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

   1 <?php
   2 /**
   3  * A general file-based stack class
   4  *
   5  * @author              Roland Haeder <webmaster@ship-simu.org>
   6  * @version             0.0.0
   7  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2015 Core Developer Team
   8  * @license             GNU GPL 3.0 or any newer version
   9  * @link                http://www.ship-simu.org
  10  *
  11  * This program is free software: you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation, either version 3 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23  */
  24 class BaseFileStack extends BaseStacker {
  25         /**
  26          * Magic for this stack
  27          */
  28         const STACK_MAGIC = 'STACKv0.1';
  29
  30         /**
  31          * Name of array index for gap position
  32          */
  33         const ARRAY_INDEX_GAP_POSITION = 'gap';
  34
  35         /**
  36          * Name of array index for hash
  37          */
  38         const ARRAY_INDEX_HASH = 'hash';
  39
  40         /**
  41          * Name of array index for length of raw data
  42          */
  43         const ARRAY_INDEX_DATA_LENGTH = 'length';
  44
  45         /**
  46          * Protected constructor
  47          *
  48          * @param       $className      Name of the class
  49          * @return      void
  50          */
  51         protected function __construct ($className) {
  52                 // Call parent constructor
  53                 parent::__construct($className);
  54         }
  55
  56         /**
  57          * Reads the file header
  58          *
  59          * @return      void
  60          * @todo        To hard assertions here, better rewrite them to exceptions
  61          */
  62         public function readFileHeader () {
  63                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
  64
  65                 // First rewind to beginning as the header sits at the beginning ...
  66                 $this->getIteratorInstance()->rewind();
  67
  68                 // Then read it (see constructor for calculation)
  69                 $data = $this->getIteratorInstance()->read($this->getIteratorInstance()->getHeaderSize());
  70                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Read %d bytes (%d wanted).', __METHOD__, __LINE__, strlen($data), $this->getIteratorInstance()->getHeaderSize()));
  71
  72                 // Have all requested bytes been read?
  73                 assert(strlen($data) == $this->getIteratorInstance()->getHeaderSize());
  74                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  75
  76                 // Last character must be the separator
  77                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] data(-1)=%s', __METHOD__, __LINE__, dechex(ord(substr($data, -1, 1)))));
  78                 assert(substr($data, -1, 1) == chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES));
  79                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  80
  81                 // Okay, then remove it
  82                 $data = substr($data, 0, -1);
  83
  84                 // And update seek position
  85                 $this->getIteratorInstance()->updateSeekPosition();
  86
  87                 /*
  88                  * Now split it:
  89                  *
  90                  * 0 => magic
  91                  * 1 => total entries
  92                  * 2 => current seek position
  93                  */
  94                 $header = explode(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA), $data);
  95
  96                 // Set header here
  97                 $this->getIteratorInstance()->setHeader($header);
  98
  99                 // Check if the array has only 3 elements
 100                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] header(%d)=%s', __METHOD__, __LINE__, count($header), print_r($header, TRUE)));
 101                 assert(count($header) == 3);
 102                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 103
 104                 // Check magic
 105                 assert($header[0] == self::STACK_MAGIC);
 106                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 107
 108                 // Check length of count and seek position
 109                 assert(strlen($header[1]) == BaseBinaryFile::LENGTH_COUNT);
 110                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 111                 assert(strlen($header[2]) == BaseBinaryFile::LENGTH_POSITION);
 112                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 113
 114                 // Decode count and seek position
 115                 $header[1] = hex2bin($header[1]);
 116                 $header[2] = hex2bin($header[2]);
 117
 118                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 119         }
 120
 121         /**
 122          * Flushes the file header
 123          *
 124          * @return      void
 125          */
 126         public function flushFileHeader () {
 127                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 128
 129                 // Put all informations together
 130                 $header = sprintf('%s%s%s%s%s%s',
 131                         // Magic
 132                         self::STACK_MAGIC,
 133
 134                         // Separator magic<->count
 135                         chr(BaseBinaryFile::SEPARATOR_HEADER_DATA),
 136
 137                         // Total entries (will be zero) and pad it to 20 chars
 138                         str_pad($this->dec2hex($this->getIteratorInstance()->getCounter()), BaseBinaryFile::LENGTH_COUNT, '0', STR_PAD_LEFT),
 139
 140                         // Separator count<->seek position
 141                         chr(BaseBinaryFile::SEPARATOR_HEADER_DATA),
 142
 143                         // Position (will be zero)
 144                         str_pad($this->dec2hex($this->getIteratorInstance()->getSeekPosition(), 2), BaseBinaryFile::LENGTH_POSITION, '0', STR_PAD_LEFT),
 145
 146                         // Separator position<->entries
 147                         chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES)
 148                 );
 149
 150                 // Write it to disk (header is always at seek position 0)
 151                 $this->getIteratorInstance()->writeData(0, $header, FALSE);
 152
 153                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 154         }
 155
 156         /**
 157          * Initializes this file-based stack.
 158          *
 159          * @param       $fileName       File name of this stack
 160          * @param       $type           Type of this stack (e.g. url_source for URL sources)
 161          * @return      void
 162          * @todo        Currently the stack file is not cached, please implement a memory-handling class and if enough RAM is found, cache the whole stack file.
 163          */
 164         protected function initFileStack ($fileName, $type) {
 165                 // Get a stack file instance
 166                 $fileInstance = ObjectFactory::createObjectByConfiguredName('stack_file_class', array($fileName, $this));
 167
 168                 // Get iterator instance
 169                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_iterator_class', array($fileInstance));
 170
 171                 // Is the instance implementing the right interface?
 172                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 173
 174                 // Set iterator here
 175                 $this->setIteratorInstance($iteratorInstance);
 176
 177                 // Calculate header size
 178                 $this->getIteratorInstance()->setHeaderSize(
 179                         strlen(self::STACK_MAGIC) +
 180                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA)) +
 181                         BaseBinaryFile::LENGTH_COUNT +
 182                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA)) +
 183                         BaseBinaryFile::LENGTH_POSITION +
 184                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES))
 185                 );
 186
 187                 // Init counters and gaps array
 188                 $this->getIteratorInstance()->initCountersGapsArray();
 189
 190                 // Is the file's header initialized?
 191                 if (!$this->getIteratorInstance()->isFileHeaderInitialized()) {
 192                         // No, then create it (which may pre-allocate the stack)
 193                         $this->getIteratorInstance()->createFileHeader();
 194
 195                         // And pre-allocate a bit
 196                         $this->getIteratorInstance()->preAllocateFile('file_stack');
 197                 } // END - if
 198
 199                 // Load the file header
 200                 $this->readFileHeader();
 201
 202                 // Count all entries in file
 203                 $this->getIteratorInstance()->analyzeFile();
 204
 205                 /*
 206                  * Get stack index instance. This can be used for faster
 207                  * "defragmentation" and startup.
 208                  */
 209                 $indexInstance = FileStackIndexFactory::createFileStackIndexInstance($fileName, $type);
 210
 211                 // And set it here
 212                 $this->setIndexInstance($indexInstance);
 213         }
 214
 215         /**
 216          * Adds a value to given stack
 217          *
 218          * @param       $stackerName    Name of the stack
 219          * @param       $value                  Value to add to this stacker
 220          * @return      void
 221          * @throws      FullStackerException    If the stack is full
 222          */
 223         protected function addValue ($stackerName, $value) {
 224                 // Do some tests
 225                 if ($this->isStackFull($stackerName)) {
 226                         // Stacker is full
 227                         throw new FullStackerException(array($this, $stackerName, $value), self::EXCEPTION_STACKER_IS_FULL);
 228                 } // END - if
 229
 230                 // Debug message
 231                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName . ',value[' . gettype($value) . ']=' . print_r($value, TRUE));
 232
 233                 // No objects/resources are allowed as their serialization takes to long
 234                 assert(!is_object($value));
 235                 assert(!is_resource($value));
 236
 237                 // Now add the value to the file stack (which returns a hash)
 238                 $data = $this->getIteratorInstance()->writeValueToFile($stackerName, $value);
 239
 240                 // Add the hash and gap position to the index
 241                 $this->getIndexInstance()->addHashToIndex($stackerName, $data);
 242         }
 243
 244         /**
 245          * Get last value from named stacker
 246          *
 247          * @param       $stackerName    Name of the stack
 248          * @return      $value                  Value of last added value
 249          * @throws      EmptyStackerException   If the stack is empty
 250          */
 251         protected function getLastValue ($stackerName) {
 252                 // Is the stack not yet initialized or full?
 253                 if ($this->isStackEmpty($stackerName)) {
 254                         // Throw an exception
 255                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 256                 } // END - if
 257
 258                 // Now get the last value
 259                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 260                 $value = NULL;
 261
 262                 // Return it
 263                 return $value;
 264         }
 265
 266         /**
 267          * Get first value from named stacker
 268          *
 269          * @param       $stackerName    Name of the stack
 270          * @return      $value                  Value of last added value
 271          * @throws      EmptyStackerException   If the stack is empty
 272          */
 273         protected function getFirstValue ($stackerName) {
 274                 // Is the stack not yet initialized or full?
 275                 if ($this->isStackEmpty($stackerName)) {
 276                         // Throw an exception
 277                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 278                 } // END - if
 279
 280                 // Now get the first value
 281                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 282                 $value = NULL;
 283
 284                 // Return it
 285                 return $value;
 286         }
 287
 288         /**
 289          * "Pops" last entry from stack
 290          *
 291          * @param       $stackerName    Name of the stack
 292          * @return      $value                  Value "poped" from array
 293          * @throws      EmptyStackerException   If the stack is empty
 294          */
 295         protected function popLast ($stackerName) {
 296                 // Is the stack not yet initialized or full?
 297                 if ($this->isStackEmpty($stackerName)) {
 298                         // Throw an exception
 299                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 300                 } // END - if
 301
 302                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 303                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 304                 return NULL;
 305         }
 306
 307         /**
 308          * "Pops" first entry from stack
 309          *
 310          * @param       $stackerName    Name of the stack
 311          * @return      $value                  Value "shifted" from array
 312          * @throws      EmptyStackerException   If the named stacker is empty
 313          */
 314         protected function popFirst ($stackerName) {
 315                 // Is the stack not yet initialized or full?
 316                 if ($this->isStackEmpty($stackerName)) {
 317                         // Throw an exception
 318                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 319                 } // END - if
 320
 321                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 322                 /* NOISY-DEBUG: */ $this->partialStub('[' . __METHOD__ . ':' . __LINE__ . '] stackerName=' . $stackerName);
 323                 return NULL;
 324         }
 325
 326         /**
 327          * Checks whether the given stack is full
 328          *
 329          * @param       $stackerName    Name of the stack
 330          * @return      $isFull                 Whether the stack is full
 331          */
 332         protected function isStackFull ($stackerName) {
 333                 // File-based stacks will only run full if the disk space is low.
 334                 // @TODO Please implement this, returning FALSE
 335                 $isFull = FALSE;
 336
 337                 // Return result
 338                 return $isFull;
 339         }
 340
 341         /**
 342          * Checks whether the given stack is empty
 343          *
 344          * @param       $stackerName            Name of the stack
 345          * @return      $isEmpty                        Whether the stack is empty
 346          * @throws      NoStackerException      If given stack is missing
 347          */
 348         public function isStackEmpty ($stackerName) {
 349                 // So, is the stack empty?
 350                 $isEmpty = (($this->getStackCount($stackerName)) == 0);
 351
 352                 // Return result
 353                 return $isEmpty;
 354         }
 355
 356         /**
 357          * Initializes given stacker
 358          *
 359          * @param       $stackerName    Name of the stack
 360          * @param       $forceReInit    Force re-initialization
 361          * @return      void
 362          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 363          */
 364         public function initStack ($stackerName, $forceReInit = FALSE) {
 365                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 366         }
 367
 368         /**
 369          * Initializes all stacks
 370          *
 371          * @return      void
 372          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 373          */
 374         public function initStacks (array $stacks, $forceReInit = FALSE) {
 375                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 376         }
 377
 378         /**
 379          * Checks whether the given stack is initialized (set in array $stackers)
 380          *
 381          * @param       $stackerName    Name of the stack
 382          * @return      $isInitialized  Whether the stack is initialized
 383          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 384          */
 385         public function isStackInitialized ($stackerName) {
 386                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 387         }
 388
 389         /**
 390          * Determines whether the EOF has been reached
 391          *
 392          * @return      $isEndOfFileReached             Whether the EOF has been reached
 393          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 394          */
 395         public function isEndOfFileReached () {
 396                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 397         }
 398
 399         /**
 400          * Getter for file name
 401          *
 402          * @return      $fileName       The current file name
 403          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 404          */
 405         public function getFileName () {
 406                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 407         }
 408
 409         /**
 410          * Getter for size of given stack (array count)
 411          *
 412          * @param       $stackerName    Name of the stack
 413          * @return      $count                  Size of stack (array count)
 414          */
 415         public function getStackCount ($stackerName) {
 416                 // Now, simply return the found count value, this must be up-to-date then!
 417                 return $this->getIteratorInstance()->getCounter();
 418         }
 419
 420         /**
 421          * Calculates minimum length for one entry/block
 422          *
 423          * @return      $length         Minimum length for one entry/block
 424          */
 425         public function calculateMinimumBlockLength () {
 426                 // Calulcate it
 427                 $length =
 428                         // Length of entry group
 429                         BaseBinaryFile::LENGTH_GROUP + strlen(chr(BaseBinaryFile::SEPARATOR_GROUP_HASH)) +
 430                         // Hash + value
 431                         self::getHashLength() + strlen(chr(BaseBinaryFile::SEPARATOR_HASH_VALUE)) + 1 +
 432                         // Final separator
 433                         strlen(chr(BaseBinaryFile::SEPARATOR_ENTRIES));
 434
 435                 // Return it
 436                 return $length;
 437         }
 438
 439         /**
 440          * Initializes counter for valid entries, arrays for damaged entries and
 441          * an array for gap seek positions. If you call this method on your own,
 442          * please re-analyze the file structure. So you are better to call
 443          * analyzeFile() instead of this method.
 444          *
 445          * @return      void
 446          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 447          */
 448         public function initCountersGapsArray () {
 449                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 450         }
 451
 452         /**
 453          * Getter for header size
 454          *
 455          * @return      $totalEntries   Size of file header
 456          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 457          */
 458         public final function getHeaderSize () {
 459                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 460         }
 461
 462         /**
 463          * Setter for header size
 464          *
 465          * @param       $headerSize             Size of file header
 466          * @return      void
 467          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 468          */
 469         public final function setHeaderSize ($headerSize) {
 470                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 471         }
 472
 473         /**
 474          * Getter for header array
 475          *
 476          * @return      $totalEntries   Size of file header
 477          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 478          */
 479         public final function getHeader () {
 480                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 481         }
 482
 483         /**
 484          * Setter for header
 485          *
 486          * @param       $header         Array for a file header
 487          * @return      void
 488          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 489          */
 490         public final function setHeader (array $header) {
 491                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 492         }
 493
 494         /**
 495          * Updates seekPosition attribute from file to avoid to much access on file.
 496          *
 497          * @return      void
 498          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 499          */
 500         public function updateSeekPosition () {
 501                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 502         }
 503
 504         /**
 505          * Getter for total entries
 506          *
 507          * @return      $totalEntries   Total entries in this file
 508          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 509          */
 510         public final function getCounter () {
 511                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 512         }
 513
 514         /**
 515          * Writes data at given position
 516          *
 517          * @param       $seekPosition   Seek position
 518          * @param       $data                   Data to be written
 519          * @param       $flushHeader    Whether to flush the header (default: flush)
 520          * @return      void
 521          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 522          */
 523         public function writeData ($seekPosition, $data, $flushHeader = TRUE) {
 524                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] seekPosition=%s,data[]=%s,flushHeader=%d', __METHOD__, __LINE__, $seekPosition, gettype($data), intval($flushHeader)));
 525                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 526         }
 527
 528         /**
 529          * Writes given value to the file and returns a hash and gap position for it
 530          *
 531          * @param       $groupId        Group identifier
 532          * @param       $value          Value to be added to the stack
 533          * @return      $data           Hash and gap position
 534          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 535          */
 536         public function writeValueToFile ($groupId, $value) {
 537                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] groupId=%s,value[%s]=%s', __METHOD__, __LINE__, $groupId, gettype($value), print_r($value, TRUE)));
 538                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 539         }
 540
 541         /**
 542          * Searches for next suitable gap the given length of data can fit in
 543          * including padding bytes.
 544          *
 545          * @param       $length                 Length of raw data
 546          * @return      $seekPosition   Found next gap's seek position
 547          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 548          */
 549         public function searchNextGap ($length) {
 550                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] length=%s', __METHOD__, __LINE__, $length));
 551                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 552         }
 553
 554         /**
 555          * "Getter" for file size
 556          *
 557          * @return      $fileSize       Size of currently loaded file
 558          */
 559         public function getFileSize () {
 560                 // Call iterator's method
 561                 return $this->getIteratorInstance()->getFileSize();
 562         }
 563
 564         /**
 565          * Writes given raw data to the file and returns a gap position and length
 566          *
 567          * @param       $groupId        Group identifier
 568          * @param       $hash           Hash from encoded value
 569          * @param       $encoded        Encoded value to be written to the file
 570          * @return      $data           Gap position and length of the raw data
 571          */
 572         public function writeDataToFreeGap ($groupId, $hash, $encoded) {
 573                 // Debug message
 574                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,encoded()=%s - CALLED!', __METHOD__, __LINE__, $groupId, $hash, strlen($encoded)));
 575
 576                 // Raw data been written to the file
 577                 $rawData = sprintf('%s%s%s%s%s',
 578                         $groupId,
 579                         BaseBinaryFile::SEPARATOR_GROUP_HASH,
 580                         hex2bin($hash),
 581                         BaseBinaryFile::SEPARATOR_HASH_VALUE,
 582                         $encoded
 583                 );
 584
 585                 // Debug message
 586                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,rawData()=%s', __METHOD__, __LINE__, $groupId, $hash, strlen($rawData)));
 587
 588                 // Search for next free gap
 589                 $gapPosition = $this->getIteratorInstance()->searchNextGap(strlen($rawData));
 590
 591                 // Gap position cannot be smaller than header length + 1
 592                 assert($gapPosition > $this->getIteratorInstance()->getHeaderSize());
 593
 594                 // Debug message
 595                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,gapPosition=%s', __METHOD__, __LINE__, $groupId, $hash, $gapPosition));
 596
 597                 // Then write the data at that gap
 598                 $this->getIteratorInstance()->writeData($gapPosition, $rawData);
 599
 600                 // Debug message
 601                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] groupId=%s,hash=%s,rawData()=%s - EXIT!', __METHOD__, __LINE__, $groupId, $hash, strlen($rawData)));
 602
 603                 // Return gap position, hash and length of raw data
 604                 return array(
 605                         self::ARRAY_INDEX_GAP_POSITION => $gapPosition,
 606                         self::ARRAY_INDEX_HASH         => $hash,
 607                         self::ARRAY_INDEX_DATA_LENGTH  => strlen($rawData)
 608                 );
 609         }
 610 }
 611
 612 // [EOF]
 613 ?>