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