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 - 2011 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          * Last error message
  57          */
  58         private $lastError = '';
  59
  60         /**
  61          * Last exception
  62          */
  63         private $lastException = NULL;
  64
  65         /**
  66          * Table information array
  67          */
  68         private $tableInfo = array();
  69
  70         /**
  71          * Element for index
  72          */
  73         private $indexKey = '__idx';
  74
  75         /**
  76          * The protected constructor. Do never instance from outside! You need to
  77          * set a local file path. The class will then validate it.
  78          *
  79          * @return      void
  80          */
  81         protected function __construct () {
  82                 // Call parent constructor
  83                 parent::__construct(__CLASS__);
  84         }
  85
  86         /**
  87          * Create an object of LocalFileDatabase and set the save path from
  88          * configuration for local files.
  89          *
  90          * @return      $databaseInstance       An instance of LocalFileDatabase
  91          */
  92         public static final function createLocalFileDatabase () {
  93                 // Get an instance
  94                 $databaseInstance = new LocalFileDatabase();
  95
  96                 // Get a new compressor channel instance
  97                 $compressorInstance = ObjectFactory::createObjectByConfiguredName('compressor_channel_class');
  98
  99                 // Set the compressor channel
 100                 $databaseInstance->setCompressorChannel($compressorInstance);
 101
 102                 // "Connect" to the database
 103                 $databaseInstance->connectToDatabase();
 104
 105                 // Return database instance
 106                 return $databaseInstance;
 107         }
 108
 109         /**
 110          * Getter for last error message
 111          *
 112          * @return      $lastError      Last error message
 113          */
 114         public final function getLastError () {
 115                 return $this->lastError;
 116         }
 117
 118         /**
 119          * Getter for last exception
 120          *
 121          * @return      $lastException  Last thrown exception
 122          */
 123         public final function getLastException () {
 124                 return $this->lastException;
 125         }
 126
 127         /**
 128          * Setter for the last read file
 129          *
 130          * @param       $fqfn   The FQFN of the last read file
 131          * @return      void
 132          */
 133         private final function setLastFile ($fqfn) {
 134                 // Cast string and set it
 135                 $this->lastFile = (string) $fqfn;
 136         }
 137
 138         /**
 139          * Reset the last error and exception instance. This should be done after
 140          * a successfull "query"
 141          *
 142          * @return      void
 143          */
 144         private final function resetLastError () {
 145                 $this->lastError = '';
 146                 $this->lastException = NULL;
 147         }
 148
 149         /**
 150          * Getter for last read file
 151          *
 152          * @return      $lastFile               The last read file's name with full path
 153          */
 154         public final function getLastFile () {
 155                 return $this->lastFile;
 156         }
 157
 158         /**
 159          * Setter for contents of the last read file
 160          *
 161          * @param               $contents               An array with header and data elements
 162          * @return      void
 163          */
 164         private final function setLastFileContents (array $contents) {
 165                 // Set array
 166                 $this->lastContents = $contents;
 167         }
 168
 169         /**
 170          * Getter for last read file's content as an array
 171          *
 172          * @return      $lastContent    The array with elements 'header' and 'data'.
 173          */
 174         public final function getLastContents () {
 175                 return $this->lastContents;
 176         }
 177
 178         /**
 179          * Getter for file extension
 180          *
 181          * @return      $fileExtension  The array with elements 'header' and 'data'.
 182          */
 183         public final function getFileExtension () {
 184                 return $this->fileExtension;
 185         }
 186
 187         /**
 188          * Getter for index key
 189          *
 190          * @return      $indexKey       Index key
 191          */
 192         public final function getIndexKey () {
 193                 return $this->indexKey;
 194         }
 195
 196         /**
 197          * Reads a local data file  and returns it's contents in an array
 198          *
 199          * @param       $fqfn   The FQFN for the requested file
 200          * @return      $dataArray
 201          */
 202         private function getDataArrayFromFile ($fqfn) {
 203                 // Get a file pointer
 204                 $fileInstance = FrameworkFileInputPointer::createFrameworkFileInputPointer($fqfn);
 205
 206                 // Get the raw data and BASE64-decode it
 207                 $compressedData = base64_decode($fileInstance->readLinesFromFile());
 208
 209                 // Close the file and throw the instance away
 210                 $fileInstance->closeFile();
 211                 unset($fileInstance);
 212
 213                 // Decompress it
 214                 $serializedData = $this->getCompressorChannel()->getCompressor()->decompressStream($compressedData);
 215
 216                 // Unserialize it
 217                 $dataArray = unserialize($serializedData);
 218
 219                 // Finally return it
 220                 return $dataArray;
 221         }
 222
 223         /**
 224          * Writes data array to local file
 225          *
 226          * @param       $fqfn           The FQFN of the local file
 227          * @param       $dataArray      An array with all the data we shall write
 228          * @return      void
 229          */
 230         private function writeDataArrayToFqfn ($fqfn, array $dataArray) {
 231                 // Get a file pointer instance
 232                 $fileInstance = FrameworkFileOutputPointer::createFrameworkFileOutputPointer($fqfn, 'w');
 233
 234                 // Serialize and compress it
 235                 $compressedData = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($dataArray));
 236
 237                 // Write this data BASE64 encoded to the file
 238                 $fileInstance->writeToFile(base64_encode($compressedData));
 239
 240                 // Close the file pointer
 241                 $fileInstance->closeFile();
 242         }
 243
 244         /**
 245          * Getter for table information file contents or an empty if info file was not created
 246          *
 247          * @param       $dataSetInstance        An instance of a database set class
 248          * @return      $infoArray                      An array with all table informations
 249          */
 250         private function getContentsFromTableInfoFile (StoreableCriteria $dataSetInstance) {
 251                 // Default content is no data
 252                 $infoArray = array();
 253
 254                 // Create FQFN for getting the table information file
 255                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
 256
 257                 // Get the file contents
 258                 try {
 259                         $infoArray = $this->getDataArrayFromFile($fqfn);
 260                 } catch (FileIoException $e) {
 261                         // Not found, so ignore it here
 262                 }
 263
 264                 // ... and return it
 265                 return $infoArray;
 266         }
 267
 268         /**
 269          * Generates an FQFN from given dataset instance and string
 270          *
 271          * @param       $dataSetInstance        An instance of a database set class
 272          * @param       $rowName                        Name of the row
 273          * @return      $fqfn                           The FQFN for this row
 274          */
 275         private function generateFqfnFromDataSet (Criteria $dataSetInstance, $rowName) {
 276                 // This is the FQFN
 277                 $fqfn = $this->getConfigInstance()->getConfigEntry('local_db_path') . $dataSetInstance->getTableName() . '/' . $rowName . '.' . $this->getFileExtension();
 278
 279                 // Return it
 280                 return $fqfn;
 281         }
 282
 283         /**
 284          * Creates the table info file from given dataset instance
 285          *
 286          * @param       $dataSetInstance        An instance of a database set class
 287          * @return      void
 288          */
 289         private function createTableInfoFile (StoreableCriteria $dataSetInstance) {
 290                 // Create FQFN for creating the table information file
 291                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, 'info');
 292
 293                 // Get the data out from dataset in a local array
 294                 $this->tableInfo[$dataSetInstance->getTableName()] = array(
 295                         'primary'      => $dataSetInstance->getPrimaryKey(),
 296                         'created'      => time(),
 297                         'last_updated' => time()
 298                 );
 299
 300                 // Write the data to the file
 301                 $this->writeDataArrayToFqfn($fqfn, $this->tableInfo[$dataSetInstance->getTableName()]);
 302         }
 303
 304         /**
 305          * Updates the primary key information or creates the table info file if not found
 306          *
 307          * @param       $dataSetInstance        An instance of a database set class
 308          * @return      void
 309          */
 310         private function updatePrimaryKey (StoreableCriteria $dataSetInstance) {
 311                 // Get the information array from lower method
 312                 $infoArray = $this->getContentsFromTableInfoFile($dataSetInstance);
 313
 314                 // Is the primary key there?
 315                 if (!isset($this->tableInfo['primary'])) {
 316                         // Then create the info file
 317                         $this->createTableInfoFile($dataSetInstance);
 318                 } elseif (($this->getConfigInstance()->getConfigEntry('db_update_primary_forced') == 'Y') && ($dataSetInstance->getPrimaryKey() != $this->tableInfo['primary'])) {
 319                         // Set the array element
 320                         $this->tableInfo[$dataSetInstance->getTableName()]['primary'] = $dataSetInstance->getPrimaryKey();
 321
 322                         // Update the entry
 323                         $this->updateTableInfoFile($dataSetInstance);
 324                 }
 325         }
 326
 327         /**
 328          * Makes sure that the database connection is alive
 329          *
 330          * @return      void
 331          * @todo        Do some checks on the database directory and files here
 332          */
 333         public function connectToDatabase () {
 334         }
 335
 336         /**
 337          * Starts a SELECT query on the database by given return type, table name
 338          * and search criteria
 339          *
 340          * @param       $tableName              Name of the database table
 341          * @param       $criteria               Local search criteria class
 342          * @return      $resultData             Result data of the query
 343          * @throws      UnsupportedCriteriaException    If the criteria is unsupported
 344          * @throws      SqlException                                    If an 'SQL error' occurs
 345          */
 346         public function querySelect ($tableName, LocalSearchCriteria $criteriaInstance) {
 347                 // The result is null by any errors
 348                 $resultData = NULL;
 349
 350                 // Create full path name
 351                 $pathName = $this->getConfigInstance()->getConfigEntry('local_db_path') . $tableName . '/';
 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                 try {
 356                         // Get a directory pointer instance
 357                         $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
 358
 359                         // Initialize the result data, this need to be rewritten e.g. if a local file cannot be read
 360                         $resultData = array(
 361                                 BaseDatabaseFrontend::RESULT_INDEX_STATUS => LocalfileDatabase::RESULT_OKAY,
 362                                 BaseDatabaseFrontend::RESULT_INDEX_ROWS   => array()
 363                         );
 364
 365                         // Initialize limit/skip
 366                         $limitFound = 0;
 367                         $skipFound = 0;
 368                         $idx = 1;
 369
 370                         // Read the directory with some exceptions
 371                         while (($dataFile = $directoryInstance->readDirectoryExcept(array('.', '..', '.htaccess', '.svn', 'info.' . $this->getFileExtension()))) && (($limitFound < $criteriaInstance->getLimit()) || ($criteriaInstance->getLimit() == 0))) {
 372                                 // Does the extension match?
 373                                 if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
 374                                         // Skip this file!
 375                                         continue;
 376                                 } // END - if
 377
 378                                 // Read the file
 379                                 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 380
 381                                 // Is this an array?
 382                                 if (is_array($dataArray)) {
 383                                         // Search in the criteria with FMFW (First Matches, First Wins)
 384                                         foreach ($dataArray as $key => $value) {
 385                                                 // Get criteria element
 386                                                 $criteria = $criteriaInstance->getCriteriaElemnent($key);
 387
 388                                                 // Is the criteria met?
 389                                                 //* NOISY-DEBUG: */ $this->debugOutput('DATABASE: criteria[' . gettype($criteria) . ']=' . $criteria . ',()=' . strlen($criteria) . ',value=' . $value . ',()=' . strlen($value));
 390                                                 if ((!is_null($criteria)) && ($criteria == $value))  {
 391                                                         // Shall we skip this entry?
 392                                                         if ($criteriaInstance->getSkip() > 0) {
 393                                                                 // We shall skip some entries
 394                                                                 if ($skipFound < $criteriaInstance->getSkip()) {
 395                                                                         // Skip this entry
 396                                                                         $skipFound++;
 397                                                                         break;
 398                                                                 } // END - if
 399                                                         } // END - if
 400
 401                                                         // Set id number
 402                                                         $dataArray[$this->getIndexKey()] = $idx;
 403
 404                                                         // Entry found!
 405                                                         //* NOISY-DEBUG: */ $this->debugOutput('DATABASE: indexKey=' . $this->getIndexKey() . ',idx=' . $idx . ',dataArray=' . print_r($dataArray, true));
 406                                                         $resultData[BaseDatabaseFrontend::RESULT_INDEX_ROWS][] = $dataArray;
 407
 408                                                         // Count found entries up
 409                                                         $limitFound++;
 410                                                         break;
 411                                                 } // END - if
 412                                         } // END - foreach
 413                                 } else {
 414                                         // Throw an exception here
 415                                         throw new SqlException(array($this, sprintf("File &#39;%s&#39; contains invalid data.", $dataFile), self::DB_CODE_DATA_FILE_CORRUPT), self::EXCEPTION_SQL_QUERY);
 416                                 }
 417
 418                                 // Count entry up
 419                                 $idx++;
 420                         } // END - while
 421
 422                         // Close directory and throw the instance away
 423                         $directoryInstance->closeDirectory();
 424                         unset($directoryInstance);
 425
 426                         // Reset last error message and exception
 427                         $this->resetLastError();
 428                 } catch (PathIsNoDirectoryException $e) {
 429                         // Path not found means "table not found" for real databases...
 430                         $this->lastException = $e;
 431                         $this->lastError     = $e->getMessage();
 432
 433                         // So throw an SqlException here with faked error message
 434                         throw new SqlException (array($this, sprintf("Table &#39;%s&#39; not found", $tableName), self::DB_CODE_TABLE_MISSING), self::EXCEPTION_SQL_QUERY);
 435                 } catch (FrameworkException $e) {
 436                         // Catch all exceptions and store them in last error
 437                         $this->lastException = $e;
 438                         $this->lastError     = $e->getMessage();
 439                 }
 440
 441                 // Return the gathered result
 442                 return $resultData;
 443         }
 444
 445         /**
 446          * "Inserts" a data set instance into a local file database folder
 447          *
 448          * @param       $dataSetInstance        A storeable data set
 449          * @return      void
 450          * @throws      SqlException    If an SQL error occurs
 451          */
 452         public function queryInsertDataSet (StoreableCriteria $dataSetInstance) {
 453                 // Create full path name
 454                 $fqfn = $this->generateFqfnFromDataSet($dataSetInstance, md5($dataSetInstance->getUniqueValue()));
 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;, is the table created?", $dataSetInstance->getTableName()), 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->getConfigInstance()->getConfigEntry('local_db_path') . $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;, is the table created?", $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 ?>