inc/classes/main/database/databases/class_LocalFileDatabase.php

   1 <?php
   2 /**
   3  * Database backend class for storing objects in locally created files.
   4  *
   5  * This class serializes objects and saves them to local files.
   6  *
   7  * @author              Roland Haeder <webmaster@ship-simu.org>
   8  * @version             0.0.0
   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
  12  *
  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.
  17  *
  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.
  22  *
  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/>.
  25  */
  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;
  31
  32         // Status results
  33         const RESULT_OKAY = 'ok';
  34
  35         /**
  36          * The file's extension
  37          */
  38         private $fileExtension = 'serialized';
  39
  40         /**
  41          * The last read file's name
  42          */
  43         private $lastFile = '';
  44
  45         /**
  46          * The last read file's content including header information
  47          */
  48         private $lastContents = array();
  49
  50         /**
  51          * Whether the "connection is already up
  52          */
  53         private $alreadyConnected = false;
  54
  55         /**
  56          * Table information array
  57          */
  58         private $tableInfo = array();
  59
  60         /**
  61          * Element for index
  62          */
  63         private $indexKey = '__idx';
  64
  65         /**
  66          * The protected constructor. Do never instance from outside! You need to
  67          * set a local file path. The class will then validate it.
  68          *
  69          * @return      void
  70          */
  71         protected function __construct () {
  72                 // Call parent constructor
  73                 parent::__construct(__CLASS__);
  74         }
  75
  76         /**
  77          * Create an object of LocalFileDatabase and set the save path from
  78          * configuration for local files.
  79          *
  80          * @return      $databaseInstance       An instance of LocalFileDatabase
  81          */
  82         public static final function createLocalFileDatabase () {
  83                 // Get an instance
  84                 $databaseInstance = new LocalFileDatabase();
  85
  86                 // Get a new compressor channel instance
  87                 $compressorInstance = ObjectFactory::createObjectByConfiguredName('compressor_channel_class');
  88
  89                 // Set the compressor channel
  90                 $databaseInstance->setCompressorChannel($compressorInstance);
  91
  92                 // "Connect" to the database
  93                 $databaseInstance->connectToDatabase();
  94
  95                 // Return database instance
  96                 return $databaseInstance;
  97         }
  98
  99         /**
 100          * Setter for the last read file
 101          *
 102          * @param       $fqfn   The FQFN of the last read file
 103          * @return      void
 104          */
 105         private final function setLastFile ($fqfn) {
 106                 // Cast string and set it
 107                 $this->lastFile = (string) $fqfn;
 108         }
 109
 110         /**
 111          * Getter for last read file
 112          *
 113          * @return      $lastFile               The last read file's name with full path
 114          */
 115         public final function getLastFile () {
 116                 return $this->lastFile;
 117         }
 118
 119         /**
 120          * Setter for contents of the last read file
 121          *
 122          * @param               $contents               An array with header and data elements
 123          * @return      void
 124          */
 125         private final function setLastFileContents (array $contents) {
 126                 // Set array
 127                 $this->lastContents = $contents;
 128         }
 129
 130         /**
 131          * Getter for last read file's content as an array
 132          *
 133          * @return      $lastContent    The array with elements 'header' and 'data'.
 134          */
 135         public final function getLastContents () {
 136                 return $this->lastContents;
 137         }
 138
 139         /**
 140          * Getter for file extension
 141          *
 142          * @return      $fileExtension  The array with elements 'header' and 'data'.
 143          */
 144         public final function getFileExtension () {
 145                 return $this->fileExtension;
 146         }
 147
 148         /**
 149          * Getter for index key
 150          *
 151          * @return      $indexKey       Index key
 152          */
 153         public final function getIndexKey () {
 154                 return $this->indexKey;
 155         }
 156
 157         /**
 158          * Reads a local data file  and returns it's contents in an array
 159          *
 160          * @param       $fqfn   The FQFN for the requested file
 161          * @return      $dataArray
 162          */
 163         private function getDataArrayFromFile ($fqfn) {
 164                 // Get a file pointer
 165                 $fileInstance = FrameworkFileInputPointer::createFrameworkFileInputPointer($fqfn);
 166
 167                 // Get the raw data and BASE64-decode it
 168                 $compressedData = base64_decode($fileInstance->readLinesFromFile());
 169
 170                 // Close the file and throw the instance away
 171                 $fileInstance->closeFile();
 172                 unset($fileInstance);
 173
 174                 // Decompress it
 175                 $serializedData = $this->getCompressorChannel()->getCompressor()->decompressStream($compressedData);
 176
 177                 // Unserialize it
 178                 $dataArray = unserialize($serializedData);
 179
 180                 // Finally return it
 181                 return $dataArray;
 182         }
 183
 184         /**
 185          * Writes data array to local file
 186          *
 187          * @param       $fqfn           The FQFN of the local file
 188          * @param       $dataArray      An array with all the data we shall write
 189          * @return      void
 190          */
 191         private function writeDataArrayToFqfn ($fqfn, array $dataArray) {
 192                 // Get a file pointer instance
 193                 $fileInstance = FrameworkFileOutputPointer::createFrameworkFileOutputPointer($fqfn, 'w');
 194
 195                 // Serialize and compress it
 196                 $compressedData = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($dataArray));
 197
 198                 // Write this data BASE64 encoded to the file
 199                 $fileInstance->writeToFile(base64_encode($compressedData));
 200
 201                 // Close the file pointer
 202                 $fileInstance->closeFile();
 203         }
 204
 205         /**
 206          * Getter for table information file contents or an empty if info file was not created
 207          *
 208          * @param       $dataSetInstance        An instance of a database set class
 209          * @return      $infoArray                      An array with all table informations
 210          */
 211         private function getContentsFromTableInfoFile (StoreableCriteria $dataSetInstance) {
 212                 // Default content is no data
 213                 $infoArray = array();
 214
 215                 // Create FQFN for getting the table information file
 216                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
 217
 218                 // Get the file contents
 219                 try {
 220                         $infoArray = $this->getDataArrayFromFile($fqfn);
 221                 } catch (FileIoException $e) {
 222                         // Not found, so ignore it here
 223                 }
 224
 225                 // ... and return it
 226                 return $infoArray;
 227         }
 228
 229         /**
 230          * Generates an FQFN from given dataset instance and string
 231          *
 232          * @param       $dataSetInstance        An instance of a database set class
 233          * @param       $rowName                        Name of the row
 234          * @return      $fqfn                           The FQFN for this row
 235          */
 236         private function generateFqfnFromDataSet (Criteria $dataSetInstance, $rowName) {
 237                 // This is the FQFN
 238                 $fqfn = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/' . $rowName . '.' . $this->getFileExtension();
 239
 240                 // Return it
 241                 return $fqfn;
 242         }
 243
 244         /**
 245          * Creates the table info file from given dataset instance
 246          *
 247          * @param       $dataSetInstance        An instance of a database set class
 248          * @return      void
 249          */
 250         private function createTableInfoFile (StoreableCriteria $dataSetInstance) {
 251                 // Create FQFN for creating the table information file
 252                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
 253
 254                 // Get the data out from dataset in a local array
 255                 $this->tableInfo[$dataSetInstance->getTableName()] = array(
 256                         'primary'      => $dataSetInstance->getPrimaryKey(),
 257                         'created'      => time(),
 258                         'last_updated' => time()
 259                 );
 260
 261                 // Write the data to the file
 262                 $this->writeDataArrayToFqfn($fqfn, $this->tableInfo[$dataSetInstance->getTableName()]);
 263         }
 264
 265         /**
 266          * Updates the primary key information or creates the table info file if not found
 267          *
 268          * @param       $dataSetInstance        An instance of a database set class
 269          * @return      void
 270          */
 271         private function updatePrimaryKey (StoreableCriteria $dataSetInstance) {
 272                 // Get the information array from lower method
 273                 $infoArray = $this->getContentsFromTableInfoFile($dataSetInstance);
 274
 275                 // Is the primary key there?
 276                 if (!isset($this->tableInfo['primary'])) {
 277                         // Then create the info file
 278                         $this->createTableInfoFile($dataSetInstance);
 279                 } elseif (($this->getConfigInstance()->getConfigEntry('db_update_primary_forced') == 'Y') && ($dataSetInstance->getPrimaryKey() != $this->tableInfo['primary'])) {
 280                         // Set the array element
 281                         $this->tableInfo[$dataSetInstance->getTableName()]['primary'] = $dataSetInstance->getPrimaryKey();
 282
 283                         // Update the entry
 284                         $this->updateTableInfoFile($dataSetInstance);
 285                 }
 286         }
 287
 288         /**
 289          * Makes sure that the database connection is alive
 290          *
 291          * @return      void
 292          * @todo        Do some checks on the database directory and files here
 293          */
 294         public function connectToDatabase () {
 295         }
 296
 297         /**
 298          * Starts a SELECT query on the database by given return type, table name
 299          * and search criteria
 300          *
 301          * @param       $tableName              Name of the database table
 302          * @param       $criteria               Local search criteria class
 303          * @return      $resultData             Result data of the query
 304          * @throws      UnsupportedCriteriaException    If the criteria is unsupported
 305          * @throws      SqlException                                    If an 'SQL error' occurs
 306          */
 307         public function querySelect ($tableName, LocalSearchCriteria $criteriaInstance) {
 308                 // The result is null by any errors
 309                 $resultData = NULL;
 310
 311                 // Create full path name
 312                 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $tableName . '/';
 313
 314                 // A 'select' query is not that easy on local files, so first try to
 315                 // find the 'table' which is in fact a directory on the server
 316                 try {
 317                         // Get a directory pointer instance
 318                         $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
 319
 320                         // Initialize the result data, this need to be rewritten e.g. if a local file cannot be read
 321                         $resultData = array(
 322                                 BaseDatabaseFrontend::RESULT_INDEX_STATUS => LocalfileDatabase::RESULT_OKAY,
 323                                 BaseDatabaseFrontend::RESULT_INDEX_ROWS   => array()
 324                         );
 325
 326                         // Initialize limit/skip
 327                         $limitFound = 0;
 328                         $skipFound = 0;
 329                         $idx = 1;
 330
 331                         // Read the directory with some exceptions
 332                         while (($dataFile = $directoryInstance->readDirectoryExcept(array('.', '..', '.htaccess', '.svn', 'info.' . $this->getFileExtension()))) && (($limitFound < $criteriaInstance->getLimit()) || ($criteriaInstance->getLimit() == 0))) {
 333                                 // Does the extension match?
 334                                 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
 335                                         // Skip this file!
 336                                         continue;
 337                                 } // END - if
 338
 339                                 // Read the file
 340                                 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 341
 342                                 // Is this an array?
 343                                 if (is_array($dataArray)) {
 344                                         // Search in the criteria with FMFW (First Matches, First Wins)
 345                                         foreach ($dataArray as $key => $value) {
 346                                                 // Get criteria element
 347                                                 $criteria = $criteriaInstance->getCriteriaElemnent($key);
 348
 349                                                 // Is the criteria met?
 350                                                 //* NOISY-DEBUG: */ $this->debugOutput('DATABASE: criteria[' . gettype($criteria) . ']=' . $criteria . ',()=' . strlen($criteria) . ',value=' . $value . ',()=' . strlen($value));
 351                                                 if ((!is_null($criteria)) && ($criteria == $value))  {
 352                                                         // Shall we skip this entry?
 353                                                         if ($criteriaInstance->getSkip() > 0) {
 354                                                                 // We shall skip some entries
 355                                                                 if ($skipFound < $criteriaInstance->getSkip()) {
 356                                                                         // Skip this entry
 357                                                                         $skipFound++;
 358                                                                         break;
 359                                                                 } // END - if
 360                                                         } // END - if
 361
 362                                                         // Set id number
 363                                                         $dataArray[$this->getIndexKey()] = $idx;
 364
 365                                                         // Entry found!
 366                                                         //* NOISY-DEBUG: */ $this->debugOutput('DATABASE: indexKey=' . $this->getIndexKey() . ',idx=' . $idx . ',dataArray=' . print_r($dataArray, true));
 367                                                         $resultData[BaseDatabaseFrontend::RESULT_INDEX_ROWS][] = $dataArray;
 368
 369                                                         // Count found entries up
 370                                                         $limitFound++;
 371                                                         break;
 372                                                 } // END - if
 373                                         } // END - foreach
 374                                 } else {
 375                                         // Throw an exception here
 376                                         throw new SqlException(array($this, sprintf("File &#39;%s&#39; contains invalid data.", $dataFile), self::DB_CODE_DATA_FILE_CORRUPT), self::EXCEPTION_SQL_QUERY);
 377                                 }
 378
 379                                 // Count entry up
 380                                 $idx++;
 381                         } // END - while
 382
 383                         // Close directory and throw the instance away
 384                         $directoryInstance->closeDirectory();
 385                         unset($directoryInstance);
 386
 387                         // Reset last exception
 388                         $this->resetLastException();
 389                 } catch (PathIsNoDirectoryException $e) {
 390                         // Path not found means "table not found" for real databases...
 391                         $this->setLastException($e);
 392
 393                         // So throw an SqlException here with faked error message
 394                         throw new SqlException (array($this, sprintf("Table &#39;%s&#39; not found", $tableName), self::DB_CODE_TABLE_MISSING), self::EXCEPTION_SQL_QUERY);
 395                 } catch (FrameworkException $e) {
 396                         // Catch all exceptions and store them in last error
 397                         $this->setLastException($e);
 398                 }
 399
 400                 // Return the gathered result
 401                 return $resultData;
 402         }
 403
 404         /**
 405          * "Inserts" a data set instance into a local file database folder
 406          *
 407          * @param       $dataSetInstance        A storeable data set
 408          * @return      void
 409          * @throws      SqlException    If an SQL error occurs
 410          */
 411         public function queryInsertDataSet (StoreableCriteria $dataSetInstance) {
 412                 // Create full path name
 413                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, md5($dataSetInstance->getUniqueValue()));
 414
 415                 // Try to save the request away
 416                 try {
 417                         // Write the data away
 418                         $this->writeDataArrayToFqfn($fqfn, $dataSetInstance->getCriteriaArray());
 419
 420                         // Update the primary key
 421                         $this->updatePrimaryKey($dataSetInstance);
 422
 423                         // Reset last exception
 424                         $this->resetLastException();
 425                 } catch (FrameworkException $e) {
 426                         // Catch all exceptions and store them in last error
 427                         $this->setLastException($e);
 428
 429                         // Throw an SQL exception
 430                         throw new SqlException(array($this, sprintf("Cannot write data to table &#39;%s&#39;, is the table created?", $dataSetInstance->getTableName()), self::DB_CODE_TABLE_UNWRITEABLE), self::EXCEPTION_SQL_QUERY);
 431                 }
 432         }
 433
 434         /**
 435          * "Updates" a data set instance with a database layer
 436          *
 437          * @param       $dataSetInstance        A storeable data set
 438          * @return      void
 439          * @throws      SqlException    If an SQL error occurs
 440          */
 441         public function queryUpdateDataSet (StoreableCriteria $dataSetInstance) {
 442                 // Create full path name
 443                 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/';
 444
 445                 // Try all the requests
 446                 try {
 447                         // Get a file pointer instance
 448                         $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
 449
 450                         // Initialize limit/skip
 451                         $limitFound = 0;
 452                         $skipFound = 0;
 453
 454                         // Get the criteria array from the dataset
 455                         $criteriaArray = $dataSetInstance->getCriteriaArray();
 456
 457                         // Get search criteria
 458                         $searchInstance = $dataSetInstance->getSearchInstance();
 459
 460                         // Read the directory with some exceptions
 461                         while (($dataFile = $directoryInstance->readDirectoryExcept(array('.', '..', '.htaccess', '.svn', 'info.' . $this->getFileExtension()))) && ($limitFound < $searchInstance->getLimit())) {
 462                                 // Does the extension match?
 463                                 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
 464                                         // Skip this file!
 465                                         continue;
 466                                 }
 467
 468                                 // Open this file for reading
 469                                 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 470
 471                                 // Is this an array?
 472                                 if (is_array($dataArray)) {
 473                                         // Search in the criteria with FMFW (First Matches, First Wins)
 474                                         foreach ($dataArray as $key => $value) {
 475                                                 // Get criteria element
 476                                                 $criteria = $searchInstance->getCriteriaElemnent($key);
 477
 478                                                 // Is the criteria met?
 479                                                 if ((!is_null($criteria)) && ($criteria == $value))  {
 480
 481                                                         // Shall we skip this entry?
 482                                                         if ($searchInstance->getSkip() > 0) {
 483                                                                 // We shall skip some entries
 484                                                                 if ($skipFound < $searchInstance->getSkip()) {
 485                                                                         // Skip this entry
 486                                                                         $skipFound++;
 487                                                                         break;
 488                                                                 } // END - if
 489                                                         } // END - if
 490
 491                                                         // Entry found, so update it
 492                                                         foreach ($criteriaArray as $criteriaKey => $criteriaValue) {
 493                                                                 $dataArray[$criteriaKey] = $criteriaValue;
 494                                                         } // END - foreach
 495
 496                                                         // Write the data to a local file
 497                                                         $this->writeDataArrayToFqfn($pathName . $dataFile, $dataArray);
 498
 499                                                         // Count it
 500                                                         $limitFound++;
 501                                                         break;
 502                                                 } // END - if
 503                                         } // END - foreach
 504                                 } // END - if
 505                         } // END - while
 506
 507                         // Close the file pointer
 508                         $directoryInstance->closeDirectory();
 509
 510                         // Update the primary key
 511                         $this->updatePrimaryKey($dataSetInstance);
 512
 513                         // Reset last exception
 514                         $this->resetLastException();
 515                 } catch (FrameworkException $e) {
 516                         // Catch all exceptions and store them in last error
 517                         $this->setLastException($e);
 518
 519                         // Throw an SQL exception
 520                         throw new SqlException(array($this, sprintf("Cannot write data to table &#39;%s&#39;, is the table created?", $dataSetInstance->getTableName()), self::DB_CODE_TABLE_UNWRITEABLE), self::EXCEPTION_SQL_QUERY);
 521                 }
 522         }
 523
 524         /**
 525          * Getter for primary key of specified table or if not found null will be
 526          * returned. This must be database-specific.
 527          *
 528          * @param       $tableName              Name of the table we need the primary key from
 529          * @return      $primaryKey             Primary key column of the given table
 530          */
 531         public function getPrimaryKeyOfTable ($tableName) {
 532                 // Default key is null
 533                 $primaryKey = NULL;
 534
 535                 // Does the table information exist?
 536                 if (isset($this->tableInfo[$tableName])) {
 537                         // Then return the primary key
 538                         $primaryKey = $this->tableInfo[$tableName]['primary'];
 539                 } // END - if
 540
 541                 // Return the column
 542                 return $primaryKey;
 543         }
 544 }
 545
 546 // [EOF]
 547 ?>