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     = 0x010;
  30         const DB_CODE_TABLE_UNWRITEABLE = 0x011;
  31         const DB_CODE_DATA_FILE_CORRUPT = 0x012;
  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          * The protected constructor. Do never instance from outside! You need to
  70          * set a local file path. The class will then validate it.
  71          *
  72          * @return      void
  73          */
  74         protected function __construct() {
  75                 // Call parent constructor
  76                 parent::__construct(__CLASS__);
  77
  78                 // Set description
  79                 $this->setObjectDescription("Class for local file databases");
  80
  81                 // Create unique ID
  82                 $this->generateUniqueId();
  83
  84                 // Clean up a little
  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          * Analyses if a unique ID has already been used or not by search in the
 155          * local database folder.
 156          *
 157          * @param       $uniqueID               A unique ID number which shall be checked
 158          *                                                      before it will be used
 159          * @param       $inConstructor  If we got called in a de/con-structor or
 160          *                                                      from somewhere else
 161          * @return      $isUnused               true    = The unique ID was not found in the database,
 162          *                                                      false = It is already in use by an other object
 163          * @throws      NoArrayCreatedException         If explode() fails to create an array
 164          * @throws      InvalidArrayCountException      If the array contains less or
 165          *                                                                      more than two elements
 166          */
 167         public function isUniqueIdUsed ($uniqueID, $inConstructor = false) {
 168                 // Currently not used... ;-)
 169                 $isUsed = false;
 170
 171                 // Split the unique ID up in path and file name
 172                 $pathFile = explode("@", $uniqueID);
 173
 174                 // Are there two elements? Index 0 is the path, 1 the file name + global extension
 175                 if (!is_array($pathFile)) {
 176                         // No array found
 177                         if ($inConstructor) {
 178                                 return false;
 179                         } else {
 180                                 throw new NoArrayCreatedException(array($this, "pathFile"), self::EXCEPTION_ARRAY_EXPECTED);
 181                         }
 182                 } elseif (count($pathFile) != 2) {
 183                         // Invalid ID returned!
 184                         if ($inConstructor) {
 185                                 return false;
 186                         } else {
 187                                 throw new InvalidArrayCountException(array($this, "pathFile", count($pathFile), 2), self::EXCEPTION_ARRAY_HAS_INVALID_COUNT);
 188                         }
 189                 }
 190
 191                 // Create full path name
 192                 $pathName = $this->getSavePath() . $pathFile[0];
 193
 194                 // Check if the file is there with a file handler
 195                 if ($inConstructor) {
 196                         // No exceptions in constructors and destructors!
 197                         $dirInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName, true);
 198
 199                         // Has an object being created?
 200                         if (!is_object($dirInstance)) return false;
 201                 } else {
 202                         // Outside a constructor
 203                         try {
 204                                 $dirInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
 205                         } catch (PathIsNoDirectoryException $e) {
 206                                 // Okay, path not found
 207                                 return false;
 208                         }
 209                 }
 210
 211                 // Initialize the search loop
 212                 $isValid = false;
 213                 while ($dataFile = $dirInstance->readDirectoryExcept(array(".", "..", ".htaccess", ".svn"))) {
 214                         // Generate FQFN for testing
 215                         $fqfn = sprintf("%s/%s", $pathName, $dataFile);
 216                         $this->setLastFile($fqfn);
 217
 218                         // Get instance for file handler
 219                         $inputHandler = $this->getFileIoInstance();
 220
 221                         // Try to read from it. This makes it sure that the file is
 222                         // readable and a valid database file
 223                         $this->setLastFileContents($inputHandler->loadFileContents($fqfn));
 224
 225                         // Extract filename (= unique ID) from it
 226                         $ID = substr(basename($fqfn), 0, -(strlen($this->getFileExtension()) + 1));
 227
 228                         // Is this the required unique ID?
 229                         if ($ID == $pathFile[1]) {
 230                                 // Okay, already in use!
 231                                 $isUsed = true;
 232                         }
 233                 }
 234
 235                 // Close the directory handler
 236                 $dirInstance->closeDirectory();
 237
 238                 // Now the same for the file...
 239                 return $isUsed;
 240         }
 241
 242         /**
 243          * Setter for the last read file
 244          *
 245          * @param               $fqfn   The FQFN of the last read file
 246          * @return      void
 247          */
 248         private final function setLastFile ($fqfn) {
 249                 // Cast string
 250                 $fqfn = (string) $fqfn;
 251                 $this->lastFile = $fqfn;
 252         }
 253
 254         /**
 255          * Reset the last error and exception instance. This should be done after
 256          * a successfull "query"
 257          *
 258          * @return      void
 259          */
 260         private final function resetLastError () {
 261                 $this->lastError = "";
 262                 $this->lastException = null;
 263         }
 264
 265         /**
 266          * Getter for last read file
 267          *
 268          * @return      $lastFile               The last read file's name with full path
 269          */
 270         public final function getLastFile () {
 271                 return $this->lastFile;
 272         }
 273
 274         /**
 275          * Setter for contents of the last read file
 276          *
 277          * @param               $contents               An array with header and data elements
 278          * @return      void
 279          */
 280         private final function setLastFileContents ($contents) {
 281                 // Cast array
 282                 $contents = (array) $contents;
 283                 $this->lastContents = $contents;
 284         }
 285
 286         /**
 287          * Getter for last read file's content as an array
 288          *
 289          * @return      $lastContent    The array with elements 'header' and 'data'.
 290          */
 291         public final function getLastContents () {
 292                 return $this->lastContents;
 293         }
 294
 295         /**
 296          * Getter for file extension
 297          *
 298          * @return      $fileExtension  The array with elements 'header' and 'data'.
 299          */
 300         public final function getFileExtension () {
 301                 return $this->fileExtension;
 302         }
 303
 304         /**
 305          * Reads a local data file  and returns it's contents in an array
 306          *
 307          * @param       $fqfn   The FQFN for the requested file
 308          * @return      $dataArray
 309          */
 310         private function getDataArrayFromFile ($fqfn) {
 311                 // Get a file pointer
 312                 $fileInstance = FrameworkFileInputPointer::createFrameworkFileInputPointer($fqfn);
 313
 314                 // Get the raw data and BASE64-decode it
 315                 $compressedData = base64_decode($fileInstance->readLinesFromFile());
 316
 317                 // Close the file and throw the instance away
 318                 $fileInstance->closeFile();
 319                 unset($fileInstance);
 320
 321                 // Decompress it
 322                 $serializedData = $this->getCompressorChannel()->getCompressor()->decompressStream($compressedData);
 323
 324                 // Unserialize it
 325                 $dataArray = unserialize($serializedData);
 326
 327                 // Finally return it
 328                 return $dataArray;
 329         }
 330
 331         /**
 332          * Writes data array to local file
 333          *
 334          * @param       $fqfn           The FQFN of the local file
 335          * @param       $dataArray      An array with all the data we shall write
 336          * @return      void
 337          */
 338         private function writeDataArrayToFqfn ($fqfn, array $dataArray) {
 339                 // Get a file pointer instance
 340                 $fileInstance = FrameworkFileOutputPointer::createFrameworkFileOutputPointer($fqfn, 'w');
 341
 342                 // Serialize and compress it
 343                 $compressedData = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($dataArray));
 344
 345                 // Write this data BASE64 encoded to the file
 346                 $fileInstance->writeToFile(base64_encode($compressedData));
 347
 348                 // Close the file pointer
 349                 $fileInstance->closeFile();
 350         }
 351
 352         /**
 353          * Makes sure that the database connection is alive
 354          *
 355          * @return      void
 356          */
 357         public function connectToDatabase () {
 358                 /* @todo Do some checks on the database directory and files here */
 359         }
 360
 361         /**
 362          * Starts a SELECT query on the database by given return type, table name
 363          * and search criteria
 364          *
 365          * @param       $resultType             Result type ("array", "object" and "indexed" are valid)
 366          * @param       $tableName              Name of the database table
 367          * @param       $criteria               Local search criteria class
 368          * @return      $resultData             Result data of the query
 369          * @throws      UnsupportedCriteriaException    If the criteria is unsupported
 370          * @throws      SqlException                                    If an "SQL error" occurs
 371          */
 372         public function querySelect ($resultType, $tableName, LocalSearchCriteria $criteriaInstance) {
 373                 // The result is null by any errors
 374                 $resultData = null;
 375
 376                 // Create full path name
 377                 $pathName = $this->getSavePath() . $tableName . '/';
 378
 379                 // A "select" query is not that easy on local files, so first try to
 380                 // find the "table" which is in fact a directory on the server
 381                 try {
 382                         // Get a directory pointer instance
 383                         $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
 384
 385                         // Initialize the result data, this need to be rewritten e.g. if a local file cannot be read
 386                         $resultData = array(
 387                                 'status'        => "ok",
 388                                 'rows'          => array()
 389                         );
 390
 391                         // Initialize limit/skip
 392                         $limitFound = 0; $skipFound = 0;
 393
 394                         // Read the directory with some exceptions
 395                         while (($dataFile = $directoryInstance->readDirectoryExcept(array(".", "..", ".htaccess", ".svn"))) && ($limitFound < $criteriaInstance->getLimit())) {
 396                                 // Read the file
 397                                 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 398
 399                                 // Is this an array?
 400                                 if (is_array($dataArray)) {
 401                                         // Search in the criteria with FMFW (First Matches, First Wins)
 402                                         foreach ($dataArray as $key=>$value) {
 403                                                 // Get criteria element
 404                                                 $criteria = $criteriaInstance->getCriteriaElemnent($key);
 405
 406                                                 // Is the criteria met?
 407                                                 if ((!is_null($criteria)) && ($criteria == $value))  {
 408
 409                                                         // Shall we skip this entry?
 410                                                         if ($criteriaInstance->getSkip() > 0) {
 411                                                                 // We shall skip some entries
 412                                                                 if ($skipFound < $criteriaInstance->getSkip()) {
 413                                                                         // Skip this entry
 414                                                                         $skipFound++;
 415                                                                         break;
 416                                                                 } // END - if
 417                                                         } // END - if
 418
 419                                                         // Entry found!
 420                                                         $resultData['rows'][] = $dataArray;
 421                                                         $limitFound++;
 422                                                         break;
 423                                                 } // END - if
 424                                         } // END - foreach
 425                                 } else {
 426                                         // Throw an exception here
 427                                         throw new SqlException(sprintf("File &#39;%s&#39; contains invalid data.", $dataFile), self::DB_CODE_DATA_FILE_CORRUPT);
 428                                 }
 429                         } // END - while
 430
 431                         // Close directory and throw the instance away
 432                         $directoryInstance->closeDirectory();
 433                         unset($directoryInstance);
 434
 435                         // Reset last error message and exception
 436                         $this->resetLastError();
 437                 } catch (PathIsNoDirectoryException $e) {
 438                         // Path not found means "table not found" for real databases...
 439                         $this->lastException = $e;
 440                         $this->lastError = $e->getMessage();
 441
 442                         // So throw an SqlException here with faked error message
 443                         throw new SqlException (array($this, sprintf("Table &#39;%s&#39; not found", $tableName), self::DB_CODE_TABLE_MISSING), self::EXCEPTION_SQL_QUERY);
 444                 } catch (FrameworkException $e) {
 445                         // Catch all exceptions and store them in last error
 446                         $this->lastException = $e;
 447                         $this->lastError = $e->getMessage();
 448                 }
 449
 450                 // Return the gathered result
 451                 return $resultData;
 452         }
 453
 454         /**
 455          * "Inserts" a data set instance into a local file database folder
 456          *
 457          * @param       $dataSetInstance        A storeable data set
 458          * @return      void
 459          * @throws      SqlException    If an SQL error occurs
 460          */
 461         public function queryInsertDataSet (StoreableCriteria $dataSetInstance) {
 462                 // Create full path name
 463                 $fqfn = sprintf("%s%s/%s.%s",
 464                         $this->getSavePath(),
 465                         $dataSetInstance->getTableName(),
 466                         md5($dataSetInstance->getUniqueValue()),
 467                         $this->getFileExtension()
 468                 );
 469
 470                 // Try to save the request away
 471                 try {
 472                         // Write the data away
 473                         $this->writeDataArrayToFqfn($fqfn, $dataSetInstance->getCriteriaArray());
 474
 475                         // Reset last error message and exception
 476                         $this->resetLastError();
 477                 } catch (FrameworkException $e) {
 478                         // Catch all exceptions and store them in last error
 479                         $this->lastException = $e;
 480                         $this->lastError = $e->getMessage();
 481
 482                         // Throw an SQL exception
 483                         throw new SqlException (array($this, sprintf("Cannot write data to table &#39;%s&#39;", $tableName), self::DB_CODE_TABLE_UNWRITEABLE), self::EXCEPTION_SQL_QUERY);
 484                 }
 485         }
 486
 487         /**
 488          * "Updates" a data set instance with a database layer
 489          *
 490          * @param       $dataSetInstance        A storeable data set
 491          * @return      void
 492          * @throws      SqlException    If an SQL error occurs
 493          */
 494         public function queryUpdateDataSet (StoreableCriteria $dataSetInstance) {
 495                 // Create full path name
 496                 $pathName = $this->getSavePath() . $dataSetInstance->getTableName() . '/';
 497
 498                 // Try all the requests
 499                 try {
 500                         // Get a file pointer instance
 501                         $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
 502
 503                         // Initialize limit/skip
 504                         $limitFound = 0; $skipFound = 0;
 505
 506                         // Get the criteria array from the dataset
 507                         $criteriaArray = $dataSetInstance->getCriteriaArray();
 508
 509                         // Get search criteria
 510                         $searchInstance = $dataSetInstance->getSearchInstance();
 511
 512                         // Read the directory with some exceptions
 513                         while (($dataFile = $directoryInstance->readDirectoryExcept(array(".", "..", ".htaccess", ".svn"))) && ($limitFound < $searchInstance->getLimit())) {
 514                                 // Open this file for reading
 515                                 $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 516
 517                                 // Is this an array?
 518                                 if (is_array($dataArray)) {
 519                                         // Search in the criteria with FMFW (First Matches, First Wins)
 520                                         foreach ($dataArray as $key=>$value) {
 521                                                 // Get criteria element
 522                                                 $criteria = $searchInstance->getCriteriaElemnent($key);
 523
 524                                                 // Is the criteria met?
 525                                                 if ((!is_null($criteria)) && ($criteria == $value))  {
 526
 527                                                         // Shall we skip this entry?
 528                                                         if ($searchInstance->getSkip() > 0) {
 529                                                                 // We shall skip some entries
 530                                                                 if ($skipFound < $searchInstance->getSkip()) {
 531                                                                         // Skip this entry
 532                                                                         $skipFound++;
 533                                                                         break;
 534                                                                 } // END - if
 535                                                         } // END - if
 536
 537                                                         // Entry found, so update it
 538                                                         foreach ($criteriaArray as $criteriaKey=>$criteriaValue) {
 539                                                                 $dataArray[$criteriaKey] = $criteriaValue;
 540                                                         } // END - foreach
 541
 542                                                         // Write the data to a local file
 543                                                         $this->writeDataArrayToFqfn($pathName . $dataFile, $dataArray);
 544
 545                                                         // Count it
 546                                                         $limitFound++;
 547                                                         break;
 548                                                 } // END - if
 549                                         } // END - foreach
 550                                 } // END - if
 551                         } // END - while
 552
 553                         // Close the file pointer
 554                         $directoryInstance->closeDirectory();
 555
 556                         // Reset last error message and exception
 557                         $this->resetLastError();
 558                 } catch (FrameworkException $e) {
 559                         // Catch all exceptions and store them in last error
 560                         $this->lastException = $e;
 561                         $this->lastError = $e->getMessage();
 562
 563                         // Throw an SQL exception
 564                         throw new SqlException (array($this, sprintf("Cannot write data to table &#39;%s&#39;", $tableName), self::DB_CODE_TABLE_UNWRITEABLE), self::EXCEPTION_SQL_QUERY);
 565                 }
 566         }
 567 }
 568
 569 // [EOF]
 570 ?>