framework/main/classes/stacker/file/class_BaseFileStack.php

   1 <?php
   2 // Own namespace
   3 namespace Org\Mxchange\CoreFramework\Stack\File;
   4
   5 // Import framework stuff
   6 use Org\Mxchange\CoreFramework\Factory\Stack\File\FileStackIndexFactory;
   7 use Org\Mxchange\CoreFramework\Factory\ObjectFactory;
   8 use Org\Mxchange\CoreFramework\Filesystem\File\BaseBinaryFile;
   9 use Org\Mxchange\CoreFramework\Generic\UnsupportedOperationException;
  10 use Org\Mxchange\CoreFramework\Iterator\Filesystem\SeekableWritableFileIterator;
  11 use Org\Mxchange\CoreFramework\Stack\BaseStacker;
  12 use Org\Mxchange\CoreFramework\Stack\File\InvalidMagicException;
  13 use Org\Mxchange\CoreFramework\Stack\File\StackableFile;
  14 use Org\Mxchange\CoreFramework\Traits\Index\IndexableTrait;
  15 use Org\Mxchange\CoreFramework\Traits\Iterator\IteratorTrait;
  16 use Org\Mxchange\CoreFramework\Utils\String\StringUtils;
  17
  18 // Import SPL stuff
  19 use \InvalidArgumentException;
  20 use \SplFileInfo;
  21 use \UnexpectedValueException;
  22
  23 /**
  24  * A general file-based stack class
  25  *
  26  * @author              Roland Haeder <webmaster@ship-simu.org>
  27  * @version             0.0.0
  28  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2020 Core Developer Team
  29  * @license             GNU GPL 3.0 or any newer version
  30  * @link                http://www.ship-simu.org
  31  *
  32  * This program is free software: you can redistribute it and/or modify
  33  * it under the terms of the GNU General Public License as published by
  34  * the Free Software Foundation, either version 3 of the License, or
  35  * (at your option) any later version.
  36  *
  37  * This program is distributed in the hope that it will be useful,
  38  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  39  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  40  * GNU General Public License for more details.
  41  *
  42  * You should have received a copy of the GNU General Public License
  43  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  44  */
  45 abstract class BaseFileStack extends BaseStacker implements StackableFile {
  46         // Load traits
  47         use IteratorTrait;
  48
  49         // Exception codes
  50         const EXCEPTION_BAD_MAGIC = 0xe100;
  51
  52         /**
  53          * Protected constructor
  54          *
  55          * @param       $className      Name of the class
  56          * @return      void
  57          */
  58         protected function __construct (string $className) {
  59                 // Call parent constructor
  60                 parent::__construct($className);
  61         }
  62
  63         /**
  64          * Reads the file header
  65          *
  66          * @return      void
  67          * @todo        To hard assertions here, better rewrite them to exceptions
  68          * @throws      UnexpectedValueException        If header is not proper length
  69          * @throws      InvalidMagicException   If a bad magic was found
  70          */
  71         public function readFileHeader () {
  72                 // First rewind to beginning as the header sits at the beginning ...
  73                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: CALLED!', __METHOD__, __LINE__));
  74                 $this->getIteratorInstance()->rewind();
  75
  76                 // Then read it (see constructor for calculation)
  77                 $data = $this->getIteratorInstance()->read($this->getIteratorInstance()->getHeaderSize());
  78                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: Read %d bytes (%d wanted).', strlen($data), $this->getIteratorInstance()->getHeaderSize()));
  79
  80                 // Have all requested bytes been read?
  81                 if (strlen($data) != $this->getIteratorInstance()->getHeaderSize()) {
  82                         // Bad data length
  83                         throw new UnexpectedValueException(sprintf('data(%d)=%s does not match iteratorInstance->headerSize=%d',
  84                                 strlen($data),
  85                                 $data,
  86                                 $this->getIteratorInstance()->getHeaderSize()
  87                         ));
  88                 }
  89
  90                 // Last character must be the separator
  91                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: data(-1)=%s', dechex(ord(substr($data, -1, 1)))));
  92                 if (substr($data, -1, 1) !== chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES)) {
  93                         // Not valid separator
  94                         throw new UnexpectedValueException(sprintf('data=%s does not have separator=%s at the end.',
  95                                 $data,
  96                                 BaseBinaryFile::SEPARATOR_HEADER_ENTRIES
  97                         ));
  98                 }
  99
 100                 // Okay, then remove it
 101                 $data = substr($data, 0, -1);
 102
 103                 // And update seek position
 104                 $this->getIteratorInstance()->updateSeekPosition();
 105
 106                 /*
 107                  * Now split it:
 108                  *
 109                  * 0 => magic
 110                  * 1 => total entries
 111                  * 2 => current seek position
 112                  */
 113                 $header = explode(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA), $data);
 114
 115                 // Check if the array has only 3 elements
 116                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: header(%d)=%s', count($header), print_r($header, true)));
 117                 if (count($header) != 3) {
 118                         // Header array count is not expected
 119                         throw new UnexpectedValueException(sprintf('data=%s has %d elements, expected 3',
 120                                 $data,
 121                                 count($header)
 122                         ));
 123                 } elseif ($header[0] != StackableFile::STACK_MAGIC) {
 124                         // Bad magic
 125                         throw new InvalidMagicException($data, self::EXCEPTION_BAD_MAGIC);
 126                 }
 127
 128                 // Check length of count and seek position
 129                 if (strlen($header[1]) != BaseBinaryFile::LENGTH_COUNT) {
 130                         // Count length not valid
 131                         throw new UnexpectedValueException(sprintf('header[1](%d)=%s is not expected %d length',
 132                                 strlen($header[1]),
 133                                 $header[1],
 134                                 BaseBinaryFile::LENGTH_COUNT
 135                         ));
 136                 } elseif (strlen($header[1]) != BaseBinaryFile::LENGTH_POSITION) {
 137                         // Position length not valid
 138                         throw new UnexpectedValueException(sprintf('header[2](%d)=%s is not expected %d length',
 139                                 strlen($header[1]),
 140                                 $header[1],
 141                                 BaseBinaryFile::LENGTH_POSITION
 142                         ));
 143                 }
 144
 145                 // Decode count and seek position
 146                 $header[1] = hex2bin($header[1]);
 147                 $header[2] = hex2bin($header[2]);
 148
 149                 // Set header here
 150                 $this->getIteratorInstance()->setHeader($header);
 151
 152                 // Trace message
 153                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: EXIT!', __METHOD__, __LINE__));
 154         }
 155
 156         /**
 157          * Flushes the file header
 158          *
 159          * @return      void
 160          */
 161         public function flushFileHeader () {
 162                 // Put all informations together
 163                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: CALLED!', __METHOD__, __LINE__));
 164                 $header = sprintf('%s%s%s%s%s%s',
 165                         // Magic
 166                         StackableFile::STACK_MAGIC,
 167
 168                         // Separator magic<->count
 169                         chr(BaseBinaryFile::SEPARATOR_HEADER_DATA),
 170
 171                         // Total entries (will be zero) and pad it to 20 chars
 172                         str_pad(StringUtils::dec2hex($this->getIteratorInstance()->getCounter()), BaseBinaryFile::LENGTH_COUNT, '0', STR_PAD_LEFT),
 173
 174                         // Separator count<->seek position
 175                         chr(BaseBinaryFile::SEPARATOR_HEADER_DATA),
 176
 177                         // Position (will be zero)
 178                         str_pad(StringUtils::dec2hex($this->getIteratorInstance()->getSeekPosition(), 2), BaseBinaryFile::LENGTH_POSITION, '0', STR_PAD_LEFT),
 179
 180                         // Separator position<->entries
 181                         chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES)
 182                 );
 183
 184                 // Write it to disk (header is always at seek position 0)
 185                 $this->getIteratorInstance()->writeData(0, $header, false);
 186
 187                 // Trace message
 188                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: EXIT!', __METHOD__, __LINE__));
 189         }
 190
 191         /**
 192          * Initializes this file-based stack.
 193          *
 194          * @param       $fileInfoInstance       An instance of a SplFileInfo class
 195          * @param       $type           Type of this stack (e.g. url_source for URL sources)
 196          * @return      void
 197          * @throws      InvalidArgumentException        If a parameter is invalid
 198          * @todo        Currently the stack file is not cached, please implement a memory-handling class and if enough RAM is found, cache the whole stack file.
 199          */
 200         protected function initFileStack (SplFileInfo $fileInfoInstance, string $type) {
 201                 // Validate parameter
 202                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: fileInfoInstance[%s]=%s,type=%s - CALLED!', get_class($fileInfoInstance), $fileInfoInstance, $type));
 203                 if (empty($type)) {
 204                         // Invalid parameter
 205                         throw new InvalidArgumentException('Parameter "type" is empty');
 206                 }
 207
 208                 // Get a stack file instance
 209                 $stackInstance = ObjectFactory::createObjectByConfiguredName('stack_file_class', array($fileInfoInstance, $this));
 210
 211                 // Get iterator instance
 212                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_iterator_class', array($stackInstance));
 213
 214                 // Set iterator here
 215                 $this->setIteratorInstance($iteratorInstance);
 216
 217                 // Calculate header size
 218                 $this->getIteratorInstance()->setHeaderSize(
 219                         strlen(StackableFile::STACK_MAGIC) +
 220                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA)) +
 221                         BaseBinaryFile::LENGTH_COUNT +
 222                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA)) +
 223                         BaseBinaryFile::LENGTH_POSITION +
 224                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES))
 225                 );
 226
 227                 // Init counters and gaps array
 228                 $this->getIteratorInstance()->initCountersGapsArray();
 229
 230                 // Is the file's header initialized?
 231                 if (!$this->getIteratorInstance()->isFileHeaderInitialized()) {
 232                         // No, then create it (which may pre-allocate the stack)
 233                         $this->getIteratorInstance()->createFileHeader();
 234
 235                         // And pre-allocate a bit
 236                         $this->getIteratorInstance()->preAllocateFile('file_stack');
 237                 }
 238
 239                 // Load the file header
 240                 $this->readFileHeader();
 241
 242                 // Count all entries in file
 243                 $this->getIteratorInstance()->analyzeFile();
 244
 245                 /*
 246                  * Get stack index instance. This can be used for faster
 247                  * "defragmentation" and startup.
 248                  */
 249                 $indexInstance = FileStackIndexFactory::createFileStackIndexInstance($fileInfoInstance, $type);
 250
 251                 // And set it here
 252                 $this->setIndexInstance($indexInstance);
 253         }
 254
 255         /**
 256          * Adds a value to given stack
 257          *
 258          * @param       $stackerName    Name of the stack
 259          * @param       $value                  Value to add to this stacker
 260          * @return      void
 261          * @throws      FullStackerException    If the stack is full
 262          * @throws      InvalidArgumentException        Not all variable types are wanted here
 263          */
 264         protected function addValue (string $stackerName, $value) {
 265                 // Do some tests
 266                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('stackerName=%s,value[%s]=%s - CALLED!', $stackerName, gettype($value), print_r($value, true)));
 267                 if ($this->isStackFull($stackerName)) {
 268                         // Stacker is full
 269                         throw new FullStackerException(array($this, $stackerName, $value), self::EXCEPTION_STACKER_IS_FULL);
 270                 } elseif (is_resource($value) || is_object($value)) {
 271                         // Not wanted type
 272                         throw new InvalidArgumentException(sprintf('value[]=%s is not supported', gettype($value)));
 273                 }
 274
 275                 /*
 276                  * Now add the value to the file stack which returns gap position, a
 277                  * hash and length of the raw data.
 278                  */
 279                 $data = $this->getIteratorInstance()->writeValueToFile($stackerName, $value);
 280
 281                 // Add the hash and gap position to the index
 282                 $this->getIndexInstance()->addHashToIndex($stackerName, $data);
 283         }
 284
 285         /**
 286          * Get last value from named stacker
 287          *
 288          * @param       $stackerName    Name of the stack
 289          * @return      $value                  Value of last added value
 290          * @throws      BadMethodCallException  If the stack is empty
 291          */
 292         protected function getLastValue (string $stackerName) {
 293                 // Is the stack not yet initialized or full?
 294                 if ($this->isStackEmpty($stackerName)) {
 295                         // Throw an exception
 296                         throw new BadMethodCallException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 297                 } // END - if
 298
 299                 // Now get the last value
 300                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 301                 $value = NULL;
 302
 303                 // Return it
 304                 return $value;
 305         }
 306
 307         /**
 308          * Get first value from named stacker
 309          *
 310          * @param       $stackerName    Name of the stack
 311          * @return      $value                  Value of last added value
 312          * @throws      BadMethodCallException  If the stack is empty
 313          */
 314         protected function getFirstValue (string $stackerName) {
 315                 // Is the stack not yet initialized or full?
 316                 if ($this->isStackEmpty($stackerName)) {
 317                         // Throw an exception
 318                         throw new BadMethodCallException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 319                 } // END - if
 320
 321                 // Now get the first value
 322                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 323                 $value = NULL;
 324
 325                 // Return it
 326                 return $value;
 327         }
 328
 329         /**
 330          * "Pops" last entry from stack
 331          *
 332          * @param       $stackerName    Name of the stack
 333          * @return      $value                  Value "poped" from array
 334          * @throws      BadMethodCallException  If the stack is empty
 335          */
 336         protected function popLast (string $stackerName) {
 337                 // Is the stack not yet initialized or full?
 338                 if ($this->isStackEmpty($stackerName)) {
 339                         // Throw an exception
 340                         throw new BadMethodCallException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 341                 } // END - if
 342
 343                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 344                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 345                 return NULL;
 346         }
 347
 348         /**
 349          * "Pops" first entry from stack
 350          *
 351          * @param       $stackerName    Name of the stack
 352          * @return      $value                  Value "shifted" from array
 353          * @throws      BadMethodCallException  If the named stacker is empty
 354          */
 355         protected function popFirst (string $stackerName) {
 356                 // Is the stack not yet initialized or full?
 357                 if ($this->isStackEmpty($stackerName)) {
 358                         // Throw an exception
 359                         throw new BadMethodCallException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 360                 } // END - if
 361
 362                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 363                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 364                 return NULL;
 365         }
 366
 367         /**
 368          * Checks whether the given stack is full
 369          *
 370          * @param       $stackerName    Name of the stack
 371          * @return      $isFull                 Whether the stack is full
 372          */
 373         protected function isStackFull (string $stackerName) {
 374                 // File-based stacks will only run full if the disk space is low.
 375                 // @TODO Please implement this, returning false
 376                 $isFull = false;
 377
 378                 // Return result
 379                 return $isFull;
 380         }
 381
 382         /**
 383          * Checks whether the given stack is empty
 384          *
 385          * @param       $stackerName            Name of the stack
 386          * @return      $isEmpty                        Whether the stack is empty
 387          * @throws      BadMethodCallException  If given stack is missing
 388          */
 389         public function isStackEmpty (string $stackerName) {
 390                 // So, is the stack empty?
 391                 $isEmpty = (($this->getStackCount($stackerName)) == 0);
 392
 393                 // Return result
 394                 return $isEmpty;
 395         }
 396
 397         /**
 398          * Initializes given stacker
 399          *
 400          * @param       $stackerName    Name of the stack
 401          * @param       $forceReInit    Force re-initialization
 402          * @return      void
 403          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 404          */
 405         public function initStack (string $stackerName, bool $forceReInit = false) {
 406                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 407         }
 408
 409         /**
 410          * Initializes all stacks
 411          *
 412          * @return      void
 413          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 414          */
 415         public function initStacks (array $stacks, bool $forceReInit = false) {
 416                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 417         }
 418
 419         /**
 420          * Checks whether the given stack is initialized (set in array $stackers)
 421          *
 422          * @param       $stackerName    Name of the stack
 423          * @return      $isInitialized  Whether the stack is initialized
 424          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 425          */
 426         public function isStackInitialized (string $stackerName) {
 427                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 428         }
 429
 430         /**
 431          * Determines whether the EOF has been reached
 432          *
 433          * @return      $isEndOfFileReached             Whether the EOF has been reached
 434          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 435          */
 436         public function isEndOfFileReached () {
 437                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 438         }
 439
 440         /**
 441          * Getter for size of given stack (array count)
 442          *
 443          * @param       $stackerName    Name of the stack
 444          * @return      $count                  Size of stack (array count)
 445          */
 446         public function getStackCount (string $stackerName) {
 447                 // Now, simply return the found count value, this must be up-to-date then!
 448                 return $this->getIteratorInstance()->getCounter();
 449         }
 450
 451         /**
 452          * Calculates minimum length for one entry/block
 453          *
 454          * @return      $length         Minimum length for one entry/block
 455          */
 456         public function calculateMinimumBlockLength () {
 457                 // Calulcate it
 458                 $length =
 459                         // Length of entry group
 460                         BaseBinaryFile::LENGTH_GROUP + strlen(chr(BaseBinaryFile::SEPARATOR_GROUP_HASH)) +
 461                         // Hash + value
 462                         self::getHashLength() + strlen(chr(BaseBinaryFile::SEPARATOR_HASH_VALUE)) + 1 +
 463                         // Final separator
 464                         strlen(chr(BaseBinaryFile::SEPARATOR_ENTRIES));
 465
 466                 // Return it
 467                 return $length;
 468         }
 469
 470         /**
 471          * Initializes counter for valid entries, arrays for damaged entries and
 472          * an array for gap seek positions. If you call this method on your own,
 473          * please re-analyze the file structure. So you are better to call
 474          * analyzeFile() instead of this method.
 475          *
 476          * @return      void
 477          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 478          */
 479         public function initCountersGapsArray () {
 480                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 481         }
 482
 483         /**
 484          * Getter for header size
 485          *
 486          * @return      $totalEntries   Size of file header
 487          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 488          */
 489         public final function getHeaderSize () {
 490                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 491         }
 492
 493         /**
 494          * Setter for header size
 495          *
 496          * @param       $headerSize             Size of file header
 497          * @return      void
 498          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 499          */
 500         public final function setHeaderSize (int $headerSize) {
 501                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 502         }
 503
 504         /**
 505          * Getter for header array
 506          *
 507          * @return      $totalEntries   Size of file header
 508          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 509          */
 510         public final function getHeader () {
 511                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 512         }
 513
 514         /**
 515          * Setter for header
 516          *
 517          * @param       $header         Array for a file header
 518          * @return      void
 519          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 520          */
 521         public final function setHeader (array $header) {
 522                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 523         }
 524
 525         /**
 526          * Updates seekPosition attribute from file to avoid to much access on file.
 527          *
 528          * @return      void
 529          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 530          */
 531         public function updateSeekPosition () {
 532                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 533         }
 534
 535         /**
 536          * Getter for total entries
 537          *
 538          * @return      $totalEntries   Total entries in this file
 539          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 540          */
 541         public final function getCounter () {
 542                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 543         }
 544
 545         /**
 546          * Writes data at given position
 547          *
 548          * @param       $seekPosition   Seek position
 549          * @param       $data                   Data to be written
 550          * @param       $flushHeader    Whether to flush the header (default: flush)
 551          * @return      void
 552          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 553          */
 554         public function writeData (int $seekPosition, string $data, bool $flushHeader = true) {
 555                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: seekPosition=%s,data[]=%s,flushHeader=%d', $seekPosition, gettype($data), intval($flushHeader)));
 556                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 557         }
 558
 559         /**
 560          * Writes given value to the file and returns a hash and gap position for it
 561          *
 562          * @param       $groupId        Group identifier
 563          * @param       $value          Value to be added to the stack
 564          * @return      $data           Hash and gap position
 565          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 566          */
 567         public function writeValueToFile (string $groupId, $value) {
 568                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: groupId=%s,value[%s]=%s', $groupId, gettype($value), print_r($value, true)));
 569                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 570         }
 571
 572         /**
 573          * Searches for next suitable gap the given length of data can fit in
 574          * including padding bytes.
 575          *
 576          * @param       $length                 Length of raw data
 577          * @return      $seekPosition   Found next gap's seek position
 578          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 579          */
 580         public function searchNextGap (int $length) {
 581                 // Not supported here
 582                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: length=%d - CALLED!', $length));
 583                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 584         }
 585
 586         /**
 587          * "Getter" for file size
 588          *
 589          * @return      $fileSize       Size of currently loaded file
 590          */
 591         public function getFileSize () {
 592                 // Call iterator's method
 593                 return $this->getIteratorInstance()->getFileSize();
 594         }
 595
 596         /**
 597          * Writes given raw data to the file and returns a gap position and length
 598          *
 599          * @param       $groupId        Group identifier
 600          * @param       $hash           Hash from encoded value
 601          * @param       $encoded        Encoded value to be written to the file
 602          * @return      $data           Gap position and length of the raw data
 603          */
 604         public function writeDataToFreeGap (string $groupId, string $hash, string $encoded) {
 605                 // Raw data been written to the file
 606                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: groupId=%s,hash=%s,encoded()=%d - CALLED!', $groupId, $hash, strlen($encoded)));
 607                 $rawData = sprintf('%s%s%s%s%s',
 608                         $groupId,
 609                         BaseBinaryFile::SEPARATOR_GROUP_HASH,
 610                         hex2bin($hash),
 611                         BaseBinaryFile::SEPARATOR_HASH_VALUE,
 612                         $encoded
 613                 );
 614
 615                 // Search for next free gap
 616                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: groupId=%s,hash=%s,rawData()=%d', $groupId, $hash, strlen($rawData)));
 617                 $gapPosition = $this->getIteratorInstance()->searchNextGap(strlen($rawData));
 618
 619                 // Gap position cannot be smaller than header length + 1
 620                 if ($gapPosition <= $this->getIteratorInstance()->getHeaderSize()) {
 621                         // Improper gap position
 622                         throw new UnexpectedValueException(sprintf('gapPosition[%s]=%d is not larger than headerSize=%d',
 623                                 gettype($gapPosition),
 624                                 $gapPosition,
 625                                 $this->getIteratorInstance()->getHeaderSize()
 626                         ));
 627                 }
 628
 629                 // Then write the data at that gap
 630                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: groupId=%s,hash=%s,gapPosition=%s', $groupId, $hash, $gapPosition));
 631                 $this->getIteratorInstance()->writeData($gapPosition, $rawData);
 632
 633                 // Return gap position, hash and length of raw data
 634                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: groupId=%s,hash=%s,rawData()=%d - EXIT!', $groupId, $hash, strlen($rawData)));
 635                 return [
 636                         self::ARRAY_NAME_GAP_POSITION => $gapPosition,
 637                         self::ARRAY_NAME_HASH         => $hash,
 638                         self::ARRAY_NAME_DATA_LENGTH  => strlen($rawData),
 639                 ];
 640         }
 641
 642 }