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

   1 <?php
   2 // Own namespace
   3 namespace CoreFramework\Stack\File;
   4
   5 // Import framework stuff
   6 use CoreFramework\Factory\ObjectFactory;
   7 use CoreFramework\Filesystem\File\BaseBinaryFile;
   8 use CoreFramework\Generic\UnsupportedOperationException;
   9 use CoreFramework\Iterator\Filesystem\SeekableWritableFileIterator;
  10
  11 /**
  12  * A general file-based stack class
  13  *
  14  * @author              Roland Haeder <webmaster@ship-simu.org>
  15  * @version             0.0.0
  16  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  17  * @license             GNU GPL 3.0 or any newer version
  18  * @link                http://www.ship-simu.org
  19  *
  20  * This program is free software: you can redistribute it and/or modify
  21  * it under the terms of the GNU General Public License as published by
  22  * the Free Software Foundation, either version 3 of the License, or
  23  * (at your option) any later version.
  24  *
  25  * This program is distributed in the hope that it will be useful,
  26  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  27  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28  * GNU General Public License for more details.
  29  *
  30  * You should have received a copy of the GNU General Public License
  31  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  32  */
  33 class BaseFileStack extends BaseStacker {
  34         /**
  35          * Magic for this stack
  36          */
  37         const STACK_MAGIC = 'STACKv0.1';
  38
  39         /**
  40          * Name of array index for gap position
  41          */
  42         const ARRAY_INDEX_GAP_POSITION = 'gap';
  43
  44         /**
  45          * Name of array index for hash
  46          */
  47         const ARRAY_INDEX_HASH = 'hash';
  48
  49         /**
  50          * Name of array index for length of raw data
  51          */
  52         const ARRAY_INDEX_DATA_LENGTH = 'length';
  53
  54         /**
  55          * Protected constructor
  56          *
  57          * @param       $className      Name of the class
  58          * @return      void
  59          */
  60         protected function __construct ($className) {
  61                 // Call parent constructor
  62                 parent::__construct($className);
  63         }
  64
  65         /**
  66          * Reads the file header
  67          *
  68          * @return      void
  69          * @todo        To hard assertions here, better rewrite them to exceptions
  70          */
  71         public function readFileHeader () {
  72                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
  73
  74                 // First rewind to beginning as the header sits at the beginning ...
  75                 $this->getIteratorInstance()->rewind();
  76
  77                 // Then read it (see constructor for calculation)
  78                 $data = $this->getIteratorInstance()->read($this->getIteratorInstance()->getHeaderSize());
  79                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Read %d bytes (%d wanted).', __METHOD__, __LINE__, strlen($data), $this->getIteratorInstance()->getHeaderSize()));
  80
  81                 // Have all requested bytes been read?
  82                 assert(strlen($data) == $this->getIteratorInstance()->getHeaderSize());
  83                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  84
  85                 // Last character must be the separator
  86                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] data(-1)=%s', __METHOD__, __LINE__, dechex(ord(substr($data, -1, 1)))));
  87                 assert(substr($data, -1, 1) == chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES));
  88                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  89
  90                 // Okay, then remove it
  91                 $data = substr($data, 0, -1);
  92
  93                 // And update seek position
  94                 $this->getIteratorInstance()->updateSeekPosition();
  95
  96                 /*
  97                  * Now split it:
  98                  *
  99                  * 0 => magic
 100                  * 1 => total entries
 101                  * 2 => current seek position
 102                  */
 103                 $header = explode(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA), $data);
 104
 105                 // Set header here
 106                 $this->getIteratorInstance()->setHeader($header);
 107
 108                 // Check if the array has only 3 elements
 109                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] header(%d)=%s', __METHOD__, __LINE__, count($header), print_r($header, true)));
 110                 assert(count($header) == 3);
 111                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 112
 113                 // Check magic
 114                 assert($header[0] == self::STACK_MAGIC);
 115                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 116
 117                 // Check length of count and seek position
 118                 assert(strlen($header[1]) == BaseBinaryFile::LENGTH_COUNT);
 119                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 120                 assert(strlen($header[2]) == BaseBinaryFile::LENGTH_POSITION);
 121                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 122
 123                 // Decode count and seek position
 124                 $header[1] = hex2bin($header[1]);
 125                 $header[2] = hex2bin($header[2]);
 126
 127                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 128         }
 129
 130         /**
 131          * Flushes the file header
 132          *
 133          * @return      void
 134          */
 135         public function flushFileHeader () {
 136                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 137
 138                 // Put all informations together
 139                 $header = sprintf('%s%s%s%s%s%s',
 140                         // Magic
 141                         self::STACK_MAGIC,
 142
 143                         // Separator magic<->count
 144                         chr(BaseBinaryFile::SEPARATOR_HEADER_DATA),
 145
 146                         // Total entries (will be zero) and pad it to 20 chars
 147                         str_pad($this->dec2hex($this->getIteratorInstance()->getCounter()), BaseBinaryFile::LENGTH_COUNT, '0', STR_PAD_LEFT),
 148
 149                         // Separator count<->seek position
 150                         chr(BaseBinaryFile::SEPARATOR_HEADER_DATA),
 151
 152                         // Position (will be zero)
 153                         str_pad($this->dec2hex($this->getIteratorInstance()->getSeekPosition(), 2), BaseBinaryFile::LENGTH_POSITION, '0', STR_PAD_LEFT),
 154
 155                         // Separator position<->entries
 156                         chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES)
 157                 );
 158
 159                 // Write it to disk (header is always at seek position 0)
 160                 $this->getIteratorInstance()->writeData(0, $header, false);
 161
 162                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 163         }
 164
 165         /**
 166          * Initializes this file-based stack.
 167          *
 168          * @param       $fileName       File name of this stack
 169          * @param       $type           Type of this stack (e.g. url_source for URL sources)
 170          * @return      void
 171          * @todo        Currently the stack file is not cached, please implement a memory-handling class and if enough RAM is found, cache the whole stack file.
 172          */
 173         protected function initFileStack ($fileName, $type) {
 174                 // Get a stack file instance
 175                 $fileInstance = ObjectFactory::createObjectByConfiguredName('stack_file_class', array($fileName, $this));
 176
 177                 // Get iterator instance
 178                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_iterator_class', array($fileInstance));
 179
 180                 // Is the instance implementing the right interface?
 181                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 182
 183                 // Set iterator here
 184                 $this->setIteratorInstance($iteratorInstance);
 185
 186                 // Calculate header size
 187                 $this->getIteratorInstance()->setHeaderSize(
 188                         strlen(self::STACK_MAGIC) +
 189                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA)) +
 190                         BaseBinaryFile::LENGTH_COUNT +
 191                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA)) +
 192                         BaseBinaryFile::LENGTH_POSITION +
 193                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES))
 194                 );
 195
 196                 // Init counters and gaps array
 197                 $this->getIteratorInstance()->initCountersGapsArray();
 198
 199                 // Is the file's header initialized?
 200                 if (!$this->getIteratorInstance()->isFileHeaderInitialized()) {
 201                         // No, then create it (which may pre-allocate the stack)
 202                         $this->getIteratorInstance()->createFileHeader();
 203
 204                         // And pre-allocate a bit
 205                         $this->getIteratorInstance()->preAllocateFile('file_stack');
 206                 } // END - if
 207
 208                 // Load the file header
 209                 $this->readFileHeader();
 210
 211                 // Count all entries in file
 212                 $this->getIteratorInstance()->analyzeFile();
 213
 214                 /*
 215                  * Get stack index instance. This can be used for faster
 216                  * "defragmentation" and startup.
 217                  */
 218                 $indexInstance = FileStackIndexFactory::createFileStackIndexInstance($fileName, $type);
 219
 220                 // And set it here
 221                 $this->setIndexInstance($indexInstance);
 222         }
 223
 224         /**
 225          * Adds a value to given stack
 226          *
 227          * @param       $stackerName    Name of the stack
 228          * @param       $value                  Value to add to this stacker
 229          * @return      void
 230          * @throws      FullStackerException    If the stack is full
 231          */
 232         protected function addValue ($stackerName, $value) {
 233                 // Do some tests
 234                 if ($this->isStackFull($stackerName)) {
 235                         // Stacker is full
 236                         throw new FullStackerException(array($this, $stackerName, $value), self::EXCEPTION_STACKER_IS_FULL);
 237                 } // END - if
 238
 239                 // Debug message
 240                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName . ',value[' . gettype($value) . ']=' . print_r($value, true));
 241
 242                 // No objects/resources are allowed as their serialization takes to long
 243                 assert(!is_object($value));
 244                 assert(!is_resource($value));
 245
 246                 /*
 247                  * Now add the value to the file stack which returns gap position, a
 248                  * hash and length of the raw data.
 249                  */
 250                 $data = $this->getIteratorInstance()->writeValueToFile($stackerName, $value);
 251
 252                 // Add the hash and gap position to the index
 253                 $this->getIndexInstance()->addHashToIndex($stackerName, $data);
 254         }
 255
 256         /**
 257          * Get last value from named stacker
 258          *
 259          * @param       $stackerName    Name of the stack
 260          * @return      $value                  Value of last added value
 261          * @throws      EmptyStackerException   If the stack is empty
 262          */
 263         protected function getLastValue ($stackerName) {
 264                 // Is the stack not yet initialized or full?
 265                 if ($this->isStackEmpty($stackerName)) {
 266                         // Throw an exception
 267                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 268                 } // END - if
 269
 270                 // Now get the last value
 271                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 272                 $value = NULL;
 273
 274                 // Return it
 275                 return $value;
 276         }
 277
 278         /**
 279          * Get first value from named stacker
 280          *
 281          * @param       $stackerName    Name of the stack
 282          * @return      $value                  Value of last added value
 283          * @throws      EmptyStackerException   If the stack is empty
 284          */
 285         protected function getFirstValue ($stackerName) {
 286                 // Is the stack not yet initialized or full?
 287                 if ($this->isStackEmpty($stackerName)) {
 288                         // Throw an exception
 289                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 290                 } // END - if
 291
 292                 // Now get the first value
 293                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 294                 $value = NULL;
 295
 296                 // Return it
 297                 return $value;
 298         }
 299
 300         /**
 301          * "Pops" last entry from stack
 302          *
 303          * @param       $stackerName    Name of the stack
 304          * @return      $value                  Value "poped" from array
 305          * @throws      EmptyStackerException   If the stack is empty
 306          */
 307         protected function popLast ($stackerName) {
 308                 // Is the stack not yet initialized or full?
 309                 if ($this->isStackEmpty($stackerName)) {
 310                         // Throw an exception
 311                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 312                 } // END - if
 313
 314                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 315                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 316                 return NULL;
 317         }
 318
 319         /**
 320          * "Pops" first entry from stack
 321          *
 322          * @param       $stackerName    Name of the stack
 323          * @return      $value                  Value "shifted" from array
 324          * @throws      EmptyStackerException   If the named stacker is empty
 325          */
 326         protected function popFirst ($stackerName) {
 327                 // Is the stack not yet initialized or full?
 328                 if ($this->isStackEmpty($stackerName)) {
 329                         // Throw an exception
 330                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 331                 } // END - if
 332
 333                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 334                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 335                 return NULL;
 336         }
 337
 338         /**
 339          * Checks whether the given stack is full
 340          *
 341          * @param       $stackerName    Name of the stack
 342          * @return      $isFull                 Whether the stack is full
 343          */
 344         protected function isStackFull ($stackerName) {
 345                 // File-based stacks will only run full if the disk space is low.
 346                 // @TODO Please implement this, returning false
 347                 $isFull = false;
 348
 349                 // Return result
 350                 return $isFull;
 351         }
 352
 353         /**
 354          * Checks whether the given stack is empty
 355          *
 356          * @param       $stackerName            Name of the stack
 357          * @return      $isEmpty                        Whether the stack is empty
 358          * @throws      NoStackerException      If given stack is missing
 359          */
 360         public function isStackEmpty ($stackerName) {
 361                 // So, is the stack empty?
 362                 $isEmpty = (($this->getStackCount($stackerName)) == 0);
 363
 364                 // Return result
 365                 return $isEmpty;
 366         }
 367
 368         /**
 369          * Initializes given stacker
 370          *
 371          * @param       $stackerName    Name of the stack
 372          * @param       $forceReInit    Force re-initialization
 373          * @return      void
 374          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 375          */
 376         public function initStack ($stackerName, $forceReInit = false) {
 377                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 378         }
 379
 380         /**
 381          * Initializes all stacks
 382          *
 383          * @return      void
 384          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 385          */
 386         public function initStacks (array $stacks, $forceReInit = false) {
 387                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 388         }
 389
 390         /**
 391          * Checks whether the given stack is initialized (set in array $stackers)
 392          *
 393          * @param       $stackerName    Name of the stack
 394          * @return      $isInitialized  Whether the stack is initialized
 395          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 396          */
 397         public function isStackInitialized ($stackerName) {
 398                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 399         }
 400
 401         /**
 402          * Determines whether the EOF has been reached
 403          *
 404          * @return      $isEndOfFileReached             Whether the EOF has been reached
 405          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 406          */
 407         public function isEndOfFileReached () {
 408                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 409         }
 410
 411         /**
 412          * Getter for file name
 413          *
 414          * @return      $fileName       The current file name
 415          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 416          */
 417         public function getFileName () {
 418                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 419         }
 420
 421         /**
 422          * Getter for size of given stack (array count)
 423          *
 424          * @param       $stackerName    Name of the stack
 425          * @return      $count                  Size of stack (array count)
 426          */
 427         public function getStackCount ($stackerName) {
 428                 // Now, simply return the found count value, this must be up-to-date then!
 429                 return $this->getIteratorInstance()->getCounter();
 430         }
 431
 432         /**
 433          * Calculates minimum length for one entry/block
 434          *
 435          * @return      $length         Minimum length for one entry/block
 436          */
 437         public function calculateMinimumBlockLength () {
 438                 // Calulcate it
 439                 $length =
 440                         // Length of entry group
 441                         BaseBinaryFile::LENGTH_GROUP + strlen(chr(BaseBinaryFile::SEPARATOR_GROUP_HASH)) +
 442                         // Hash + value
 443                         self::getHashLength() + strlen(chr(BaseBinaryFile::SEPARATOR_HASH_VALUE)) + 1 +
 444                         // Final separator
 445                         strlen(chr(BaseBinaryFile::SEPARATOR_ENTRIES));
 446
 447                 // Return it
 448                 return $length;
 449         }
 450
 451         /**
 452          * Initializes counter for valid entries, arrays for damaged entries and
 453          * an array for gap seek positions. If you call this method on your own,
 454          * please re-analyze the file structure. So you are better to call
 455          * analyzeFile() instead of this method.
 456          *
 457          * @return      void
 458          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 459          */
 460         public function initCountersGapsArray () {
 461                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 462         }
 463
 464         /**
 465          * Getter for header size
 466          *
 467          * @return      $totalEntries   Size of file header
 468          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 469          */
 470         public final function getHeaderSize () {
 471                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 472         }
 473
 474         /**
 475          * Setter for header size
 476          *
 477          * @param       $headerSize             Size of file header
 478          * @return      void
 479          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 480          */
 481         public final function setHeaderSize ($headerSize) {
 482                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 483         }
 484
 485         /**
 486          * Getter for header array
 487          *
 488          * @return      $totalEntries   Size of file header
 489          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 490          */
 491         public final function getHeader () {
 492                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 493         }
 494
 495         /**
 496          * Setter for header
 497          *
 498          * @param       $header         Array for a file header
 499          * @return      void
 500          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 501          */
 502         public final function setHeader (array $header) {
 503                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 504         }
 505
 506         /**
 507          * Updates seekPosition attribute from file to avoid to much access on file.
 508          *
 509          * @return      void
 510          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 511          */
 512         public function updateSeekPosition () {
 513                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 514         }
 515
 516         /**
 517          * Getter for total entries
 518          *
 519          * @return      $totalEntries   Total entries in this file
 520          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 521          */
 522         public final function getCounter () {
 523                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 524         }
 525
 526         /**
 527          * Writes data at given position
 528          *
 529          * @param       $seekPosition   Seek position
 530          * @param       $data                   Data to be written
 531          * @param       $flushHeader    Whether to flush the header (default: flush)
 532          * @return      void
 533          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 534          */
 535         public function writeData ($seekPosition, $data, $flushHeader = true) {
 536                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] seekPosition=%s,data[]=%s,flushHeader=%d', __METHOD__, __LINE__, $seekPosition, gettype($data), intval($flushHeader)));
 537                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 538         }
 539
 540         /**
 541          * Writes given value to the file and returns a hash and gap position for it
 542          *
 543          * @param       $groupId        Group identifier
 544          * @param       $value          Value to be added to the stack
 545          * @return      $data           Hash and gap position
 546          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 547          */
 548         public function writeValueToFile ($groupId, $value) {
 549                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] groupId=%s,value[%s]=%s', __METHOD__, __LINE__, $groupId, gettype($value), print_r($value, true)));
 550                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 551         }
 552
 553         /**
 554          * Searches for next suitable gap the given length of data can fit in
 555          * including padding bytes.
 556          *
 557          * @param       $length                 Length of raw data
 558          * @return      $seekPosition   Found next gap's seek position
 559          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 560          */
 561         public function searchNextGap ($length) {
 562                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] length=%s', __METHOD__, __LINE__, $length));
 563                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 564         }
 565
 566         /**
 567          * "Getter" for file size
 568          *
 569          * @return      $fileSize       Size of currently loaded file
 570          */
 571         public function getFileSize () {
 572                 // Call iterator's method
 573                 return $this->getIteratorInstance()->getFileSize();
 574         }
 575
 576         /**
 577          * Writes given raw data to the file and returns a gap position and length
 578          *
 579          * @param       $groupId        Group identifier
 580          * @param       $hash           Hash from encoded value
 581          * @param       $encoded        Encoded value to be written to the file
 582          * @return      $data           Gap position and length of the raw data
 583          */
 584         public function writeDataToFreeGap ($groupId, $hash, $encoded) {
 585                 // Debug message
 586                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,encoded()=%d - CALLED!', __METHOD__, __LINE__, $groupId, $hash, strlen($encoded)));
 587
 588                 // Raw data been written to the file
 589                 $rawData = sprintf('%s%s%s%s%s',
 590                         $groupId,
 591                         BaseBinaryFile::SEPARATOR_GROUP_HASH,
 592                         hex2bin($hash),
 593                         BaseBinaryFile::SEPARATOR_HASH_VALUE,
 594                         $encoded
 595                 );
 596
 597                 // Debug message
 598                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,rawData()=%d', __METHOD__, __LINE__, $groupId, $hash, strlen($rawData)));
 599
 600                 // Search for next free gap
 601                 $gapPosition = $this->getIteratorInstance()->searchNextGap(strlen($rawData));
 602
 603                 // Gap position cannot be smaller than header length + 1
 604                 assert($gapPosition > $this->getIteratorInstance()->getHeaderSize());
 605
 606                 // Debug message
 607                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,gapPosition=%s', __METHOD__, __LINE__, $groupId, $hash, $gapPosition));
 608
 609                 // Then write the data at that gap
 610                 $this->getIteratorInstance()->writeData($gapPosition, $rawData);
 611
 612                 // Debug message
 613                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__, __LINE__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,rawData()=%d - EXIT!', __METHOD__, __LINE__, $groupId, $hash, strlen($rawData)));
 614
 615                 // Return gap position, hash and length of raw data
 616                 return array(
 617                         self::ARRAY_INDEX_GAP_POSITION => $gapPosition,
 618                         self::ARRAY_INDEX_HASH         => $hash,
 619                         self::ARRAY_INDEX_DATA_LENGTH  => strlen($rawData)
 620                 );
 621         }
 622
 623 }