+++ /dev/null
-<?php
-// Own namespace
-namespace CoreFramework\Filesystem\File;
-
-// Import framework stuff
-use CoreFramework\Factory\ObjectFactory;
-
-/**
- * A general binary file class
- *
- * @author Roland Haeder <webmaster@ship-simu.org>
- * @version 0.0.0
- * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
- * @license GNU GPL 3.0 or any newer version
- * @link http://www.ship-simu.org
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-class BaseBinaryFile extends BaseAbstractFile {
- /**
- * Separator for header data
- */
- const SEPARATOR_HEADER_DATA = 0x01;
-
- /**
- * Separator header->entries
- */
- const SEPARATOR_HEADER_ENTRIES = 0x02;
-
- /**
- * Separator group->hash
- */
- const SEPARATOR_GROUP_HASH = 0x03;
-
- /**
- * Separator hash->value
- */
- const SEPARATOR_HASH_VALUE = 0x04;
-
- /**
- * Separator entry->entry
- */
- const SEPARATOR_ENTRIES = 0x05;
-
- /**
- * Separator type->position
- */
- const SEPARATOR_TYPE_POSITION = 0x06;
-
- /**
- * Length of count
- */
- const LENGTH_COUNT = 20;
-
- /**
- * Length of position
- */
- const LENGTH_POSITION = 20;
-
- /**
- * Length of group
- */
- const LENGTH_GROUP = 10;
-
- /**
- * Maximum length of entry type
- */
- const LENGTH_TYPE = 20;
-
- //***** Array elements for 'gaps' array *****
-
- /**
- * Start of gap
- */
- const GAPS_INDEX_START = 'start';
-
- /**
- * End of gap
- */
- const GAPS_INDEX_END = 'end';
-
- /**
- * Current seek position
- */
- private $seekPosition = 0;
-
- /**
- * Size of header
- */
- private $headerSize = 0;
-
- /**
- * File header
- */
- private $header = array();
-
- /**
- * Seek positions for gaps ("fragmentation")
- */
- private $gaps = array();
-
- /**
- * Seek positions for damaged entries (e.g. mismatching hash sum, ...)
- */
- private $damagedEntries = array();
-
- /**
- * Back-buffer
- */
- private $backBuffer = '';
-
- /**
- * Currently loaded block (will be returned by current())
- */
- private $currentBlock = '';
-
- /**
- * Protected constructor
- *
- * @param $className Name of the class
- * @return void
- */
- protected function __construct ($className) {
- // Call parent constructor
- parent::__construct($className);
-
- // Init counters and gaps array
- $this->initCountersGapsArray();
- }
-
- /**
- * Checks whether the abstracted file only contains gaps by counting all
- * gaps' bytes together and compare it to total length.
- *
- * @return $isGapsOnly Whether the abstracted file only contains gaps
- */
- private function isFileOnlyGaps () {
- // First/last gap found?
- /* Only for debugging
- if (isset($this->gaps[0])) {
- // Output first and last gap
- self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] this->gaps[0]=%s,this->gaps[%s]=%s', __METHOD__, __LINE__, print_r($this->gaps[0], TRUE), (count($this->gaps) - 1), print_r($this->gaps[count($this->gaps) - 1], TRUE)));
- } // END - if
- */
-
- // Now count every gap
- $gapsSize = 0;
- foreach ($this->gaps as $gap) {
- // Calculate size of found gap: end-start including both
- $gapsSize += ($gap[self::GAPS_INDEX_END] - $gap[self::GAPS_INDEX_START]);
- } // END - if
-
- // Debug output
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] gapsSize=%s,this->headerSize=%s', __METHOD__, __LINE__, $gapsSize, $this->getHeaderSize()));
-
- // Total gap size + header size must be same as file size
- $isGapsOnly = (($this->getHeaderSize() + $gapsSize) == $this->getFileSize());
-
- // Return status
- return $isGapsOnly;
- }
-
- /**
- * Initializes counter for valid entries, arrays for damaged entries and
- * an array for gap seek positions. If you call this method on your own,
- * please re-analyze the file structure. So you are better to call
- * analyzeFile() instead of this method.
- *
- * @return void
- */
- public function initCountersGapsArray () {
- // Init counter and seek position
- $this->setCounter(0);
- $this->setSeekPosition(0);
-
- // Init arrays
- $this->gaps = array();
- $this->damagedEntries = array();
- }
-
- /**
- * Getter for header size
- *
- * @return $totalEntries Size of file header
- */
- public final function getHeaderSize () {
- // Get it
- return $this->headerSize;
- }
-
- /**
- * Setter for header size
- *
- * @param $headerSize Size of file header
- * @return void
- */
- public final function setHeaderSize ($headerSize) {
- // Set it
- $this->headerSize = $headerSize;
- }
-
- /**
- * Getter for header array
- *
- * @return $totalEntries Size of file header
- */
- public final function getHeader () {
- // Get it
- return $this->header;
- }
-
- /**
- * Setter for header
- *
- * @param $header Array for a file header
- * @return void
- */
- public final function setHeader (array $header) {
- // Set it
- $this->header = $header;
- }
-
- /**
- * Getter for seek position
- *
- * @return $seekPosition Current seek position (stored here in object)
- */
- public final function getSeekPosition () {
- // Get it
- return $this->seekPosition;
- }
-
- /**
- * Setter for seek position
- *
- * @param $seekPosition Current seek position (stored here in object)
- * @return void
- */
- protected final function setSeekPosition ($seekPosition) {
- // And set it
- $this->seekPosition = $seekPosition;
- }
-
- /**
- * Updates seekPosition attribute from file to avoid to much access on file.
- *
- * @return void
- */
- public function updateSeekPosition () {
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
-
- // Get key (= seek position)
- $seekPosition = $this->key();
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Setting seekPosition=%s', __METHOD__, __LINE__, $seekPosition));
-
- // And set it here
- $this->setSeekPosition($seekPosition);
-
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
- }
-
- /**
- * Seeks to beginning of file, updates seek position in this object and
- * flushes the header.
- *
- * @return void
- */
- protected function rewindUpdateSeekPosition () {
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
-
- // flushFileHeader must be callable
- assert(is_callable(array($this, 'flushFileHeader')));
-
- // Seek to beginning of file
- $this->rewind();
-
- // And update seek position ...
- $this->updateSeekPosition();
-
- // ... to write it back into the file
- $this->flushFileHeader();
-
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
- }
-
- /**
- * Seeks to old position
- *
- * @return void
- */
- protected function seekToOldPosition () {
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
-
- // Seek to currently ("old") saved position
- $this->seek($this->getSeekPosition());
-
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
- }
-
- /**
- * Checks whether the block separator has been found
- *
- * @param $str String to look in
- * @return $isFound Whether the block separator has been found
- */
- public static function isBlockSeparatorFound ($str) {
- // Determine it
- $isFound = (strpos($str, chr(self::SEPARATOR_ENTRIES)) !== FALSE);
-
- // Return result
- return $isFound;
- }
-
- /**
- * 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 getCurrentBlock () {
- // Return it
- return $this->currentBlock;
- }
-
- /**
- * Initializes this file class
- *
- * @param $fileName Name of this abstract file
- * @return void
- */
- protected function initFile ($fileName) {
- // Get a file i/o pointer instance
- $pointerInstance = ObjectFactory::createObjectByConfiguredName('file_raw_input_output_class', array($fileName));
-
- // ... and set it here
- $this->setPointerInstance($pointerInstance);
- }
-
- /**
- * Writes data at given position
- *
- * @param $seekPosition Seek position
- * @param $data Data to be written
- * @param $flushHeader Whether to flush the header (default: flush)
- * @return void
- */
- public function writeData ($seekPosition, $data, $flushHeader = TRUE) {
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] seekPosition=%s,data()=%d - CALLED!', __METHOD__, __LINE__, $seekPosition, strlen($data)));
-
- // Write data at given position
- $this->getPointerInstance()->writeAtPosition($seekPosition, $data);
-
- // Increment counter
- $this->incrementCounter();
-
- // Update seek position
- $this->updateSeekPosition();
-
- // Flush the header?
- if ($flushHeader === TRUE) {
- // Flush header
- $this->flushFileHeader();
-
- // Seek to old position
- $this->seekToOldPosition();
- } // END - if
-
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
- }
-
- /**
- * Marks the currently loaded block as empty (with length of the block)
- *
- * @param $length Length of the block
- * @return void
- */
- protected function markCurrentBlockAsEmpty ($length) {
- // Get current seek position
- $currentPosition = $this->key();
-
- // Now add it as gap entry
- array_push($this->gaps, array(
- self::GAPS_INDEX_START => ($currentPosition - $length),
- self::GAPS_INDEX_END => $currentPosition,
- ));
- }
-
- /**
- * Checks whether the file header is initialized
- *
- * @return $isInitialized Whether the file header is initialized
- */
- public function isFileHeaderInitialized () {
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
-
- // Default is not initialized
- $isInitialized = FALSE;
-
- // Is the file initialized?
- if ($this->isFileInitialized()) {
- // Some bytes has been written, so rewind to start of it.
- $rewindStatus = $this->rewind();
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] rewindStatus=%s', __METHOD__, __LINE__, $rewindStatus));
-
- // Is the rewind() call successfull?
- if ($rewindStatus != 1) {
- // Something bad happened
- self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Could not rewind().', __METHOD__, __LINE__));
- } // END - if
-
- // Read file header
- $this->readFileHeader();
-
- // The above method does already check the header
- $isInitialized = TRUE;
- } // END - if
-
- // Return result
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] isInitialized=%d - EXIT!', __METHOD__, __LINE__, intval($isInitialized)));
- return $isInitialized;
- }
-
- /**
- * Checks whether the assigned file has been initialized
- *
- * @return $isInitialized Whether the file's size is zero
- */
- public function isFileInitialized () {
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
-
- // Get it from iterator which holds the pointer instance. If FALSE is returned
- $fileSize = $this->size();
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] fileSize=%s', __METHOD__, __LINE__, $fileSize));
-
- /*
- * The returned file size should not be FALSE or NULL as this means
- * that the pointer class does not work correctly.
- */
- assert(is_int($fileSize));
-
- // Is more than 0 returned?
- $isInitialized = ($fileSize > 0);
-
- // Return result
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] isInitialized=%d - EXIT!', __METHOD__, __LINE__, intval($isInitialized)));
- return $isInitialized;
- }
-
- /**
- * Creates the assigned file
- *
- * @return void
- */
- public function createFileHeader () {
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
-
- // The file's header should not be initialized here
- assert(!$this->isFileHeaderInitialized());
-
- // Simple flush file header which will create it.
- $this->flushFileHeader();
-
- // Rewind seek position (to beginning of file) and update/flush file header
- $this->rewindUpdateSeekPosition();
-
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
- }
-
- /**
- * Pre-allocates file (if enabled) with some space for later faster write access.
- *
- * @param $type Type of the file
- * @return void
- */
- public function preAllocateFile ($type) {
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
-
- // Is it enabled?
- if ($this->getConfigInstance()->getConfigEntry($type . '_pre_allocate_enabled') != 'Y') {
- // Not enabled
- self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Not pre-allocating file.', __METHOD__, __LINE__));
-
- // Don't continue here.
- return;
- } // END - if
-
- // Message to user
- self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Pre-allocating file ...', __METHOD__, __LINE__));
-
- // Calculate minimum length for one entry
- $minLengthEntry = $this->getBlockInstance()->calculateMinimumBlockLength();
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] minLengthEntry=%s', __METHOD__, __LINE__, $minLengthEntry));
-
- // Calulcate seek position
- $seekPosition = $minLengthEntry * $this->getConfigInstance()->getConfigEntry($type . '_pre_allocate_count');
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] seekPosition=%s', __METHOD__, __LINE__, $seekPosition));
-
- // Now simply write a NUL there. This will pre-allocate the file.
- $this->writeData($seekPosition, chr(0));
-
- // Rewind seek position (to beginning of file) and update/flush file header
- $this->rewindUpdateSeekPosition();
-
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
- }
-
- /**
- * Determines seek position
- *
- * @return $seekPosition Current seek position
- */
- public function determineSeekPosition () {
- // Call pointer instance
- return $this->getPointerInstance()->determineSeekPosition();
- }
-
- /**
- * Seek to given offset (default) or other possibilities as fseek() gives.
- *
- * @param $offset Offset to seek to (or used as "base" for other seeks)
- * @param $whence Added to offset (default: only use offset to seek to)
- * @return $status Status of file seek: 0 = success, -1 = failed
- */
- public function seek ($offset, $whence = SEEK_SET) {
- // Call pointer instance
- return $this->getPointerInstance()->seek($offset, $whence);
- }
-
- /**
- * Reads given amount of bytes from file.
- *
- * @param $bytes Amount of bytes to read
- * @return $data Data read from file
- */
- public function read ($bytes = NULL) {
- // $bytes shall be integer
- assert(is_int($bytes));
-
- // Call pointer instance
- return $this->getPointerInstance()->read($bytes);
- }
-
- /**
- * Rewinds to the beginning of the file
- *
- * @return $status Status of this operation
- */
- public function rewind () {
- // Call pointer instance
- return $this->getPointerInstance()->rewind();
- }
-
- /**
- * Analyzes entries in index file. This will count all found (and valid)
- * entries, mark invalid as damaged and count gaps ("fragmentation"). If
- * only gaps are found, the file is considered as "virgin" (no entries).
- *
- * @return void
- */
- public function analyzeFile () {
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
-
- // Make sure the file is initialized
- assert($this->isFileInitialized());
-
- // Init counters and gaps array
- $this->initCountersGapsArray();
-
- // Output message (as this may take some time)
- self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Analyzing file structure ... (this may take some time)', __METHOD__, __LINE__));
-
- // First rewind to the begining
- $this->rewind();
-
- // Then try to load all entries
- while ($this->valid()) {
- // Go to next entry
- $this->next();
-
- // Get current entry
- $current = $this->getCurrentBlock();
-
- /*
- * If the block is empty, maybe the whole file is? This could mean
- * that the file has been pre-allocated.
- */
- if (empty($current)) {
- // Then skip this part
- continue;
- } // END - if
-
- // Debug message
- /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] current()=%d', __METHOD__, __LINE__, strlen($current)));
- } // END - while
-
- // If the last read block is empty, check gaps
- if (empty($current)) {
- // Output message
- self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Found a total of %s gaps.', __METHOD__, __LINE__, count($this->gaps)));
-
- // Check gaps, if the whole file is empty.
- if ($this->isFileOnlyGaps()) {
- // Only gaps, so don't continue here.
- return;
- } // END - if
-
- /*
- * The above call has calculated a total size of all gaps. If the
- * percentage of gaps passes a "soft" limit and last
- * defragmentation is to far in the past, or if a "hard" limit has
- * reached, run defragmentation.
- */
- if ($this->isDefragmentationNeeded()) {
- // Run "defragmentation"
- $this->doRunDefragmentation();
- } // END - if
- } // END - if
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
- }
-
- /**
- * Advances to next "block" of bytes
- *
- * @return void
- */
- public function next () {
- // Is there nothing to read?
- if (!$this->valid()) {
- // Nothing to read
- return;
- } // END - if
-
- // Debug message
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d] key()=%d', __FUNCTION__, __LINE__, $this->key()));
-
- // Make sure the block instance is set
- assert($this->getBlockInstance() instanceof CalculatableBlock);
-
- // First calculate minimum block length
- $length = $this->getBlockInstance()->calculateMinimumBlockLength();
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d] length=%s', __FUNCTION__, __LINE__, $length));
-
- // Short be more than zero!
- assert($length > 0);
-
- // Read possibly back-buffered bytes from previous call of next().
- $data = $this->getBackBuffer();
-
- /*
- * Read until a entry/block separator has been found. The next read
- * "block" may not fit, so this loop will continue until the EOB or EOF
- * has been reached whatever comes first.
- */
- while ((!$this->isEndOfFileReached()) && (!self::isBlockSeparatorFound($data))) {
- // Then read the next possible block
- $block = $this->read($length);
-
- // Debug message
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d] block()=%d,length=%s', __FUNCTION__, __LINE__, strlen($block), $length));
-
- // Is it all empty?
- if (strlen(trim($block)) == 0) {
- // Mark this block as empty
- $this->markCurrentBlockAsEmpty(strlen($block));
-
- // Skip to next block
- continue;
- } // END - if
-
- // At this block then
- $data .= $block;
-
- // A debug message
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d] data()=%d', __FUNCTION__, __LINE__, strlen($data)));
- } // END - while
-
- // EOF reached?
- if ($this->isEndOfFileReached()) {
- // Set whole data as current read block
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('Calling setCurrentBlock(' . strlen($data) . ') ...');
- $this->setCurrentBlock($data);
-
- // Then abort here silently
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->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(chr(self::SEPARATOR_ENTRIES), $data);
-
- // This array must contain two elements
- //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('dataArray=' . print_r($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 $isValid Whether the next entry is valid
- */
- public function valid () {
- // Make sure the block instance is set
- assert($this->getBlockInstance() instanceof Block);
-
- // First calculate minimum block length
- $length = $this->getBlockInstance()->calculateMinimumBlockLength();
-
- // Short be more than zero!
- assert($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 = $this->getHeaderSize();
-
- // Is the seek position at or beyond the header?
- if ($seekPosition >= $headerSize) {
- // Seek back to old position
- $this->seek($seekPosition);
- } else {
- // Seek directly behind the header
- $this->seek($headerSize);
- }
-
- // Return result
- return $isValid;
- }
-
- /**
- * Gets current seek position ("key").
- *
- * @return $key Current key in iteration
- */
- public function key () {
- // Call pointer instance
- return $this->getPointerInstance()->determineSeekPosition();
- }
-
- /**
- * Reads the file header
- *
- * @return void
- */
- public function readFileHeader () {
- // Make sure the block instance is set
- assert($this->getBlockInstance() instanceof Block);
-
- // Call block instance
- $this->getBlockInstance()->readFileHeader();
- }
-
- /**
- * Flushes the file header
- *
- * @return void
- */
- public function flushFileHeader () {
- // Make sure the block instance is set
- assert($this->getBlockInstance() instanceof Block);
-
- // Call block instance
- $this->getBlockInstance()->flushFileHeader();
- }
-
- /**
- * Searches for next suitable gap the given length of data can fit in
- * including padding bytes.
- *
- * @param $length Length of raw data
- * @return $seekPosition Found next gap's seek position
- */
- public function searchNextGap ($length) {
- // If the file is only gaps, no need to seek
- if ($this->isFileOnlyGaps()) {
- // The first empty block is the first one right after the header
- return ($this->getHeaderSize() + 1);
- } // END - if
-
- // @TODO Unfinished
- $this->partialStub('length=' . $length);
- }
-
-}