*/
const STACK_MAGIC = 'STACKv0.1';
- /**
- * Separator magic->count
- */
- const SEPARATOR_MAGIC_COUNT = 0x00;
-
- /**
- * Separator position->entries
- */
- const SEPARATOR_SEEK_POS_ENTRIES = 0xff;
-
- /**
- * Separator hash->name
- */
- const SEPARATOR_HASH_NAME = 0x05;
-
/**
* Protected constructor
*
protected function __construct ($className) {
// Call parent constructor
parent::__construct($className);
+
+ // Calculate header size
+ $this->setHeaderSize(
+ strlen(self::STACK_MAGIC) +
+ strlen(self::SEPARATOR_HEADER_DATA) +
+ self::LENGTH_COUNT +
+ strlen(self::SEPARATOR_HEADER_DATA) +
+ self::LENGTH_POSITION +
+ strlen(self::SEPARATOR_HEADER_ENTRIES)
+ );
+
+ // Init counters and gaps array
+ $this->initCountersGapsArray();
}
/**
- * Checks whether the file header is initialized
+ * Reads the file header
*
- * @return $isInitialized Whether the file header is initialized
+ * @return void
*/
- private function isFileHeaderInitialized () {
- // Default is not initialized
- $isInitialized = FALSE;
+ protected function readFileHeader () {
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
- // Is the file initialized?
- if ($this->isFileInitialized()) {
- // Some bytes has been written, so rewind to start of it.
- $this->getIteratorInstance()->rewind();
+ // First rewind to beginning as the header sits at the beginning ...
+ $this->getIteratorInstance()->rewind();
- // Read file header
- $this->readFileHeader();
- } // END - if
+ // 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()));
- // Return result
- return $isInitialized;
+ // Have all requested bytes been read?
+ assert(strlen($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(self::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
+ * 2 => current seek position
+ */
+ $header = explode(chr(self::SEPARATOR_HEADER_DATA), $data);
+
+ // Set header 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($header) == 3);
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
+
+ // Check magic
+ assert($header[0] == self::STACK_MAGIC);
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
+
+ // Check length of count and seek position
+ assert(strlen($header[1]) == self::LENGTH_COUNT);
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
+ assert(strlen($header[2]) == self::LENGTH_POSITION);
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
+
+ // Decode count and seek position
+ $header[1] = hex2bin($header[1]);
+ $header[2] = hex2bin($header[2]);
+
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
}
/**
- * Checks whether the file-based stack has been initialized
+ * Flushes the file header
*
- * @return $isInitialized Whether the file's size is zero
+ * @return void
*/
- private function isFileInitialized () {
- // Default is not initialized
- $isInitialized = FALSE;
+ protected function flushFileHeader () {
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
- // Get it from iterator which holds the pointer instance. If FALSE is returned
- $fileSize = $this->getIteratorInstance()->size();
+ // Put all informations together
+ $header = sprintf('%s%s%s%s%s%s',
+ // Magic
+ self::STACK_MAGIC,
- /*
- * The returned file size should not be FALSE or NULL as this means
- * that the pointer class does not work correctly.
- */
- assert(is_int($fileSize));
+ // Separator magic<->count
+ chr(self::SEPARATOR_HEADER_DATA),
- // Is more than 0 returned?
- if ($fileSize > 0) {
- // So is the header written?
- $isInitialized = $this->getIteratorInstance()->isHeaderInitialized();
- } // END - if
+ // Total entries (will be zero) and pad it to 20 chars
+ str_pad($this->dec2hex($this->getCounter()), self::LENGTH_COUNT, '0', STR_PAD_LEFT),
- // Return result
- return $isInitialized;
+ // Separator count<->seek position
+ chr(self::SEPARATOR_HEADER_DATA),
+
+ // Position (will be zero)
+ str_pad($this->dec2hex($this->getSeekPosition(), 2), self::LENGTH_POSITION, '0', STR_PAD_LEFT),
+
+ // Separator position<->entries
+ chr(self::SEPARATOR_HEADER_ENTRIES)
+ );
+
+ // Write it to disk (header is always at seek position 0)
+ $this->writeData(0, $header, FALSE);
+
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
+ }
+
+ /**
+ * Analyzes entries in stack file. This will count all found (and valid)
+ * entries, mark invalid as damaged and count gaps ("fragmentation"). If
+ * only gaps are found, the file is considered as "virgin" (no entries).
+ *
+ * @return void
+ */
+ private function analyzeFile () {
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
+
+ // Make sure the file is initialized
+ assert($this->isFileInitialized());
+
+ // Init counters and gaps array
+ $this->initCountersGapsArray();
+
+ // Output message (as this may take some time)
+ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Analyzing file structure ... (this may take some time)', __METHOD__, __LINE__));
+
+ // First rewind to the begining
+ $this->getIteratorInstance()->rewind();
+
+ // Then try to load all entries
+ while ($this->getIteratorInstance()->valid()) {
+ // Go to next entry
+ $this->getIteratorInstance()->next();
+
+ // Get current entry
+ $current = $this->getIteratorInstance()->current();
+
+ // Simply output it
+ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] current(%s)=%s', __METHOD__, __LINE__, strlen($current), print_r($current, TRUE)));
+ } // END - while
+
+ //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
}
/**
* Initializes this file-based stack.
*
* @param $fileName File name of this stack
+ * @param $type Type of this stack (e.g. url_source for URL sources)
* @return void
+ * @todo Currently the stack file is not cached, please implement a memory-handling class and if enough RAM is found, cache the whole stack file.
*/
- protected function initFileStack ($fileName) {
- // Get a file i/o pointer instance
- $pointerInstance = ObjectFactory::createObjectByConfiguredName('file_raw_input_output_class', array($fileName));
+ protected function initFileStack ($fileName, $type) {
+ // Get a stack file instance
+ $fileInstance = ObjectFactory::createObjectByConfiguredName('stack_file_class', array($fileName));
// Get iterator instance
- $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_io_iterator_class', array($pointerInstance));
+ $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_io_iterator_class', array($fileInstance, $this));
// Is the instance implementing the right interface?
assert($iteratorInstance instanceof SeekableWritableFileIterator);
$this->setIteratorInstance($iteratorInstance);
// Is the file's header initialized?
- if ($this->isFileHeaderInitialized()) {
- // Then load it
- $this->loadFileHeader();
- } else {
+ if (!$this->isFileHeaderInitialized()) {
// No, then create it (which may pre-allocate the stack)
$this->createFileHeader();
- }
- }
- /**
- * Initializes given stacker
- *
- * @param $stackerName Name of the stack
- * @param $forceReInit Force re-initialization
- * @return void
- * @throws AlreadyInitializedStackerException If the stack is already initialized
- */
- public function initStack ($stackerName, $forceReInit = FALSE) {
- // Is the stack already initialized?
- if (($forceReInit === FALSE) && ($this->isStackInitialized($stackerName))) {
- // Then throw the exception
- throw new AlreadyInitializedStackerException(array($this, $stackerName, $forceReInit), self::EXCEPTION_STACKER_ALREADY_INITIALIZED);
+ // And pre-allocate a bit
+ $this->preAllocateFile('file_stack');
} // END - if
- // Initialize the given stack
- $this->partialStub('stackerName=' . $stackerName . ',forceReInit=' . intval($forceReInit));
- }
-
- /**
- * Checks whether the given stack is initialized (set in array $stackers)
- *
- * @param $stackerName Name of the stack
- * @return $isInitialized Whether the stack is initialized
- */
- public function isStackInitialized ($stackerName) {
- // Is is there?
- $this->partialStub('stackerName=' . $stackerName);
- $isInitialized = TRUE;
+ // Load the file header
+ $this->readFileHeader();
- // Return result
- return $isInitialized;
- }
-
- /**
- * Getter for size of given stack (array count)
- *
- * @param $stackerName Name of the stack
- * @return $count Size of stack (array count)
- * @throws NoStackerException If given stack is missing
- */
- public function getStackCount ($stackerName) {
- // Is the stack not yet initialized?
- if (!$this->isStackInitialized($stackerName)) {
- // Throw an exception
- throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
- } // END - if
+ // Count all entries in file
+ $this->analyzeFile();
- // Now, count the array of entries
- $this->partialStub('stackerName=' . $stackerName);
- $count = 0;
+ /*
+ * Get stack index instance. This can be used for faster
+ * "defragmentation" and startup.
+ */
+ $indexInstance = FileStackIndexFactory::createFileStackIndexInstance($fileName, $type);
- // Return result
- return $count;
+ // And set it here
+ $this->setIndexInstance($indexInstance);
}
/**
* @param $stackerName Name of the stack
* @param $value Value to add to this stacker
* @return void
- * @throws FullStackerException Thrown if the stack is full
+ * @throws FullStackerException If the stack is full
*/
protected function addValue ($stackerName, $value) {
- // Is the stack not yet initialized or full?
- if (!$this->isStackInitialized($stackerName)) {
- // Then do it here
- $this->initStack($stackerName);
- } elseif ($this->isStackFull($stackerName)) {
+ // Do some tests
+ if ($this->isStackFull($stackerName)) {
// Stacker is full
throw new FullStackerException(array($this, $stackerName, $value), self::EXCEPTION_STACKER_IS_FULL);
- }
+ } // END - if
// Now add the value to the stack
$this->partialStub('stackerName=' . $stackerName . ',value[]=' . gettype($value));
*
* @param $stackerName Name of the stack
* @return $value Value of last added value
- * @throws NoStackerException If the named stacker was not found
- * @throws EmptyStackerException If the named stacker is empty
+ * @throws EmptyStackerException If the stack is empty
*/
protected function getLastValue ($stackerName) {
// Is the stack not yet initialized or full?
- if (!$this->isStackInitialized($stackerName)) {
- // Throw an exception
- throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
- } elseif ($this->isStackEmpty($stackerName)) {
+ if ($this->isStackEmpty($stackerName)) {
// Throw an exception
throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
- }
+ } // END - if
// Now get the last value
$this->partialStub('stackerName=' . $stackerName);
*
* @param $stackerName Name of the stack
* @return $value Value of last added value
- * @throws NoStackerException If the named stacker was not found
- * @throws EmptyStackerException If the named stacker is empty
+ * @throws EmptyStackerException If the stack is empty
*/
protected function getFirstValue ($stackerName) {
// Is the stack not yet initialized or full?
- if (!$this->isStackInitialized($stackerName)) {
- // Throw an exception
- throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
- } elseif ($this->isStackEmpty($stackerName)) {
+ if ($this->isStackEmpty($stackerName)) {
// Throw an exception
throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
- }
+ } // END - if
// Now get the first value
$this->partialStub('stackerName=' . $stackerName);
*
* @param $stackerName Name of the stack
* @return $value Value "poped" from array
- * @throws NoStackerException If the named stacker was not found
- * @throws EmptyStackerException If the named stacker is empty
+ * @throws EmptyStackerException If the stack is empty
*/
protected function popLast ($stackerName) {
// Is the stack not yet initialized or full?
- if (!$this->isStackInitialized($stackerName)) {
- // Throw an exception
- throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
- } elseif ($this->isStackEmpty($stackerName)) {
+ if ($this->isStackEmpty($stackerName)) {
// Throw an exception
throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
- }
+ } // END - if
// Now, remove the last entry, we don't care about the return value here, see elseif() block above
$this->partialStub('stackerName=' . $stackerName);
*
* @param $stackerName Name of the stack
* @return $value Value "shifted" from array
- * @throws NoStackerException If the named stacker was not found
* @throws EmptyStackerException If the named stacker is empty
*/
protected function popFirst ($stackerName) {
// Is the stack not yet initialized or full?
- if (!$this->isStackInitialized($stackerName)) {
- // Throw an exception
- throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
- } elseif ($this->isStackEmpty($stackerName)) {
+ if ($this->isStackEmpty($stackerName)) {
// Throw an exception
throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
- }
+ } // END - if
// Now, remove the last entry, we don't care about the return value here, see elseif() block above
$this->partialStub('stackerName=' . $stackerName);
return NULL;
}
+
+ /**
+ * Checks whether the given stack is full
+ *
+ * @param $stackerName Name of the stack
+ * @return $isFull Whether the stack is full
+ */
+ protected function isStackFull ($stackerName) {
+ // File-based stacks will only run full if the disk space is low.
+ // @TODO Please implement this, returning FALSE
+ $isFull = FALSE;
+
+ // Return result
+ return $isFull;
+ }
+
+ /**
+ * Checks whether the given stack is empty
+ *
+ * @param $stackerName Name of the stack
+ * @return $isEmpty Whether the stack is empty
+ * @throws NoStackerException If given stack is missing
+ */
+ public function isStackEmpty ($stackerName) {
+ // So, is the stack empty?
+ $isEmpty = (($this->getStackCount($stackerName)) == 0);
+
+ // Return result
+ return $isEmpty;
+ }
+
+ /**
+ * Initializes given stacker
+ *
+ * @param $stackerName Name of the stack
+ * @param $forceReInit Force re-initialization
+ * @return void
+ * @throws UnsupportedOperationException This method is not (and maybe never will be) supported
+ */
+ public function initStack ($stackerName, $forceReInit = FALSE) {
+ throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
+ }
+
+ /**
+ * Initializes all stacks
+ *
+ * @return void
+ * @throws UnsupportedOperationException This method is not (and maybe never will be) supported
+ */
+ public function initStacks (array $stacks, $forceReInit = FALSE) {
+ throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
+ }
+
+ /**
+ * Checks whether the given stack is initialized (set in array $stackers)
+ *
+ * @param $stackerName Name of the stack
+ * @return $isInitialized Whether the stack is initialized
+ * @throws UnsupportedOperationException This method is not (and maybe never will be) supported
+ */
+ public function isStackInitialized ($stackerName) {
+ throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
+ }
+
+ /**
+ * Getter for size of given stack (array count)
+ *
+ * @param $stackerName Name of the stack
+ * @return $count Size of stack (array count)
+ */
+ public function getStackCount ($stackerName) {
+ // Now, simply return the found count value, this must be up-to-date then!
+ return $this->getCounter();
+ }
+
+ /**
+ * Calculates minimum length for one entry/block
+ *
+ * @return $length Minimum length for one entry/block
+ */
+ public function caluclateMinimumBlockLength () {
+ // Calulcate it
+ $length = self::getHashLength() + strlen(chr(self::SEPARATOR_HASH_NAME)) + self::LENGTH_NAME + 1 + strlen(self::getBlockSeparator());
+
+ // Return it
+ return $length;
+ }
}
// [EOF]