]> git.mxchange.org Git - shipsimu.git/blobdiff - inc/classes/main/database/databases/class_LocalFileDatabase.php
Setting index is now much nicer (more abstract!)
[shipsimu.git] / inc / classes / main / database / databases / class_LocalFileDatabase.php
index f599673a400e259ce5865038ff492b8336f12a32..29e2e5e0f397f3dab498d8dc80ce70565a1598ce 100644 (file)
@@ -6,7 +6,7 @@
  *
  * @author             Roland Haeder <webmaster@ship-simu.org>
  * @version            0.0.0
- * @copyright  Copyright(c) 2007, 2008 Roland Haeder, this is free software
+ * @copyright  Copyright (c) 2007, 2008 Roland Haeder, this is free software
  * @license            GNU GPL 3.0 or any newer version
  * @link               http://www.ship-simu.org
  *
@@ -26,8 +26,9 @@
 class LocalFileDatabase extends BaseDatabaseFrontend implements DatabaseFrontendInterface {
 
        // Constants for MySQL backward-compatiblity (PLEASE FIX THEM!)
-       const DB_CODE_TABLE_MISSING     = 0x000;
-       const DB_CODE_TABLE_UNWRITEABLE = 0x001;
+       const DB_CODE_TABLE_MISSING     = 0x100;
+       const DB_CODE_TABLE_UNWRITEABLE = 0x101;
+       const DB_CODE_DATA_FILE_CORRUPT = 0x102;
 
        /**
         * Save path for "file database"
@@ -64,6 +65,16 @@ class LocalFileDatabase extends BaseDatabaseFrontend implements DatabaseFrontend
         */
        private $lastException = null;
 
+       /**
+        * Table information array
+        */
+       private $tableInfo = array();
+
+       /**
+        * Element for index
+        */
+       private $indexKey = "__idx";
+
        /**
         * The protected constructor. Do never instance from outside! You need to
         * set a local file path. The class will then validate it.
@@ -74,13 +85,8 @@ class LocalFileDatabase extends BaseDatabaseFrontend implements DatabaseFrontend
                // Call parent constructor
                parent::__construct(__CLASS__);
 
-               // Set description
-               $this->setObjectDescription("Class for local file databases");
-
-               // Create unique ID
-               $this->generateUniqueId();
-
                // Clean up a little
+               $this->removeNumberFormaters();
                $this->removeSystemArray();
        }
 
@@ -149,157 +155,15 @@ class LocalFileDatabase extends BaseDatabaseFrontend implements DatabaseFrontend
                return $this->lastException;
        }
 
-       /**
-        * Saves a given object to the local file system by serializing and
-        * transparently compressing it
-        *
-        * @param       $object                                 The object we shall save to the local file system
-        * @return      void
-        */
-       public final function saveObject (FrameworkInterface $object) {
-               // Get a string containing the serialized object. We cannot exchange
-               // $this and $object here because $object does not need to worry
-               // about it's limitations... ;-)
-               $serialized = $this->serializeObject($object);
-
-               // Get a path name plus file name and append the extension
-               $fqfn = $this->getSavePath() . $object->getPathFileNameFromObject() . "." . $this->getFileExtension();
-
-               // Save the file to disc we don't care here if the path is there,
-               // this must be done in later methods.
-               $this->getFileIoInstance()->saveFile($fqfn, array($this->getCompressorChannel()->getCompressorExtension(), $serialized));
-       }
-
-       /**
-        * Get a serialized string from the given object
-        *
-        * @param       $object                 The object we want to serialize and transparently
-        *                                                      compress
-        * @return      $serialized             A string containing the serialzed/compressed object
-        * @see         ObjectLimits    An object holding limition information
-        * @see         SerializationContainer  A special container class for e.g.
-        *                                                                      attributes from limited objects
-        */
-       private function serializeObject (FrameworkInterface $object) {
-               // If there is no limiter instance we serialize the whole object
-               // otherwise only in the limiter object (ObjectLimits) specified
-               // attributes summarized in a special container class
-               if ($this->getLimitInstance() === null) {
-                       // Serialize the whole object. This tribble call is the reason
-                       // why we need a fall-back implementation in CompressorChannel
-                       // of the methods compressStream() and decompressStream().
-                       $serialized = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($object));
-               } else {
-                       // Serialize only given attributes in a special container
-                       $container = SerializationContainer::createSerializationContainer($this->getLimitInstance(), $object);
-
-                       // Serialize the container
-                       $serialized = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($container));
-               }
-
-               // Return the serialized object string
-               return $serialized;
-       }
-
-       /**
-        * Analyses if a unique ID has already been used or not by search in the
-        * local database folder.
-        *
-        * @param       $uniqueID               A unique ID number which shall be checked
-        *                                                      before it will be used
-        * @param       $inConstructor  If we got called in a de/con-structor or
-        *                                                      from somewhere else
-        * @return      $isUnused               true    = The unique ID was not found in the database,
-        *                                                      false = It is already in use by an other object
-        * @throws      NoArrayCreatedException         If explode() fails to create an array
-        * @throws      InvalidArrayCountException      If the array contains less or
-        *                                                                      more than two elements
-        */
-       public function isUniqueIdUsed ($uniqueID, $inConstructor = false) {
-               // Currently not used... ;-)
-               $isUsed = false;
-
-               // Split the unique ID up in path and file name
-               $pathFile = explode("@", $uniqueID);
-
-               // Are there two elements? Index 0 is the path, 1 the file name + global extension
-               if (!is_array($pathFile)) {
-                       // No array found
-                       if ($inConstructor) {
-                               return false;
-                       } else {
-                               throw new NoArrayCreatedException(array($this, "pathFile"), self::EXCEPTION_ARRAY_EXPECTED);
-                       }
-               } elseif (count($pathFile) != 2) {
-                       // Invalid ID returned!
-                       if ($inConstructor) {
-                               return false;
-                       } else {
-                               throw new InvalidArrayCountException(array($this, "pathFile", count($pathFile), 2), self::EXCEPTION_ARRAY_HAS_INVALID_COUNT);
-                       }
-               }
-
-               // Create full path name
-               $pathName = $this->getSavePath() . $pathFile[0];
-
-               // Check if the file is there with a file handler
-               if ($inConstructor) {
-                       // No exceptions in constructors and destructors!
-                       $dirInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName, true);
-
-                       // Has an object being created?
-                       if (!is_object($dirInstance)) return false;
-               } else {
-                       // Outside a constructor
-                       try {
-                               $dirInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
-                       } catch (PathIsNoDirectoryException $e) {
-                               // Okay, path not found
-                               return false;
-                       }
-               }
-
-               // Initialize the search loop
-               $isValid = false;
-               while ($dataFile = $dirInstance->readDirectoryExcept(array(".", "..", ".htaccess", ".svn"))) {
-                       // Generate FQFN for testing
-                       $fqfn = sprintf("%s/%s", $pathName, $dataFile);
-                       $this->setLastFile($fqfn);
-
-                       // Get instance for file handler
-                       $inputHandler = $this->getFileIoInstance();
-
-                       // Try to read from it. This makes it sure that the file is
-                       // readable and a valid database file
-                       $this->setLastFileContents($inputHandler->loadFileContents($fqfn));
-
-                       // Extract filename (= unique ID) from it
-                       $ID = substr(basename($fqfn), 0, -(strlen($this->getFileExtension()) + 1));
-
-                       // Is this the required unique ID?
-                       if ($ID == $pathFile[1]) {
-                               // Okay, already in use!
-                               $isUsed = true;
-                       }
-               }
-
-               // Close the directory handler
-               $dirInstance->closeDirectory();
-
-               // Now the same for the file...
-               return $isUsed;
-       }
-
        /**
         * Setter for the last read file
         *
-        * @param               $fqfn   The FQFN of the last read file
+        * @param       $fqfn   The FQFN of the last read file
         * @return      void
         */
        private final function setLastFile ($fqfn) {
-               // Cast string
-               $fqfn = (string) $fqfn;
-               $this->lastFile = $fqfn;
+               // Cast string and set it
+               $this->lastFile = (string) $fqfn;
        }
 
        /**
@@ -328,9 +192,8 @@ class LocalFileDatabase extends BaseDatabaseFrontend implements DatabaseFrontend
         * @param               $contents               An array with header and data elements
         * @return      void
         */
-       private final function setLastFileContents ($contents) {
-               // Cast array
-               $contents = (array) $contents;
+       private final function setLastFileContents (array $contents) {
+               // Set array
                $this->lastContents = $contents;
        }
 
@@ -353,175 +216,137 @@ class LocalFileDatabase extends BaseDatabaseFrontend implements DatabaseFrontend
        }
 
        /**
-        * Get cached (last fetched) data from the local file database
+        * Getter for index key
         *
-        * @param       $uniqueID       The ID number for looking up the data
-        * @return      $object         The restored object from the maybe compressed
-        *                                              serialized data
-        * @throws      MismatchingCompressorsException         If the compressor from
-        *                                                                      the loaded file
-        *                                                                      mismatches with the
-        *                                                                      current used one.
-        * @throws      NullPointerException    If the restored object
-        *                                                                      is null
-        * @throws      NoObjectException               If the restored "object"
-        *                                                                      is not an object instance
-        * @throws      MissingMethodException  If the required method
-        *                                                                      toString() is missing
-        */
-       public final function getObjectFromCachedData ($uniqueID) {
-               // Get instance for file handler
-               $inputHandler = $this->getFileIoInstance();
-
-               // Get last file's name and contents
-               $fqfn = $this->repairFQFN($this->getLastFile(), $uniqueID);
-               $contents = $this->repairContents($this->getLastContents(), $fqfn);
-
-               // Let's decompress it. First we need the instance
-               $compressInstance = $this->getCompressorChannel();
-
-               // Is the compressor's extension the same as the one from the data?
-               if ($compressInstance->getCompressorExtension() != $contents['header'][0]) {
-                       /**
-                        * @todo        For now we abort here but later we need to make this a little more dynamic.
-                        */
-                       throw new MismatchingCompressorsException(array($this, $contents['header'][0], $fqfn, $compressInstance->getCompressorExtension()), self::EXCEPTION_MISMATCHING_COMPRESSORS);
-               }
+        * @return      $indexKey       Index key
+        */
+       public final function getIndexKey () {
+               return $this->indexKey;
+       }
 
-               // Decompress the data now
-               $serialized = $compressInstance->getCompressor()->decompressStream($contents['data']);
-
-               // And unserialize it...
-               $object = unserialize($serialized);
-
-               // This must become a valid object, so let's check it...
-               if (is_null($object)) {
-                       // Is null, throw exception
-                       throw new NullPointerException($object, self::EXCEPTION_IS_NULL_POINTER);
-               } elseif (!is_object($object)) {
-                       // Is not an object, throw exception
-                       throw new NoObjectException($object, self::EXCEPTION_IS_NO_OBJECT);
-               } elseif (!$object instanceof FrameworkInterface) {
-                       // A highly required method was not found... :-(
-                       throw new MissingMethodException(array($object, '__toString'), self::EXCEPTION_MISSING_METHOD);
-               }
+       /**
+        * Reads a local data file  and returns it's contents in an array
+        *
+        * @param       $fqfn   The FQFN for the requested file
+        * @return      $dataArray
+        */
+       private function getDataArrayFromFile ($fqfn) {
+               // Get a file pointer
+               $fileInstance = FrameworkFileInputPointer::createFrameworkFileInputPointer($fqfn);
 
-               // And return the object
-               return $object;
+               // Get the raw data and BASE64-decode it
+               $compressedData = base64_decode($fileInstance->readLinesFromFile());
+
+               // Close the file and throw the instance away
+               $fileInstance->closeFile();
+               unset($fileInstance);
+
+               // Decompress it
+               $serializedData = $this->getCompressorChannel()->getCompressor()->decompressStream($compressedData);
+
+               // Unserialize it
+               $dataArray = unserialize($serializedData);
+
+               // Finally return it
+               return $dataArray;
        }
 
        /**
-        * Private method for re-gathering (repairing) the FQFN
+        * Writes data array to local file
         *
-        * @param               $fqfn           The current FQFN we shall validate
-        * @param               $uniqueID               The unique ID number
-        * @return      $fqfn           The repaired FQFN when it is empty
-        * @throws      NoArrayCreatedException         If explode() has not
-        *                                                                      created an array
-        * @throws      InvalidArrayCountException      If the array count is not
-        *                                                                      as the expected
-        */
-       private function repairFQFN ($fqfn, $uniqueID) {
-               // Cast both strings
-               $fqfn     = (string) $fqfn;
-               $uniqueID = (string) $uniqueID;
-
-               // Is there pre-cached data available?
-               if (empty($fqfn)) {
-                       // Split the unique ID up in path and file name
-                       $pathFile = explode("@", $uniqueID);
-
-                       // Are there two elements? Index 0 is the path, 1 the file name + global extension
-                       if (!is_array($pathFile)) {
-                               // No array found
-                               throw new NoArrayCreatedException(array($this, "pathFile"), self::EXCEPTION_ARRAY_EXPECTED);
-                       } elseif (count($pathFile) != 2) {
-                               // Invalid ID returned!
-                               throw new InvalidArrayCountException(array($this, "pathFile", count($pathFile), 2), self::EXCEPTION_ARRAY_HAS_INVALID_COUNT);
-                       }
-
-                       // Create full path name
-                       $pathName = $this->getSavePath() . $pathFile[0];
-
-                       // Nothing cached, so let's create a FQFN first
-                       $fqfn = sprintf("%s/%s.%s", $pathName, $pathFile[1], $this->getFileExtension());
-                       $this->setLastFile($fqfn);
-               }
+        * @param       $fqfn           The FQFN of the local file
+        * @param       $dataArray      An array with all the data we shall write
+        * @return      void
+        */
+       private function writeDataArrayToFqfn ($fqfn, array $dataArray) {
+               // Get a file pointer instance
+               $fileInstance = FrameworkFileOutputPointer::createFrameworkFileOutputPointer($fqfn, 'w');
+
+               // Serialize and compress it
+               $compressedData = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($dataArray));
+
+               // Write this data BASE64 encoded to the file
+               $fileInstance->writeToFile(base64_encode($compressedData));
 
-               // Return repaired FQFN
-               return $fqfn;
+               // Close the file pointer
+               $fileInstance->closeFile();
        }
 
        /**
-        * Private method for re-gathering the contents of a given file
+        * Getter for table information file contents or an empty if the info file was not created
         *
-        * @param               $contents               The (maybe) already cached contents as an array
-        * @param               $fqfn           The current FQFN we shall validate
-        * @return      $contents               The repaired contents from the given file
-        */
-       private function repairContents ($contents, $fqfn) {
-               // Is there some content and header (2 indexes) in?
-               if ((!is_array($contents)) || (count($contents) != 2) || (!isset($contents['header'])) || (!isset($contents['data']))) {
-                       // No content found so load the file again
-                       $contents = $inputHandler->loadFileContents($fqfn);
-
-                       // And remember all data for later usage
-                       $this->setLastContents($contents);
+        * @param       $dataSetInstance        An instance of a database set class
+        * @return      $infoArray                      An array with all table informations
+        */
+       private function getContentsFromTableInfoFile (StoreableCriteria $dataSetInstance) {
+               // Default content is no data
+               $infoArray = array();
+
+               // Create FQFN for getting the table information file
+               $fqfn = $this->getSavePath() . $dataSetInstance->getTableName() . '/info.' . $this->getFileExtension();
+
+               // Get the file contents
+               try {
+                       $infoArray = $this->getDataArrayFromFile($fqfn);
+               } catch (FileNotFoundException $e) {
+                       // Not found, so ignore it here
                }
 
-               // Return the repaired contents
-               return $contents;
+               // ... and return it
+               return $infoArray;
        }
 
        /**
-        * Makes sure that the database connection is alive
+        * Creates the table info file from given dataset instance
         *
+        * @param       $dataSetInstance        An instance of a database set class
         * @return      void
         */
-       public function connectToDatabase () {
-               // @TODO Do some checks on the database directory and files here
+       private function createTableInfoFile (StoreableCriteria $dataSetInstance) {
+               // Create FQFN for creating the table information file
+               $fqfn = $this->getSavePath() . $dataSetInstance->getTableName() . '/info.' . $this->getFileExtension();
+
+               // Get the data out from dataset in a local array
+               $this->tableInfo[$dataSetInstance->getTableName()] = array(
+                       'primary'      => $dataSetInstance->getPrimaryKey(),
+                       'created'      => time(),
+                       'last_updated' => time()
+               );
+
+               // Write the data to the file
+               $this->writeDataArrayToFqfn($fqfn, $this->tableInfo[$dataSetInstance->getTableName()]);
        }
 
        /**
-        * Loads data saved with saveObject from the database and re-creates a
-        * full object from it.
-        * If limitObject() was called before a new object ObjectContainer with
-        * all requested attributes will be returned instead.
+        * Updates the primary key information or creates the table info file if not found
         *
-        * @return      Object  The fully re-created object or instance to
-        *                                      ObjectContainer
-        * @throws      SavePathIsEmptyException                If the given save path is an
-        *                                                                                      empty string
-        * @throws      SavePathIsNoDirectoryException  If the save path is no
-        *                                                                                      path (e.g. a file)
-        * @throws      SavePathReadProtectedException  If the save path is read-
-        *                                                                                      protected
-        * @throws      SavePathWriteProtectedException If the save path is write-
-        *                                                                                      protected
-        */
-       public function loadObject () {
-               // Already connected? Then abort here
-               if ($this->alreadyConnected === true) return true;
-
-               // Get the save path
-               $savePath = $this->getSavePath();
-
-               if (empty($savePath)) {
-                       // Empty string
-                       throw new SavePathIsEmptyException($dbInstance, self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
-               } elseif (!is_dir($savePath)) {
-                       // Is not a dir
-                       throw new SavePathIsNoDirectoryException($savePath, self::EXCEPTION_INVALID_PATH_NAME);
-               } elseif (!is_readable($savePath)) {
-                       // Path not readable
-                       throw new SavePathReadProtectedException($savePath, self::EXCEPTION_READ_PROTECED_PATH);
-               } elseif (!is_writeable($savePath)) {
-                       // Path not writeable
-                       throw new SavePathWriteProtectedException($savePath, self::EXCEPTION_WRITE_PROTECED_PATH);
+        * @param       $dataSetInstance        An instance of a database set class
+        * @return      void
+        */
+       private function updatePrimaryKey (StoreableCriteria $dataSetInstance) {
+               // Get the information array from lower method
+               $infoArray = $this->getContentsFromTableInfoFile($dataSetInstance);
+
+               // Is the primary key there?
+               if (!isset($this->tableInfo['primary'])) {
+                       // Then create the info file
+                       $this->createTableInfoFile($dataSetInstance);
+               } elseif (($this->getConfigInstance()->readConfig('db_update_primary_forced') === "Y") && ($dataSetInstance->getPrimaryKey() != $this->tableInfo['primary'])) {
+                       // Set the array element
+                       $this->tableInfo[$dataSetInstance->getTableName()]['primary'] = $dataSetInstance->getPrimaryKey();
+
+                       // Update the entry
+                       $this->updateTableInfoFile($dataSetInstance);
                }
+       }
 
-               // "Connection" established... ;-)
-               $this->alreadyConnected = true;
+       /**
+        * Makes sure that the database connection is alive
+        *
+        * @return      void
+        * @todo        Do some checks on the database directory and files here
+        */
+       public function connectToDatabase () {
        }
 
        /**
@@ -555,30 +380,25 @@ class LocalFileDatabase extends BaseDatabaseFrontend implements DatabaseFrontend
                        );
 
                        // Initialize limit/skip
-                       $limitFound = 0; $skipFound = 0;
+                       $limitFound = 0;
+                       $skipFound = 0;
+                       $idx = 1;
 
                        // Read the directory with some exceptions
-                       while (($dataFile = $directoryInstance->readDirectoryExcept(array(".", "..", ".htaccess", ".svn"))) && ($limitFound < $criteriaInstance->getLimit())) {
-                               // Open this file for reading
-                               $filePointer = FrameworkFileInputPointer::createFrameworkFileInputPointer($pathName . $dataFile);
-
-                               // Get the raw data and BASE64-decode it
-                               $compressedData = base64_decode($filePointer->readLinesFromFile());
-
-                               // Close the file and throw the instance away
-                               $filePointer->closeFile();
-                               unset($filePointer);
-
-                               // Decompress it
-                               $serializedData = $this->getCompressorChannel()->getCompressor()->decompressStream($compressedData);
+                       while (($dataFile = $directoryInstance->readDirectoryExcept(array(".", "..", ".htaccess", ".svn", "info." . $this->getFileExtension()))) && ($limitFound < $criteriaInstance->getLimit())) {
+                               // Does the extension match?
+                               if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
+                                       // Skip this file!
+                                       continue;
+                               } // END - if
 
-                               // Unserialize it
-                               $dataArray = unserialize($serializedData);
+                               // Read the file
+                               $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
 
                                // Is this an array?
                                if (is_array($dataArray)) {
                                        // Search in the criteria with FMFW (First Matches, First Wins)
-                                       foreach ($dataArray as $key=>$value) {
+                                       foreach ($dataArray as $key => $value) {
                                                // Get criteria element
                                                $criteria = $criteriaInstance->getCriteriaElemnent($key);
 
@@ -595,13 +415,24 @@ class LocalFileDatabase extends BaseDatabaseFrontend implements DatabaseFrontend
                                                                } // END - if
                                                        } // END - if
 
+                                                       // Set id number
+                                                       $dataArray[$this->getIndexKey()] = $idx;
+
                                                        // Entry found!
-                                                       $resultData['rows'][]    = $dataArray;
+                                                       $resultData['rows'][] = $dataArray;
+
+                                                       // Count found entries up
                                                        $limitFound++;
                                                        break;
                                                } // END - if
                                        } // END - foreach
-                               } // END - if
+                               } else {
+                                       // Throw an exception here
+                                       throw new SqlException(array($this, sprintf("File &#39;%s&#39; contains invalid data.", $dataFile), self::DB_CODE_DATA_FILE_CORRUPT), self::EXCEPTION_SQL_QUERY);
+                               }
+
+                               // Count entry up
+                               $idx++;
                        } // END - while
 
                        // Close directory and throw the instance away
@@ -644,21 +475,103 @@ class LocalFileDatabase extends BaseDatabaseFrontend implements DatabaseFrontend
                );
 
                // Try to save the request away
+               try {
+                       // Write the data away
+                       $this->writeDataArrayToFqfn($fqfn, $dataSetInstance->getCriteriaArray());
+
+                       // Update the primary key
+                       $this->updatePrimaryKey($dataSetInstance);
+
+                       // Reset last error message and exception
+                       $this->resetLastError();
+               } catch (FrameworkException $e) {
+                       // Catch all exceptions and store them in last error
+                       $this->lastException = $e;
+                       $this->lastError = $e->getMessage();
+
+                       // Throw an SQL exception
+                       throw new SqlException (array($this, sprintf("Cannot write data to table &#39;%s&#39;", $tableName), self::DB_CODE_TABLE_UNWRITEABLE), self::EXCEPTION_SQL_QUERY);
+               }
+       }
+
+       /**
+        * "Updates" a data set instance with a database layer
+        *
+        * @param       $dataSetInstance        A storeable data set
+        * @return      void
+        * @throws      SqlException    If an SQL error occurs
+        */
+       public function queryUpdateDataSet (StoreableCriteria $dataSetInstance) {
+               // Create full path name
+               $pathName = $this->getSavePath() . $dataSetInstance->getTableName() . '/';
+
+               // Try all the requests
                try {
                        // Get a file pointer instance
-                       $filePointer = FrameworkFileOutputPointer::createFrameworkFileOutputPointer($fqfn, 'w');
+                       $directoryInstance = FrameworkDirectoryPointer::createFrameworkDirectoryPointer($pathName);
+
+                       // Initialize limit/skip
+                       $limitFound = 0;
+                       $skipFound = 0;
 
                        // Get the criteria array from the dataset
                        $criteriaArray = $dataSetInstance->getCriteriaArray();
 
-                       // Serialize and compress it
-                       $compressedData = $this->getCompressorChannel()->getCompressor()->compressStream(serialize($criteriaArray));
+                       // Get search criteria
+                       $searchInstance = $dataSetInstance->getSearchInstance();
 
-                       // Write this data BASE64 encoded to the file
-                       $filePointer->writeToFile(base64_encode($compressedData));
+                       // Read the directory with some exceptions
+                       while (($dataFile = $directoryInstance->readDirectoryExcept(array(".", "..", ".htaccess", ".svn", "info." . $this->getFileExtension()))) && ($limitFound < $searchInstance->getLimit())) {
+                               // Does the extension match?
+                               if (substr($dataFile, -(strlen($this->getFileExtension()))) !== $this->getFileExtension()) {
+                                       // Skip this file!
+                                       continue;
+                               }
+
+                               // Open this file for reading
+                               $dataArray = $this->getDataArrayFromFile($pathName . $dataFile);
+
+                               // Is this an array?
+                               if (is_array($dataArray)) {
+                                       // Search in the criteria with FMFW (First Matches, First Wins)
+                                       foreach ($dataArray as $key => $value) {
+                                               // Get criteria element
+                                               $criteria = $searchInstance->getCriteriaElemnent($key);
+
+                                               // Is the criteria met?
+                                               if ((!is_null($criteria)) && ($criteria == $value))  {
+
+                                                       // Shall we skip this entry?
+                                                       if ($searchInstance->getSkip() > 0) {
+                                                               // We shall skip some entries
+                                                               if ($skipFound < $searchInstance->getSkip()) {
+                                                                       // Skip this entry
+                                                                       $skipFound++;
+                                                                       break;
+                                                               } // END - if
+                                                       } // END - if
+
+                                                       // Entry found, so update it
+                                                       foreach ($criteriaArray as $criteriaKey => $criteriaValue) {
+                                                               $dataArray[$criteriaKey] = $criteriaValue;
+                                                       } // END - foreach
+
+                                                       // Write the data to a local file
+                                                       $this->writeDataArrayToFqfn($pathName . $dataFile, $dataArray);
+
+                                                       // Count it
+                                                       $limitFound++;
+                                                       break;
+                                               } // END - if
+                                       } // END - foreach
+                               } // END - if
+                       } // END - while
 
                        // Close the file pointer
-                       $filePointer->closeFile();
+                       $directoryInstance->closeDirectory();
+
+                       // Update the primary key
+                       $this->updatePrimaryKey($dataSetInstance);
 
                        // Reset last error message and exception
                        $this->resetLastError();
@@ -668,9 +581,30 @@ class LocalFileDatabase extends BaseDatabaseFrontend implements DatabaseFrontend
                        $this->lastError = $e->getMessage();
 
                        // Throw an SQL exception
-                       throw new SqlException (array($this, sprintf("Cannot write data to table &#39;%s&#39;", $tableName), self::DB_CODE_TABLE_UNWRITEABLE), self::EXCEPTION_SQL_QUERY);
+                       throw new SqlException (array($this, sprintf("Cannot write data to table &#39;%s&#39;", $dataSetInstance->getTableName()), self::DB_CODE_TABLE_UNWRITEABLE), self::EXCEPTION_SQL_QUERY);
                }
        }
+
+       /**
+        * Getter for primary key of specified table or if not found null will be
+        * returned. This must be database-specific.
+        *
+        * @param       $tableName              Name of the table we need the primary key from
+        * @return      $primaryKey             Primary key column of the given table
+        */
+       public function getPrimaryKeyOfTable ($tableName) {
+               // Default key is null
+               $primaryKey = null;
+
+               // Does the table information exist?
+               if (isset($this->tableInfo[$tableName])) {
+                       // Then return the primary key
+                       $primaryKey = $this->tableInfo[$tableName]['primary'];
+               } // END - if
+
+               // Return the column
+               return $primaryKey;
+       }
 }
 
 // [EOF]