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, 2010 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          * Save path for "file database"
  37          */
  38         private $savePath = '';
  39
  40         /**
  41          * The file's extension
  42          */
  43         private $fileExtension = 'serialized';
  44
  45         /**
  46          * The last read file's name
  47          */
  48         private $lastFile = '';
  49
  50         /**
  51          * The last read file's content including header information
  52          */
  53         private $lastContents = array();
  54
  55         /**
  56          * Wether the "connection is already up
  57          */
  58         private $alreadyConnected = false;
  59
  60         /**
  61          * Last error message
  62          */
  63         private $lastError = '';
  64
  65         /**
  66          * Last exception
  67          */
  68         private $lastException = null;
  69
  70         /**
  71          * Table information array
  72          */
  73         private $tableInfo = array();
  74
  75         /**
  76          * Element for index
  77          */
  78         private $indexKey = '__idx';
  79
  80         /**
  81          * The protected constructor. Do never instance from outside! You need to
  82          * set a local file path. The class will then validate it.
  83          *
  84          * @return      void
  85          */
  86         protected function __construct() {
  87                 // Call parent constructor
  88                 parent::__construct(__CLASS__);
  89         }
  90
  91         /**
  92          * Create an object of LocalFileDatabase and set the save path for local files.
  93          * This method also validates the given file path.
  94          *
  95          * @param               $savePath               The local file path string
  96          * @param               $ioInstance             The input/output handler. This
  97          *                                                              should be FileIoHandler
  98          * @return      $dbInstance                     An instance of LocalFileDatabase
  99          */
 100         public final static function createLocalFileDatabase ($savePath, FileIoHandler $ioInstance) {
 101                 // Get an instance
 102                 $databaseInstance = new LocalFileDatabase();
 103
 104                 // Set save path and IO instance
 105                 $databaseInstance->setSavePath($savePath);
 106                 $databaseInstance->setFileIoInstance($ioInstance);
 107
 108                 // Set the compressor channel
 109                 $databaseInstance->setCompressorChannel(CompressorChannel::createCompressorChannel(
 110                         $databaseInstance->getConfigInstance()->getConfigEntry('base_path').
 111                         $databaseInstance->getConfigInstance()->getConfigEntry('compressor_base_path')
 112                 ));
 113
 114                 // "Connect" to the database
 115                 $databaseInstance->connectToDatabase();
 116
 117                 // Return database instance
 118                 return $databaseInstance;
 119         }
 120
 121         /**
 122          * Setter for save path
 123          *
 124          * @param               $savePath               The local save path where we shall put our serialized classes
 125          * @return      void
 126          */
 127         public final function setSavePath ($savePath) {
 128                 // Set save path
 129                 $this->savePath = (string) $savePath;
 130         }
 131
 132         /**
 133          * Getter for save path
 134          *
 135          * @return      $savePath               The local save path where we shall put our serialized classes
 136          */
 137         public final function getSavePath () {
 138                 return $this->savePath;
 139         }
 140
 141         /**
 142          * Getter for last error message
 143          *
 144          * @return      $lastError      Last error message
 145          */
 146         public final function getLastError () {
 147                 return $this->lastError;
 148         }
 149
 150         /**
 151          * Getter for last exception
 152          *
 153          * @return      $lastException  Last thrown exception
 154          */
 155         public final function getLastException () {
 156                 return $this->lastException;
 157         }
 158
 159         /**
 160          * Setter for the last read file
 161          *
 162          * @param       $fqfn   The FQFN of the last read file
 163          * @return      void
 164          */
 165         private final function setLastFile ($fqfn) {
 166                 // Cast string and set it
 167                 $this->lastFile = (string) $fqfn;
 168         }
 169
 170         /**
 171          * Reset the last error and exception instance. This should be done after
 172          * a successfull "query"
 173          *
 174          * @return      void
 175          */
 176         private final function resetLastError () {
 177                 $this->lastError = '';
 178                 $this->lastException = null;
 179         }
 180
 181         /**
 182          * Getter for last read file
 183          *
 184          * @return      $lastFile               The last read file's name with full path
 185          */
 186         public final function getLastFile () {
 187                 return $this->lastFile;
 188         }
 189
 190         /**
 191          * Setter for contents of the last read file
 192          *
 193          * @param               $contents               An array with header and data elements
 194          * @return      void
 195          */
 196         private final function setLastFileContents (array $contents) {
 197                 // Set array
 198                 $this->lastContents = $contents;
 199         }
 200
 201         /**
 202          * Getter for last read file's content as an array
 203          *
 204          * @return      $lastContent    The array with elements 'header' and 'data'.
 205          */
 206         public final function getLastContents () {
 207                 return $this->lastContents;
 208         }
 209
 210         /**
 211          * Getter for file extension
 212          *
 213          * @return      $fileExtension  The array with elements 'header' and 'data'.
 214          */
 215         public final function getFileExtension () {
 216                 return $this->fileExtension;
 217         }
 218
 219         /**
 220          * Getter for index key
 221          *
 222          * @return      $indexKey       Index key
 223          */
 224         public final function getIndexKey () {
 225                 return $this->indexKey;
 226         }
 227
 228         /**
 229          * Reads a local data file  and returns it's contents in an array
 230          *
 231          * @param       $fqfn   The FQFN for the requested file
 232          * @return      $dataArray
 233          */
 234         private function getDataArrayFromFile ($fqfn) {
 235                 // Get a file pointer
 236                 $fileInstance = FrameworkFileInputPointer::createFrameworkFileInputPointer($fqfn);
 237
 238                 // Get the raw data and BASE64-decode it
 239                 $compressedData = base64_decode($fileInstance->readLinesFromFile());
 240
 241                 // Close the file and throw the instance away
 242                 $fileInstance->closeFile();
 243                 unset($fileInstance);
 244
 245                 // Decompress it
 246                 $serializedData = $this->getCompressorChannel()->getCompressor()->decompressStream($compressedData);
 247
 248                 // Unserialize it
 249                 $dataArray = unserialize($serializedData);
 250
 251                 // Finally return it
 252                 return $dataArray;
 253         }
 254
 255         /**
 256          * Writes data array to local file
 257          *
 258          * @param       $fqfn           The FQFN of the local file
 259          * @param       $dataArray      An array with all the data we shall write
 260          * @return      void
 261          */
 262         private function writeDataArrayToFqfn ($fqfn, array $dataArray) {
 263                 // Get a file pointer instance
 264                 $fileInstance = FrameworkFileOutputPointer::createFrameworkFileOutputPointer($fqfn, 'w');
 265
 266                 // Serialize and compress it
 267                 $compressedData = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($dataArray));
 268
 269                 // Write this data BASE64 encoded to the file
 270                 $fileInstance->writeToFile(base64_encode($compressedData));
 271
 272                 // Close the file pointer
 273                 $fileInstance->closeFile();
 274         }
 275
 276         /**
 277          * Getter for table information file contents or an empty if info file was not created
 278          *
 279          * @param       $dataSetInstance        An instance of a database set class
 280          * @return      $infoArray                      An array with all table informations
 281          */
 282         private function getContentsFromTableInfoFile (StoreableCriteria $dataSetInstance) {
 283                 // Default content is no data
 284                 $infoArray = array();
 285
 286                 // Create FQFN for getting the table information file
 287                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
 288
 289                 // Get the file contents
 290                 try {
 291                         $infoArray = $this->getDataArrayFromFile($fqfn);
 292                 } catch (FileIoException $e) {
 293                         // Not found, so ignore it here
 294                 }
 295
 296                 // ... and return it
 297                 return $infoArray;
 298         }
 299
 300         /**
 301          * Generates an FQFN from given dataset instance and string
 302          *
 303          * @param       $dataSetInstance        An instance of a database set class
 304          * @param       $rowName                        Name of the row
 305          * @return      $fqfn                           The FQFN for this row
 306          */
 307         private function generateFqfnFromDataSet (Criteria $dataSetInstance, $rowName) {
 308                 // This is the FQFN
 309                 $fqfn = $this->getSavePath() . $dataSetInstance->getTableName() . '/' . $rowName . '.' . $this->getFileExtension();
 310
 311                 // Return it
 312                 return $fqfn;
 313         }
 314
 315         /**
 316          * Creates the table info file from given dataset instance
 317          *
 318          * @param       $dataSetInstance        An instance of a database set class
 319          * @return      void
 320          */
 321         private function createTableInfoFile (StoreableCriteria $dataSetInstance) {
 322                 // Create FQFN for creating the table information file
 323                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
 324
 325                 // Get the data out from dataset in a local array
 326                 $this->tableInfo[$dataSetInstance->getTableName()] = array(
 327                         'primary'      => $dataSetInstance->getPrimaryKey(),
 328                         'created'      => time(),
 329                         'last_updated' => time()
 330                 );
 331
 332                 // Write the data to the file
 333                 $this->writeDataArrayToFqfn($fqfn, $this->tableInfo[$dataSetInstance->getTableName()]);
 334         }
 335
 336         /**
 337          * Updates the primary key information or creates the table info file if not found
 338          *
 339          * @param       $dataSetInstance        An instance of a database set class
 340          * @return      void
 341          */
 342         private function updatePrimaryKey (StoreableCriteria $dataSetInstance) {
 343                 // Get the information array from lower method
 344                 $infoArray = $this->getContentsFromTableInfoFile($dataSetInstance);
 345
 346                 // Is the primary key there?
 347                 if (!isset($this->tableInfo['primary'])) {
 348                         // Then create the info file
 349                         $this->createTableInfoFile($dataSetInstance);
 350                 } elseif (($this->getConfigInstance()->getConfigEntry('db_update_primary_forced') == 'Y') && ($dataSetInstance->getPrimaryKey() != $this->tableInfo['primary'])) {
 351                         // Set the array element
 352                         $this->tableInfo[$dataSetInstance->getTableName()]['primary'] = $dataSetInstance->getPrimaryKey();
 353
 354                         // Update the entry
 355                         $this->updateTableInfoFile($dataSetInstance);
 356                 }
 357         }
 358
 359         /**
 360          * Makes sure that the database connection is alive
 361          *
 362          * @return      void
 363          * @todo        Do some checks on the database directory and files here
 364          */
 365         public function connectToDatabase () {
 366         }
 367
 368         /**
 369          * Starts a SELECT query on the database by given return type, table name
 370          * and search criteria
 371          *
 372          * @param       $resultType             Result type ('array', 'object' and 'indexed' are valid)
 373          * @param       $tableName              Name of the database table
 374          * @param       $criteria               Local search criteria class
 375          * @return      $resultData             Result data of the query
 376          * @throws      UnsupportedCriteriaException    If the criteria is unsupported
 377          * @throws      SqlException                                    If an 'SQL error' occurs
 378          */
 379         public function querySelect ($resultType, $tableName, LocalSearchCriteria $criteriaInstance) {
 380                 // The result is null by any errors
 381                 $resultData = null;
 382
 383                 // Create full path name
 384                 $pathName = $this->getSavePath() . $tableName . '/';
 385
 386                 // A 'select' query is not that easy on local files, so first try to
 387                 // find the 'table' which is in fact a directory on the server
 388                 try {
 389                         // Get a directory pointer instance
 390                         $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
 391
 392                         // Initialize the result data, this need to be rewritten e.g. if a local file cannot be read
 393                         $resultData = array(
 394                                 'status'        => LocalfileDatabase::RESULT_OKAY,
 395                                 'rows'          => array()
 396                         );
 397
 398                         // Initialize limit/skip
 399                         $limitFound = 0;
 400                         $skipFound = 0;
 401                         $idx = 1;
 402
 403                         // Read the directory with some exceptions
 404                         while (($dataFile = $directoryInstance->readDirectoryExcept(array('.', '..', '.htaccess', '.svn', "info." . $this->getFileExtension()))) && ($limitFound < $criteriaInstance->getLimit())) {
 405                                 // Does the extension match?
 406                                 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
 407                                         // Skip this file!
 408                                         continue;
 409                                 } // END - if
 410
 411                                 // Read the file
 412                                 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 413
 414                                 // Is this an array?
 415                                 if (is_array($dataArray)) {
 416                                         // Search in the criteria with FMFW (First Matches, First Wins)
 417                                         foreach ($dataArray as $key => $value) {
 418                                                 // Get criteria element
 419                                                 $criteria = $criteriaInstance->getCriteriaElemnent($key);
 420
 421                                                 // Is the criteria met?
 422                                                 if ((!is_null($criteria)) && ($criteria == $value))  {
 423
 424                                                         // Shall we skip this entry?
 425                                                         if ($criteriaInstance->getSkip() > 0) {
 426                                                                 // We shall skip some entries
 427                                                                 if ($skipFound < $criteriaInstance->getSkip()) {
 428                                                                         // Skip this entry
 429                                                                         $skipFound++;
 430                                                                         break;
 431                                                                 } // END - if
 432                                                         } // END - if
 433
 434                                                         // Set id number
 435                                                         $dataArray[$this->getIndexKey()] = $idx;
 436
 437                                                         // Entry found!
 438                                                         $resultData['rows'][] = $dataArray;
 439
 440                                                         // Count found entries up
 441                                                         $limitFound++;
 442                                                         break;
 443                                                 } // END - if
 444                                         } // END - foreach
 445                                 } else {
 446                                         // Throw an exception here
 447                                         throw new SqlException(array($this, sprintf("File &#39;%s&#39; contains invalid data.", $dataFile), self::DB_CODE_DATA_FILE_CORRUPT), self::EXCEPTION_SQL_QUERY);
 448                                 }
 449
 450                                 // Count entry up
 451                                 $idx++;
 452                         } // END - while
 453
 454                         // Close directory and throw the instance away
 455                         $directoryInstance->closeDirectory();
 456                         unset($directoryInstance);
 457
 458                         // Reset last error message and exception
 459                         $this->resetLastError();
 460                 } catch (PathIsNoDirectoryException $e) {
 461                         // Path not found means "table not found" for real databases...
 462                         $this->lastException = $e;
 463                         $this->lastError = $e->getMessage();
 464
 465                         // So throw an SqlException here with faked error message
 466                         throw new SqlException (array($this, sprintf("Table &#39;%s&#39; not found", $tableName), self::DB_CODE_TABLE_MISSING), self::EXCEPTION_SQL_QUERY);
 467                 } catch (FrameworkException $e) {
 468                         // Catch all exceptions and store them in last error
 469                         $this->lastException = $e;
 470                         $this->lastError = $e->getMessage();
 471                 }
 472
 473                 // Return the gathered result
 474                 return $resultData;
 475         }
 476
 477         /**
 478          * "Inserts" a data set instance into a local file database folder
 479          *
 480          * @param       $dataSetInstance        A storeable data set
 481          * @return      void
 482          * @throws      SqlException    If an SQL error occurs
 483          */
 484         public function queryInsertDataSet (StoreableCriteria $dataSetInstance) {
 485                 // Create full path name
 486                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, md5($dataSetInstance->getUniqueValue()));
 487
 488                 // Try to save the request away
 489                 try {
 490                         // Write the data away
 491                         $this->writeDataArrayToFqfn($fqfn, $dataSetInstance->getCriteriaArray());
 492
 493                         // Update the primary key
 494                         $this->updatePrimaryKey($dataSetInstance);
 495
 496                         // Reset last error message and exception
 497                         $this->resetLastError();
 498                 } catch (FrameworkException $e) {
 499                         // Catch all exceptions and store them in last error
 500                         $this->lastException = $e;
 501                         $this->lastError = $e->getMessage();
 502
 503                         // Throw an SQL exception
 504                         throw new SqlException (array($this, sprintf("Cannot write data to table &#39;%s&#39;", $tableName), self::DB_CODE_TABLE_UNWRITEABLE), self::EXCEPTION_SQL_QUERY);
 505                 }
 506         }
 507
 508         /**
 509          * "Updates" a data set instance with a database layer
 510          *
 511          * @param       $dataSetInstance        A storeable data set
 512          * @return      void
 513          * @throws      SqlException    If an SQL error occurs
 514          */
 515         public function queryUpdateDataSet (StoreableCriteria $dataSetInstance) {
 516                 // Create full path name
 517                 $pathName = $this->getSavePath() . $dataSetInstance->getTableName() . '/';
 518
 519                 // Try all the requests
 520                 try {
 521                         // Get a file pointer instance
 522                         $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
 523
 524                         // Initialize limit/skip
 525                         $limitFound = 0;
 526                         $skipFound = 0;
 527
 528                         // Get the criteria array from the dataset
 529                         $criteriaArray = $dataSetInstance->getCriteriaArray();
 530
 531                         // Get search criteria
 532                         $searchInstance = $dataSetInstance->getSearchInstance();
 533
 534                         // Read the directory with some exceptions
 535                         while (($dataFile = $directoryInstance->readDirectoryExcept(array('.', '..', '.htaccess', '.svn', "info." . $this->getFileExtension()))) && ($limitFound < $searchInstance->getLimit())) {
 536                                 // Does the extension match?
 537                                 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
 538                                         // Skip this file!
 539                                         continue;
 540                                 }
 541
 542                                 // Open this file for reading
 543                                 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 544
 545                                 // Is this an array?
 546                                 if (is_array($dataArray)) {
 547                                         // Search in the criteria with FMFW (First Matches, First Wins)
 548                                         foreach ($dataArray as $key => $value) {
 549                                                 // Get criteria element
 550                                                 $criteria = $searchInstance->getCriteriaElemnent($key);
 551
 552                                                 // Is the criteria met?
 553                                                 if ((!is_null($criteria)) && ($criteria == $value))  {
 554
 555                                                         // Shall we skip this entry?
 556                                                         if ($searchInstance->getSkip() > 0) {
 557                                                                 // We shall skip some entries
 558                                                                 if ($skipFound < $searchInstance->getSkip()) {
 559                                                                         // Skip this entry
 560                                                                         $skipFound++;
 561                                                                         break;
 562                                                                 } // END - if
 563                                                         } // END - if
 564
 565                                                         // Entry found, so update it
 566                                                         foreach ($criteriaArray as $criteriaKey => $criteriaValue) {
 567                                                                 $dataArray[$criteriaKey] = $criteriaValue;
 568                                                         } // END - foreach
 569
 570                                                         // Write the data to a local file
 571                                                         $this->writeDataArrayToFqfn($pathName . $dataFile, $dataArray);
 572
 573                                                         // Count it
 574                                                         $limitFound++;
 575                                                         break;
 576                                                 } // END - if
 577                                         } // END - foreach
 578                                 } // END - if
 579                         } // END - while
 580
 581                         // Close the file pointer
 582                         $directoryInstance->closeDirectory();
 583
 584                         // Update the primary key
 585                         $this->updatePrimaryKey($dataSetInstance);
 586
 587                         // Reset last error message and exception
 588                         $this->resetLastError();
 589                 } catch (FrameworkException $e) {
 590                         // Catch all exceptions and store them in last error
 591                         $this->lastException = $e;
 592                         $this->lastError = $e->getMessage();
 593
 594                         // Throw an SQL exception
 595                         throw new SqlException (array($this, sprintf("Cannot write data to table &#39;%s&#39;", $dataSetInstance->getTableName()), self::DB_CODE_TABLE_UNWRITEABLE), self::EXCEPTION_SQL_QUERY);
 596                 }
 597         }
 598
 599         /**
 600          * Getter for primary key of specified table or if not found null will be
 601          * returned. This must be database-specific.
 602          *
 603          * @param       $tableName              Name of the table we need the primary key from
 604          * @return      $primaryKey             Primary key column of the given table
 605          */
 606         public function getPrimaryKeyOfTable ($tableName) {
 607                 // Default key is null
 608                 $primaryKey = null;
 609
 610                 // Does the table information exist?
 611                 if (isset($this->tableInfo[$tableName])) {
 612                         // Then return the primary key
 613                         $primaryKey = $this->tableInfo[$tableName]['primary'];
 614                 } // END - if
 615
 616                 // Return the column
 617                 return $primaryKey;
 618         }
 619 }
 620
 621 // [EOF]
 622 ?>