From: Roland Häder <roland@mxchange.org>
Date: Wed, 6 Jan 2021 19:28:35 +0000 (+0100)
Subject: WIP:
X-Git-Url: https://git.mxchange.org/?p=core.git;a=commitdiff_plain;h=6dd6e82fe8514a88af39fbbec5c4e3a73956f308

WIP:
- thrown exceptions when parameter values/types are not valid
- added type-hints for primitive variables
- partially fixed writing index files for other non-humanreadable files (see
  BaseBinaryFile class)

Signed-off-by: Roland Häder <roland@mxchange.org>
---

diff --git a/framework/main/classes/criteria/search/class_SearchCriteria.php b/framework/main/classes/criteria/search/class_SearchCriteria.php
index 7aca5390..b9286d0e 100644
--- a/framework/main/classes/criteria/search/class_SearchCriteria.php
+++ b/framework/main/classes/criteria/search/class_SearchCriteria.php
@@ -7,6 +7,9 @@ use Org\Mxchange\CoreFramework\Bootstrap\FrameworkBootstrap;
 use Org\Mxchange\CoreFramework\Criteria\BaseCriteria;
 use Org\Mxchange\CoreFramework\Criteria\Local\LocalSearchCriteria;
 
+// Import SPL stuff
+use \InvalidArgumentException;
+
 /**
  * Search criteria for e.g. searching in databases. Do not use this class if
  * you are looking for a ship or company, or what ever. Instead use this class
@@ -77,7 +80,7 @@ class SearchCriteria extends BaseCriteria implements LocalSearchCriteria {
 	 * @return	void
 	 * @todo	Find a nice casting here. (int) allows until and including 32766.
 	 */
-	public final function setLimit ($limit) {
+	public final function setLimit (int $limit) {
 		$this->limit = $limit;
 	}
 
@@ -87,7 +90,7 @@ class SearchCriteria extends BaseCriteria implements LocalSearchCriteria {
 	 * @param	$configEntry	The configuration entry which hold a number as limit
 	 * @return	void
 	 */
-	public final function setConfiguredLimit ($configEntry) {
+	public final function setConfiguredLimit (string $configEntry) {
 		// Get the limit from config entry and set it
 		$limit = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry($configEntry);
 		$this->setLimit($limit);
@@ -109,7 +112,7 @@ class SearchCriteria extends BaseCriteria implements LocalSearchCriteria {
 	 * @return	void
 	 * @todo	Find a nice casting here. (int) allows until and including 32766.
 	 */
-	public final function setSkip ($skip) {
+	public final function setSkip (int $skip) {
 		$this->skip = $skip;
 	}
 
@@ -130,39 +133,53 @@ class SearchCriteria extends BaseCriteria implements LocalSearchCriteria {
 	 * @param	$value			Value to check
 	 * @param	$separator		Separator for "exploding" $value (default: ',')
 	 * @return	$isMatching		Whether the key/value is matching or excluded
+	 * @throws	InvalidArgumentException	If a parameter is invalid
 	 */
-	public function isCriteriaMatching ($key, $value, $separator = ',') {
+	public function isCriteriaMatching (string $key, $value, string $separator = ',') {
 		// $key/$value cannot be array/NULL/bool, value can be NULL but then NULL must be loocked for
-		assert((!is_array($value)) && (!is_bool($value)) && (!is_array($key)) && (!is_null($key)) && (!is_bool($key)));
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('SEARCH-CRITERIA: key=%s,value[]=%s,separator=%s - CALLED!', $key, gettype($value), $separator));
+		if (empty($key)) {
+			// Throw IAE
+			throw new InvalidArgumentException('Parameter "key" cannot be empty');
+		} elseif (is_array($value) || is_bool($value) || is_bool($value) || is_object($value) || is_resource($value)) {
+			// Throw it again
+			throw new InvalidArgumentException(sprintf('value[]=%s is not supported/valid', gettype($value)));
+		} elseif (empty($separator)) {
+			// Throw IAE
+			throw new InvalidArgumentException('Parameter "separator" cannot be empty');
+		}
 
 		// "Explode" value
 		$valueArray = explode($separator, $value);
 
-		// Debug message
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('SEARCH-CRITERIA: key=' . $key . ',value[' . gettype($value) . ']=' . $value . ' - CALLED!');
-
 		// Get 'default' search value
 		$searchDefault = $this->getCriteriaElemnent($key);
 
-		// Debug message
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('SEARCH-CRITERIA: getCriteriaElement(' . $key . ')[' . gettype($searchDefault) . ']=' . $searchDefault);
-
 		// 'default' check
-		$isMatching = (((($searchDefault !== false) && ($searchDefault == $value)) || ((is_null($searchDefault)) && (is_null($value)))) || ($searchDefault === false));
-
-		// Debug message
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('SEARCH-CRITERIA: getCriteriaElement(' . $key . ')[' . gettype($searchDefault) . ']=' . $searchDefault . ',isMatching=' . intval($isMatching));
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('SEARCH-CRITERIA: getCriteriaElement(' . $key . ')[' . gettype($searchDefault) . ']=' . $searchDefault);
+		$isMatching = (
+			(
+				(
+					($searchDefault !== false) &&
+					($searchDefault == $value)
+				) || (
+					is_null($searchDefault) &&
+					is_null($value)
+				)
+			) || (
+				$searchDefault === false
+			)
+		);
 
 		// Get 'choice' search value (can be NULL or $separator-separated string)
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('SEARCH-CRITERIA: getCriteriaElement(' . $key . ')[' . gettype($searchDefault) . ']=' . $searchDefault . ',isMatching=' . intval($isMatching));
 		$searchChoice = $this->getCriteriaChoiceElemnent($key);
 
 		// May be false or array
 		assert(($searchChoice === false) || (is_array($searchChoice)));
 
-		// Debug message
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('SEARCH-CRITERIA: getCriteriaChoiceElement(' . $key . ')[' . gettype($searchChoice) . ']=' . print_r($searchChoice, true));
-
 		// 'choice' check
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('SEARCH-CRITERIA: getCriteriaChoiceElement(' . $key . ')[' . gettype($searchChoice) . ']=' . print_r($searchChoice, true));
 		if ((is_array($searchChoice)) && (count($valueArray) == 1)) {
 			// $value is a single-search value, so use in_[]
 			$isMatching = ((($isMatching === true) || (($searchDefault === false) && (!is_null($value)))) && (in_array($value, $searchChoice)));
@@ -195,16 +212,12 @@ class SearchCriteria extends BaseCriteria implements LocalSearchCriteria {
 			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('SEARCH-CRITERIA: getCriteriaChoiceElement(' . $key . ')[]=' . gettype($searchChoice) . ',value[' . gettype($value) . ']=' . $value . ',isMatching=' . intval($isMatching) . ' - false-MATCH');
 		}
 
-		// Debug message
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('SEARCH-CRITERIA: getCriteriaChoiceElement(' . $key . ')[]=' . gettype($searchChoice) . ',isMatching=' . intval($isMatching));
-
 		// Get 'exclude' search value
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('SEARCH-CRITERIA: getCriteriaChoiceElement(' . $key . ')[]=' . gettype($searchChoice) . ',isMatching=' . intval($isMatching));
 		$searchExclude = $this->getCriteriaExcludeElemnent($key);
 
-		// Debug message
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('SEARCH-CRITERIA: getCriteriaExcludeElement(' . $key . ')[' . gettype($searchExclude) . ']=' . $searchExclude);
-
 		// 'exclude' check
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('SEARCH-CRITERIA: getCriteriaExcludeElement(' . $key . ')[' . gettype($searchExclude) . ']=' . $searchExclude);
 		$isMatching = (
 			(
 				(
diff --git a/framework/main/classes/database/backend/lfdb_legacy/class_CachedLocalFileDatabase.php b/framework/main/classes/database/backend/lfdb_legacy/class_CachedLocalFileDatabase.php
index b2d9041e..3c021c7d 100644
--- a/framework/main/classes/database/backend/lfdb_legacy/class_CachedLocalFileDatabase.php
+++ b/framework/main/classes/database/backend/lfdb_legacy/class_CachedLocalFileDatabase.php
@@ -391,7 +391,7 @@ class CachedLocalFileDatabase extends BaseDatabaseBackend implements DatabaseBac
 			$idx = 1;
 
 			// Read the directory with some exceptions
-			while (($fileInfoInstance = $directoryInstance->readDirectoryExcept(array('.htaccess', 'info.' . $this->getFileExtension()))) && (($limitFound < $searchInstance->getLimit()) || ($searchInstance->getLimit() == 0))) {
+			while (($fileInfoInstance = $directoryInstance->readDirectoryExcept(['.gitkeep', 'info.' . $this->getFileExtension()])) && (($limitFound < $searchInstance->getLimit()) || ($searchInstance->getLimit() == 0))) {
 				// Does the extension match?
 				//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('CACHED-LFDB: fileInfoInstance->extension=%s,this->fileExtension=%s', $fileInfoInstance->getExtension(), $this->getFileExtension()));
 				if ($fileInfoInstance->getExtension() !== $this->getFileExtension()) {
@@ -413,9 +413,6 @@ class CachedLocalFileDatabase extends BaseDatabaseBackend implements DatabaseBac
 					// Search in the criteria with FMFW (First Matches, First Wins)
 					//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('CACHED-LFDB: data[]=%d', count($dataArray)));
 					foreach ($dataArray as $key => $value) {
-						// Make sure value is not bool
-						assert(!is_bool($value));
-
 						// Found one entry?
 						$isFound = (($isFound === true) && ($searchInstance->isCriteriaMatching($key, $value)));
 						//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('CACHED-LFDB: key=%s,value[%s]=%s,isFound=%s', $key, gettype($value), $value, intval($isFound)));
@@ -547,7 +544,7 @@ class CachedLocalFileDatabase extends BaseDatabaseBackend implements DatabaseBac
 			$searchInstance = $dataSetInstance->getSearchInstance();
 
 			// Read the directory with some exceptions
-			while (($fileInfoInstance = $directoryInstance->readDirectoryExcept(array('.htaccess', 'info.' . $this->getFileExtension()))) && (($limitFound < $searchInstance->getLimit()) || ($searchInstance->getLimit() == 0))) {
+			while (($fileInfoInstance = $directoryInstance->readDirectoryExcept(['.gitkeep', 'info.' . $this->getFileExtension()])) && (($limitFound < $searchInstance->getLimit()) || ($searchInstance->getLimit() == 0))) {
 				// Does the extension match?
 				//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('CACHED-LFDB: fileInfoInstance->extension=' . $fileInfoInstance->getExtension() . ',this->getFileExtension()=' . $this->getFileExtension());
 				if ($fileInfoInstance->getExtension() !== $this->getFileExtension()) {
@@ -568,9 +565,6 @@ class CachedLocalFileDatabase extends BaseDatabaseBackend implements DatabaseBac
 
 					// Search in the criteria with FMFW (First Matches, First Wins)
 					foreach ($dataArray as $key => $value) {
-						// Make sure value is not bool
-						assert(!is_bool($value));
-
 						// Found one entry?
 						$isFound = (($isFound === true) && ($searchInstance->isCriteriaMatching($key, $value)));
 					}
@@ -704,7 +698,7 @@ class CachedLocalFileDatabase extends BaseDatabaseBackend implements DatabaseBac
 			$count = 0;
 
 			// Read the directory with some exceptions
-			while ($fileInfoInstance = $directoryInstance->readDirectoryExcept(array('.htaccess', 'info.' . $this->getFileExtension()))) {
+			while ($fileInfoInstance = $directoryInstance->readDirectoryExcept(['.gitkeep', 'info.' . $this->getFileExtension()])) {
 				// Does the extension match?
 				//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('CACHED-LFDB: fileInfoInstance->extension=' . $fileInfoInstance->getExtension() . ',this->getFileExtension()=' . $this->getFileExtension());
 				if ($fileInfoInstance->getExtension() !== $this->getFileExtension()) {
diff --git a/framework/main/classes/file_directories/binary/class_BaseBinaryFile.php b/framework/main/classes/file_directories/binary/class_BaseBinaryFile.php
index 95c642eb..2bfc2771 100644
--- a/framework/main/classes/file_directories/binary/class_BaseBinaryFile.php
+++ b/framework/main/classes/file_directories/binary/class_BaseBinaryFile.php
@@ -7,6 +7,7 @@ use Org\Mxchange\CoreFramework\Bootstrap\FrameworkBootstrap;
 use Org\Mxchange\CoreFramework\EntryPoint\ApplicationEntryPoint;
 use Org\Mxchange\CoreFramework\Factory\Object\ObjectFactory;
 use Org\Mxchange\CoreFramework\Filesystem\File\BaseAbstractFile;
+use Org\Mxchange\CoreFramework\Filesystem\FilePointer;
 use Org\Mxchange\CoreFramework\Index\Indexable;
 use Org\Mxchange\CoreFramework\Stack\File\StackableFile;
 use Org\Mxchange\CoreFramework\Traits\Index\IndexableTrait;
@@ -153,9 +154,6 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 	protected function __construct (string $className) {
 		// Call parent constructor
 		parent::__construct($className);
-
-		// Init counters and gaps array
-		$this->initCountersGapsArray();
 	}
 
 	/**
@@ -263,36 +261,18 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 		$this->seekPosition = $seekPosition;
 	}
 
-	/**
-	 * Marks whole file as gaps-only (freshly created file
-	 *
-	 * @param	$type	Type of file
-	 * @param	$minimumBlockLength		Minimum block length
-	 * @return	void
-	 */
-	private function markFileGapsOnly (string $type, int $minimumBlockLength) {
-		// Very simple to do ...
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: type=%s,minimumBlockLength=%d - CALLED!', $type, $minimumBlockLength));
-		for ($idx = 0; $idx < FrameworkBootstrap::getConfigurationInstance()->getConfigEntry($type . '_pre_allocate_count'); $idx++) {
-			// Mark start and end position as gap
-			$this->addGap($idx * $minimumBlockLength, $idx * $minimumBlockLength + $minimumBlockLength);
-		}
-
-		// Trace message
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: EXIT!');
-	}
-
 	/**
 	 * 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
+	 * @throws	OutOfBoundsException	If calculated file size is larger than actual
 	 */
-	private function isFileGapsOnly () {
+	public function isFileGapsOnly () {
 		// Count every gap
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: CALLED!');
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: CALLED!');
 		$gapsSize = 0;
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: this->gaps()=%d', count($this->gaps)));
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: this->gaps()=%d', count($this->gaps)));
 		foreach ($this->gaps as $gap) {
 			// Calculate size of found gap: end-start including both
 			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: gap[%s]=%d,ga[%s]=%d', self::GAPS_INDEX_START, $gap[self::GAPS_INDEX_START], self::GAPS_INDEX_END, $gap[self::GAPS_INDEX_END]));
@@ -302,15 +282,49 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: gapsSize=%d', $gapsSize));
 		}
 
-		// Total gap size + header size must be same as file size
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: gapsSize=%d,this->fileSize=%d', $gapsSize, $this->getFileSize()));
-		$isGapsOnly = ($gapsSize + 1 == $this->getFileSize());
+		// Total gap size + header size + 1 must be same as file size
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: gapsSize=%d,this->headerSize=%d,this->fileSize=%d', $gapsSize, $this->getHeaderSize(), $this->getFileSize()));
+		$determinedFileSize = ($gapsSize + $this->getHeaderSize() + 1);
 
-		// Return status
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: isGapsOnly=%d - EXIT!', intval($isGapsOnly)));
+		// Should not be more!
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: determinedFileSize=%d,this->fileSize=%d', $determinedFileSize, $this->getFileSize()));
+		if ($determinedFileSize > $this->getFileSize()) {
+			// Should not happen
+			throw new OutOfBoundsException(sprintf('determinedFileSize=%d is larger than this->fileSize=%d', $determinedFileSize, $this->getFileSize()));
+		}
+
+		// Is it same?
+		$isGapsOnly = ($determinedFileSize == $this->getFileSize());
+
+		// Return flag
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: isGapsOnly=%d - EXIT!', intval($isGapsOnly)));
 		return $isGapsOnly;
 	}
 
+	/**
+	 * Marks whole file as gaps-only (freshly created file
+	 *
+	 * @param	$type	Type of file
+	 * @param	$minimumBlockLength		Minimum block length
+	 * @return	void
+	 */
+	private function markFileGapsOnly (string $type, int $minimumBlockLength) {
+		// Very simple to do ...
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: type=%s,minimumBlockLength=%d - CALLED!', $type, $minimumBlockLength));
+		for ($idx = 0; $idx < FrameworkBootstrap::getConfigurationInstance()->getConfigEntry($type . '_pre_allocate_count'); $idx++) {
+			// Calculate start/end positions
+			$startPosition = $idx * $minimumBlockLength;
+			$endPosition = $idx * $minimumBlockLength + $minimumBlockLength;
+
+			// Mark start and end position as gap
+			/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Calling this->addGap(%d, %d) ...', $startPosition, $endPosition));
+			$this->addGap($startPosition, $endPosition);
+		}
+
+		// Trace message
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: EXIT!');
+	}
+
 	/**
 	 * Adds a gap for given start and end position
 	 *
@@ -423,7 +437,7 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 		$currentPosition = $this->determineSeekPosition();
 
 		// Now add it as gap entry
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: currentPosition=%d', $currentPosition));
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Calling this->addGap(%d, %d) ..', ($currentPosition - $length), $currentPosition));
 		$this->addGap(($currentPosition - $length), $currentPosition);
 
 		// Trace message
@@ -440,14 +454,28 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 	 */
 	public function initCountersGapsArray () {
 		// Init counter and seek position to header size
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: CALLED!');
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->determineSeekPosition() - CALLED!');
+		$seekPosition = $this->getSeekPosition();
+
+		// Set counter
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: seekPosition=%d', $seekPosition));
 		$this->setCounter(0);
-		$this->setSeekPosition($this->getHeaderSize());
+
+		// Get header size
+		$headerSize = $this->getHeaderSize();
+
+		// Set it
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Setting this->seekPosition=%d ...', $headerSize));
+		$this->setSeekPosition($headerSize);
 
 		// Init arrays
 		$this->gaps = [];
 		$this->damagedEntries = [];
 
+		// Seek back to old position
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Calling this->seek(%d) ...', $seekPosition));
+		$this->seek($seekPosition);
+
 		// Trace message
 		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: EXIT!');
 	}
@@ -505,7 +533,7 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 	 */
 	public function writeData (int $seekPosition, string $data, bool $flushHeader = true) {
 		// Validate parameter
-		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: seekPosition=%s,data()=%d,flushHeader=%d - CALLED!', $seekPosition, strlen($data), intval($flushHeader)));
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: seekPosition=%s,data()=%d,flushHeader=%d - CALLED!', $seekPosition, strlen($data), intval($flushHeader)));
 		if ($seekPosition < 0) {
 			// Invalid seek position
 			throw new OutOfBoundsException(sprintf('seekPosition=%d is not valid', $seekPosition));
@@ -515,31 +543,31 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 		}
 
 		// Write data at given position
-		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Calling this->writeAtPosition(%d,%s) ...', $seekPosition, $data));
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Calling this->writeAtPosition(%d,%s) ...', $seekPosition, $data));
 		$this->writeAtPosition($seekPosition, $data);
 
 		// Increment counter
-		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->incrementCounter() ...');
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->incrementCounter() ...');
 		$this->incrementCounter();
 
 		// Update seek position
-		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->updateSeekPosition() ...');
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->updateSeekPosition() ...');
 		$this->updateSeekPosition();
 
 		// Flush the header?
-		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: flushHeader=%d', intval($flushHeader)));
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: flushHeader=%d', intval($flushHeader)));
 		if ($flushHeader === true) {
 			// Flush header
-			/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->flushFileHeader() ...');
+			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->flushFileHeader() ...');
 			$this->flushFileHeader();
 
 			// Seek to old position
-			/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->seekToOldPosition() ...');
+			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->seekToOldPosition() ...');
 			$this->seekToOldPosition();
 		}
 
 		// Trace message
-		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: EXIT!');
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: EXIT!');
 	}
 
 	/**
@@ -659,60 +687,6 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: EXIT!');
 	}
 
-	/**
-	 * Pre-allocates file (if enabled) with some space for later faster write access.
-	 *
-	 * @param	$type	Type of the file
-	 * @return	void
-	 * @throws	InvalidArgumentException	If a parameter is empty
-	 */
-	public function preAllocateFile (string $type) {
-		// Is it enabled?
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: type=%s - CALLED!', $type));
-		if (empty($type)) {
-			// Empty type
-			throw new InvalidArgumentException('Parameter "type" is empty');
-		} elseif (FrameworkBootstrap::getConfigurationInstance()->getConfigEntry($type . '_pre_allocate_enabled') != 'Y') {
-			// Don't continue here.
-			self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Not pre-allocating file.'));
-			return;
-		}
-
-		// Message to user
-		self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Pre-allocating file ...');
-
-		// Calculate minimum length for one entry and get file size
-		$minimumBlockLength = $this->getIndexInstance()->calculateMinimumBlockLength();
-		$fileSize = $this->getFileSize();
-
-		// Calulcate seek position
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: minimumBlockLength=%d,fileSize=%d', $minimumBlockLength, $fileSize));
-		$seekPosition = $minimumBlockLength * FrameworkBootstrap::getConfigurationInstance()->getConfigEntry($type . '_pre_allocate_count') + $fileSize ;
-
-		// Now simply write a NUL there. This will pre-allocate the file.
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Calling this->writeAtPosition(%d,NUL) ...', $seekPosition));
-		$this->writeAtPosition($seekPosition, chr(0));
-
-		// Is the seek position zero?
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: fileSize=%d', $fileSize));
-		if ($fileSize == 0) {
-			// Mark file as gaps-only
-			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Calling this->markGapsOnly(%s,%d) ...', $type, $minimumBlockLength));
-			$this->markFileGapsOnly($type, $minimumBlockLength);
-		} else {
-			// Analyze file structure
-			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->analyzeFileStructure() ...');
-			$this->analyzeFileStructure();
-		}
-
-		// Rewind seek position
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->rewind() ...');
-		$this->rewind();
-
-		// Trace message
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: EXIT!');
-	}
-
 	/**
 	 * Determines seek position
 	 *
@@ -768,8 +742,13 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 		}
 
 		// Call pointer instance
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Calling this->pointerInstance->read(%d) ...', $bytes));
 		$data = $this->getPointerInstance()->read($bytes);
 
+		// Update seek position
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->updateSeekPosition() ...');
+		$this->updateSeekPosition();
+
 		// Return data
 		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: data[%s]=%s - EXIT!', gettype($data), $data));
 		return $data;
@@ -799,25 +778,25 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 	 */
 	public function analyzeFileStructure () {
 		// Make sure the file is initialized
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: CALLED!');
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: CALLED!');
 		if (!$this->isFileInitialized()) {
 			// Bad method call
 			throw new BadMethodCallException('Method called but file is not initialized.');
 		}
 
 		// Init counters and gaps array
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->initCounterGapsArrays() ...');
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->initCounterGapsArrays() ...');
 		$this->initCountersGapsArray();
 
 		// Output message (as this may take some time)
 		self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('Analyzing file structure ... (this may take some time)'));
 
 		// First rewind to the begining
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->rewind() ...');
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->rewind() ...');
 		$this->rewind();
 
 		// Then try to load all entries
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Looping through file');
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Looping through file');
 		while ($this->isValid()) {
 			// Get current entry
 			$current = $this->getCurrentBlock();
@@ -831,68 +810,62 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 			 * that the file has been pre-allocated.
 			 */
 			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: current(%d)[]=%s', strlen($current), gettype($current)));
-			if (empty($current)) {
+			if (empty(trim($current, chr(0)))) {
 				// Then skip this part
 				//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: current[]=%s is empty - CONTINUE!', gettype($current)));
 				continue;
 			}
 
 			// Handle current record
-			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: current(%d)[]=%s', strlen($current), gettype($current)));
+			/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: current(%d)[%s]=%s', strlen($current), gettype($current), $current));
 		}
 
 		// If the last read block is empty, check gaps
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: current()=%d', strlen($current)));
-		if (empty($current)) {
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: current()=%d', strlen($current)));
+		if (empty(trim($current, chr(0)))) {
 			// Output message
 			self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Found a total of %d gaps.', count($this->gaps)));
 
 			// Check gaps, if the whole file is empty.
-			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->isFileGapsOnly() ...');
+			/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->isFileGapsOnly() ...');
 			if ($this->isFileGapsOnly()) {
 				// Only gaps, so don't continue here.
-				//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: File is gaps-only - EXIT!');
+				/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: File is gaps-only - EXIT!');
 				return;
 			}
+		}
 
-			/*
-			 * 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.
-			 */
-			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->isDefragmentationNeeded() ...');
-			if ($this->isDefragmentationNeeded()) {
-				// Run "defragmentation"
-				//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->doRunDefragmentation() ...');
-				$this->doRunDefragmentation();
-			}
+		/*
+		 * The above call has calculated a total size of all gaps. If the
+		 * percentage of gaps passes a "soft" limit and last
+		 * defragmentation is to far in the past, or if a "hard" limit has
+		 * reached, run defragmentation.
+		 */
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->isDefragmentationNeeded() ...');
+		if ($this->isDefragmentationNeeded()) {
+			// Run "defragmentation"
+			/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->doRunDefragmentation() ...');
+			$this->doRunDefragmentation();
 		}
 
 		// Trace message
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: EXIT!');
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: EXIT!');
 	}
 
 	/**
-	 * Reads next "block" of bytes into $currentBlock field
+	 * Reads next "block" of bytes into $currentBlock field. THis method loads
+	 * the whole file into memory when the file is just freshly initialized
+	 * (only zeros in it).
 	 *
 	 * @return	void
-	 * @throws	BadMethodCallException	If this method was called without prior valid() call
 	 */
-	public function readNextBlock () {
-		// Is there nothing to read?
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: CALLED!');
-		if (!$this->isValid()) {
-			// Nothing to read
-			throw new BadMethodCallException('next() invoked but no valid current block (EOF?)');
-		}
-
+	private function readNextBlock () {
 		// First calculate minimum block length
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: this->seekPosition=%d', $this->determineSeekPosition()));
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: this->seekPosition=%d - CALLED!', $this->getSeekPosition()));
 		$length = $this->getIndexInstance()->calculateMinimumBlockLength();
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: length=%d', $length));
 
 		// Read possibly back-buffered bytes from previous call of next().
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: this->seekPosition=%d,length=%d', $this->getSeekPosition(), $length));
 		$data = $this->getBackBuffer();
 
 		/*
@@ -900,42 +873,40 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 		 * "block" may not fit, so this loop will continue until the EOB or EOF
 		 * has been reached whatever comes first.
 		 */
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: data()=%d', strlen($data)));
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: this->seekPosition=%d,data()=%d', $this->getSeekPosition(), strlen($data)));
 		while ((!$this->isEndOfFileReached()) && (empty($data) || !self::isBlockSeparatorFound($data))) {
 			// Then read the next possible block
-			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Calling this->read(%d) ...', $length));
+			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: this->seekPosition=%d, calling this->read(%d) ...', $this->getSeekPosition(), $length));
 			$block = $this->read($length);
 
-			// Is it all empty?
+			// Is the block empty?
 			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: block()=%d,length=%d', strlen($block), $length));
-			if (strlen(trim($block, chr(0))) == 0) {
-				// Mark this block as empty
-				//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Calling this->markCurrentBlockAsEmpty(%d) ...', strlen($block)));
-				$this->markCurrentBlockAsEmpty(strlen($block));
-
-				// Exit look
-				//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Empty block found ... - BREAK!');
-				break;
+			if (empty(trim($block, chr(0)))) {
+				// Mark it as empty
+				//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: this->seekPosition=%d, calling this->markCurrentBlockAsEmpty(%d) ...', $this->getSeekPosition(), $length));
+				$this->markCurrentBlockAsEmpty($length);
 			}
 
 			// At this block then
 			$data .= $block;
 
-			// A debug message
-			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: data(%d)=%s', strlen($data), $data));
+			// Debug message
+			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: this->seekPosition=%d,data()=%d', $this->getSeekPosition(), strlen($data)));
 		}
 
 		/*
 		 * Init back-buffer which is the data that has been found beyond the
 		 * separator.
 		 */
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->initBackBuffer(), clearing this->currentBlock ...');
 		$this->initBackBuffer();
+		$this->setCurrentBlock('');
 
 		// Is $data empty?
 		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: data(%d)=%s', strlen($data), $data));
-		if (empty($data)) {
+		if (empty(trim($data, chr(0)))) {
 			// Yes, maybe whole file was ...
-			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Maybe empty file found - EXIT!');
+			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: this->seekPosition=%d, maybe empty file found - EXIT!', $this->getSeekPosition()));
 			return;
 		}
 
@@ -948,8 +919,9 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 		$this->setCurrentBlock($dataArray[0]);
 
 		// Is back buffere data found?
-		if (isset($dataArray[1])) {
+		if (!empty(trim($dataArray[1], chr(0)))) {
 			// Set back buffer
+			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Setting this->backBuffer=%s ...', $dataArray[1]));
 			$this->setBackBuffer($dataArray[1]);
 		}
 
@@ -957,42 +929,92 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: EXIT!');
 	}
 
+	/**
+	 * Pre-allocates file (if enabled) with some space for later faster write access.
+	 *
+	 * @param	$type	Type of the file
+	 * @return	void
+	 * @throws	InvalidArgumentException	If a parameter is empty
+	 * @throws	BadMethodCallException	If this->stackInstance is not properly set
+	 */
+	protected function preAllocateFileByTypeLength (string $type, int $minimumBlockLength) {
+		// Is it enabled?
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: type=%s,minimumBlockLength=%d - CALLED!', $type, $minimumBlockLength));
+		if (empty($type)) {
+			// Empty type
+			throw new InvalidArgumentException('Parameter "type" is empty');
+		} elseif ($minimumBlockLength < 1) {
+			// Invalid block length
+			throw new InvalidArgumentException(sprintf('Parameter minimumBlockLength=%d is not valid', $minimumBlockLength));
+		} elseif (FrameworkBootstrap::getConfigurationInstance()->getConfigEntry($type . '_pre_allocate_enabled') != 'Y') {
+			// Don't continue here.
+			self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Not pre-allocating file.'));
+			return;
+		}
+
+		// Get file size
+		$fileSize = $this->getFileSize();
+
+		// Calulcate seek position
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: minimumBlockLength=%d,fileSize=%d', $minimumBlockLength, $fileSize));
+		$seekPosition = $this->getHeaderSize() + $minimumBlockLength * FrameworkBootstrap::getConfigurationInstance()->getConfigEntry($type . '_pre_allocate_count') + $fileSize ;
+
+		// Now simply write a NUL there. This will pre-allocate the file.
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Calling this->writeAtPosition(%d,NUL) ...', $seekPosition));
+		$this->writeAtPosition($seekPosition, chr(0));
+
+		// Is the seek position zero?
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: fileSize=%d', $fileSize));
+		if ($fileSize == 0) {
+			// Mark file as gaps-only
+			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: Calling this->markGapsOnly(%s,%d) ...', $type, $minimumBlockLength));
+			$this->markFileGapsOnly($type, $minimumBlockLength);
+		} else {
+			// Analyze file structure
+			//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->analyzeFileStructure() ...');
+			$this->analyzeFileStructure();
+		}
+
+		// Rewind seek position
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: Calling this->rewind() ...');
+		$this->rewind();
+
+		// Trace message
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: EXIT!');
+	}
+
 	/**
 	 * 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
-	 * @throws	UnexpectedValueException	If some value is not expected
+	 * @throws	InvalidArgumentException	If a parameter is not valid
 	 */
-	public function isValid () {
-		// First calculate minimum block length
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: CALLED!');
-		$length = $this->getIndexInstance()->calculateMinimumBlockLength();
-
-		// Short be more than zero!
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: length=%d', $length));
+	protected function isValidByLength (int $length) {
+		// Validate parameter
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: length=%d - CALLED!', $length));
 		if ($length < 1) {
-			// Throw UVE
-			throw new UnexpectedValueException(sprintf('length=%d is not expected', $length));
+			// Throw IAE
+			throw new InvalidArgumentException(sprintf('Parameter length=%d is not valid', $length));
 		}
 
 		// Get current seek position
 		$seekPosition = $this->determineSeekPosition();
 
 		// Then try to read it
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: seekPosition=%d', $seekPosition));
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: seekPosition=%d', $seekPosition));
 		$data = $this->read($length);
 
 		// If some bytes could be read, all is fine
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: data[%s]()=%d', gettype($data), strlen($data)));
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: data[%s]()=%d', gettype($data), strlen($data)));
 		$isValid = ((is_string($data)) && (strlen($data) > 0));
 
 		// Get header size
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: isValid=%d', intval($isValid)));
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: isValid=%d', intval($isValid)));
 		$headerSize = $this->getHeaderSize();
 
 		// Is the seek position at or beyond the header?
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: seekPosition=%d,headerSize=%d', $seekPosition, $headerSize));
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: seekPosition=%d,headerSize=%d', $seekPosition, $headerSize));
 		if ($seekPosition >= $headerSize) {
 			// Seek back to old position
 			$isValid = ($isValid && $this->seek($seekPosition) === 0);
@@ -1002,7 +1024,7 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 		}
 
 		// Return result
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: isValid=%d - EXIT!', intval($isValid)));
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-BINARY-FILE: isValid=%d - EXIT!', intval($isValid)));
 		return $isValid;
 	}
 
@@ -1032,20 +1054,6 @@ abstract class BaseBinaryFile extends BaseAbstractFile implements BinaryFile {
 		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: EXIT!');
 	}
 
-	/**
-	 * Flushes the file header
-	 *
-	 * @return	void
-	 */
-	public function flushFileHeader () {
-		// Call block instance
-		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: CALLED!');
-		$this->getIndexInstance()->flushFileHeader();
-
-		// Trace message
-		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-BINARY-FILE: EXIT!');
-	}
-
 	/**
 	 * Searches for next suitable gap the given length of data can fit in
 	 * including padding bytes.
diff --git a/framework/main/classes/file_directories/binary/index/class_IndexFile.php b/framework/main/classes/file_directories/binary/index/class_IndexFile.php
index 98eeede6..fd07bd64 100644
--- a/framework/main/classes/file_directories/binary/index/class_IndexFile.php
+++ b/framework/main/classes/file_directories/binary/index/class_IndexFile.php
@@ -3,12 +3,15 @@
 namespace Org\Mxchange\CoreFramework\Filesystem\Index;
 
 // Import framework stuff
+use Org\Mxchange\CoreFramework\Bootstrap\FrameworkBootstrap;
 use Org\Mxchange\CoreFramework\Filesystem\File\BaseBinaryFile;
 use Org\Mxchange\CoreFramework\Filesystem\Index\IndexableFile;
 use Org\Mxchange\CoreFramework\Generic\UnsupportedOperationException;
 use Org\Mxchange\CoreFramework\Index\Indexable;
 
 // Import SPL stuff
+use \BadMethodCallException;
+use \InvalidArgumentException;
 use \SplFileInfo;
 
 /**
@@ -65,11 +68,97 @@ class IndexFile extends BaseBinaryFile implements IndexableFile {
 		// Init this abstract file
 		$indexFileInstance->initFile($indexInfoInstance);
 
+		// Init counters and gaps array
+		$indexFileInstance->initCountersGapsArray();
+
 		// Return the prepared instance
 		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('INDEX-FILE: indexFileInstance=%s - EXIT!', $indexFileInstance->__toString()));
 		return $indexFileInstance;
 	}
 
+	/**
+	 * Flushes the file header
+	 *
+	 * @return	void
+	 * @throws	BadMethodCallException	If this->indexInstance is not properly set
+	 */
+	public function flushFileHeader () {
+		// Validate call
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('INDEX-FILE: CALLED!');
+		if (!($this->getIndexInstance() instanceof Indexable)) {
+			// Index instance not set
+			throw new BadMethodCallException('this->indexInstance[] is not properly set.');
+		}
+
+		// Call block instance
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('INDEX-FILE: Calling this->indexInstance->flushFileHeader() ...');
+		$this->getIndexInstance()->flushFileHeader();
+
+		// Trace message
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('INDEX-FILE: EXIT!');
+	}
+
+	/**
+	 * Pre-allocates file (if enabled) with some space for later faster write access.
+	 *
+	 * @param	$type	Type of the file
+	 * @return	void
+	 * @throws	InvalidArgumentException	If a parameter is empty
+	 * @throws	BadMethodCallException	If this->indexInstance is not properly set
+	 */
+	public function preAllocateFile (string $type) {
+		// Is it enabled?
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('INDEX-FILE: type=%s - CALLED!', $type));
+		if (empty($type)) {
+			// Empty type
+			throw new InvalidArgumentException('Parameter "type" is empty');
+		} elseif (!($this->getIndexInstance() instanceof Indexable)) {
+			// Index instance not set
+			throw new BadMethodCallException('this->indexInstance[] is not properly set.');
+		}
+
+		// Message to user
+		self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('INDEX-FILE: Pre-allocating file ...');
+
+		// Calculate minimum block length
+		$minimumBlockLength = $this->getIndexInstance()->calculateMinimumBlockLength();
+
+		// Call protected method
+		$this->preAllocateFileByTypeLength($type, $minimumBlockLength);
+
+		// Trace message
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('INDEX-FILE: EXIT!');
+	}
+
+	/**
+	 * 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	$isValid	Whether the next entry is valid
+	 * @throws	UnexpectedValueException	If some value is not expected
+	 * @throws	BadMethodCallException	If this->indexInstance is not properly set
+	 */
+	public function isValid () {
+		// Validate call
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('INDEX-FILE: CALLED!');
+		if (!($this->getIndexInstance() instanceof Indexable)) {
+			// Index instance not set
+			throw new BadMethodCallException('this->indexInstance[] is not properly set.');
+		}
+
+		// Get length from index
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('INDEX-FILE: Calling this->indexInstance->calculateMinimumBlockLength() ...');
+		$length = $this->getIndexInstance()->calculateMinimumBlockLength();
+
+		// Call protected method
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('INDEX-FILE: Calling this->isValidByLength(%d) ...', $length));
+		$isValid = $this->isValidByLength($length);
+
+		// Return result
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('INDEX-FILE: isValid=%d - EXIT!', intval($isValid)));
+		return $isValid;
+	}
+
 	/**
 	 * Writes given value to the file and returns a hash and gap position for it
 	 *
diff --git a/framework/main/classes/file_directories/binary/stack/class_StackFile.php b/framework/main/classes/file_directories/binary/stack/class_StackFile.php
index ed3497d5..d211aa1f 100644
--- a/framework/main/classes/file_directories/binary/stack/class_StackFile.php
+++ b/framework/main/classes/file_directories/binary/stack/class_StackFile.php
@@ -3,6 +3,7 @@
 namespace Org\Mxchange\CoreFramework\Stack\File;
 
 // Import framework stuff
+use Org\Mxchange\CoreFramework\Bootstrap\FrameworkBootstrap;
 use Org\Mxchange\CoreFramework\Filesystem\Stack\FileStacker;
 use Org\Mxchange\CoreFramework\Filesystem\File\BaseBinaryFile;
 use Org\Mxchange\CoreFramework\Generic\UnsupportedOperationException;
@@ -10,6 +11,7 @@ use Org\Mxchange\CoreFramework\Stack\File\StackableFile;
 use Org\Mxchange\CoreFramework\Utils\String\StringUtils;
 
 // Import SPL stuff
+use \BadMethodCallException;
 use \InvalidArgumentException;
 use \SplFileInfo;
 
@@ -51,22 +53,108 @@ class StackFile extends BaseBinaryFile implements FileStacker {
 	 *
 	 * @param	$infoInstance	An instance of a SplFileInfo class
 	 * @param	$stackInstance	An instance of a StackableFile class
-	 * @return	$fileInstance	An instance of this File class
+	 * @return	$stackFileInstance	An instance of this File class
 	 */
 	public final static function createStackFile (SplFileInfo $infoInstance, StackableFile $stackInstance) {
 		// Get a new instance
 		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('STACK-FILE: infoInstance[%s]=%s,stackInstance=%s - CALLED!', get_class($infoInstance), $infoInstance, $stackInstance->__toString()));
-		$fileInstance = new StackFile();
+		$stackFileInstance = new StackFile();
 
 		// Set stack instance here for callbacks
-		$fileInstance->setStackInstance($stackInstance);
+		$stackFileInstance->setStackInstance($stackInstance);
 
 		// Init this abstract file
-		$fileInstance->initFile($infoInstance);
+		$stackFileInstance->initFile($infoInstance);
+
+		// Init counters and gaps array
+		$stackFileInstance->initCountersGapsArray();
 
 		// Return the prepared instance
-		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('STACK-FILE: fileInstance=%s - EXIT!', $fileInstance->__toString()));
-		return $fileInstance;
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('STACK-FILE: stackFileInstance=%s - EXIT!', $stackFileInstance->__toString()));
+		return $stackFileInstance;
+	}
+
+	/**
+	 * Flushes the file header
+	 *
+	 * @return	void
+	 * @throws	BadMethodCallException	If this->stackInstance is not properly set
+	 */
+	public function flushFileHeader () {
+		// Validate call
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('STACK-FILE: CALLED!');
+		if (!($this->getStackInstance() instanceof StackableFIle)) {
+			// Index instance not set
+			throw new BadMethodCallException('this->stackInstance[] is not properly set.');
+		}
+
+		// Call block instance
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('STACK-FILE: Calling this->indexInstance->flushFileHeader() ...');
+		$this->getStackInstance()->flushFileHeader();
+
+		// Trace message
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('STACK-FILE: EXIT!');
+	}
+
+	/**
+	 * Pre-allocates file (if enabled) with some space for later faster write access.
+	 *
+	 * @param	$type	Type of the file
+	 * @return	void
+	 * @throws	InvalidArgumentException	If a parameter is empty
+	 * @throws	BadMethodCallException	If this->stackInstance is not properly set
+	 */
+	public function preAllocateFile (string $type) {
+		// Is it enabled?
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('STACK-FILE: type=%s - CALLED!', $type));
+		if (empty($type)) {
+			// Empty type
+			throw new InvalidArgumentException('Parameter "type" is empty');
+		} elseif (!($this->getStackInstance() instanceof StackableFile) && !($this->getStackInstance() instanceof StackableFile)) {
+			// Index instance not set
+			throw new BadMethodCallException('this->stackInstance[] and this->pointerInstance are not properly set.');
+		}
+
+		// Message to user
+		self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('STACK-FILE: Pre-allocating file ...');
+
+		// Calculate minimum block length and get file size
+		$minimumBlockLength = $this->getStackInstance()->calculateMinimumBlockLength();
+
+		// Call protected method
+		$this->preAllocateFileByTypeLength($type, $minimumBlockLength);
+
+		// Trace message
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('STACK-FILE: EXIT!');
+	}
+
+	/**
+	 * 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	$isValid	Whether the next entry is valid
+	 * @throws	UnexpectedValueException	If some value is not expected
+	 * @throws	BadMethodCallException	If this->stackInstance is not properly set
+	 */
+	public function isValid () {
+		// Validate call
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('STACK-FILE: CALLED!');
+		if (!($this->getStackInstance() instanceof StackableFile)) {
+			// Index instance not set
+			throw new BadMethodCallException('this->stackInstance[] is not properly set.');
+		}
+
+		// Get length from index
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('STACK-FILE: Calling this->stackInstance->calculateMinimumBlockLength() ...');
+		$length = $this->getStackInstance()->calculateMinimumBlockLength();
+
+		// Call protected method
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('STACK-FILE: Calling this->isValidByLength(%d) ...', $length));
+		$isValid = $this->isValidByLength($length);
+
+		// Return result
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('STACK-FILE: isValid=%d - EXIT!', intval($isValid)));
+		return $isValid;
 	}
 
 	/**
diff --git a/framework/main/classes/index/class_BaseIndex.php b/framework/main/classes/index/class_BaseIndex.php
index 1db19d8c..6ac3f2c6 100644
--- a/framework/main/classes/index/class_BaseIndex.php
+++ b/framework/main/classes/index/class_BaseIndex.php
@@ -53,15 +53,4 @@ abstract class BaseIndex extends BaseFrameworkSystem implements Indexable {
 		parent::__construct($className);
 	}
 
-	/**
-	 * Checks if this index has been fully and properly loaded.
-	 *
-	 * @return	$isLoaded	Whether this index has been loaded
-	 */
-	public function isIndexLoaded () {
-		// Trace message
-		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-INDEX: CALLED!');
-		/* DEBUG-DIE: */ ApplicationEntryPoint::exitApplication(sprintf('[%s:%d]: this=%s', __METHOD__, __LINE__, print_r($this, true)));
-	}
-
 }
diff --git a/framework/main/classes/index/file/class_BaseFileIndex.php b/framework/main/classes/index/file/class_BaseFileIndex.php
index 84cd7834..073907dc 100644
--- a/framework/main/classes/index/file/class_BaseFileIndex.php
+++ b/framework/main/classes/index/file/class_BaseFileIndex.php
@@ -315,8 +315,15 @@ abstract class BaseFileIndex extends BaseIndex implements FileIndexer {
 	 * @return	$isLoaded	Whether this index has been loaded
 	 */
 	public function isIndexLoaded () {
-		// Trace message
-		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-FILE-INDEX: CALLED!');
+		// Is the file gaps-only?
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-INDEX: CALLED!');
+		if ($this->getIteratorInstance()->isFileGapsOnly()) {
+			// Then skip below code as this implies the file has been fully analyzed and "loaded"
+			/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-INDEX: Underlaying file is gaps-only: Returning TRUE ... - EXIT!');
+			return TRUE;
+		}
+
+		// Debug message
 		/* DEBUG-DIE: */ ApplicationEntryPoint::exitApplication(sprintf('[%s:%d]: this=%s', __METHOD__, __LINE__, print_r($this, true)));
 	}
 
diff --git a/framework/main/classes/iterator/file/class_FileIterator.php b/framework/main/classes/iterator/file/class_FileIterator.php
index f6eaaae3..ac47c774 100644
--- a/framework/main/classes/iterator/file/class_FileIterator.php
+++ b/framework/main/classes/iterator/file/class_FileIterator.php
@@ -227,11 +227,11 @@ class FileIterator extends BaseIterator implements SeekableWritableFileIterator
 	 */
 	public function analyzeFileStructure () {
 		// Just call the file instance
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('FILE-ITERATOR: CALLED!');
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('FILE-ITERATOR: CALLED!');
 		$this->getBinaryFileInstance()->analyzeFileStructure();
 
 		// Trace message
-		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('FILE-ITERATOR: EXIT!');
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('FILE-ITERATOR: EXIT!');
 	}
 
 	/**
@@ -279,6 +279,7 @@ class FileIterator extends BaseIterator implements SeekableWritableFileIterator
 		}
 
 		// Just call the file instance
+		//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('FILE-ITERATOR: Calling this->binaryFileInstance->preAllocateFile(%s) ...', $type));
 		$this->getBinaryFileInstance()->preAllocateFile($type);
 
 		// Trace message
@@ -550,4 +551,20 @@ class FileIterator extends BaseIterator implements SeekableWritableFileIterator
 		return $seekPosition;
 	}
 
+	/**
+	 * 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
+	 */
+	public function isFileGapsOnly () {
+		// Call file instance
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('FILE-ITERATOR: CALLED!');
+		$isGapsOnly = $this->getBinaryFileInstance()->isFileGapsOnly();
+
+		// Return position
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('FILE-ITERATOR: isGapsOnly=%d - EXIT!', $isGapsOnly));
+		return $isGapsOnly;
+	}
+
 }
diff --git a/framework/main/classes/stacker/file/class_BaseFileStack.php b/framework/main/classes/stacker/file/class_BaseFileStack.php
index 6b4a8bfb..4d236a09 100644
--- a/framework/main/classes/stacker/file/class_BaseFileStack.php
+++ b/framework/main/classes/stacker/file/class_BaseFileStack.php
@@ -242,6 +242,17 @@ abstract class BaseFileStack extends BaseStacker {
 		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-FILE-STACK: Calling this->iteratorInstance->initCountersGapsArray() ...');
 		$this->getIteratorInstance()->initCountersGapsArray();
 
+		/*
+		 * Get stack index instance. This can be used for faster
+		 * "defragmentation" and startup.
+		 */
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: Creating index instance for fileInfoInstance[%s]=%s,type=%s ...', get_class($fileInfoInstance), $fileInfoInstance, $type));
+		$indexInstance = FileStackIndexFactory::createFileStackIndexInstance($fileInfoInstance, $type);
+
+		// And set it here
+		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: indexInstance=%s', $indexInstance->__toString()));
+		$this->setIndexInstance($indexInstance);
+
 		// Is the file's header initialized?
 		if (!$this->getIteratorInstance()->isFileHeaderInitialized()) {
 			// First pre-allocate a bit
@@ -257,17 +268,6 @@ abstract class BaseFileStack extends BaseStacker {
 		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-FILE-STACK: Calling this->readStackHeader() ...');
 		$this->readStackHeader();
 
-		/*
-		 * Get stack index instance. This can be used for faster
-		 * "defragmentation" and startup.
-		 */
-		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: Creating index instance for fileInfoInstance[%s]=%s,type=%s ...', get_class($fileInfoInstance), $fileInfoInstance, $type));
-		$indexInstance = FileStackIndexFactory::createFileStackIndexInstance($fileInfoInstance, $type);
-
-		// And set it here
-		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: indexInstance=%s', $indexInstance->__toString()));
-		$this->setIndexInstance($indexInstance);
-
 		// Is the index loaded correctly and the stack file is just created?
 		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('BASE-FILE-STACK: Calling this->indexInstance->isIndexLoaded() ...');
 		if (!$this->getIndexInstance()->isIndexLoaded()) {
@@ -729,9 +729,9 @@ abstract class BaseFileStack extends BaseStacker {
 		// Return gap position, hash and length of raw data
 		/* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: stackName=%s,hash=%s,rawData()=%d - EXIT!', $stackName, $hash, strlen($rawData)));
 		return [
-			self::ARRAY_NAME_GAP_POSITION => $gapPosition,
-			self::ARRAY_NAME_HASH         => $hash,
-			self::ARRAY_NAME_DATA_LENGTH  => strlen($rawData),
+			StackableFile::ARRAY_NAME_GAP_POSITION => $gapPosition,
+			StackableFile::ARRAY_NAME_HASH         => $hash,
+			StackableFile::ARRAY_NAME_DATA_LENGTH  => strlen($rawData),
 		];
 	}
 
diff --git a/framework/main/interfaces/criteria/search/class_LocalSearchCriteria.php b/framework/main/interfaces/criteria/search/class_LocalSearchCriteria.php
index 1272c20f..59be75a1 100644
--- a/framework/main/interfaces/criteria/search/class_LocalSearchCriteria.php
+++ b/framework/main/interfaces/criteria/search/class_LocalSearchCriteria.php
@@ -35,7 +35,7 @@ interface LocalSearchCriteria extends Criteria {
 	 * @return	void
 	 * @todo	Find a nice casting here. (int) allows until and including 32766.
 	 */
-	function setLimit ($limit);
+	function setLimit (int $limit);
 
 	/**
 	 * "Setter" for limit from a configuration entry
@@ -43,7 +43,7 @@ interface LocalSearchCriteria extends Criteria {
 	 * @param	$configEntry	The configuration entry which hold a number as limit
 	 * @return	void
 	 */
-	function setConfiguredLimit ($configEntry);
+	function setConfiguredLimit (string $configEntry);
 
 	/**
 	 * Getter for limit
@@ -59,7 +59,7 @@ interface LocalSearchCriteria extends Criteria {
 	 * @return	void
 	 * @todo	Find a nice casting here. (int) allows until and including 32766.
 	 */
-	function setSkip ($skip);
+	function setSkip (int $skip);
 
 	/**
 	 * Getter for skip
@@ -76,7 +76,8 @@ interface LocalSearchCriteria extends Criteria {
 	 * @param	$value			Value to check
 	 * @param	$separator		Separator for "exploding" $value (default: ',')
 	 * @return	$isMatching		Whether the key/value is matching or excluded
+	 * @throws	InvalidArgumentException	If parameter is invalid
 	 */
-	function isCriteriaMatching ($key, $value, $separator = ',');
+	function isCriteriaMatching (string $key, $value, string $separator = ',');
 
 }
diff --git a/framework/main/interfaces/filesystem/binary/class_BinaryFile.php b/framework/main/interfaces/filesystem/binary/class_BinaryFile.php
index 5dcd2c4f..04bc7499 100644
--- a/framework/main/interfaces/filesystem/binary/class_BinaryFile.php
+++ b/framework/main/interfaces/filesystem/binary/class_BinaryFile.php
@@ -110,6 +110,14 @@ interface BinaryFile extends Filesystem {
 	 */
 	function getFileSize ();
 
+	/**
+	 * 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
+	 */
+	function isFileGapsOnly();
+
 	/**
 	 * Searches for next suitable gap the given length of data can fit in
 	 * including padding bytes.
diff --git a/framework/main/interfaces/iterator/file/class_SeekableWritableFileIterator.php b/framework/main/interfaces/iterator/file/class_SeekableWritableFileIterator.php
index 64e49f53..65c57c30 100644
--- a/framework/main/interfaces/iterator/file/class_SeekableWritableFileIterator.php
+++ b/framework/main/interfaces/iterator/file/class_SeekableWritableFileIterator.php
@@ -136,6 +136,30 @@ interface SeekableWritableFileIterator extends SeekableIterator {
 	 */
 	function getFileSize ();
 
+	/**
+	 * Getter for seek position
+	 *
+	 * @return	$seekPosition	Current seek position (stored here in object)
+	 */
+	function getSeekPosition ();
+
+	/**
+	 * 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
+	 */
+	function searchNextGap (int $length);
+
+	/**
+	 * 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
+	 */
+	function isFileGapsOnly();
+
 	/**
 	 * Writes data at given position
 	 *
@@ -155,13 +179,6 @@ interface SeekableWritableFileIterator extends SeekableIterator {
 	 */
 	function writeAtPosition (int $seedPosition, string $data);
 
-	/**
-	 * Getter for seek position
-	 *
-	 * @return	$seekPosition	Current seek position (stored here in object)
-	 */
-	function getSeekPosition ();
-
 	/**
 	 * Writes given value to the file and returns a hash and gap position for it
 	 *
@@ -181,13 +198,4 @@ interface SeekableWritableFileIterator extends SeekableIterator {
 	 */
 	function writeDataToFreeGap (string $groupId, string $hash, string $encoded);
 
-	/**
-	 * 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
-	 */
-	function searchNextGap (int $length);
-
 }
diff --git a/framework/main/middleware/compressor/class_CompressorChannel.php b/framework/main/middleware/compressor/class_CompressorChannel.php
index 57c7a646..a471b203 100644
--- a/framework/main/middleware/compressor/class_CompressorChannel.php
+++ b/framework/main/middleware/compressor/class_CompressorChannel.php
@@ -70,7 +70,7 @@ class CompressorChannel extends BaseMiddleware implements Registerable {
 			$directoryInstance = ObjectFactory::createObjectByConfiguredName('directory_class', array($baseDir));
 
 			// Read all directories but no sub directories, .htaccess files and NullCompressor class
-			while ($directoryEntry = $directoryInstance->readDirectoryExcept(array('.htaccess', 'class_NullCompressor.php'))) {
+			while ($directoryEntry = $directoryInstance->readDirectoryExcept(array('class_NullCompressor.php'))) {
 				// Debug message
 				//* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('COMPRESSOR: directoryEntry=' . $directoryEntry);