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                 // Debug message
 193                 /* NOISY-DEBUG: */ $this->debugOutput('DATABASE: Flushing ' . count($dataArray) . ' elements to database file ' . $fqfn . ' ...');
 194
 195                 // Get a file pointer instance
 196                 $fileInstance = FrameworkFileOutputPointer::createFrameworkFileOutputPointer($fqfn, 'w');
 197
 198                 // Serialize and compress it
 199                 $compressedData = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($dataArray));
 200
 201                 // Write this data BASE64 encoded to the file
 202                 $fileInstance->writeToFile(base64_encode($compressedData));
 203
 204                 // Close the file pointer
 205                 $fileInstance->closeFile();
 206
 207                 // Debug message
 208                 /* NOISY-DEBUG: */ $this->debugOutput('DATABASE: Flushing ' . count($dataArray) . ' elements to database file completed.');
 209         }
 210
 211         /**
 212          * Getter for table information file contents or an empty if info file was not created
 213          *
 214          * @param       $dataSetInstance        An instance of a database set class
 215          * @return      $infoArray                      An array with all table informations
 216          */
 217         private function getContentsFromTableInfoFile (StoreableCriteria $dataSetInstance) {
 218                 // Default content is no data
 219                 $infoArray = array();
 220
 221                 // Create FQFN for getting the table information file
 222                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
 223
 224                 // Get the file contents
 225                 try {
 226                         $infoArray = $this->getDataArrayFromFile($fqfn);
 227                 } catch (FileIoException $e) {
 228                         // Not found, so ignore it here
 229                 }
 230
 231                 // ... and return it
 232                 return $infoArray;
 233         }
 234
 235         /**
 236          * Generates an FQFN from given dataset instance and string
 237          *
 238          * @param       $dataSetInstance        An instance of a database set class
 239          * @param       $rowName                        Name of the row
 240          * @return      $fqfn                           The FQFN for this row
 241          */
 242         private function generateFqfnFromDataSet (Criteria $dataSetInstance, $rowName) {
 243                 // This is the FQFN
 244                 $fqfn = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/' . $rowName . '.' . $this->getFileExtension();
 245
 246                 // Return it
 247                 return $fqfn;
 248         }
 249
 250         /**
 251          * Creates the table info file from given dataset instance
 252          *
 253          * @param       $dataSetInstance        An instance of a database set class
 254          * @return      void
 255          */
 256         private function createTableInfoFile (StoreableCriteria $dataSetInstance) {
 257                 // Create FQFN for creating the table information file
 258                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
 259
 260                 // Get the data out from dataset in a local array
 261                 $this->tableInfo[$dataSetInstance->getTableName()] = array(
 262                         'primary'      => $dataSetInstance->getPrimaryKey(),
 263                         'created'      => time(),
 264                         'last_updated' => time()
 265                 );
 266
 267                 // Write the data to the file
 268                 $this->writeDataArrayToFqfn($fqfn, $this->tableInfo[$dataSetInstance->getTableName()]);
 269         }
 270
 271         /**
 272          * Updates the primary key information or creates the table info file if not found
 273          *
 274          * @param       $dataSetInstance        An instance of a database set class
 275          * @return      void
 276          */
 277         private function updatePrimaryKey (StoreableCriteria $dataSetInstance) {
 278                 // Get the information array from lower method
 279                 $infoArray = $this->getContentsFromTableInfoFile($dataSetInstance);
 280
 281                 // Is the primary key there?
 282                 if (!isset($this->tableInfo['primary'])) {
 283                         // Then create the info file
 284                         $this->createTableInfoFile($dataSetInstance);
 285                 } elseif (($this->getConfigInstance()->getConfigEntry('db_update_primary_forced') == 'Y') && ($dataSetInstance->getPrimaryKey() != $this->tableInfo['primary'])) {
 286                         // Set the array element
 287                         $this->tableInfo[$dataSetInstance->getTableName()]['primary'] = $dataSetInstance->getPrimaryKey();
 288
 289                         // Update the entry
 290                         $this->updateTableInfoFile($dataSetInstance);
 291                 }
 292         }
 293
 294         /**
 295          * Makes sure that the database connection is alive
 296          *
 297          * @return      void
 298          * @todo        Do some checks on the database directory and files here
 299          */
 300         public function connectToDatabase () {
 301         }
 302
 303         /**
 304          * Starts a SELECT query on the database by given return type, table name
 305          * and search criteria
 306          *
 307          * @param       $tableName              Name of the database table
 308          * @param       $criteria               Local search criteria class
 309          * @return      $resultData             Result data of the query
 310          * @throws      UnsupportedCriteriaException    If the criteria is unsupported
 311          * @throws      SqlException                                    If an 'SQL error' occurs
 312          */
 313         public function querySelect ($tableName, LocalSearchCriteria $criteriaInstance) {
 314                 // The result is null by any errors
 315                 $resultData = NULL;
 316
 317                 // Create full path name
 318                 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $tableName . '/';
 319
 320                 // A 'select' query is not that easy on local files, so first try to
 321                 // find the 'table' which is in fact a directory on the server
 322                 try {
 323                         // Get a directory pointer instance
 324                         $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
 325
 326                         // Initialize the result data, this need to be rewritten e.g. if a local file cannot be read
 327                         $resultData = array(
 328                                 BaseDatabaseFrontend::RESULT_INDEX_STATUS => LocalfileDatabase::RESULT_OKAY,
 329                                 BaseDatabaseFrontend::RESULT_INDEX_ROWS   => array()
 330                         );
 331
 332                         // Initialize limit/skip
 333                         $limitFound = 0;
 334                         $skipFound = 0;
 335                         $idx = 1;
 336
 337                         // Read the directory with some exceptions
 338                         while (($dataFile = $directoryInstance->readDirectoryExcept(array('.', '..', '.htaccess', '.svn', 'info.' . $this->getFileExtension()))) && (($limitFound < $criteriaInstance->getLimit()) || ($criteriaInstance->getLimit() == 0))) {
 339                                 // Does the extension match?
 340                                 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
 341                                         // Skip this file!
 342                                         continue;
 343                                 } // END - if
 344
 345                                 // Read the file
 346                                 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 347
 348                                 // Is this an array?
 349                                 if (is_array($dataArray)) {
 350                                         // Search in the criteria with FMFW (First Matches, First Wins)
 351                                         foreach ($dataArray as $key => $value) {
 352                                                 // Get criteria element
 353                                                 $criteria = $criteriaInstance->getCriteriaElemnent($key);
 354
 355                                                 // Is the criteria met?
 356                                                 //* NOISY-DEBUG: */ $this->debugOutput('DATABASE: criteria[' . gettype($criteria) . ']=' . $criteria . ',()=' . strlen($criteria) . ',value=' . $value . ',()=' . strlen($value));
 357                                                 if ((!is_null($criteria)) && ($criteria == $value))  {
 358                                                         // Shall we skip this entry?
 359                                                         if ($criteriaInstance->getSkip() > 0) {
 360                                                                 // We shall skip some entries
 361                                                                 if ($skipFound < $criteriaInstance->getSkip()) {
 362                                                                         // Skip this entry
 363                                                                         $skipFound++;
 364                                                                         break;
 365                                                                 } // END - if
 366                                                         } // END - if
 367
 368                                                         // Set id number
 369                                                         $dataArray[$this->getIndexKey()] = $idx;
 370
 371                                                         // Entry found!
 372                                                         //* NOISY-DEBUG: */ $this->debugOutput('DATABASE: indexKey=' . $this->getIndexKey() . ',idx=' . $idx . ',dataArray=' . print_r($dataArray, true));
 373                                                         $resultData[BaseDatabaseFrontend::RESULT_INDEX_ROWS][] = $dataArray;
 374
 375                                                         // Count found entries up
 376                                                         $limitFound++;
 377                                                         break;
 378                                                 } // END - if
 379                                         } // END - foreach
 380                                 } else {
 381                                         // Throw an exception here
 382                                         throw new SqlException(array($this, sprintf("File &#39;%s&#39; contains invalid data.", $dataFile), self::DB_CODE_DATA_FILE_CORRUPT), self::EXCEPTION_SQL_QUERY);
 383                                 }
 384
 385                                 // Count entry up
 386                                 $idx++;
 387                         } // END - while
 388
 389                         // Close directory and throw the instance away
 390                         $directoryInstance->closeDirectory();
 391                         unset($directoryInstance);
 392
 393                         // Reset last exception
 394                         $this->resetLastException();
 395                 } catch (PathIsNoDirectoryException $e) {
 396                         // Path not found means "table not found" for real databases...
 397                         $this->setLastException($e);
 398
 399                         // So throw an SqlException here with faked error message
 400                         throw new SqlException (array($this, sprintf("Table &#39;%s&#39; not found", $tableName), self::DB_CODE_TABLE_MISSING), self::EXCEPTION_SQL_QUERY);
 401                 } catch (FrameworkException $e) {
 402                         // Catch all exceptions and store them in last error
 403                         $this->setLastException($e);
 404                 }
 405
 406                 // Return the gathered result
 407                 return $resultData;
 408         }
 409
 410         /**
 411          * "Inserts" a data set instance into a local file database folder
 412          *
 413          * @param       $dataSetInstance        A storeable data set
 414          * @return      void
 415          * @throws      SqlException    If an SQL error occurs
 416          */
 417         public function queryInsertDataSet (StoreableCriteria $dataSetInstance) {
 418                 // Create full path name
 419                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, md5($dataSetInstance->getUniqueValue()));
 420
 421                 // Try to save the request away
 422                 try {
 423                         // Write the data away
 424                         $this->writeDataArrayToFqfn($fqfn, $dataSetInstance->getCriteriaArray());
 425
 426                         // Update the primary key
 427                         $this->updatePrimaryKey($dataSetInstance);
 428
 429                         // Reset last exception
 430                         $this->resetLastException();
 431                 } catch (FrameworkException $e) {
 432                         // Catch all exceptions and store them in last error
 433                         $this->setLastException($e);
 434
 435                         // Throw an SQL exception
 436                         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);
 437                 }
 438         }
 439
 440         /**
 441          * "Updates" a data set instance with a database layer
 442          *
 443          * @param       $dataSetInstance        A storeable data set
 444          * @return      void
 445          * @throws      SqlException    If an SQL error occurs
 446          */
 447         public function queryUpdateDataSet (StoreableCriteria $dataSetInstance) {
 448                 // Create full path name
 449                 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/';
 450
 451                 // Try all the requests
 452                 try {
 453                         // Get a file pointer instance
 454                         $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
 455
 456                         // Initialize limit/skip
 457                         $limitFound = 0;
 458                         $skipFound = 0;
 459
 460                         // Get the criteria array from the dataset
 461                         $criteriaArray = $dataSetInstance->getCriteriaArray();
 462
 463                         // Get search criteria
 464                         $searchInstance = $dataSetInstance->getSearchInstance();
 465
 466                         // Read the directory with some exceptions
 467                         while (($dataFile = $directoryInstance->readDirectoryExcept(array('.', '..', '.htaccess', '.svn', 'info.' . $this->getFileExtension()))) && ($limitFound < $searchInstance->getLimit())) {
 468                                 // Does the extension match?
 469                                 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
 470                                         // Skip this file!
 471                                         continue;
 472                                 } // END - if
 473
 474                                 // Open this file for reading
 475                                 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 476
 477                                 // Is this an array?
 478                                 if (is_array($dataArray)) {
 479                                         // Search in the criteria with FMFW (First Matches, First Wins)
 480                                         foreach ($dataArray as $key => $value) {
 481                                                 // Get criteria element
 482                                                 $criteria = $searchInstance->getCriteriaElemnent($key);
 483
 484                                                 // Is the criteria met?
 485                                                 if ((!is_null($criteria)) && ($criteria == $value))  {
 486                                                         // Shall we skip this entry?
 487                                                         if ($searchInstance->getSkip() > 0) {
 488                                                                 // We shall skip some entries
 489                                                                 if ($skipFound < $searchInstance->getSkip()) {
 490                                                                         // Skip this entry
 491                                                                         $skipFound++;
 492                                                                         break;
 493                                                                 } // END - if
 494                                                         } // END - if
 495
 496                                                         // Entry found, so update it
 497                                                         foreach ($criteriaArray as $criteriaKey => $criteriaValue) {
 498                                                                 $dataArray[$criteriaKey] = $criteriaValue;
 499                                                         } // END - foreach
 500
 501                                                         // Write the data to a local file
 502                                                         $this->writeDataArrayToFqfn($pathName . $dataFile, $dataArray);
 503
 504                                                         // Count it
 505                                                         $limitFound++;
 506                                                         break;
 507                                                 } // END - if
 508                                         } // END - foreach
 509                                 } // END - if
 510                         } // END - while
 511
 512                         // Close the file pointer
 513                         $directoryInstance->closeDirectory();
 514
 515                         // Update the primary key
 516                         $this->updatePrimaryKey($dataSetInstance);
 517
 518                         // Reset last exception
 519                         $this->resetLastException();
 520                 } catch (FrameworkException $e) {
 521                         // Catch all exceptions and store them in last error
 522                         $this->setLastException($e);
 523
 524                         // Throw an SQL exception
 525                         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);
 526                 }
 527         }
 528
 529         /**
 530          * Getter for primary key of specified table or if not found null will be
 531          * returned. This must be database-specific.
 532          *
 533          * @param       $tableName              Name of the table we need the primary key from
 534          * @return      $primaryKey             Primary key column of the given table
 535          */
 536         public function getPrimaryKeyOfTable ($tableName) {
 537                 // Default key is null
 538                 $primaryKey = NULL;
 539
 540                 // Does the table information exist?
 541                 if (isset($this->tableInfo[$tableName])) {
 542                         // Then return the primary key
 543                         $primaryKey = $this->tableInfo[$tableName]['primary'];
 544                 } // END - if
 545
 546                 // Return the column
 547                 return $primaryKey;
 548         }
 549 }
 550
 551 // [EOF]
 552 ?>