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

   1 <?php
   2 // Own namespace
   3 namespace Org\Mxchange\CoreFramework\Stacker\Filesystem;
   4
   5 // Import framework stuff
   6 use Org\Mxchange\CoreFramework\Factory\Filesystem\Stack\FileStackIndexFactory;
   7 use Org\Mxchange\CoreFramework\Factory\ObjectFactory;
   8 use Org\Mxchange\CoreFramework\FileStack\InvalidMagicException;
   9 use Org\Mxchange\CoreFramework\Filesystem\File\BaseBinaryFile;
  10 use Org\Mxchange\CoreFramework\Generic\UnsupportedOperationException;
  11 use Org\Mxchange\CoreFramework\Index\Indexable;
  12 use Org\Mxchange\CoreFramework\Iterator\Filesystem\SeekableWritableFileIterator;
  13 use Org\Mxchange\CoreFramework\Stacker\BaseStacker;
  14 use Org\Mxchange\CoreFramework\Traits\Iterator\IteratorTrait;
  15 use Org\Mxchange\CoreFramework\Utils\String\StringUtils;
  16
  17 // Import SPL stuff
  18 use \SplFileInfo;
  19 use \UnexpectedValueException;
  20
  21 /**
  22  * A general file-based stack class
  23  *
  24  * @author              Roland Haeder <webmaster@ship-simu.org>
  25  * @version             0.0.0
  26  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2020 Core Developer Team
  27  * @license             GNU GPL 3.0 or any newer version
  28  * @link                http://www.ship-simu.org
  29  *
  30  * This program is free software: you can redistribute it and/or modify
  31  * it under the terms of the GNU General Public License as published by
  32  * the Free Software Foundation, either version 3 of the License, or
  33  * (at your option) any later version.
  34  *
  35  * This program is distributed in the hope that it will be useful,
  36  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  37  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  38  * GNU General Public License for more details.
  39  *
  40  * You should have received a copy of the GNU General Public License
  41  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  42  */
  43 abstract class BaseFileStack extends BaseStacker {
  44         // Load traits
  45         use IteratorTrait;
  46
  47         // Exception codes
  48         const EXCEPTION_BAD_MAGIC = 0xe100;
  49
  50         /**
  51          * Magic for this stack
  52          */
  53         const STACK_MAGIC = 'STACKv0.1';
  54
  55         /**
  56          * Name of array index for gap position
  57          */
  58         const ARRAY_INDEX_GAP_POSITION = 'gap';
  59
  60         /**
  61          * Name of array index for hash
  62          */
  63         const ARRAY_INDEX_HASH = 'hash';
  64
  65         /**
  66          * Name of array index for length of raw data
  67          */
  68         const ARRAY_INDEX_DATA_LENGTH = 'length';
  69
  70         /**
  71          * An instance of an Indexable class
  72          */
  73         private $indexInstance = NULL;
  74
  75         /**
  76          * Protected constructor
  77          *
  78          * @param       $className      Name of the class
  79          * @return      void
  80          */
  81         protected function __construct (string $className) {
  82                 // Call parent constructor
  83                 parent::__construct($className);
  84         }
  85
  86         /**
  87          * Setter for Indexable instance
  88          *
  89          * @param       $indexInstance  An instance of an Indexable class
  90          * @return      void
  91          */
  92         protected final function setIndexInstance (Indexable $indexInstance) {
  93                 $this->indexInstance = $indexInstance;
  94         }
  95
  96         /**
  97          * Getter for Indexable instance
  98          *
  99          * @return      $indexInstance  An instance of an Indexable class
 100          */
 101         public final function getIndexInstance () {
 102                 return $this->indexInstance;
 103         }
 104
 105         /**
 106          * Reads the file header
 107          *
 108          * @return      void
 109          * @todo        To hard assertions here, better rewrite them to exceptions
 110          * @throws      UnexpectedValueException        If header is not proper length
 111          * @throws      InvalidMagicException   If a bad magic was found
 112          */
 113         public function readFileHeader () {
 114                 // First rewind to beginning as the header sits at the beginning ...
 115                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: CALLED!', __METHOD__, __LINE__));
 116                 $this->getIteratorInstance()->rewind();
 117
 118                 // Then read it (see constructor for calculation)
 119                 $data = $this->getIteratorInstance()->read($this->getIteratorInstance()->getHeaderSize());
 120                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: Read %d bytes (%d wanted).', strlen($data), $this->getIteratorInstance()->getHeaderSize()));
 121
 122                 // Have all requested bytes been read?
 123                 if (strlen($data) != $this->getIteratorInstance()->getHeaderSize()) {
 124                         // Bad data length
 125                         throw new UnexpectedValueException(sprintf('data(%d)=%s does not match iteratorInstance->headerSize=%d',
 126                                 strlen($data),
 127                                 $data,
 128                                 $this->getIteratorInstance()->getHeaderSize()
 129                         ));
 130                 }
 131
 132                 // Last character must be the separator
 133                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: data(-1)=%s', dechex(ord(substr($data, -1, 1)))));
 134                 if (substr($data, -1, 1) !== chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES)) {
 135                         // Not valid separator
 136                         throw new UnexpectedValueException(sprintf('data=%s does not have separator=%s at the end.',
 137                                 $data,
 138                                 BaseBinaryFile::SEPARATOR_HEADER_ENTRIES
 139                         ));
 140                 }
 141
 142                 // Okay, then remove it
 143                 $data = substr($data, 0, -1);
 144
 145                 // And update seek position
 146                 $this->getIteratorInstance()->updateSeekPosition();
 147
 148                 /*
 149                  * Now split it:
 150                  *
 151                  * 0 => magic
 152                  * 1 => total entries
 153                  * 2 => current seek position
 154                  */
 155                 $header = explode(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA), $data);
 156
 157                 // Set header here
 158                 $this->getIteratorInstance()->setHeader($header);
 159
 160                 // Check if the array has only 3 elements
 161                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: header(%d)=%s', count($header), print_r($header, true)));
 162                 if (count($header) != 3) {
 163                         // Header array count is not expected
 164                         throw new UnexpectedValueException(sprintf('data=%s has %d elements, expected 3',
 165                                 $data,
 166                                 count($header)
 167                         ));
 168                 } elseif ($header[0] != self::STACK_MAGIC) {
 169                         // Bad magic
 170                         throw new InvalidMagicException($data, self::EXCEPTION_BAD_MAGIC);
 171                 }
 172
 173                 // Check length of count and seek position
 174                 if (strlen($header[1]) != BaseBinaryFile::LENGTH_COUNT) {
 175                         // Count length not valid
 176                         throw new UnexpectedValueException(sprintf('header[1](%d)=%s is not expected %d length',
 177                                 strlen($header[1]),
 178                                 $header[1],
 179                                 BaseBinaryFile::LENGTH_COUNT
 180                         ));
 181                 } elseif (strlen($header[1]) != BaseBinaryFile::LENGTH_POSITION) {
 182                         // Position length not valid
 183                         throw new UnexpectedValueException(sprintf('header[2](%d)=%s is not expected %d length',
 184                                 strlen($header[1]),
 185                                 $header[1],
 186                                 BaseBinaryFile::LENGTH_POSITION
 187                         ));
 188                 }
 189
 190                 // Decode count and seek position
 191                 $header[1] = hex2bin($header[1]);
 192                 $header[2] = hex2bin($header[2]);
 193
 194                 // Trace message
 195                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: EXIT!', __METHOD__, __LINE__));
 196         }
 197
 198         /**
 199          * Flushes the file header
 200          *
 201          * @return      void
 202          */
 203         public function flushFileHeader () {
 204                 // Put all informations together
 205                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: CALLED!', __METHOD__, __LINE__));
 206                 $header = sprintf('%s%s%s%s%s%s',
 207                         // Magic
 208                         self::STACK_MAGIC,
 209
 210                         // Separator magic<->count
 211                         chr(BaseBinaryFile::SEPARATOR_HEADER_DATA),
 212
 213                         // Total entries (will be zero) and pad it to 20 chars
 214                         str_pad(StringUtils::dec2hex($this->getIteratorInstance()->getCounter()), BaseBinaryFile::LENGTH_COUNT, '0', STR_PAD_LEFT),
 215
 216                         // Separator count<->seek position
 217                         chr(BaseBinaryFile::SEPARATOR_HEADER_DATA),
 218
 219                         // Position (will be zero)
 220                         str_pad(StringUtils::dec2hex($this->getIteratorInstance()->getSeekPosition(), 2), BaseBinaryFile::LENGTH_POSITION, '0', STR_PAD_LEFT),
 221
 222                         // Separator position<->entries
 223                         chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES)
 224                 );
 225
 226                 // Write it to disk (header is always at seek position 0)
 227                 $this->getIteratorInstance()->writeData(0, $header, false);
 228
 229                 // Trace message
 230                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: EXIT!', __METHOD__, __LINE__));
 231         }
 232
 233         /**
 234          * Initializes this file-based stack.
 235          *
 236          * @param       $fileInfoInstance       An instance of a SplFileInfo class
 237          * @param       $type           Type of this stack (e.g. url_source for URL sources)
 238          * @return      void
 239          * @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.
 240          */
 241         protected function initFileStack (SplFileInfo $fileInfoInstance, string $type) {
 242                 // Get a stack file instance
 243                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: fileInfoInstance=%s,type=%s - CALLED!', $fileInfoInstance, $type));
 244                 $fileInstance = ObjectFactory::createObjectByConfiguredName('stack_file_class', array($fileInfoInstance, $this));
 245
 246                 // Get iterator instance
 247                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_iterator_class', array($fileInstance));
 248
 249                 // Set iterator here
 250                 $this->setIteratorInstance($iteratorInstance);
 251
 252                 // Calculate header size
 253                 $this->getIteratorInstance()->setHeaderSize(
 254                         strlen(self::STACK_MAGIC) +
 255                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA)) +
 256                         BaseBinaryFile::LENGTH_COUNT +
 257                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA)) +
 258                         BaseBinaryFile::LENGTH_POSITION +
 259                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES))
 260                 );
 261
 262                 // Init counters and gaps array
 263                 $this->getIteratorInstance()->initCountersGapsArray();
 264
 265                 // Is the file's header initialized?
 266                 if (!$this->getIteratorInstance()->isFileHeaderInitialized()) {
 267                         // No, then create it (which may pre-allocate the stack)
 268                         $this->getIteratorInstance()->createFileHeader();
 269
 270                         // And pre-allocate a bit
 271                         $this->getIteratorInstance()->preAllocateFile('file_stack');
 272                 }
 273
 274                 // Load the file header
 275                 $this->readFileHeader();
 276
 277                 // Count all entries in file
 278                 $this->getIteratorInstance()->analyzeFile();
 279
 280                 /*
 281                  * Get stack index instance. This can be used for faster
 282                  * "defragmentation" and startup.
 283                  */
 284                 $indexInstance = FileStackIndexFactory::createFileStackIndexInstance($fileInfoInstance, $type);
 285
 286                 // And set it here
 287                 $this->setIndexInstance($indexInstance);
 288         }
 289
 290         /**
 291          * Adds a value to given stack
 292          *
 293          * @param       $stackerName    Name of the stack
 294          * @param       $value                  Value to add to this stacker
 295          * @return      void
 296          * @throws      FullStackerException    If the stack is full
 297          * @throws      InvalidArgumentException        Not all variable types are wanted here
 298          */
 299         protected function addValue (string $stackerName, $value) {
 300                 // Do some tests
 301                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('stackerName=%s,value[%s]=%s - CALLED!', $stackerName, gettype($value), print_r($value, true)));
 302                 if ($this->isStackFull($stackerName)) {
 303                         // Stacker is full
 304                         throw new FullStackerException(array($this, $stackerName, $value), self::EXCEPTION_STACKER_IS_FULL);
 305                 } elseif (is_resource($value) || is_object($value)) {
 306                         // Not wanted type
 307                         throw new InvalidArgumentException(sprintf('value[]=%s is not supported', gettype($value)));
 308                 }
 309
 310                 /*
 311                  * Now add the value to the file stack which returns gap position, a
 312                  * hash and length of the raw data.
 313                  */
 314                 $data = $this->getIteratorInstance()->writeValueToFile($stackerName, $value);
 315
 316                 // Add the hash and gap position to the index
 317                 $this->getIndexInstance()->addHashToIndex($stackerName, $data);
 318         }
 319
 320         /**
 321          * Get last value from named stacker
 322          *
 323          * @param       $stackerName    Name of the stack
 324          * @return      $value                  Value of last added value
 325          * @throws      BadMethodCallException  If the stack is empty
 326          */
 327         protected function getLastValue (string $stackerName) {
 328                 // Is the stack not yet initialized or full?
 329                 if ($this->isStackEmpty($stackerName)) {
 330                         // Throw an exception
 331                         throw new BadMethodCallException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 332                 } // END - if
 333
 334                 // Now get the last value
 335                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 336                 $value = NULL;
 337
 338                 // Return it
 339                 return $value;
 340         }
 341
 342         /**
 343          * Get first value from named stacker
 344          *
 345          * @param       $stackerName    Name of the stack
 346          * @return      $value                  Value of last added value
 347          * @throws      BadMethodCallException  If the stack is empty
 348          */
 349         protected function getFirstValue (string $stackerName) {
 350                 // Is the stack not yet initialized or full?
 351                 if ($this->isStackEmpty($stackerName)) {
 352                         // Throw an exception
 353                         throw new BadMethodCallException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 354                 } // END - if
 355
 356                 // Now get the first value
 357                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 358                 $value = NULL;
 359
 360                 // Return it
 361                 return $value;
 362         }
 363
 364         /**
 365          * "Pops" last entry from stack
 366          *
 367          * @param       $stackerName    Name of the stack
 368          * @return      $value                  Value "poped" from array
 369          * @throws      BadMethodCallException  If the stack is empty
 370          */
 371         protected function popLast (string $stackerName) {
 372                 // Is the stack not yet initialized or full?
 373                 if ($this->isStackEmpty($stackerName)) {
 374                         // Throw an exception
 375                         throw new BadMethodCallException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 376                 } // END - if
 377
 378                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 379                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 380                 return NULL;
 381         }
 382
 383         /**
 384          * "Pops" first entry from stack
 385          *
 386          * @param       $stackerName    Name of the stack
 387          * @return      $value                  Value "shifted" from array
 388          * @throws      BadMethodCallException  If the named stacker is empty
 389          */
 390         protected function popFirst (string $stackerName) {
 391                 // Is the stack not yet initialized or full?
 392                 if ($this->isStackEmpty($stackerName)) {
 393                         // Throw an exception
 394                         throw new BadMethodCallException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 395                 } // END - if
 396
 397                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 398                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 399                 return NULL;
 400         }
 401
 402         /**
 403          * Checks whether the given stack is full
 404          *
 405          * @param       $stackerName    Name of the stack
 406          * @return      $isFull                 Whether the stack is full
 407          */
 408         protected function isStackFull (string $stackerName) {
 409                 // File-based stacks will only run full if the disk space is low.
 410                 // @TODO Please implement this, returning false
 411                 $isFull = false;
 412
 413                 // Return result
 414                 return $isFull;
 415         }
 416
 417         /**
 418          * Checks whether the given stack is empty
 419          *
 420          * @param       $stackerName            Name of the stack
 421          * @return      $isEmpty                        Whether the stack is empty
 422          * @throws      BadMethodCallException  If given stack is missing
 423          */
 424         public function isStackEmpty (string $stackerName) {
 425                 // So, is the stack empty?
 426                 $isEmpty = (($this->getStackCount($stackerName)) == 0);
 427
 428                 // Return result
 429                 return $isEmpty;
 430         }
 431
 432         /**
 433          * Initializes given stacker
 434          *
 435          * @param       $stackerName    Name of the stack
 436          * @param       $forceReInit    Force re-initialization
 437          * @return      void
 438          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 439          */
 440         public function initStack (string $stackerName, bool $forceReInit = false) {
 441                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 442         }
 443
 444         /**
 445          * Initializes all stacks
 446          *
 447          * @return      void
 448          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 449          */
 450         public function initStacks (array $stacks, bool $forceReInit = false) {
 451                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 452         }
 453
 454         /**
 455          * Checks whether the given stack is initialized (set in array $stackers)
 456          *
 457          * @param       $stackerName    Name of the stack
 458          * @return      $isInitialized  Whether the stack is initialized
 459          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 460          */
 461         public function isStackInitialized (string $stackerName) {
 462                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 463         }
 464
 465         /**
 466          * Determines whether the EOF has been reached
 467          *
 468          * @return      $isEndOfFileReached             Whether the EOF has been reached
 469          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 470          */
 471         public function isEndOfFileReached () {
 472                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 473         }
 474
 475         /**
 476          * Getter for size of given stack (array count)
 477          *
 478          * @param       $stackerName    Name of the stack
 479          * @return      $count                  Size of stack (array count)
 480          */
 481         public function getStackCount (string $stackerName) {
 482                 // Now, simply return the found count value, this must be up-to-date then!
 483                 return $this->getIteratorInstance()->getCounter();
 484         }
 485
 486         /**
 487          * Calculates minimum length for one entry/block
 488          *
 489          * @return      $length         Minimum length for one entry/block
 490          */
 491         public function calculateMinimumBlockLength () {
 492                 // Calulcate it
 493                 $length =
 494                         // Length of entry group
 495                         BaseBinaryFile::LENGTH_GROUP + strlen(chr(BaseBinaryFile::SEPARATOR_GROUP_HASH)) +
 496                         // Hash + value
 497                         self::getHashLength() + strlen(chr(BaseBinaryFile::SEPARATOR_HASH_VALUE)) + 1 +
 498                         // Final separator
 499                         strlen(chr(BaseBinaryFile::SEPARATOR_ENTRIES));
 500
 501                 // Return it
 502                 return $length;
 503         }
 504
 505         /**
 506          * Initializes counter for valid entries, arrays for damaged entries and
 507          * an array for gap seek positions. If you call this method on your own,
 508          * please re-analyze the file structure. So you are better to call
 509          * analyzeFile() instead of this method.
 510          *
 511          * @return      void
 512          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 513          */
 514         public function initCountersGapsArray () {
 515                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 516         }
 517
 518         /**
 519          * Getter for header size
 520          *
 521          * @return      $totalEntries   Size of file header
 522          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 523          */
 524         public final function getHeaderSize () {
 525                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 526         }
 527
 528         /**
 529          * Setter for header size
 530          *
 531          * @param       $headerSize             Size of file header
 532          * @return      void
 533          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 534          */
 535         public final function setHeaderSize (int $headerSize) {
 536                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 537         }
 538
 539         /**
 540          * Getter for header array
 541          *
 542          * @return      $totalEntries   Size of file header
 543          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 544          */
 545         public final function getHeader () {
 546                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 547         }
 548
 549         /**
 550          * Setter for header
 551          *
 552          * @param       $header         Array for a file header
 553          * @return      void
 554          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 555          */
 556         public final function setHeader (array $header) {
 557                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 558         }
 559
 560         /**
 561          * Updates seekPosition attribute from file to avoid to much access on file.
 562          *
 563          * @return      void
 564          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 565          */
 566         public function updateSeekPosition () {
 567                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 568         }
 569
 570         /**
 571          * Getter for total entries
 572          *
 573          * @return      $totalEntries   Total entries in this file
 574          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 575          */
 576         public final function getCounter () {
 577                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 578         }
 579
 580         /**
 581          * Writes data at given position
 582          *
 583          * @param       $seekPosition   Seek position
 584          * @param       $data                   Data to be written
 585          * @param       $flushHeader    Whether to flush the header (default: flush)
 586          * @return      void
 587          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 588          */
 589         public function writeData (int $seekPosition, string $data, bool $flushHeader = true) {
 590                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: seekPosition=%s,data[]=%s,flushHeader=%d', $seekPosition, gettype($data), intval($flushHeader)));
 591                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 592         }
 593
 594         /**
 595          * Writes given value to the file and returns a hash and gap position for it
 596          *
 597          * @param       $groupId        Group identifier
 598          * @param       $value          Value to be added to the stack
 599          * @return      $data           Hash and gap position
 600          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 601          */
 602         public function writeValueToFile (string $groupId, $value) {
 603                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: groupId=%s,value[%s]=%s', $groupId, gettype($value), print_r($value, true)));
 604                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 605         }
 606
 607         /**
 608          * Searches for next suitable gap the given length of data can fit in
 609          * including padding bytes.
 610          *
 611          * @param       $length                 Length of raw data
 612          * @return      $seekPosition   Found next gap's seek position
 613          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 614          */
 615         public function searchNextGap (int $length) {
 616                 // Not supported here
 617                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: length=%d - CALLED!', $length));
 618                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 619         }
 620
 621         /**
 622          * "Getter" for file size
 623          *
 624          * @return      $fileSize       Size of currently loaded file
 625          */
 626         public function getFileSize () {
 627                 // Call iterator's method
 628                 return $this->getIteratorInstance()->getFileSize();
 629         }
 630
 631         /**
 632          * Writes given raw data to the file and returns a gap position and length
 633          *
 634          * @param       $groupId        Group identifier
 635          * @param       $hash           Hash from encoded value
 636          * @param       $encoded        Encoded value to be written to the file
 637          * @return      $data           Gap position and length of the raw data
 638          */
 639         public function writeDataToFreeGap (string $groupId, string $hash, string $encoded) {
 640                 // Raw data been written to the file
 641                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: groupId=%s,hash=%s,encoded()=%d - CALLED!', $groupId, $hash, strlen($encoded)));
 642                 $rawData = sprintf('%s%s%s%s%s',
 643                         $groupId,
 644                         BaseBinaryFile::SEPARATOR_GROUP_HASH,
 645                         hex2bin($hash),
 646                         BaseBinaryFile::SEPARATOR_HASH_VALUE,
 647                         $encoded
 648                 );
 649
 650                 // Search for next free gap
 651                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: groupId=%s,hash=%s,rawData()=%d', $groupId, $hash, strlen($rawData)));
 652                 $gapPosition = $this->getIteratorInstance()->searchNextGap(strlen($rawData));
 653
 654                 // Gap position cannot be smaller than header length + 1
 655                 if ($gapPosition <= $this->getIteratorInstance()->getHeaderSize()) {
 656                         // Improper gap position
 657                         throw new UnexpectedValueException(sprintf('gapPosition[%s]=%d is not larger than headerSize=%d',
 658                                 gettype($gapPosition),
 659                                 $gapPosition,
 660                                 $this->getIteratorInstance()->getHeaderSize()
 661                         ));
 662                 }
 663
 664                 // Then write the data at that gap
 665                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: groupId=%s,hash=%s,gapPosition=%s', $groupId, $hash, $gapPosition));
 666                 $this->getIteratorInstance()->writeData($gapPosition, $rawData);
 667
 668                 // Return gap position, hash and length of raw data
 669                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('BASE-FILE-STACK: groupId=%s,hash=%s,rawData()=%d - EXIT!', $groupId, $hash, strlen($rawData)));
 670                 return [
 671                         self::ARRAY_INDEX_GAP_POSITION => $gapPosition,
 672                         self::ARRAY_INDEX_HASH         => $hash,
 673                         self::ARRAY_INDEX_DATA_LENGTH  => strlen($rawData),
 674                 ];
 675         }
 676
 677 }