Every file (except 'info') represents a single line. Every
7 * directory within the 'db' (base) directory represents a table.
9 * A configurable 'file_io_class' is being used as "storage backend".
11 * @author Roland Haeder <webmaster@ship-simu.org>
13 * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2012 Core Developer Team
14 * @license GNU GPL 3.0 or any newer version
15 * @link http://www.ship-simu.org
17 * This program is free software: you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation, either version 3 of the License, or
20 * (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
27 * You should have received a copy of the GNU General Public License
28 * along with this program. If not, see <http://www.gnu.org/licenses/>.
30 class LocalFileDatabase extends BaseDatabaseBackend implements DatabaseBackendInterface {
32 * The file's extension
34 private $fileExtension = 'serialized';
37 * The last read file's name
39 private $lastFile = '';
42 * The last read file's content including header information
44 private $lastContents = array();
47 * Whether the "connection is already up
49 private $alreadyConnected = false;
52 * Table information array
54 private $tableInfo = array();
59 private $indexKey = '__idx';
62 * The protected constructor. Do never instance from outside! You need to
63 * set a local file path. The class will then validate it.
67 protected function __construct () {
68 // Call parent constructor
69 parent::__construct(__CLASS__);
73 * Create an object of LocalFileDatabase and set the save path from
74 * configuration for local files.
76 * @return $databaseInstance An instance of LocalFileDatabase
78 public static final function createLocalFileDatabase () {
80 $databaseInstance = new LocalFileDatabase();
82 // Get a new compressor channel instance
83 $compressorInstance = ObjectFactory::createObjectByConfiguredName('compressor_channel_class');
85 // Set the compressor channel
86 $databaseInstance->setCompressorChannel($compressorInstance);
88 // Get a file IO handler
89 $fileIoInstance = ObjectFactory::createObjectByConfiguredName('file_io_class');
92 $databaseInstance->setFileIoInstance($fileIoInstance);
94 // "Connect" to the database
95 $databaseInstance->connectToDatabase();
97 // Return database instance
98 return $databaseInstance;
102 * Setter for the last read file
104 * @param $fqfn The FQFN of the last read file
107 private final function setLastFile ($fqfn) {
108 // Cast string and set it
109 $this->lastFile = (string) $fqfn;
113 * Getter for last read file
115 * @return $lastFile The last read file's name with full path
117 public final function getLastFile () {
118 return $this->lastFile;
122 * Setter for contents of the last read file
124 * @param $contents An array with header and data elements
127 private final function setLastFileContents (array $contents) {
129 $this->lastContents = $contents;
133 * Getter for last read file's content as an array
135 * @return $lastContent The array with elements 'header' and 'data'.
137 public final function getLastContents () {
138 return $this->lastContents;
142 * Getter for file extension
144 * @return $fileExtension The array with elements 'header' and 'data'.
146 public final function getFileExtension () {
147 return $this->fileExtension;
151 * Getter for index key
153 * @return $indexKey Index key
155 public final function getIndexKey () {
156 return $this->indexKey;
160 * Reads a local data file and returns it's contents in an array
162 * @param $fqfn The FQFN for the requested file
165 private function getDataArrayFromFile ($fqfn) {
167 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Reading elements from database file ' . $fqfn . ' ...');
169 // Init compressed data
170 $compressedData = $this->getFileIoInstance()->loadFileContents($fqfn);
171 $compressedData = $compressedData['data'];
173 // Close the file and throw the instance away
174 unset($fileInstance);
177 $serializedData = $this->getCompressorChannel()->getCompressor()->decompressStream($compressedData);
180 $dataArray = unserialize($serializedData);
183 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Read ' . count($dataArray) . ' elements from database file ' . $fqfn . '.');
190 * Writes data array to local file
192 * @param $fqfn The FQFN of the local file
193 * @param $dataArray An array with all the data we shall write
196 private function writeDataArrayToFqfn ($fqfn, array $dataArray) {
198 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Flushing ' . count($dataArray) . ' elements to database file ' . $fqfn . ' ...');
200 // Serialize and compress it
201 $compressedData = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($dataArray));
204 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Writing ' . strlen($compressedData) . ' bytes ...');
206 // Write this data BASE64 encoded to the file
207 $this->getFileIoInstance()->saveFile($fqfn, $compressedData);
210 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Flushing ' . count($dataArray) . ' elements to database file completed.');
214 * Getter for table information file contents or an empty if info file was not created
216 * @param $dataSetInstance An instance of a database set class
217 * @return $infoArray An array with all table informations
219 private function getContentsFromTableInfoFile (StoreableCriteria $dataSetInstance) {
220 // Default content is no data
221 $infoArray = array();
223 // Create FQFN for getting the table information file
224 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
226 // Get the file contents
228 $infoArray = $this->getDataArrayFromFile($fqfn);
229 } catch (FileIoException $e) {
230 // Not found, so ignore it here
238 * Generates an FQFN from given dataset instance and string
240 * @param $dataSetInstance An instance of a database set class
241 * @param $rowName Name of the row
242 * @return $fqfn The FQFN for this row
244 private function generateFqfnFromDataSet (Criteria $dataSetInstance, $rowName) {
246 $fqfn = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/' . $rowName . '.' . $this->getFileExtension();
253 * Creates the table info file from given dataset instance
255 * @param $dataSetInstance An instance of a database set class
258 private function createTableInfoFile (StoreableCriteria $dataSetInstance) {
259 // Create FQFN for creating the table information file
260 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
262 // Get the data out from dataset in a local array
263 $this->tableInfo[$dataSetInstance->getTableName()] = array(
264 'primary' => $dataSetInstance->getPrimaryKey(),
266 'last_updated' => time()
269 // Write the data to the file
270 $this->writeDataArrayToFqfn($fqfn, $this->tableInfo[$dataSetInstance->getTableName()]);
274 * Updates the primary key information or creates the table info file if not found
276 * @param $dataSetInstance An instance of a database set class
279 private function updatePrimaryKey (StoreableCriteria $dataSetInstance) {
280 // Get the information array from lower method
281 $infoArray = $this->getContentsFromTableInfoFile($dataSetInstance);
283 // Is the primary key there?
284 if (!isset($this->tableInfo['primary'])) {
285 // Then create the info file
286 $this->createTableInfoFile($dataSetInstance);
287 } elseif (($this->getConfigInstance()->getConfigEntry('db_update_primary_forced') == 'Y') && ($dataSetInstance->getPrimaryKey() != $this->tableInfo['primary'])) {
288 // Set the array element
289 $this->tableInfo[$dataSetInstance->getTableName()]['primary'] = $dataSetInstance->getPrimaryKey();
292 $this->updateTableInfoFile($dataSetInstance);
297 * Makes sure that the database connection is alive
300 * @todo Do some checks on the database directory and files here
302 public function connectToDatabase () {
306 * Starts a SELECT query on the database by given return type, table name
307 * and search criteria
309 * @param $tableName Name of the database table
310 * @param $criteria Local search criteria class
311 * @return $resultData Result data of the query
312 * @throws UnsupportedCriteriaException If the criteria is unsupported
313 * @throws SqlException If an 'SQL error' occurs
315 public function querySelect ($tableName, LocalSearchCriteria $criteriaInstance) {
316 // The result is null by any errors
319 // Create full path name
320 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $tableName . '/';
322 // A 'select' query is not that easy on local files, so first try to
323 // find the 'table' which is in fact a directory on the server
325 // Get a directory pointer instance
326 $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
328 // Initialize the result data, this need to be rewritten e.g. if a local file cannot be read
330 BaseDatabaseBackend::RESULT_INDEX_STATUS => self::RESULT_OKAY,
331 BaseDatabaseBackend::RESULT_INDEX_ROWS => array()
334 // Initialize limit/skip
339 // Read the directory with some exceptions
340 while (($dataFile = $directoryInstance->readDirectoryExcept(array('.', '..', '.htaccess', '.svn', 'info.' . $this->getFileExtension()))) && (($limitFound < $criteriaInstance->getLimit()) || ($criteriaInstance->getLimit() == 0))) {
341 // Does the extension match?
342 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
348 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
349 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataFile=' . $dataFile . ',dataArray='.print_r($dataArray,true));
352 if (is_array($dataArray)) {
353 // Search in the criteria with FMFW (First Matches, First Wins)
354 foreach ($dataArray as $key => $value) {
355 // Get criteria element
356 $criteria = $criteriaInstance->getCriteriaElemnent($key);
358 // Is the criteria met or none set?
359 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: criteria[' . gettype($criteria) . ']=' . $criteria . ';()=' . strlen($criteria) . ',criteriaInstance()=' . $criteriaInstance->count() . ',value(' . strlen($value) . ')=' . $value);
360 if (((!is_null($criteria)) && ($criteria == $value)) || ($criteriaInstance->count() == 0)) {
361 // Shall we skip this entry?
362 if ($criteriaInstance->getSkip() > 0) {
363 // We shall skip some entries
364 if ($skipFound < $criteriaInstance->getSkip()) {
372 $dataArray[$this->getIndexKey()] = $idx;
375 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: indexKey=' . $this->getIndexKey() . ',idx=' . $idx . ',dataArray=' . print_r($dataArray, true));
376 $resultData[BaseDatabaseBackend::RESULT_INDEX_ROWS][] = $dataArray;
378 // Count found entries up
384 // Throw an exception here
385 throw new SqlException(array($this, sprintf("File '%s' contains invalid data.", $dataFile), self::DB_CODE_DATA_FILE_CORRUPT), self::EXCEPTION_SQL_QUERY);
392 // Close directory and throw the instance away
393 $directoryInstance->closeDirectory();
394 unset($directoryInstance);
396 // Reset last exception
397 $this->resetLastException();
398 } catch (PathIsNoDirectoryException $e) {
399 // Path not found means "table not found" for real databases...
400 $this->setLastException($e);
402 // So throw an SqlException here with faked error message
403 throw new SqlException (array($this, sprintf("Table '%s' not found", $tableName), self::DB_CODE_TABLE_MISSING), self::EXCEPTION_SQL_QUERY);
404 } catch (FrameworkException $e) {
405 // Catch all exceptions and store them in last error
406 $this->setLastException($e);
409 // Return the gathered result
414 * "Inserts" a data set instance into a local file database folder
416 * @param $dataSetInstance A storeable data set
418 * @throws SqlException If an SQL error occurs
420 public function queryInsertDataSet (StoreableCriteria $dataSetInstance) {
421 // Create full path name
422 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, md5($dataSetInstance->getUniqueValue()));
424 // Try to save the request away
426 // Write the data away
427 $this->writeDataArrayToFqfn($fqfn, $dataSetInstance->getCriteriaArray());
429 // Update the primary key
430 $this->updatePrimaryKey($dataSetInstance);
432 // Reset last exception
433 $this->resetLastException();
434 } catch (FrameworkException $e) {
435 // Catch all exceptions and store them in last error
436 $this->setLastException($e);
438 // Throw an SQL exception
439 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);
444 * "Updates" a data set instance with a database layer
446 * @param $dataSetInstance A storeable data set
448 * @throws SqlException If an SQL error occurs
450 public function queryUpdateDataSet (StoreableCriteria $dataSetInstance) {
451 // Create full path name
452 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/';
454 // Try all the requests
456 // Get a file pointer instance
457 $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
459 // Initialize limit/skip
463 // Get the criteria array from the dataset
464 $criteriaArray = $dataSetInstance->getCriteriaArray();
466 // Get search criteria
467 $searchInstance = $dataSetInstance->getSearchInstance();
469 // Read the directory with some exceptions
470 while (($dataFile = $directoryInstance->readDirectoryExcept(array('.', '..', '.htaccess', '.svn', 'info.' . $this->getFileExtension()))) && ($limitFound < $searchInstance->getLimit())) {
471 // Does the extension match?
472 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
474 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataFile=' . $dataFile . ',getFileExtension()=' . $this->getFileExtension() . ' - SKIPPED!');
479 // Open this file for reading
480 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
481 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataFile=' . $dataFile . ',dataArray='.print_r($dataArray,true));
484 if (is_array($dataArray)) {
485 // Search in the criteria with FMFW (First Matches, First Wins)
486 foreach ($dataArray as $key => $value) {
487 // Get criteria element
488 $criteria = $searchInstance->getCriteriaElemnent($key);
489 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataFile=' . $dataFile . ',key=' . $key . ',criteria=' . $criteria);
491 // Is the criteria met?
492 if (((!is_null($criteria)) && ($criteria == $value)) || ($searchInstance->count() == 0)) {
493 // Shall we skip this entry?
494 if ($searchInstance->getSkip() > 0) {
495 // We shall skip some entries
496 if ($skipFound < $searchInstance->getSkip()) {
503 // Entry found, so update it
504 foreach ($criteriaArray as $criteriaKey => $criteriaValue) {
505 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: criteriaKey=' . $criteriaKey . ',criteriaValue=' . $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'];