inc/classes/main/database/backend/class_CachedLocalFileDatabase.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@shipsimu.org>
  12  * @version             0.0.0
  13  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2014 Core Developer Team
  14  * @license             GNU GPL 3.0 or any newer version
  15  * @link                http://www.shipsimu.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 CachedLocalFileDatabase extends BaseDatabaseBackend implements DatabaseBackend {
  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 CachedLocalFileDatabase and set the save path from
  74          * configuration for local files.
  75          *
  76          * @return      $databaseInstance       An instance of CachedLocalFileDatabase
  77          */
  78         public static final function createCachedLocalFileDatabase () {
  79                 // Get an instance
  80                 $databaseInstance = new CachedLocalFileDatabase();
  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 ' . $fqfn . '.');
 184                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataArray=' . print_r($dataArray, TRUE));
 185
 186                 // Finally return it
 187                 return $dataArray;
 188         }
 189
 190         /**
 191          * Writes data array to local file
 192          *
 193          * @param       $fqfn           The FQFN of the local file
 194          * @param       $dataArray      An array with all the data we shall write
 195          * @return      void
 196          */
 197         private function writeDataArrayToFqfn ($fqfn, array $dataArray) {
 198                 // Debug message
 199                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Flushing ' . count($dataArray) . ' elements to database file ' . $fqfn . ' ...');
 200                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataArray=' . print_r($dataArray, TRUE));
 201
 202                 // Serialize and compress it
 203                 $compressedData = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($dataArray));
 204
 205                 // Write data
 206                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Writing ' . strlen($compressedData) . ' bytes ...');
 207
 208                 // Write this data BASE64 encoded to the file
 209                 $this->getFileIoInstance()->saveStreamToFile($fqfn, $compressedData, $this);
 210
 211                 // Debug message
 212                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Flushing ' . count($dataArray) . ' elements to database file completed.');
 213         }
 214
 215         /**
 216          * Getter for table information file contents or an empty if info file was not created
 217          *
 218          * @param       $dataSetInstance        An instance of a database set class
 219          * @return      $infoArray                      An array with all table informations
 220          */
 221         private function getContentsFromTableInfoFile (StoreableCriteria $dataSetInstance) {
 222                 // Default content is no data
 223                 $infoArray = array();
 224
 225                 // Create FQFN for getting the table information file
 226                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
 227
 228                 // Get the file contents
 229                 try {
 230                         $infoArray = $this->getDataArrayFromFile($fqfn);
 231                 } catch (FileIoException $e) {
 232                         // Not found, so ignore it here
 233                 }
 234
 235                 // ... and return it
 236                 return $infoArray;
 237         }
 238
 239         /**
 240          * Generates an FQFN from given dataset instance and string
 241          *
 242          * @param       $dataSetInstance        An instance of a database set class
 243          * @param       $rowName                        Name of the row
 244          * @return      $fqfn                           The FQFN for this row
 245          */
 246         private function generateFqfnFromDataSet (Criteria $dataSetInstance, $rowName) {
 247                 // This is the FQFN
 248                 $fqfn = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/' . $rowName . '.' . $this->getFileExtension();
 249
 250                 // Return it
 251                 return $fqfn;
 252         }
 253
 254         /**
 255          * Creates the table info file from given dataset instance
 256          *
 257          * @param       $dataSetInstance        An instance of a database set class
 258          * @return      void
 259          */
 260         private function createTableInfoFile (StoreableCriteria $dataSetInstance) {
 261                 // Create FQFN for creating the table information file
 262                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
 263
 264                 // Get the data out from dataset in a local array
 265                 $this->tableInfo[$dataSetInstance->getTableName()] = array(
 266                         'primary'      => $dataSetInstance->getPrimaryKey(),
 267                         'created'      => time(),
 268                         'last_updated' => time()
 269                 );
 270
 271                 // Write the data to the file
 272                 $this->writeDataArrayToFqfn($fqfn, $this->tableInfo[$dataSetInstance->getTableName()]);
 273         }
 274
 275         /**
 276          * Updates the table info file from given dataset instance
 277          *
 278          * @param       $dataSetInstance        An instance of a database set class
 279          * @return      void
 280          */
 281         private function updateTableInfoFile (StoreableCriteria $dataSetInstance) {
 282                 // "Cache" table name
 283                 $tableName = $dataSetInstance->getTableName();
 284
 285                 // Create FQFN for creating the table information file
 286                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
 287
 288                 // Get the data out from dataset in a local array
 289                 $this->tableInfo[$tableName]['primary']      = $dataSetInstance->getPrimaryKey();
 290                 $this->tableInfo[$tableName]['last_updated'] = time();
 291
 292                 // Write the data to the file
 293                 $this->writeDataArrayToFqfn($fqfn, $this->tableInfo[$tableName]);
 294         }
 295
 296         /**
 297          * Updates the primary key information or creates the table info file if not found
 298          *
 299          * @param       $dataSetInstance        An instance of a database set class
 300          * @return      void
 301          */
 302         private function updatePrimaryKey (StoreableCriteria $dataSetInstance) {
 303                 // "Cache" table name
 304                 $tableName = $dataSetInstance->getTableName();
 305
 306                 // Get the information array from lower method
 307                 $infoArray = $this->getContentsFromTableInfoFile($dataSetInstance);
 308
 309                 // Is the primary key there?
 310                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: tableInfo=' . print_r($this->tableInfo, TRUE));
 311                 if (!isset($this->tableInfo[$tableName]['primary'])) {
 312                         // Then create the info file
 313                         $this->createTableInfoFile($dataSetInstance);
 314                 } elseif (($this->getConfigInstance()->getConfigEntry('db_update_primary_forced') == 'Y') && ($dataSetInstance->getPrimaryKey() != $this->tableInfo[$tableName]['primary'])) {
 315                         // Set the array element
 316                         $this->tableInfo[$tableName]['primary'] = $dataSetInstance->getPrimaryKey();
 317
 318                         // Update the entry
 319                         $this->updateTableInfoFile($dataSetInstance);
 320                 }
 321         }
 322
 323         /**
 324          * Makes sure that the database connection is alive
 325          *
 326          * @return      void
 327          * @todo        Do some checks on the database directory and files here
 328          */
 329         public function connectToDatabase () {
 330         }
 331
 332         /**
 333          * Starts a SELECT query on the database by given return type, table name
 334          * and search criteria
 335          *
 336          * @param       $tableName                      Name of the database table
 337          * @param       $searchInstance         Local search criteria class
 338          * @return      $resultData                     Result data of the query
 339          * @throws      UnsupportedCriteriaException    If the criteria is unsupported
 340          * @throws      SqlException                                    If an 'SQL error' occurs
 341          */
 342         public function querySelect ($tableName, LocalSearchCriteria $searchInstance) {
 343                 // Debug message
 344                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: tableName=' . $tableName . ' - CALLED!');
 345
 346                 // The result is null by any errors
 347                 $resultData = NULL;
 348
 349                 // Create full path name
 350                 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $tableName . '/';
 351
 352                 /*
 353                  * A 'select' query is not that easy on local files, so first try to
 354                  * find the 'table' which is in fact a directory on the server
 355                  */
 356                 try {
 357                         // Get a directory pointer instance
 358                         $directoryInstance = ObjectFactory::createObjectByConfiguredName('directory_class', array($pathName));
 359
 360                         // Initialize the result data, this need to be rewritten e.g. if a local file cannot be read
 361                         $resultData = array(
 362                                 BaseDatabaseBackend::RESULT_INDEX_STATUS => self::RESULT_OKAY,
 363                                 BaseDatabaseBackend::RESULT_INDEX_ROWS   => array()
 364                         );
 365
 366                         // Initialize limit/skip
 367                         $limitFound = 0;
 368                         $skipFound = 0;
 369                         $idx = 1;
 370
 371                         // Read the directory with some exceptions
 372                         while (($dataFile = $directoryInstance->readDirectoryExcept(array('.htaccess', 'info.' . $this->getFileExtension()))) && (($limitFound < $searchInstance->getLimit()) || ($searchInstance->getLimit() == 0))) {
 373                                 // Debug message
 374                                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataFile=' . $dataFile . ',this->getFileExtension()=' . $this->getFileExtension());
 375
 376                                 // Does the extension match?
 377                                 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
 378                                         // Skip this file!
 379                                         continue;
 380                                 } // END - if
 381
 382                                 // Read the file
 383                                 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 384                                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataFile=' . $dataFile . ',dataArray='.print_r($dataArray, TRUE));
 385
 386                                 // Is this an array?
 387                                 if (is_array($dataArray)) {
 388                                         // Default is nothing found
 389                                         $isFound = TRUE;
 390
 391                                         // Search in the criteria with FMFW (First Matches, First Wins)
 392                                         foreach ($dataArray as $key => $value) {
 393                                                 // Make sure value is not bool
 394                                                 assert(!is_bool($value));
 395
 396                                                 // Found one entry?
 397                                                 $isFound = (($isFound === TRUE) && ($searchInstance->isCriteriaMatching($key, $value)));
 398                                                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: key=' . $key . ',value=' . $value . ',isFound=' . intval($isFound));
 399                                         } // END - foreach
 400
 401                                         // Is all found?
 402                                         //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: isFound=' . intval($isFound) . ',limitFound=' . $limitFound . ',limit=' . $searchInstance->getLimit());
 403                                         if ($isFound === TRUE) {
 404                                                 // Shall we skip this entry?
 405                                                 if ($searchInstance->getSkip() > 0) {
 406                                                         // We shall skip some entries
 407                                                         if ($skipFound < $searchInstance->getSkip()) {
 408                                                                 // Skip this entry
 409                                                                 $skipFound++;
 410                                                                 break;
 411                                                         } // END - if
 412                                                 } // END - if
 413
 414                                                 // Set id number
 415                                                 $dataArray[$this->getIndexKey()] = $idx;
 416
 417                                                 // Entry found!
 418                                                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: indexKey=' . $this->getIndexKey() . ',idx=' . $idx . ',dataArray=' . print_r($dataArray, TRUE));
 419                                                 array_push($resultData[BaseDatabaseBackend::RESULT_INDEX_ROWS], $dataArray);
 420
 421                                                 // Count found entries up
 422                                                 $limitFound++;
 423                                         } // END - if
 424                                 } else {
 425                                         // Throw an exception here
 426                                         throw new SqlException(array($this, sprintf('File &#39;%s&#39; contains invalid data.', $dataFile), self::DB_CODE_DATA_FILE_CORRUPT), self::EXCEPTION_SQL_QUERY);
 427                                 }
 428
 429                                 // Count entry up
 430                                 $idx++;
 431                         } // END - while
 432
 433                         // Close directory and throw the instance away
 434                         $directoryInstance->closeDirectory();
 435                         unset($directoryInstance);
 436
 437                         // Reset last exception
 438                         $this->resetLastException();
 439                 } catch (PathIsNoDirectoryException $e) {
 440                         // Path not found means "table not found" for real databases...
 441                         $this->setLastException($e);
 442
 443                         // So throw an SqlException here with faked error message
 444                         throw new SqlException (array($this, sprintf('Table &#39;%s&#39; not found', $tableName), self::DB_CODE_TABLE_MISSING), self::EXCEPTION_SQL_QUERY);
 445                 } catch (FrameworkException $e) {
 446                         // Catch all exceptions and store them in last error
 447                         $this->setLastException($e);
 448                 }
 449
 450                 // Return the gathered result
 451                 return $resultData;
 452         }
 453
 454         /**
 455          * "Inserts" a data set instance into a local file database folder
 456          *
 457          * @param       $dataSetInstance        A storeable data set
 458          * @return      void
 459          * @throws      SqlException    If an SQL error occurs
 460          */
 461         public function queryInsertDataSet (StoreableCriteria $dataSetInstance) {
 462                 // Try to save the request away
 463                 try {
 464                         // Create full path name
 465                         $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, md5($dataSetInstance->getUniqueValue()));
 466
 467                         // Write the data away
 468                         $this->writeDataArrayToFqfn($fqfn, $dataSetInstance->getCriteriaArray());
 469
 470                         // Update the primary key
 471                         $this->updatePrimaryKey($dataSetInstance);
 472
 473                         // Reset last exception
 474                         $this->resetLastException();
 475                 } catch (FrameworkException $e) {
 476                         // Catch all exceptions and store them in last error
 477                         $this->setLastException($e);
 478
 479                         // Throw an SQL exception
 480                         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);
 481                 }
 482         }
 483
 484         /**
 485          * "Updates" a data set instance with a database layer
 486          *
 487          * @param       $dataSetInstance        A storeable data set
 488          * @return      void
 489          * @throws      SqlException    If an SQL error occurs
 490          */
 491         public function queryUpdateDataSet (StoreableCriteria $dataSetInstance) {
 492                 // Create full path name
 493                 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/';
 494
 495                 // Try all the requests
 496                 try {
 497                         // Get a file pointer instance
 498                         $directoryInstance = ObjectFactory::createObjectByConfiguredName('directory_class', array($pathName));
 499
 500                         // Initialize limit/skip
 501                         $limitFound = 0;
 502                         $skipFound = 0;
 503
 504                         // Get the criteria array from the dataset
 505                         $searchArray = $dataSetInstance->getCriteriaArray();
 506
 507                         // Get search criteria
 508                         $searchInstance = $dataSetInstance->getSearchInstance();
 509
 510                         // Read the directory with some exceptions
 511                         while (($dataFile = $directoryInstance->readDirectoryExcept(array('.htaccess', 'info.' . $this->getFileExtension()))) && (($limitFound < $searchInstance->getLimit()) || ($searchInstance->getLimit() == 0))) {
 512                                 // Does the extension match?
 513                                 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
 514                                         // Debug message
 515                                         //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataFile=' . $dataFile . ',getFileExtension()=' . $this->getFileExtension() . ' - SKIPPED!');
 516                                         // Skip this file!
 517                                         continue;
 518                                 } // END - if
 519
 520                                 // Open this file for reading
 521                                 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 522                                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: dataFile=' . $dataFile . ',dataArray='.print_r($dataArray, TRUE));
 523
 524                                 // Is this an array?
 525                                 if (is_array($dataArray)) {
 526                                         // Default is nothing found
 527                                         $isFound = TRUE;
 528
 529                                         // Search in the criteria with FMFW (First Matches, First Wins)
 530                                         foreach ($dataArray as $key => $value) {
 531                                                 // Make sure value is not bool
 532                                                 assert(!is_bool($value));
 533
 534                                                 // Found one entry?
 535                                                 $isFound = (($isFound === TRUE) && ($searchInstance->isCriteriaMatching($key, $value)));
 536                                         } // END - foreach
 537
 538                                         // Is all found?
 539                                         //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: isFound=' . intval($isFound));
 540                                         if ($isFound === TRUE) {
 541                                                 // Shall we skip this entry?
 542                                                 if ($searchInstance->getSkip() > 0) {
 543                                                         // We shall skip some entries
 544                                                         if ($skipFound < $searchInstance->getSkip()) {
 545                                                                 // Skip this entry
 546                                                                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Found entry, but skipping ...');
 547                                                                 $skipFound++;
 548                                                                 break;
 549                                                         } // END - if
 550                                                 } // END - if
 551
 552                                                 // Entry found, so update it
 553                                                 foreach ($searchArray as $searchKey => $searchValue) {
 554                                                         // Make sure the value is not bool again
 555                                                         assert(!is_bool($searchValue));
 556                                                         assert($searchKey != $this->indexKey);
 557
 558                                                         // Debug message + add/update it
 559                                                         //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: criteriaKey=' . $searchKey . ',criteriaValue=' . $searchValue);
 560                                                         $dataArray[$searchKey] = $searchValue;
 561                                                 } // END - foreach
 562
 563                                                 // Write the data to a local file
 564                                                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: Writing dataArray()=' . count($dataArray) . ' to ' . $dataFile . ' ...');
 565                                                 $this->writeDataArrayToFqfn($pathName . $dataFile, $dataArray);
 566
 567                                                 // Count found entries up
 568                                                 $limitFound++;
 569                                         } // END - if
 570                                 } // END - if
 571                         } // END - while
 572
 573                         // Close the file pointer
 574                         $directoryInstance->closeDirectory();
 575
 576                         // Update the primary key
 577                         $this->updatePrimaryKey($dataSetInstance);
 578
 579                         // Reset last exception
 580                         $this->resetLastException();
 581                 } catch (FrameworkException $e) {
 582                         // Catch all exceptions and store them in last error
 583                         $this->setLastException($e);
 584
 585                         // Throw an SQL exception
 586                         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);
 587                 }
 588         }
 589
 590         /**
 591          * Getter for primary key of specified table or if not found null will be
 592          * returned. This must be database-specific.
 593          *
 594          * @param       $tableName              Name of the table we need the primary key from
 595          * @return      $primaryKey             Primary key column of the given table
 596          */
 597         public function getPrimaryKeyOfTable ($tableName) {
 598                 // Default key is null
 599                 $primaryKey = NULL;
 600
 601                 // Does the table information exist?
 602                 if (isset($this->tableInfo[$tableName])) {
 603                         // Then return the primary key
 604                         $primaryKey = $this->tableInfo[$tableName]['primary'];
 605                 } // END - if
 606
 607                 // Return the column
 608                 return $primaryKey;
 609         }
 610
 611         /**
 612          * Removes non-public data from given array.
 613          *
 614          * @param       $data   An array with possible non-public data that needs to be removed.
 615          * @return      $data   A cleaned up array with only public data.
 616          * @todo        Add more generic non-public data for removal
 617          */
 618         public function removeNonPublicDataFromArray (array $data) {
 619                 // Remove '__idx'
 620                 unset($data[$this->indexKey]);
 621
 622                 // Return it
 623                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('DATABASE: data[' . gettype($data) . ']='.print_r($data, TRUE));
 624                 return $data;
 625         }
 626 }
 627
 628 // [EOF]
 629 ?>