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 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.
   8  *
   9  * A configurable 'file_io_class' is being used as "storage backend".
  10  *
  11  * @author              Roland Haeder <webmaster@ship-simu.org>
  12  * @version             0.0.0
  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
  16  *
  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.
  21  *
  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.
  26  *
  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/>.
  29  */
  30 class LocalFileDatabase extends BaseDatabaseBackend implements DatabaseBackendInterface {
  31         /**
  32          * The file's extension
  33          */
  34         private $fileExtension = 'serialized';
  35
  36         /**
  37          * The last read file's name
  38          */
  39         private $lastFile = '';
  40
  41         /**
  42          * The last read file's content including header information
  43          */
  44         private $lastContents = array();
  45
  46         /**
  47          * Whether the "connection is already up
  48          */
  49         private $alreadyConnected = false;
  50
  51         /**
  52          * Table information array
  53          */
  54         private $tableInfo = array();
  55
  56         /**
  57          * Element for index
  58          */
  59         private $indexKey = '__idx';
  60
  61         /**
  62          * The protected constructor. Do never instance from outside! You need to
  63          * set a local file path. The class will then validate it.
  64          *
  65          * @return      void
  66          */
  67         protected function __construct () {
  68                 // Call parent constructor
  69                 parent::__construct(__CLASS__);
  70         }
  71
  72         /**
  73          * Create an object of LocalFileDatabase and set the save path from
  74          * configuration for local files.
  75          *
  76          * @return      $databaseInstance       An instance of LocalFileDatabase
  77          */
  78         public static final function createLocalFileDatabase () {
  79                 // Get an instance
  80                 $databaseInstance = new LocalFileDatabase();
  81
  82                 // Get a new compressor channel instance
  83                 $compressorInstance = ObjectFactory::createObjectByConfiguredName('compressor_channel_class');
  84
  85                 // Set the compressor channel
  86                 $databaseInstance->setCompressorChannel($compressorInstance);
  87
  88                 // Get a file IO handler
  89                 $fileIoInstance = ObjectFactory::createObjectByConfiguredName('file_io_class');
  90
  91                 // ... and set it
  92                 $databaseInstance->setFileIoInstance($fileIoInstance);
  93
  94                 // "Connect" to the database
  95                 $databaseInstance->connectToDatabase();
  96
  97                 // Return database instance
  98                 return $databaseInstance;
  99         }
 100
 101         /**
 102          * Setter for the last read file
 103          *
 104          * @param       $fqfn   The FQFN of the last read file
 105          * @return      void
 106          */
 107         private final function setLastFile ($fqfn) {
 108                 // Cast string and set it
 109                 $this->lastFile = (string) $fqfn;
 110         }
 111
 112         /**
 113          * Getter for last read file
 114          *
 115          * @return      $lastFile       The last read file's name with full path
 116          */
 117         public final function getLastFile () {
 118                 return $this->lastFile;
 119         }
 120
 121         /**
 122          * Setter for contents of the last read file
 123          *
 124          * @param               $contents       An array with header and data elements
 125          * @return      void
 126          */
 127         private final function setLastFileContents (array $contents) {
 128                 // Set array
 129                 $this->lastContents = $contents;
 130         }
 131
 132         /**
 133          * Getter for last read file's content as an array
 134          *
 135          * @return      $lastContent    The array with elements 'header' and 'data'.
 136          */
 137         public final function getLastContents () {
 138                 return $this->lastContents;
 139         }
 140
 141         /**
 142          * Getter for file extension
 143          *
 144          * @return      $fileExtension  The array with elements 'header' and 'data'.
 145          */
 146         public final function getFileExtension () {
 147                 return $this->fileExtension;
 148         }
 149
 150         /**
 151          * Getter for index key
 152          *
 153          * @return      $indexKey       Index key
 154          */
 155         public final function getIndexKey () {
 156                 return $this->indexKey;
 157         }
 158
 159         /**
 160          * Reads a local data file  and returns it's contents in an array
 161          *
 162          * @param       $fqfn   The FQFN for the requested file
 163          * @return      $dataArray
 164          */
 165         private function getDataArrayFromFile ($fqfn) {
 166                 // Debug message
 167                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Reading elements from database file ' . $fqfn . ' ...');
 168
 169                 // Init compressed data
 170                 $compressedData = $this->getFileIoInstance()->loadFileContents($fqfn);
 171                 $compressedData = $compressedData['data'];
 172
 173                 // Close the file and throw the instance away
 174                 unset($fileInstance);
 175
 176                 // Decompress it
 177                 $serializedData = $this->getCompressorChannel()->getCompressor()->decompressStream($compressedData);
 178
 179                 // Unserialize it
 180                 $dataArray = unserialize($serializedData);
 181
 182                 // Debug message
 183                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Read ' . count($dataArray) . ' elements from database file ' . $fqfn . '.');
 184
 185                 // Finally return it
 186                 return $dataArray;
 187         }
 188
 189         /**
 190          * Writes data array to local file
 191          *
 192          * @param       $fqfn           The FQFN of the local file
 193          * @param       $dataArray      An array with all the data we shall write
 194          * @return      void
 195          */
 196         private function writeDataArrayToFqfn ($fqfn, array $dataArray) {
 197                 // Debug message
 198                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Flushing ' . count($dataArray) . ' elements to database file ' . $fqfn . ' ...');
 199
 200                 // Serialize and compress it
 201                 $compressedData = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($dataArray));
 202
 203                 // Write data
 204                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Writing ' . strlen($compressedData) . ' bytes ...');
 205
 206                 // Write this data BASE64 encoded to the file
 207                 $this->getFileIoInstance()->saveFile($fqfn, $compressedData);
 208
 209                 // Debug message
 210                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Flushing ' . count($dataArray) . ' elements to database file completed.');
 211         }
 212
 213         /**
 214          * Getter for table information file contents or an empty if info file was not created
 215          *
 216          * @param       $dataSetInstance        An instance of a database set class
 217          * @return      $infoArray                      An array with all table informations
 218          */
 219         private function getContentsFromTableInfoFile (StoreableCriteria $dataSetInstance) {
 220                 // Default content is no data
 221                 $infoArray = array();
 222
 223                 // Create FQFN for getting the table information file
 224                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
 225
 226                 // Get the file contents
 227                 try {
 228                         $infoArray = $this->getDataArrayFromFile($fqfn);
 229                 } catch (FileIoException $e) {
 230                         // Not found, so ignore it here
 231                 }
 232
 233                 // ... and return it
 234                 return $infoArray;
 235         }
 236
 237         /**
 238          * Generates an FQFN from given dataset instance and string
 239          *
 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
 243          */
 244         private function generateFqfnFromDataSet (Criteria $dataSetInstance, $rowName) {
 245                 // This is the FQFN
 246                 $fqfn = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/' . $rowName . '.' . $this->getFileExtension();
 247
 248                 // Return it
 249                 return $fqfn;
 250         }
 251
 252         /**
 253          * Creates the table info file from given dataset instance
 254          *
 255          * @param       $dataSetInstance        An instance of a database set class
 256          * @return      void
 257          */
 258         private function createTableInfoFile (StoreableCriteria $dataSetInstance) {
 259                 // Create FQFN for creating the table information file
 260                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
 261
 262                 // Get the data out from dataset in a local array
 263                 $this->tableInfo[$dataSetInstance->getTableName()] = array(
 264                         'primary'      => $dataSetInstance->getPrimaryKey(),
 265                         'created'      => time(),
 266                         'last_updated' => time()
 267                 );
 268
 269                 // Write the data to the file
 270                 $this->writeDataArrayToFqfn($fqfn, $this->tableInfo[$dataSetInstance->getTableName()]);
 271         }
 272
 273         /**
 274          * Updates the primary key information or creates the table info file if not found
 275          *
 276          * @param       $dataSetInstance        An instance of a database set class
 277          * @return      void
 278          */
 279         private function updatePrimaryKey (StoreableCriteria $dataSetInstance) {
 280                 // Get the information array from lower method
 281                 $infoArray = $this->getContentsFromTableInfoFile($dataSetInstance);
 282
 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();
 290
 291                         // Update the entry
 292                         $this->updateTableInfoFile($dataSetInstance);
 293                 }
 294         }
 295
 296         /**
 297          * Makes sure that the database connection is alive
 298          *
 299          * @return      void
 300          * @todo        Do some checks on the database directory and files here
 301          */
 302         public function connectToDatabase () {
 303         }
 304
 305         /**
 306          * Starts a SELECT query on the database by given return type, table name
 307          * and search criteria
 308          *
 309          * @param       $tableName              Name of the database table
 310          * @param       $criteria               Local search criteria class
 311          * @return      $resultData             Result data of the query
 312          * @throws      UnsupportedCriteriaException    If the criteria is unsupported
 313          * @throws      SqlException                                    If an 'SQL error' occurs
 314          */
 315         public function querySelect ($tableName, LocalSearchCriteria $criteriaInstance) {
 316                 // The result is null by any errors
 317                 $resultData = NULL;
 318
 319                 // Create full path name
 320                 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $tableName . '/';
 321
 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
 324                 try {
 325                         // Get a directory pointer instance
 326                         $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
 327
 328                         // Initialize the result data, this need to be rewritten e.g. if a local file cannot be read
 329                         $resultData = array(
 330                                 BaseDatabaseBackend::RESULT_INDEX_STATUS => self::RESULT_OKAY,
 331                                 BaseDatabaseBackend::RESULT_INDEX_ROWS   => array()
 332                         );
 333
 334                         // Initialize limit/skip
 335                         $limitFound = 0;
 336                         $skipFound = 0;
 337                         $idx = 1;
 338
 339                         // Read the directory with some exceptions
 340                         while (($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()) {
 343                                         // Skip this file!
 344                                         continue;
 345                                 } // END - if
 346
 347                                 // Read the file
 348                                 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 349                                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataFile=' . $dataFile . ',dataArray='.print_r($dataArray,true));
 350
 351                                 // Is this an array?
 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);
 357
 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()) {
 365                                                                         // Skip this entry
 366                                                                         $skipFound++;
 367                                                                         break;
 368                                                                 } // END - if
 369                                                         } // END - if
 370
 371                                                         // Set id number
 372                                                         $dataArray[$this->getIndexKey()] = $idx;
 373
 374                                                         // Entry found!
 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;
 377
 378                                                         // Count found entries up
 379                                                         $limitFound++;
 380                                                         break;
 381                                                 } // END - if
 382                                         } // END - foreach
 383                                 } else {
 384                                         // Throw an exception here
 385                                         throw new SqlException(array($this, sprintf("File &#39;%s&#39; contains invalid data.", $dataFile), self::DB_CODE_DATA_FILE_CORRUPT), self::EXCEPTION_SQL_QUERY);
 386                                 }
 387
 388                                 // Count entry up
 389                                 $idx++;
 390                         } // END - while
 391
 392                         // Close directory and throw the instance away
 393                         $directoryInstance->closeDirectory();
 394                         unset($directoryInstance);
 395
 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);
 401
 402                         // So throw an SqlException here with faked error message
 403                         throw new SqlException (array($this, sprintf("Table &#39;%s&#39; 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);
 407                 }
 408
 409                 // Return the gathered result
 410                 return $resultData;
 411         }
 412
 413         /**
 414          * "Inserts" a data set instance into a local file database folder
 415          *
 416          * @param       $dataSetInstance        A storeable data set
 417          * @return      void
 418          * @throws      SqlException    If an SQL error occurs
 419          */
 420         public function queryInsertDataSet (StoreableCriteria $dataSetInstance) {
 421                 // Try to save the request away
 422                 try {
 423                         // Create full path name
 424                         $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, md5($dataSetInstance->getUniqueValue()));
 425
 426                         // Write the data away
 427                         $this->writeDataArrayToFqfn($fqfn, $dataSetInstance->getCriteriaArray());
 428
 429                         // Update the primary key
 430                         $this->updatePrimaryKey($dataSetInstance);
 431
 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);
 437
 438                         // Throw an SQL exception
 439                         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);
 440                 }
 441         }
 442
 443         /**
 444          * "Updates" a data set instance with a database layer
 445          *
 446          * @param       $dataSetInstance        A storeable data set
 447          * @return      void
 448          * @throws      SqlException    If an SQL error occurs
 449          */
 450         public function queryUpdateDataSet (StoreableCriteria $dataSetInstance) {
 451                 // Create full path name
 452                 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/';
 453
 454                 // Try all the requests
 455                 try {
 456                         // Get a file pointer instance
 457                         $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
 458
 459                         // Initialize limit/skip
 460                         $limitFound = 0;
 461                         $skipFound = 0;
 462
 463                         // Get the criteria array from the dataset
 464                         $criteriaArray = $dataSetInstance->getCriteriaArray();
 465
 466                         // Get search criteria
 467                         $searchInstance = $dataSetInstance->getSearchInstance();
 468
 469                         // Read the directory with some exceptions
 470                         while (($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()) {
 473                                         // Debug message
 474                                         //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataFile=' . $dataFile . ',getFileExtension()=' . $this->getFileExtension() . ' - SKIPPED!');
 475                                         // Skip this file!
 476                                         continue;
 477                                 } // END - if
 478
 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));
 482
 483                                 // Is this an array?
 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=' . $criteria);
 490
 491                                                 // Is the criteria met?
 492                                                 if (((!is_null($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()) {
 497                                                                         // Skip this entry
 498                                                                         $skipFound++;
 499                                                                         break;
 500                                                                 } // END - if
 501                                                         } // END - if
 502
 503                                                         // Entry found, so update it
 504                                                         foreach ($criteriaArray as $criteriaKey => $criteriaValue) {
 505                                                                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: criteriaKey=' . $criteriaKey . ',criteriaValue=' . $criteriaValue);
 506                                                                 $dataArray[$criteriaKey] = $criteriaValue;
 507                                                         } // END - foreach
 508
 509                                                         // Write the data to a local file
 510                                                         $this->writeDataArrayToFqfn($pathName . $dataFile, $dataArray);
 511
 512                                                         // Count it
 513                                                         $limitFound++;
 514                                                         break;
 515                                                 } // END - if
 516                                         } // END - foreach
 517                                 } // END - if
 518                         } // END - while
 519
 520                         // Close the file pointer
 521                         $directoryInstance->closeDirectory();
 522
 523                         // Update the primary key
 524                         $this->updatePrimaryKey($dataSetInstance);
 525
 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);
 531
 532                         // Throw an SQL exception
 533                         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);
 534                 }
 535         }
 536
 537         /**
 538          * Getter for primary key of specified table or if not found null will be
 539          * returned. This must be database-specific.
 540          *
 541          * @param       $tableName              Name of the table we need the primary key from
 542          * @return      $primaryKey             Primary key column of the given table
 543          */
 544         public function getPrimaryKeyOfTable ($tableName) {
 545                 // Default key is null
 546                 $primaryKey = NULL;
 547
 548                 // Does the table information exist?
 549                 if (isset($this->tableInfo[$tableName])) {
 550                         // Then return the primary key
 551                         $primaryKey = $this->tableInfo[$tableName]['primary'];
 552                 } // END - if
 553
 554                 // Return the column
 555                 return $primaryKey;
 556         }
 557 }
 558
 559 // [EOF]
 560 ?>