* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
class FileIoIterator extends BaseIterator implements SeekableWritableFileIterator {
+ /**
+ * Back-buffer
+ */
+ private $backBuffer = '';
+
+ /**
+ * Currently loaded block (will be returned by current())
+ */
+ private $currentBlock = '';
+
/**
* Protected constructor
*
* Creates an instance of this class
*
* @param $pointerInstance An instance of a InputOutputPointer class
+ * @param $blockInstance An instance of a CalculatableBlock class
* @return $iteratorInstance An instance of a Iterator class
*/
- public final static function createFileIoIterator (InputOutputPointer $pointerInstance) {
+ public final static function createFileIoIterator (InputOutputPointer $pointerInstance, CalculatableBlock $blockInstance) {
// Get new instance
$iteratorInstance = new FileIoIterator();
// Set the instance here
$iteratorInstance->setPointerInstance($pointerInstance);
+ // Set the block instance here
+ $iteratorInstance->setBlockInstance($blockInstance);
+
// Return the prepared instance
return $iteratorInstance;
}
+ /**
+ * Initializes the back-buffer by setting it to an empty string.
+ *
+ * @return void
+ */
+ private function initBackBuffer () {
+ // Simply call the setter
+ $this->setBackBuffer('');
+ }
+
+ /**
+ * Setter for backBuffer field
+ *
+ * @param $backBuffer Characters to "store" in back-buffer
+ * @return void
+ */
+ private function setBackBuffer ($backBuffer) {
+ // Cast to string (so no arrays or objects)
+ $backBuffer = (string) $backBuffer;
+
+ // ... and set it
+ $this->backBuffer = $backBuffer;
+ }
+
+ /**
+ * Getter for backBuffer field
+ *
+ * @return $backBuffer Characters "stored" in back-buffer
+ */
+ private function getBackBuffer () {
+ return $this->backBuffer;
+ }
+
+ /**
+ * Setter for currentBlock field
+ *
+ * @param $currentBlock Characters to set a currently loaded block
+ * @return void
+ */
+ private function setCurrentBlock ($currentBlock) {
+ // Cast to string (so no arrays or objects)
+ $currentBlock = (string) $currentBlock;
+
+ // ... and set it
+ $this->currentBlock = $currentBlock;
+ }
+
/**
* Gets currently read data
*
* @return $current Currently read data
*/
public function current () {
- // Default is null
- $current = null;
-
- $this->partialStub('Please implement this method.');
-
// Return it
- return $current;
+ return $this->currentBlock;
}
/**
* @return void
*/
public function next () {
- $this->partialStub('Please implement this method.');
+ // Is there nothing to read?
+ if (!$this->valid()) {
+ // Nothing to read
+ return;
+ } // END - if
+
+ // First calculate minimum block length
+ $length = $this->getBlockInstance()->caluclateMinimumBlockLength();
+
+ // Short be more than zero!
+ assert($length > 0);
+
+ // Wait until a entry/block separator has been found
+ $data = $this->getBackBuffer();
+ while ((!$this->getPointerInstance()->isEndOfFileReached()) && (!$this->getBlockInstance()->isBlockSeparatorFound($data))) {
+ // Then read the block
+ $data .= $this->read($length);
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('data()=' . strlen($data));
+ } // END - if
+
+ // EOF reached?
+ if ($this->getPointerInstance()->isEndOfFileReached()) {
+ // Set whole data as current block
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('Calling setCurrentBlock(' . strlen($data) . ') ...');
+ $this->setCurrentBlock($data);
+
+ // Then abort here silently
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('EOF reached.');
+ return;
+ } // END - if
+
+ /*
+ * Init back-buffer which is the data that has been found beyond the
+ * separator.
+ */
+ $this->initBackBuffer();
+
+ // Separate data
+ $dataArray = explode(self::getBlockSeparator(), $data);
+
+ // This array must contain two elements
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('dataArray=' . print_r($dataArray, TRUE));
+ assert(count($dataArray) == 2);
+
+ // Left part is the actual block, right one the back-buffer data
+ $this->setCurrentBlock($dataArray[0]);
+ $this->setBackBuffer($dataArray[1]);
}
/**
* Checks wether the current entry is valid (not at the end of the file).
* This method will return TRUE if an emptied (nulled) entry has been found.
*
- * @return void
+ * @return $isValid Whether the next entry is valid
*/
public function valid () {
- // Call pointer instance
- return $this->getPointerInstance()->valid();
+ // First calculate minimum block length
+ $length = $this->getBlockInstance()->caluclateMinimumBlockLength();
+
+ // Short be more than zero!
+ assert($length > 0);
+
+ // Get current seek position
+ $seekPosition = $this->key();
+
+ // Then try to read it
+ $data = $this->read($length);
+
+ // If some bytes could be read, all is fine
+ $isValid = ((is_string($data)) && (strlen($data) > 0));
+
+ // Get header size
+ $headerSize = $this->getBlockInstance()->getHeaderSize();
+
+ // Is the seek position at or beyond the header?
+ if ($seekPosition >= $headerSize) {
+ // Seek back to old position
+ $this->seek($seekPosition);
+ } else {
+ // Seek directly behind the header
+ $this->seek($headerSize);
+ }
+
+ // Return result
+ return $isValid;
}
/**
projects / core.git / blobdiff