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

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