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 - 2013 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          * Separator for header data
  32          */
  33         const SEPARATOR_HEADER_DATA = 0x01;
  34
  35         /**
  36          * Separator header->entries
  37          */
  38         const SEPARATOR_HEADER_ENTRIES = 0x02;
  39
  40         /**
  41          * Separator hash->name
  42          */
  43         const SEPARATOR_HASH_NAME = 0x03;
  44
  45         /**
  46          * Length of name
  47          */
  48         const LENGTH_NAME = 10;
  49
  50         /**
  51          * Length of count
  52          */
  53         const LENGTH_COUNT = 20;
  54
  55         /**
  56          * Length of position
  57          */
  58         const LENGTH_POSITION = 20;
  59
  60         /**
  61          * Counter for total entries
  62          */
  63         private $totalEntries = 0;
  64
  65         /**
  66          * Current seek position
  67          */
  68         private $seekPosition = 0;
  69
  70         /**
  71          * Size of header
  72          */
  73         private $headerSize = 0;
  74
  75         /**
  76          * File header
  77          */
  78         private $header = array();
  79
  80         /**
  81          * Protected constructor
  82          *
  83          * @param       $className      Name of the class
  84          * @return      void
  85          */
  86         protected function __construct ($className) {
  87                 // Call parent constructor
  88                 parent::__construct($className);
  89
  90                 // Calculate header size
  91                 $this->headerSize =
  92                         strlen(self::MAGIC) +
  93                         strlen(self::SEPARATOR_HEADER_DATA) +
  94                         self::LENGTH_COUNT +
  95                         strlen(self::SEPARATOR_HEADER_DATA) +
  96                         self::LENGTH_POSITION +
  97                         strlen(self::SEPARATOR_HEADER_ENTRIES)
  98                 );
  99         }
 100
 101         /**
 102          * Getter for total entries
 103          *
 104          * @return      $totalEntries   Total entries in this stack
 105          */
 106         private function getCounter () {
 107                 // Get it
 108                 return $this->totalEntries;
 109         }
 110
 111         /**
 112          * Increment counter
 113          *
 114          * @return      void
 115          */
 116         private function incrementCounter () {
 117                 // Get it
 118                 $this->totalEntries++;
 119         }
 120
 121         /**
 122          * Getter for seek position
 123          *
 124          * @return      $seekPosition   Current seek position (stored here in object)
 125          */
 126         private function getSeekPosition () {
 127                 // Get it
 128                 return $this->seekPosition;
 129         }
 130
 131         /**
 132          * Setter for seek position
 133          *
 134          * @param       $seekPosition   Current seek position (stored here in object)
 135          * @return      void
 136          */
 137         private function setSeekPosition ($seekPosition) {
 138                 // And set it
 139                 $this->seekPosition = $seekPosition;
 140         }
 141
 142         /**
 143          * Updates seekPosition attribute from file to avoid to much access on file.
 144          *
 145          * @return      void
 146          */
 147         private function updateSeekPosition () {
 148                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 149
 150                 // Get key (= seek position)
 151                 $seekPosition = $this->getIteratorInstance()->key();
 152                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Setting seekPosition=%s', __METHOD__, __LINE__, $seekPosition));
 153
 154                 // And set it here
 155                 $this->setSeekPosition($seekPosition);
 156
 157                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 158         }
 159
 160         /**
 161          * Reads the file header
 162          *
 163          * @return      void
 164          */
 165         private function readFileHeader () {
 166                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 167
 168                 // First rewind to beginning as the header sits at the beginning ...
 169                 $this->getIteratorInstance()->rewind();
 170
 171                 // Then read it (see constructor for calculation)
 172                 $data = $this->getIteratorInstance()->read($this->headerLength);
 173
 174                 // Last character must be the separator
 175                 assert(substr($data, -1, 1) == self::SEPARATOR_HEADER_ENTRIES);
 176
 177                 // Okay, then remove it
 178                 $data = substr($data, 0, -1);
 179
 180                 // And update seek position
 181                 $this->updateSeekPosition();
 182
 183                 /*
 184                  * Now split it:
 185                  *
 186                  * 0 => Magic
 187                  * 1 => Total entries
 188                  * 2 => Current seek position
 189                  */
 190                 $this->header = explode(self::SEPARATOR_HEADER_DATA, $data);
 191
 192                 // Check if the array has only 3 elements
 193                 assert(count($this->header) == 3);
 194
 195                 // Check magic
 196                 assert($this->header[0] == self::MAGIC);
 197
 198                 // Check length of count and seek position
 199                 assert(strlen($this->header[1]) == self::LENGTH_COUNT);
 200                 assert(strlen($this->header[2]) == self::LENGTH_POSITION);
 201
 202                 // Decode count and seek position
 203                 $this->header[1] = hex2bin($this->header[1]);
 204                 $this->header[2] = hex2bin($this->header[2]);
 205
 206                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 207         }
 208
 209         /**
 210          * Checks whether the file header is initialized
 211          *
 212          * @return      $isInitialized  Whether the file header is initialized
 213          */
 214         private function isFileHeaderInitialized () {
 215                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 216                 // Default is not initialized
 217                 $isInitialized = FALSE;
 218
 219                 // Is the file initialized?
 220                 if ($this->isFileInitialized()) {
 221                         // Some bytes has been written, so rewind to start of it.
 222                         $rewindStatus = $this->getIteratorInstance()->rewind();
 223                         /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] rewindStatus=%s', __METHOD__, __LINE__, $rewindStatus));
 224
 225                         // Is the rewind() call successfull?
 226                         if ($rewindStatus != 1) {
 227                                 // Something bad happened
 228                                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Could not rewind().', __METHOD__, __LINE__));
 229                         } // END - if
 230
 231                         // Read file header
 232                         $this->readFileHeader();
 233
 234                         // Check if its format is valid.
 235                 } // END - if
 236
 237                 // Return result
 238                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] isInitialized=%d - EXIT!', __METHOD__, __LINE__, intval($isInitialized)));
 239                 return $isInitialized;
 240         }
 241
 242         /**
 243          * Checks whether the file-based stack has been initialized
 244          *
 245          * @return      $isInitialized          Whether the file's size is zero
 246          */
 247         private function isFileInitialized () {
 248                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 249
 250                 // Get it from iterator which holds the pointer instance. If FALSE is returned
 251                 $fileSize = $this->getIteratorInstance()->size();
 252                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] fileSize=%s', __METHOD__, __LINE__, $fileSize));
 253
 254                 /*
 255                  * The returned file size should not be FALSE or NULL as this means
 256                  * that the pointer class does not work correctly.
 257                  */
 258                 assert(is_int($fileSize));
 259
 260                 // Is more than 0 returned?
 261                 $isInitialized = ($fileSize > 0);
 262
 263                 // Return result
 264                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] isInitialized=%d - EXIT!', __METHOD__, __LINE__, intval($isInitialized)));
 265                 return $isInitialized;
 266         }
 267
 268         /**
 269          * Creates the file-stack's header
 270          *
 271          * @return      void
 272          */
 273         private function createFileHeader () {
 274                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 275                 // The file's header should not be initialized here
 276                 assert(!$this->isFileHeaderInitialized());
 277
 278                 // Simple flush file header which will create it.
 279                 $this->flushFileHeader();
 280
 281                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!!', __METHOD__, __LINE__));
 282         }
 283
 284         /**
 285          * Flushes the file header
 286          *
 287          * @return      void
 288          */
 289         private function flushFileHeader () {
 290                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 291
 292                 // Put all informations together
 293                 $header = sprintf('%s%s%s%s%s%s',
 294                         // Magic
 295                         self::STACK_MAGIC,
 296
 297                         // Separator magic<->count
 298                         chr(self::SEPARATOR_HEADER_DATA),
 299
 300                         // Total entries (will be zero) and pad it to 20 chars
 301                         str_pad($this->dec2hex($this->getCounter()), self::LENGTH_COUNT, '0', STR_PAD_LEFT),
 302
 303                         // Separator count<->seek position
 304                         chr(self::SEPARATOR_HEADER_DATA),
 305
 306                         // Position (will be zero)
 307                         str_pad($this->dec2hex($this->getSeekPosition(), 2), self::LENGTH_POSITION, '0', STR_PAD_LEFT),
 308
 309                         // Separator position<->entries
 310                         chr(self::SEPARATOR_HEADER_ENTRIES)
 311                 );
 312
 313                 // Write it to disk (header is always at seek position 0)
 314                 $this->writeData(0, $header);
 315
 316                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 317         }
 318
 319         /**
 320          * Writes data at given position
 321          *
 322          * @param       $seekPosition   Seek position
 323          * @param       $data                   Data to be written
 324          * @return      void
 325          */
 326         private function writeData ($seekPosition, $data) {
 327                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] seekPosition=%s,data()=%s - CALLED!', __METHOD__, __LINE__, $seekPosition, strlen($data)));
 328
 329                 // Write data at given position
 330                 $this->getIteratorInstance()->writeAtPosition($seekPosition, $data);
 331
 332                 // Update seek position
 333                 $this->updateSeekPosition();
 334
 335                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 336         }
 337
 338         /**
 339          * Pre-allocates file (if enabled) with some space for later faster write access.
 340          *
 341          * @return      void
 342          */
 343         private function preAllocateFile () {
 344                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 345
 346                 // Is it enabled?
 347                 if ($this->getConfigInstance()->getConfigEntry('file_stack_pre_allocate_enabled') != 'Y') {
 348                         // Not enabled
 349                         self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Not pre-allocating stack file.', __METHOD__, __LINE__));
 350
 351                         // Don't continue here.
 352                         return;
 353                 } // END - if
 354
 355                 // Message to user
 356                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Pre-allocating stack file ...', __METHOD__, __LINE__));
 357
 358                 /*
 359                  * Calculate minimum length for one entry:
 360                  * minimum length = hash length + separator + name + minimum entry size = ?? + 1 + 10 + 1 = ??
 361                  */
 362                 $minLengthEntry = self::getHashLength() + strlen(self::SEPARATOR_HASH_NAME) + self::LENGTH_NAME + 1;
 363                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] minLengthEntry=%s', __METHOD__, __LINE__, $minLengthEntry));
 364
 365                 // Calulcate seek position
 366                 $seekPosition = $minLengthEntry * $this->getConfigInstance()->getConfigEntry('file_stack_pre_allocate_count');
 367                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] seekPosition=%s', __METHOD__, __LINE__, $seekPosition));
 368
 369                 // Now simply write a NUL there. This will pre-allocate the file.
 370                 $this->writeData($seekPosition, chr(0));
 371
 372                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 373         }
 374
 375         /**
 376          * Initializes this file-based stack.
 377          *
 378          * @param       $fileName       File name of this stack
 379          * @return      void
 380          */
 381         protected function initFileStack ($fileName) {
 382                 // Get a file i/o pointer instance
 383                 $pointerInstance = ObjectFactory::createObjectByConfiguredName('file_raw_input_output_class', array($fileName));
 384
 385                 // Get iterator instance
 386                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_io_iterator_class', array($pointerInstance));
 387
 388                 // Is the instance implementing the right interface?
 389                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 390
 391                 // Set iterator here
 392                 $this->setIteratorInstance($iteratorInstance);
 393
 394                 // Is the file's header initialized?
 395                 if ($this->isFileHeaderInitialized()) {
 396                         // Then load it
 397                         $this->loadFileHeader();
 398                 } else {
 399                         // No, then create it (which may pre-allocate the stack)
 400                         $this->createFileHeader();
 401
 402                         // And pre-allocate a bit
 403                         $this->preAllocateFile();
 404                 }
 405         }
 406
 407         /**
 408          * Initializes given stacker
 409          *
 410          * @param       $stackerName    Name of the stack
 411          * @param       $forceReInit    Force re-initialization
 412          * @return      void
 413          * @throws      AlreadyInitializedStackerException      If the stack is already initialized
 414          */
 415         public function initStack ($stackerName, $forceReInit = FALSE) {
 416                 // Is the stack already initialized?
 417                 if (($forceReInit === FALSE) && ($this->isStackInitialized($stackerName))) {
 418                         // Then throw the exception
 419                         throw new AlreadyInitializedStackerException(array($this, $stackerName, $forceReInit), self::EXCEPTION_STACKER_ALREADY_INITIALIZED);
 420                 } // END - if
 421
 422                 // Initialize the given stack
 423                 $this->partialStub('stackerName=' . $stackerName . ',forceReInit=' . intval($forceReInit));
 424         }
 425
 426         /**
 427          * Checks whether the given stack is initialized (set in array $stackers)
 428          *
 429          * @param       $stackerName    Name of the stack
 430          * @return      $isInitialized  Whether the stack is initialized
 431          */
 432         public function isStackInitialized ($stackerName) {
 433                 // Is is there?
 434                 $this->partialStub('stackerName=' . $stackerName);
 435                 $isInitialized = TRUE;
 436
 437                 // Return result
 438                 return $isInitialized;
 439         }
 440
 441         /**
 442          * Getter for size of given stack (array count)
 443          *
 444          * @param       $stackerName    Name of the stack
 445          * @return      $count                  Size of stack (array count)
 446          * @throws      NoStackerException      If given stack is missing
 447          */
 448         public function getStackCount ($stackerName) {
 449                 // Is the stack not yet initialized?
 450                 if (!$this->isStackInitialized($stackerName)) {
 451                         // Throw an exception
 452                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 453                 } // END - if
 454
 455                 // Now, count the array of entries
 456                 $this->partialStub('stackerName=' . $stackerName);
 457                 $count = 0;
 458
 459                 // Return result
 460                 return $count;
 461         }
 462
 463         /**
 464          * Adds a value to given stack
 465          *
 466          * @param       $stackerName    Name of the stack
 467          * @param       $value                  Value to add to this stacker
 468          * @return      void
 469          * @throws      FullStackerException    Thrown if the stack is full
 470          */
 471         protected function addValue ($stackerName, $value) {
 472                 // Is the stack not yet initialized or full?
 473                 if (!$this->isStackInitialized($stackerName)) {
 474                         // Then do it here
 475                         $this->initStack($stackerName);
 476                 } elseif ($this->isStackFull($stackerName)) {
 477                         // Stacker is full
 478                         throw new FullStackerException(array($this, $stackerName, $value), self::EXCEPTION_STACKER_IS_FULL);
 479                 }
 480
 481                 // Now add the value to the stack
 482                 $this->partialStub('stackerName=' . $stackerName . ',value[]=' . gettype($value));
 483         }
 484
 485         /**
 486          * Get last value from named stacker
 487          *
 488          * @param       $stackerName    Name of the stack
 489          * @return      $value                  Value of last added value
 490          * @throws      NoStackerException      If the named stacker was not found
 491          * @throws      EmptyStackerException   If the named stacker is empty
 492          */
 493         protected function getLastValue ($stackerName) {
 494                 // Is the stack not yet initialized or full?
 495                 if (!$this->isStackInitialized($stackerName)) {
 496                         // Throw an exception
 497                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 498                 } elseif ($this->isStackEmpty($stackerName)) {
 499                         // Throw an exception
 500                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 501                 }
 502
 503                 // Now get the last value
 504                 $this->partialStub('stackerName=' . $stackerName);
 505                 $value = NULL;
 506
 507                 // Return it
 508                 return $value;
 509         }
 510
 511         /**
 512          * Get first value from named stacker
 513          *
 514          * @param       $stackerName    Name of the stack
 515          * @return      $value                  Value of last added value
 516          * @throws      NoStackerException      If the named stacker was not found
 517          * @throws      EmptyStackerException   If the named stacker is empty
 518          */
 519         protected function getFirstValue ($stackerName) {
 520                 // Is the stack not yet initialized or full?
 521                 if (!$this->isStackInitialized($stackerName)) {
 522                         // Throw an exception
 523                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 524                 } elseif ($this->isStackEmpty($stackerName)) {
 525                         // Throw an exception
 526                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 527                 }
 528
 529                 // Now get the first value
 530                 $this->partialStub('stackerName=' . $stackerName);
 531                 $value = NULL;
 532
 533                 // Return it
 534                 return $value;
 535         }
 536
 537         /**
 538          * "Pops" last entry from stack
 539          *
 540          * @param       $stackerName    Name of the stack
 541          * @return      $value                  Value "poped" from array
 542          * @throws      NoStackerException      If the named stacker was not found
 543          * @throws      EmptyStackerException   If the named stacker is empty
 544          */
 545         protected function popLast ($stackerName) {
 546                 // Is the stack not yet initialized or full?
 547                 if (!$this->isStackInitialized($stackerName)) {
 548                         // Throw an exception
 549                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 550                 } elseif ($this->isStackEmpty($stackerName)) {
 551                         // Throw an exception
 552                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 553                 }
 554
 555                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 556                 $this->partialStub('stackerName=' . $stackerName);
 557                 return NULL;
 558         }
 559
 560         /**
 561          * "Pops" first entry from stack
 562          *
 563          * @param       $stackerName    Name of the stack
 564          * @return      $value                  Value "shifted" from array
 565          * @throws      NoStackerException      If the named stacker was not found
 566          * @throws      EmptyStackerException   If the named stacker is empty
 567          */
 568         protected function popFirst ($stackerName) {
 569                 // Is the stack not yet initialized or full?
 570                 if (!$this->isStackInitialized($stackerName)) {
 571                         // Throw an exception
 572                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 573                 } elseif ($this->isStackEmpty($stackerName)) {
 574                         // Throw an exception
 575                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 576                 }
 577
 578                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 579                 $this->partialStub('stackerName=' . $stackerName);
 580                 return NULL;
 581         }
 582 }
 583
 584 // [EOF]
 585 ?>