* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
class BaseIndex extends BaseFrameworkSystem {
+ /**
+ * Magic for this index
+ */
+ const INDEX_MAGIC = 'INDEXv0.1';
+
/**
* Protected constructor
*
protected function __construct ($className) {
// Call parent constructor
parent::__construct($className);
+
+ // Calculate header size
+ $this->setHeaderSize(
+ strlen(self::INDEX_MAGIC) +
+ strlen(chr(BaseFile::SEPARATOR_HEADER_DATA)) +
+ BaseFile::LENGTH_COUNT +
+ strlen(chr(BaseFile::SEPARATOR_HEADER_ENTRIES))
+ );
+
+ // Init counters and gaps array
+ $this->initCountersGapsArray();
+ }
+
+ /**
+ * Reads the file header
+ *
+ * @return void
+ */
+ public function readFileHeader () {
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
+
+ // First rewind to beginning as the header sits at the beginning ...
+ $this->getIteratorInstance()->rewind();
+
+ // Then read it (see constructor for calculation)
+ $data = $this->getIteratorInstance()->read($this->getHeaderSize());
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Read %d bytes (%d wanted).', __METHOD__, __LINE__, strlen($data), $this->getHeaderSize()));
+
+ // Have all requested bytes been read?
+ assert(strlen($data) == $this->getHeaderSize());
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
+
+ // Last character must be the separator
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] data(-1)=%s', __METHOD__, __LINE__, dechex(ord(substr($data, -1, 1)))));
+ assert(substr($data, -1, 1) == chr(BaseFile::SEPARATOR_HEADER_ENTRIES));
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
+
+ // Okay, then remove it
+ $data = substr($data, 0, -1);
+
+ // And update seek position
+ $this->updateSeekPosition();
+
+ /*
+ * Now split it:
+ *
+ * 0 => magic
+ * 1 => total entries
+ */
+ $header = explode(chr(BaseFile::SEPARATOR_HEADER_DATA), $data);
+
+ // Set it here
+ $this->setHeader($header);
+
+ // Check if the array has only 3 elements
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] header(%d)=%s', __METHOD__, __LINE__, count($header), print_r($header, TRUE)));
+ assert(count($header) == 2);
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
+
+ // Check magic
+ assert($header[0] == self::INDEX_MAGIC);
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
+
+ // Check length of count
+ assert(strlen($header[1]) == BaseFile::LENGTH_COUNT);
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
+
+ // Decode count
+ $header[1] = hex2bin($header[1]);
+
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
+ }
+
+ /**
+ * Flushes the file header
+ *
+ * @return void
+ */
+ public function flushFileHeader () {
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
+
+ // Put all informations together
+ $header = sprintf('%s%s%s%s',
+ // Magic
+ self::INDEX_MAGIC,
+
+ // Separator header data
+ chr(BaseFile::SEPARATOR_HEADER_DATA),
+
+ // Total entries
+ str_pad($this->dec2hex($this->getCounter()), BaseFile::LENGTH_COUNT, '0', STR_PAD_LEFT),
+
+ // Separator header<->entries
+ chr(BaseFile::SEPARATOR_HEADER_ENTRIES)
+ );
+
+ // Write it to disk (header is always at seek position 0)
+ $this->writeData(0, $header, FALSE);
+
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
+ }
+
+ /**
+ * Initializes this index
+ *
+ * @param $fileName File name of this index
+ * @return void
+ * @todo Currently the index file is not cached, please implement a memory-handling class and if enough RAM is found, cache the whole index file.
+ */
+ protected function initIndex ($fileName) {
+ // Append index file extension
+ $fileName .= $this->getConfigInstance()->getConfigEntry('index_extension');
+
+ // Get a file i/o pointer instance for index file
+ $fileInstance = ObjectFactory::createObjectByConfiguredName('index_file_class', array($fileName, $this));
+
+ // Get iterator instance
+ $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_iterator_class', array($fileInstance));
+
+ // Is the instance implementing the right interface?
+ assert($iteratorInstance instanceof SeekableWritableFileIterator);
+
+ // Set iterator here
+ $this->setIteratorInstance($iteratorInstance);
+
+ // Is the file's header initialized?
+ if (!$this->getIteratorInstance()->isFileHeaderInitialized()) {
+ // No, then create it (which may pre-allocate the index)
+ $this->getIteratorInstance()->createFileHeader();
+
+ // And pre-allocate a bit
+ $this->getIteratorInstance()->preAllocateFile('index');
+ } // END - if
+
+ // Load the file header
+ $this->readFileHeader();
+
+ // Count all entries in file
+ $this->getIteratorInstance()->analyzeFile();
+ }
+
+ /**
+ * Calculates minimum length for one entry/block
+ *
+ * @return $length Minimum length for one entry/block
+ */
+ public function calculateMinimumBlockLength () {
+ // Calulcate it
+ $length = BaseFile::LENGTH_TYPE + strlen(chr(BaseFile::SEPARATOR_TYPE_POSITION)) + BaseFile::LENGTH_POSITION + strlen(chr(BaseFile::SEPARATOR_ENTRIES));
+
+ // Return it
+ return $length;
+ }
+
+ /**
+ * Close a file source and set it's instance to null and the file name
+ * to empty.
+ *
+ * @return void
+ * @throws UnsupportedOperationException If this method is called
+ */
+ public function closeFile () {
+ throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
+ }
+
+ /**
+ * Determines whether the EOF has been reached
+ *
+ * @return $isEndOfFileReached Whether the EOF has been reached
+ * @throws UnsupportedOperationException If this method is called
+ */
+ public function isEndOfFileReached () {
+ throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
+ }
+
+ /**
+ * Getter for file name
+ *
+ * @return $fileName The current file name
+ * @throws UnsupportedOperationException If this method is called
+ */
+ public function getFileName () {
+ throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
}
}