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, this is free software
  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
  28         // Constants for MySQL backward-compatiblity (PLEASE FIX THEM!)
  29         const DB_CODE_TABLE_MISSING     = 0x100;
  30         const DB_CODE_TABLE_UNWRITEABLE = 0x101;
  31         const DB_CODE_DATA_FILE_CORRUPT = 0x102;
  32
  33         /**
  34          * Save path for "file database"
  35          */
  36         private $savePath = "";
  37
  38         /**
  39          * The file's extension
  40          */
  41         private $fileExtension = "serialized";
  42
  43         /**
  44          * The last read file's name
  45          */
  46         private $lastFile = "";
  47
  48         /**
  49          * The last read file's content including header information
  50          */
  51         private $lastContents = array();
  52
  53         /**
  54          * Wether the "connection is already up
  55          */
  56         private $alreadyConnected = false;
  57
  58         /**
  59          * Last error message
  60          */
  61         private $lastError = "";
  62
  63         /**
  64          * Last exception
  65          */
  66         private $lastException = null;
  67
  68         /**
  69          * Table information array
  70          */
  71         private $tableInfo = array();
  72
  73         /**
  74          * The protected constructor. Do never instance from outside! You need to
  75          * set a local file path. The class will then validate it.
  76          *
  77          * @return      void
  78          */
  79         protected function __construct() {
  80                 // Call parent constructor
  81                 parent::__construct(__CLASS__);
  82
  83                 // Clean up a little
  84                 $this->removeNumberFormaters();
  85                 $this->removeSystemArray();
  86         }
  87
  88         /**
  89          * Create an object of LocalFileDatabase and set the save path for local files.
  90          * This method also validates the given file path.
  91          *
  92          * @param               $savePath                                       The local file path string
  93          * @param               $ioInstance                             The input/output handler. This
  94          *                                                                      should be FileIoHandler
  95          * @return      $dbInstance                             An instance of LocalFileDatabase
  96          */
  97         public final static function createLocalFileDatabase ($savePath, FileIoHandler $ioInstance) {
  98                 // Get an instance
  99                 $dbInstance = new LocalFileDatabase();
 100
 101                 // Set save path and IO instance
 102                 $dbInstance->setSavePath($savePath);
 103                 $dbInstance->setFileIoInstance($ioInstance);
 104
 105                 // "Connect" to the database
 106                 $dbInstance->connectToDatabase();
 107
 108                 // Return database instance
 109                 return $dbInstance;
 110         }
 111
 112         /**
 113          * Setter for save path
 114          *
 115          * @param               $savePath               The local save path where we shall put our serialized classes
 116          * @return      void
 117          */
 118         public final function setSavePath ($savePath) {
 119                 // Secure string
 120                 $savePath = (string) $savePath;
 121
 122                 // Set save path
 123                 $this->savePath = $savePath;
 124         }
 125
 126         /**
 127          * Getter for save path
 128          *
 129          * @return      $savePath               The local save path where we shall put our serialized classes
 130          */
 131         public final function getSavePath () {
 132                 return $this->savePath;
 133         }
 134
 135         /**
 136          * Getter for last error message
 137          *
 138          * @return      $lastError      Last error message
 139          */
 140         public final function getLastError () {
 141                 return $this->lastError;
 142         }
 143
 144         /**
 145          * Getter for last exception
 146          *
 147          * @return      $lastException  Last thrown exception
 148          */
 149         public final function getLastException () {
 150                 return $this->lastException;
 151         }
 152
 153         /**
 154          * Setter for the last read file
 155          *
 156          * @param               $fqfn   The FQFN of the last read file
 157          * @return      void
 158          */
 159         private final function setLastFile ($fqfn) {
 160                 // Cast string
 161                 $fqfn = (string) $fqfn;
 162                 $this->lastFile = $fqfn;
 163         }
 164
 165         /**
 166          * Reset the last error and exception instance. This should be done after
 167          * a successfull "query"
 168          *
 169          * @return      void
 170          */
 171         private final function resetLastError () {
 172                 $this->lastError = "";
 173                 $this->lastException = null;
 174         }
 175
 176         /**
 177          * Getter for last read file
 178          *
 179          * @return      $lastFile               The last read file's name with full path
 180          */
 181         public final function getLastFile () {
 182                 return $this->lastFile;
 183         }
 184
 185         /**
 186          * Setter for contents of the last read file
 187          *
 188          * @param               $contents               An array with header and data elements
 189          * @return      void
 190          */
 191         private final function setLastFileContents ($contents) {
 192                 // Cast array
 193                 $contents = (array) $contents;
 194                 $this->lastContents = $contents;
 195         }
 196
 197         /**
 198          * Getter for last read file's content as an array
 199          *
 200          * @return      $lastContent    The array with elements 'header' and 'data'.
 201          */
 202         public final function getLastContents () {
 203                 return $this->lastContents;
 204         }
 205
 206         /**
 207          * Getter for file extension
 208          *
 209          * @return      $fileExtension  The array with elements 'header' and 'data'.
 210          */
 211         public final function getFileExtension () {
 212                 return $this->fileExtension;
 213         }
 214
 215         /**
 216          * Reads a local data file  and returns it's contents in an array
 217          *
 218          * @param       $fqfn   The FQFN for the requested file
 219          * @return      $dataArray
 220          */
 221         private function getDataArrayFromFile ($fqfn) {
 222                 // Get a file pointer
 223                 $fileInstance = FrameworkFileInputPointer::createFrameworkFileInputPointer($fqfn);
 224
 225                 // Get the raw data and BASE64-decode it
 226                 $compressedData = base64_decode($fileInstance->readLinesFromFile());
 227
 228                 // Close the file and throw the instance away
 229                 $fileInstance->closeFile();
 230                 unset($fileInstance);
 231
 232                 // Decompress it
 233                 $serializedData = $this->getCompressorChannel()->getCompressor()->decompressStream($compressedData);
 234
 235                 // Unserialize it
 236                 $dataArray = unserialize($serializedData);
 237
 238                 // Finally return it
 239                 return $dataArray;
 240         }
 241
 242         /**
 243          * Writes data array to local file
 244          *
 245          * @param       $fqfn           The FQFN of the local file
 246          * @param       $dataArray      An array with all the data we shall write
 247          * @return      void
 248          */
 249         private function writeDataArrayToFqfn ($fqfn, array $dataArray) {
 250                 // Get a file pointer instance
 251                 $fileInstance = FrameworkFileOutputPointer::createFrameworkFileOutputPointer($fqfn, 'w');
 252
 253                 // Serialize and compress it
 254                 $compressedData = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($dataArray));
 255
 256                 // Write this data BASE64 encoded to the file
 257                 $fileInstance->writeToFile(base64_encode($compressedData));
 258
 259                 // Close the file pointer
 260                 $fileInstance->closeFile();
 261         }
 262
 263         /**
 264          * Getter for table information file contents or an empty if the info file was not created
 265          *
 266          * @param       $dataSetInstance        An instance of a database set class
 267          * @return      $infoArray                      An array with all table informations
 268          */
 269         private function getContentsFromTableInfoFile (StoreableCriteria $dataSetInstance) {
 270                 // Default content is no data
 271                 $infoArray = array();
 272
 273                 // Create FQFN for getting the table information file
 274                 $fqfn = $this->getSavePath() . $dataSetInstance->getTableName() . '/info.' . $this->getFileExtension();
 275
 276                 // Get the file contents
 277                 try {
 278                         $infoArray = $this->getDataArrayFromFile($fqfn);
 279                 } catch (FileNotFoundException $e) {
 280                         // Not found, so ignore it here
 281                 }
 282
 283                 // ... and return it
 284                 return $infoArray;
 285         }
 286
 287         /**
 288          * Creates the table info file from given dataset instance
 289          *
 290          * @param       $dataSetInstance        An instance of a database set class
 291          * @return      void
 292          */
 293         private function createTableInfoFile (StoreableCriteria $dataSetInstance) {
 294                 // Create FQFN for creating the table information file
 295                 $fqfn = $this->getSavePath() . $dataSetInstance->getTableName() . '/info.' . $this->getFileExtension();
 296
 297                 // Get the data out from dataset in a local array
 298                 $this->tableInfo[$dataSetInstance->getTableName()] = array(
 299                         'primary'      => $dataSetInstance->getPrimaryKey(),
 300                         'created'      => time(),
 301                         'last_updated' => time()
 302                 );
 303
 304                 // Write the data to the file
 305                 $this->writeDataArrayToFqfn($fqfn, $this->tableInfo[$dataSetInstance->getTableName()]);
 306         }
 307
 308         /**
 309          * Updates the primary key information or creates the table info file if not found
 310          *
 311          * @param       $dataSetInstance        An instance of a database set class
 312          * @return      void
 313          */
 314         private function updatePrimaryKey (StoreableCriteria $dataSetInstance) {
 315                 // Get the information array from lower method
 316                 $infoArray = $this->getContentsFromTableInfoFile($dataSetInstance);
 317
 318                 // Is the primary key there?
 319                 if (!isset($this->tableInfo['primary'])) {
 320                         // Then create the info file
 321                         $this->createTableInfoFile($dataSetInstance);
 322                 } elseif (($this->getConfigInstance()->readConfig('db_update_primary_forced') === "Y") && ($dataSetInstance->getPrimaryKey() != $this->tableInfo['primary'])) {
 323                         // Set the array element
 324                         $this->tableInfo[$dataSetInstance->getTableName()]['primary'] = $dataSetInstance->getPrimaryKey();
 325
 326                         // Update the entry
 327                         $this->updateTableInfoFile($dataSetInstance);
 328                 }
 329         }
 330
 331         /**
 332          * Makes sure that the database connection is alive
 333          *
 334          * @return      void
 335          * @todo        Do some checks on the database directory and files here
 336          */
 337         public function connectToDatabase () {
 338         }
 339
 340         /**
 341          * Starts a SELECT query on the database by given return type, table name
 342          * and search criteria
 343          *
 344          * @param       $resultType             Result type ("array", "object" and "indexed" are valid)
 345          * @param       $tableName              Name of the database table
 346          * @param       $criteria               Local search criteria class
 347          * @return      $resultData             Result data of the query
 348          * @throws      UnsupportedCriteriaException    If the criteria is unsupported
 349          * @throws      SqlException                                    If an "SQL error" occurs
 350          */
 351         public function querySelect ($resultType, $tableName, LocalSearchCriteria $criteriaInstance) {
 352                 // The result is null by any errors
 353                 $resultData = null;
 354
 355                 // Create full path name
 356                 $pathName = $this->getSavePath() . $tableName . '/';
 357
 358                 // A "select" query is not that easy on local files, so first try to
 359                 // find the "table" which is in fact a directory on the server
 360                 try {
 361                         // Get a directory pointer instance
 362                         $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
 363
 364                         // Initialize the result data, this need to be rewritten e.g. if a local file cannot be read
 365                         $resultData = array(
 366                                 'status'        => "ok",
 367                                 'rows'          => array()
 368                         );
 369
 370                         // Initialize limit/skip
 371                         $limitFound = 0;
 372                         $skipFound = 0;
 373
 374                         // Read the directory with some exceptions
 375                         while (($dataFile = $directoryInstance->readDirectoryExcept(array(".", "..", ".htaccess", ".svn", "info." . $this->getFileExtension()))) && ($limitFound < $criteriaInstance->getLimit())) {
 376                                 // Does the extension match?
 377                                 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
 378                                         // Skip this file!
 379                                         continue;
 380                                 }
 381
 382                                 // Read the file
 383                                 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 384
 385                                 // Is this an array?
 386                                 if (is_array($dataArray)) {
 387                                         // Search in the criteria with FMFW (First Matches, First Wins)
 388                                         foreach ($dataArray as $key=>$value) {
 389                                                 // Get criteria element
 390                                                 $criteria = $criteriaInstance->getCriteriaElemnent($key);
 391
 392                                                 // Is the criteria met?
 393                                                 if ((!is_null($criteria)) && ($criteria == $value))  {
 394
 395                                                         // Shall we skip this entry?
 396                                                         if ($criteriaInstance->getSkip() > 0) {
 397                                                                 // We shall skip some entries
 398                                                                 if ($skipFound < $criteriaInstance->getSkip()) {
 399                                                                         // Skip this entry
 400                                                                         $skipFound++;
 401                                                                         break;
 402                                                                 } // END - if
 403                                                         } // END - if
 404
 405                                                         // Entry found!
 406                                                         $resultData['rows'][] = $dataArray;
 407                                                         $limitFound++;
 408                                                         break;
 409                                                 } // END - if
 410                                         } // END - foreach
 411                                 } else {
 412                                         // Throw an exception here
 413                                         throw new SqlException(array($this, sprintf("File &#39;%s&#39; contains invalid data.", $dataFile), self::DB_CODE_DATA_FILE_CORRUPT), self::EXCEPTION_SQL_QUERY);
 414                                 }
 415                         } // END - while
 416
 417                         // Close directory and throw the instance away
 418                         $directoryInstance->closeDirectory();
 419                         unset($directoryInstance);
 420
 421                         // Reset last error message and exception
 422                         $this->resetLastError();
 423                 } catch (PathIsNoDirectoryException $e) {
 424                         // Path not found means "table not found" for real databases...
 425                         $this->lastException = $e;
 426                         $this->lastError = $e->getMessage();
 427
 428                         // So throw an SqlException here with faked error message
 429                         throw new SqlException (array($this, sprintf("Table &#39;%s&#39; not found", $tableName), self::DB_CODE_TABLE_MISSING), self::EXCEPTION_SQL_QUERY);
 430                 } catch (FrameworkException $e) {
 431                         // Catch all exceptions and store them in last error
 432                         $this->lastException = $e;
 433                         $this->lastError = $e->getMessage();
 434                 }
 435
 436                 // Return the gathered result
 437                 return $resultData;
 438         }
 439
 440         /**
 441          * "Inserts" a data set instance into a local file database folder
 442          *
 443          * @param       $dataSetInstance        A storeable data set
 444          * @return      void
 445          * @throws      SqlException    If an SQL error occurs
 446          */
 447         public function queryInsertDataSet (StoreableCriteria $dataSetInstance) {
 448                 // Create full path name
 449                 $fqfn = sprintf("%s%s/%s.%s",
 450                         $this->getSavePath(),
 451                         $dataSetInstance->getTableName(),
 452                         md5($dataSetInstance->getUniqueValue()),
 453                         $this->getFileExtension()
 454                 );
 455
 456                 // Try to save the request away
 457                 try {
 458                         // Write the data away
 459                         $this->writeDataArrayToFqfn($fqfn, $dataSetInstance->getCriteriaArray());
 460
 461                         // Update the primary key
 462                         $this->updatePrimaryKey($dataSetInstance);
 463
 464                         // Reset last error message and exception
 465                         $this->resetLastError();
 466                 } catch (FrameworkException $e) {
 467                         // Catch all exceptions and store them in last error
 468                         $this->lastException = $e;
 469                         $this->lastError = $e->getMessage();
 470
 471                         // Throw an SQL exception
 472                         throw new SqlException (array($this, sprintf("Cannot write data to table &#39;%s&#39;", $tableName), self::DB_CODE_TABLE_UNWRITEABLE), self::EXCEPTION_SQL_QUERY);
 473                 }
 474         }
 475
 476         /**
 477          * "Updates" a data set instance with a database layer
 478          *
 479          * @param       $dataSetInstance        A storeable data set
 480          * @return      void
 481          * @throws      SqlException    If an SQL error occurs
 482          */
 483         public function queryUpdateDataSet (StoreableCriteria $dataSetInstance) {
 484                 // Create full path name
 485                 $pathName = $this->getSavePath() . $dataSetInstance->getTableName() . '/';
 486
 487                 // Try all the requests
 488                 try {
 489                         // Get a file pointer instance
 490                         $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
 491
 492                         // Initialize limit/skip
 493                         $limitFound = 0;
 494                         $skipFound = 0;
 495
 496                         // Get the criteria array from the dataset
 497                         $criteriaArray = $dataSetInstance->getCriteriaArray();
 498
 499                         // Get search criteria
 500                         $searchInstance = $dataSetInstance->getSearchInstance();
 501
 502                         // Read the directory with some exceptions
 503                         while (($dataFile = $directoryInstance->readDirectoryExcept(array(".", "..", ".htaccess", ".svn", "info." . $this->getFileExtension()))) && ($limitFound < $searchInstance->getLimit())) {
 504                                 // Does the extension match?
 505                                 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
 506                                         // Skip this file!
 507                                         continue;
 508                                 }
 509
 510                                 // Open this file for reading
 511                                 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 512
 513                                 // Is this an array?
 514                                 if (is_array($dataArray)) {
 515                                         // Search in the criteria with FMFW (First Matches, First Wins)
 516                                         foreach ($dataArray as $key=>$value) {
 517                                                 // Get criteria element
 518                                                 $criteria = $searchInstance->getCriteriaElemnent($key);
 519
 520                                                 // Is the criteria met?
 521                                                 if ((!is_null($criteria)) && ($criteria == $value))  {
 522
 523                                                         // Shall we skip this entry?
 524                                                         if ($searchInstance->getSkip() > 0) {
 525                                                                 // We shall skip some entries
 526                                                                 if ($skipFound < $searchInstance->getSkip()) {
 527                                                                         // Skip this entry
 528                                                                         $skipFound++;
 529                                                                         break;
 530                                                                 } // END - if
 531                                                         } // END - if
 532
 533                                                         // Entry found, so update it
 534                                                         foreach ($criteriaArray as $criteriaKey=>$criteriaValue) {
 535                                                                 $dataArray[$criteriaKey] = $criteriaValue;
 536                                                         } // END - foreach
 537
 538                                                         // Write the data to a local file
 539                                                         $this->writeDataArrayToFqfn($pathName . $dataFile, $dataArray);
 540
 541                                                         // Count it
 542                                                         $limitFound++;
 543                                                         break;
 544                                                 } // END - if
 545                                         } // END - foreach
 546                                 } // END - if
 547                         } // END - while
 548
 549                         // Close the file pointer
 550                         $directoryInstance->closeDirectory();
 551
 552                         // Update the primary key
 553                         $this->updatePrimaryKey($dataSetInstance);
 554
 555                         // Reset last error message and exception
 556                         $this->resetLastError();
 557                 } catch (FrameworkException $e) {
 558                         // Catch all exceptions and store them in last error
 559                         $this->lastException = $e;
 560                         $this->lastError = $e->getMessage();
 561
 562                         // Throw an SQL exception
 563                         throw new SqlException (array($this, sprintf("Cannot write data to table &#39;%s&#39;", $dataSetInstance->getTableName()), self::DB_CODE_TABLE_UNWRITEABLE), self::EXCEPTION_SQL_QUERY);
 564                 }
 565         }
 566
 567         /**
 568          * Getter for primary key of specified table or if not found null will be
 569          * returned. This must be database-specific.
 570          *
 571          * @param       $tableName              Name of the table we need the primary key from
 572          * @return      $primaryKey             Primary key column of the given table
 573          */
 574         public function getPrimaryKeyOfTable ($tableName) {
 575                 // Default key is null
 576                 $primaryKey = null;
 577
 578                 // Does the table information exist?
 579                 if (isset($this->tableInfo[$tableName])) {
 580                         // Then return the primary key
 581                         $primaryKey = $this->tableInfo[$tableName]['primary'];
 582                 } // END - if
 583
 584                 // Return the column
 585                 return $primaryKey;
 586         }
 587 }
 588
 589 // [EOF]
 590 ?>