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\Filesystem\File\BaseBinaryFile;
   9 use Org\Mxchange\CoreFramework\Generic\UnsupportedOperationException;
  10 use Org\Mxchange\CoreFramework\Iterator\Filesystem\SeekableWritableFileIterator;
  11 use Org\Mxchange\CoreFramework\Stacker\BaseStacker;
  12
  13 // Import SPL stuff
  14 use \SplFileInfo;
  15
  16 /**
  17  * A general file-based stack class
  18  *
  19  * @author              Roland Haeder <webmaster@ship-simu.org>
  20  * @version             0.0.0
  21 <<<<<<< HEAD:framework/main/classes/stacker/file/class_BaseFileStack.php
  22  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  23 =======
  24  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2016 Core Developer Team
  25 >>>>>>> Some updates::inc/main/classes/stacker/file/class_BaseFileStack.php
  26  * @license             GNU GPL 3.0 or any newer version
  27  * @link                http://www.ship-simu.org
  28  *
  29  * This program is free software: you can redistribute it and/or modify
  30  * it under the terms of the GNU General Public License as published by
  31  * the Free Software Foundation, either version 3 of the License, or
  32  * (at your option) any later version.
  33  *
  34  * This program is distributed in the hope that it will be useful,
  35  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  36  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  37  * GNU General Public License for more details.
  38  *
  39  * You should have received a copy of the GNU General Public License
  40  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  41  */
  42 abstract class BaseFileStack extends BaseStacker {
  43         /**
  44          * Magic for this stack
  45          */
  46         const STACK_MAGIC = 'STACKv0.1';
  47
  48         /**
  49          * Name of array index for gap position
  50          */
  51         const ARRAY_INDEX_GAP_POSITION = 'gap';
  52
  53         /**
  54          * Name of array index for hash
  55          */
  56         const ARRAY_INDEX_HASH = 'hash';
  57
  58         /**
  59          * Name of array index for length of raw data
  60          */
  61         const ARRAY_INDEX_DATA_LENGTH = 'length';
  62
  63         /**
  64          * Protected constructor
  65          *
  66          * @param       $className      Name of the class
  67          * @return      void
  68          */
  69         protected function __construct ($className) {
  70                 // Call parent constructor
  71                 parent::__construct($className);
  72         }
  73
  74         /**
  75          * Reads the file header
  76          *
  77          * @return      void
  78          * @todo        To hard assertions here, better rewrite them to exceptions
  79          */
  80         public function readFileHeader () {
  81                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
  82
  83                 // First rewind to beginning as the header sits at the beginning ...
  84                 $this->getIteratorInstance()->rewind();
  85
  86                 // Then read it (see constructor for calculation)
  87                 $data = $this->getIteratorInstance()->read($this->getIteratorInstance()->getHeaderSize());
  88                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Read %d bytes (%d wanted).', __METHOD__, __LINE__, strlen($data), $this->getIteratorInstance()->getHeaderSize()));
  89
  90                 // Have all requested bytes been read?
  91                 assert(strlen($data) == $this->getIteratorInstance()->getHeaderSize());
  92                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  93
  94                 // Last character must be the separator
  95                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] data(-1)=%s', __METHOD__, __LINE__, dechex(ord(substr($data, -1, 1)))));
  96                 assert(substr($data, -1, 1) == chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES));
  97                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  98
  99                 // Okay, then remove it
 100                 $data = substr($data, 0, -1);
 101
 102                 // And update seek position
 103                 $this->getIteratorInstance()->updateSeekPosition();
 104
 105                 /*
 106                  * Now split it:
 107                  *
 108                  * 0 => magic
 109                  * 1 => total entries
 110                  * 2 => current seek position
 111                  */
 112                 $header = explode(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA), $data);
 113
 114                 // Set header here
 115                 $this->getIteratorInstance()->setHeader($header);
 116
 117                 // Check if the array has only 3 elements
 118                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] header(%d)=%s', __METHOD__, __LINE__, count($header), print_r($header, true)));
 119                 assert(count($header) == 3);
 120                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 121
 122                 // Check magic
 123                 assert($header[0] == self::STACK_MAGIC);
 124                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 125
 126                 // Check length of count and seek position
 127                 assert(strlen($header[1]) == BaseBinaryFile::LENGTH_COUNT);
 128                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 129                 assert(strlen($header[2]) == BaseBinaryFile::LENGTH_POSITION);
 130                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 131
 132                 // Decode count and seek position
 133                 $header[1] = hex2bin($header[1]);
 134                 $header[2] = hex2bin($header[2]);
 135
 136                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 137         }
 138
 139         /**
 140          * Flushes the file header
 141          *
 142          * @return      void
 143          */
 144         public function flushFileHeader () {
 145                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 146
 147                 // Put all informations together
 148                 $header = sprintf('%s%s%s%s%s%s',
 149                         // Magic
 150                         self::STACK_MAGIC,
 151
 152                         // Separator magic<->count
 153                         chr(BaseBinaryFile::SEPARATOR_HEADER_DATA),
 154
 155                         // Total entries (will be zero) and pad it to 20 chars
 156                         str_pad($this->dec2hex($this->getIteratorInstance()->getCounter()), BaseBinaryFile::LENGTH_COUNT, '0', STR_PAD_LEFT),
 157
 158                         // Separator count<->seek position
 159                         chr(BaseBinaryFile::SEPARATOR_HEADER_DATA),
 160
 161                         // Position (will be zero)
 162                         str_pad($this->dec2hex($this->getIteratorInstance()->getSeekPosition(), 2), BaseBinaryFile::LENGTH_POSITION, '0', STR_PAD_LEFT),
 163
 164                         // Separator position<->entries
 165                         chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES)
 166                 );
 167
 168                 // Write it to disk (header is always at seek position 0)
 169                 $this->getIteratorInstance()->writeData(0, $header, false);
 170
 171                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 172         }
 173
 174         /**
 175          * Initializes this file-based stack.
 176          *
 177          * @param       $fileInfoInstance       An instance of a SplFileInfo class
 178          * @param       $type           Type of this stack (e.g. url_source for URL sources)
 179          * @return      void
 180          * @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.
 181          */
 182         protected function initFileStack (SplFileInfo $fileInfoInstance, $type) {
 183                 // Get a stack file instance
 184                 $fileInstance = ObjectFactory::createObjectByConfiguredName('stack_file_class', array($fileInfoInstance, $this));
 185
 186                 // Get iterator instance
 187                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_iterator_class', array($fileInstance));
 188
 189                 // Is the instance implementing the right interface?
 190                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 191
 192                 // Set iterator here
 193                 $this->setIteratorInstance($iteratorInstance);
 194
 195                 // Calculate header size
 196                 $this->getIteratorInstance()->setHeaderSize(
 197                         strlen(self::STACK_MAGIC) +
 198                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA)) +
 199                         BaseBinaryFile::LENGTH_COUNT +
 200                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA)) +
 201                         BaseBinaryFile::LENGTH_POSITION +
 202                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES))
 203                 );
 204
 205                 // Init counters and gaps array
 206                 $this->getIteratorInstance()->initCountersGapsArray();
 207
 208                 // Is the file's header initialized?
 209                 if (!$this->getIteratorInstance()->isFileHeaderInitialized()) {
 210                         // No, then create it (which may pre-allocate the stack)
 211                         $this->getIteratorInstance()->createFileHeader();
 212
 213                         // And pre-allocate a bit
 214                         $this->getIteratorInstance()->preAllocateFile('file_stack');
 215                 } // END - if
 216
 217                 // Load the file header
 218                 $this->readFileHeader();
 219
 220                 // Count all entries in file
 221                 $this->getIteratorInstance()->analyzeFile();
 222
 223                 /*
 224                  * Get stack index instance. This can be used for faster
 225                  * "defragmentation" and startup.
 226                  */
 227                 $indexInstance = FileStackIndexFactory::createFileStackIndexInstance($fileInfoInstance, $type);
 228
 229                 // And set it here
 230                 $this->setIndexInstance($indexInstance);
 231         }
 232
 233         /**
 234          * Adds a value to given stack
 235          *
 236          * @param       $stackerName    Name of the stack
 237          * @param       $value                  Value to add to this stacker
 238          * @return      void
 239          * @throws      FullStackerException    If the stack is full
 240          */
 241         protected function addValue ($stackerName, $value) {
 242                 // Do some tests
 243                 if ($this->isStackFull($stackerName)) {
 244                         // Stacker is full
 245                         throw new FullStackerException(array($this, $stackerName, $value), self::EXCEPTION_STACKER_IS_FULL);
 246                 } // END - if
 247
 248                 // Debug message
 249                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName . ',value[' . gettype($value) . ']=' . print_r($value, true));
 250
 251                 // No objects/resources are allowed as their serialization takes to long
 252                 assert(!is_object($value));
 253                 assert(!is_resource($value));
 254
 255                 /*
 256                  * Now add the value to the file stack which returns gap position, a
 257                  * hash and length of the raw data.
 258                  */
 259                 $data = $this->getIteratorInstance()->writeValueToFile($stackerName, $value);
 260
 261                 // Add the hash and gap position to the index
 262                 $this->getIndexInstance()->addHashToIndex($stackerName, $data);
 263         }
 264
 265         /**
 266          * Get last value from named stacker
 267          *
 268          * @param       $stackerName    Name of the stack
 269          * @return      $value                  Value of last added value
 270          * @throws      EmptyStackerException   If the stack is empty
 271          */
 272         protected function getLastValue ($stackerName) {
 273                 // Is the stack not yet initialized or full?
 274                 if ($this->isStackEmpty($stackerName)) {
 275                         // Throw an exception
 276                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 277                 } // END - if
 278
 279                 // Now get the last value
 280                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 281                 $value = NULL;
 282
 283                 // Return it
 284                 return $value;
 285         }
 286
 287         /**
 288          * Get first value from named stacker
 289          *
 290          * @param       $stackerName    Name of the stack
 291          * @return      $value                  Value of last added value
 292          * @throws      EmptyStackerException   If the stack is empty
 293          */
 294         protected function getFirstValue ($stackerName) {
 295                 // Is the stack not yet initialized or full?
 296                 if ($this->isStackEmpty($stackerName)) {
 297                         // Throw an exception
 298                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 299                 } // END - if
 300
 301                 // Now get the first value
 302                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 303                 $value = NULL;
 304
 305                 // Return it
 306                 return $value;
 307         }
 308
 309         /**
 310          * "Pops" last entry from stack
 311          *
 312          * @param       $stackerName    Name of the stack
 313          * @return      $value                  Value "poped" from array
 314          * @throws      EmptyStackerException   If the stack is empty
 315          */
 316         protected function popLast ($stackerName) {
 317                 // Is the stack not yet initialized or full?
 318                 if ($this->isStackEmpty($stackerName)) {
 319                         // Throw an exception
 320                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 321                 } // END - if
 322
 323                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 324                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 325                 return NULL;
 326         }
 327
 328         /**
 329          * "Pops" first entry from stack
 330          *
 331          * @param       $stackerName    Name of the stack
 332          * @return      $value                  Value "shifted" from array
 333          * @throws      EmptyStackerException   If the named stacker is empty
 334          */
 335         protected function popFirst ($stackerName) {
 336                 // Is the stack not yet initialized or full?
 337                 if ($this->isStackEmpty($stackerName)) {
 338                         // Throw an exception
 339                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 340                 } // END - if
 341
 342                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 343                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 344                 return NULL;
 345         }
 346
 347         /**
 348          * Checks whether the given stack is full
 349          *
 350          * @param       $stackerName    Name of the stack
 351          * @return      $isFull                 Whether the stack is full
 352          */
 353         protected function isStackFull ($stackerName) {
 354                 // File-based stacks will only run full if the disk space is low.
 355                 // @TODO Please implement this, returning false
 356                 $isFull = false;
 357
 358                 // Return result
 359                 return $isFull;
 360         }
 361
 362         /**
 363          * Checks whether the given stack is empty
 364          *
 365          * @param       $stackerName            Name of the stack
 366          * @return      $isEmpty                        Whether the stack is empty
 367          * @throws      NoStackerException      If given stack is missing
 368          */
 369         public function isStackEmpty ($stackerName) {
 370                 // So, is the stack empty?
 371                 $isEmpty = (($this->getStackCount($stackerName)) == 0);
 372
 373                 // Return result
 374                 return $isEmpty;
 375         }
 376
 377         /**
 378          * Initializes given stacker
 379          *
 380          * @param       $stackerName    Name of the stack
 381          * @param       $forceReInit    Force re-initialization
 382          * @return      void
 383          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 384          */
 385         public function initStack ($stackerName, $forceReInit = false) {
 386                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 387         }
 388
 389         /**
 390          * Initializes all stacks
 391          *
 392          * @return      void
 393          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 394          */
 395         public function initStacks (array $stacks, $forceReInit = false) {
 396                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 397         }
 398
 399         /**
 400          * Checks whether the given stack is initialized (set in array $stackers)
 401          *
 402          * @param       $stackerName    Name of the stack
 403          * @return      $isInitialized  Whether the stack is initialized
 404          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 405          */
 406         public function isStackInitialized ($stackerName) {
 407                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 408         }
 409
 410         /**
 411          * Determines whether the EOF has been reached
 412          *
 413          * @return      $isEndOfFileReached             Whether the EOF has been reached
 414          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 415          */
 416         public function isEndOfFileReached () {
 417                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 418         }
 419
 420         /**
 421          * Getter for size of given stack (array count)
 422          *
 423          * @param       $stackerName    Name of the stack
 424          * @return      $count                  Size of stack (array count)
 425          */
 426         public function getStackCount ($stackerName) {
 427                 // Now, simply return the found count value, this must be up-to-date then!
 428                 return $this->getIteratorInstance()->getCounter();
 429         }
 430
 431         /**
 432          * Calculates minimum length for one entry/block
 433          *
 434          * @return      $length         Minimum length for one entry/block
 435          */
 436         public function calculateMinimumBlockLength () {
 437                 // Calulcate it
 438                 $length =
 439                         // Length of entry group
 440                         BaseBinaryFile::LENGTH_GROUP + strlen(chr(BaseBinaryFile::SEPARATOR_GROUP_HASH)) +
 441                         // Hash + value
 442                         self::getHashLength() + strlen(chr(BaseBinaryFile::SEPARATOR_HASH_VALUE)) + 1 +
 443                         // Final separator
 444                         strlen(chr(BaseBinaryFile::SEPARATOR_ENTRIES));
 445
 446                 // Return it
 447                 return $length;
 448         }
 449
 450         /**
 451          * Initializes counter for valid entries, arrays for damaged entries and
 452          * an array for gap seek positions. If you call this method on your own,
 453          * please re-analyze the file structure. So you are better to call
 454          * analyzeFile() instead of this method.
 455          *
 456          * @return      void
 457          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 458          */
 459         public function initCountersGapsArray () {
 460                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 461         }
 462
 463         /**
 464          * Getter for header size
 465          *
 466          * @return      $totalEntries   Size of file header
 467          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 468          */
 469         public final function getHeaderSize () {
 470                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 471         }
 472
 473         /**
 474          * Setter for header size
 475          *
 476          * @param       $headerSize             Size of file header
 477          * @return      void
 478          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 479          */
 480         public final function setHeaderSize ($headerSize) {
 481                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 482         }
 483
 484         /**
 485          * Getter for header array
 486          *
 487          * @return      $totalEntries   Size of file header
 488          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 489          */
 490         public final function getHeader () {
 491                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 492         }
 493
 494         /**
 495          * Setter for header
 496          *
 497          * @param       $header         Array for a file header
 498          * @return      void
 499          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 500          */
 501         public final function setHeader (array $header) {
 502                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 503         }
 504
 505         /**
 506          * Updates seekPosition attribute from file to avoid to much access on file.
 507          *
 508          * @return      void
 509          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 510          */
 511         public function updateSeekPosition () {
 512                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 513         }
 514
 515         /**
 516          * Getter for total entries
 517          *
 518          * @return      $totalEntries   Total entries in this file
 519          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 520          */
 521         public final function getCounter () {
 522                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 523         }
 524
 525         /**
 526          * Writes data at given position
 527          *
 528          * @param       $seekPosition   Seek position
 529          * @param       $data                   Data to be written
 530          * @param       $flushHeader    Whether to flush the header (default: flush)
 531          * @return      void
 532          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 533          */
 534         public function writeData ($seekPosition, $data, $flushHeader = true) {
 535                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] seekPosition=%s,data[]=%s,flushHeader=%d', __METHOD__, __LINE__, $seekPosition, gettype($data), intval($flushHeader)));
 536                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 537         }
 538
 539         /**
 540          * Writes given value to the file and returns a hash and gap position for it
 541          *
 542          * @param       $groupId        Group identifier
 543          * @param       $value          Value to be added to the stack
 544          * @return      $data           Hash and gap position
 545          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 546          */
 547         public function writeValueToFile ($groupId, $value) {
 548                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] groupId=%s,value[%s]=%s', __METHOD__, __LINE__, $groupId, gettype($value), print_r($value, true)));
 549                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 550         }
 551
 552         /**
 553          * Searches for next suitable gap the given length of data can fit in
 554          * including padding bytes.
 555          *
 556          * @param       $length                 Length of raw data
 557          * @return      $seekPosition   Found next gap's seek position
 558          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 559          */
 560         public function searchNextGap ($length) {
 561                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] length=%s', __METHOD__, __LINE__, $length));
 562                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 563         }
 564
 565         /**
 566          * "Getter" for file size
 567          *
 568          * @return      $fileSize       Size of currently loaded file
 569          */
 570         public function getFileSize () {
 571                 // Call iterator's method
 572                 return $this->getIteratorInstance()->getFileSize();
 573         }
 574
 575         /**
 576          * Writes given raw data to the file and returns a gap position and length
 577          *
 578          * @param       $groupId        Group identifier
 579          * @param       $hash           Hash from encoded value
 580          * @param       $encoded        Encoded value to be written to the file
 581          * @return      $data           Gap position and length of the raw data
 582          */
 583         public function writeDataToFreeGap ($groupId, $hash, $encoded) {
 584                 // Debug message
 585                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,encoded()=%d - CALLED!', __METHOD__, __LINE__, $groupId, $hash, strlen($encoded)));
 586
 587                 // Raw data been written to the file
 588                 $rawData = sprintf('%s%s%s%s%s',
 589                         $groupId,
 590                         BaseBinaryFile::SEPARATOR_GROUP_HASH,
 591                         hex2bin($hash),
 592                         BaseBinaryFile::SEPARATOR_HASH_VALUE,
 593                         $encoded
 594                 );
 595
 596                 // Debug message
 597                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,rawData()=%d', __METHOD__, __LINE__, $groupId, $hash, strlen($rawData)));
 598
 599                 // Search for next free gap
 600                 $gapPosition = $this->getIteratorInstance()->searchNextGap(strlen($rawData));
 601
 602                 // Gap position cannot be smaller than header length + 1
 603                 assert($gapPosition > $this->getIteratorInstance()->getHeaderSize());
 604
 605                 // Debug message
 606                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,gapPosition=%s', __METHOD__, __LINE__, $groupId, $hash, $gapPosition));
 607
 608                 // Then write the data at that gap
 609                 $this->getIteratorInstance()->writeData($gapPosition, $rawData);
 610
 611                 // Debug message
 612                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,rawData()=%d - EXIT!', __METHOD__, __LINE__, $groupId, $hash, strlen($rawData)));
 613
 614                 // Return gap position, hash and length of raw data
 615                 return array(
 616                         self::ARRAY_INDEX_GAP_POSITION => $gapPosition,
 617                         self::ARRAY_INDEX_HASH         => $hash,
 618                         self::ARRAY_INDEX_DATA_LENGTH  => strlen($rawData)
 619                 );
 620         }
 621
 622 }