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 magic->count
  32          */
  33         const SEPARATOR_MAGIC_COUNT = 0x01;
  34
  35         /**
  36          * Separator count->position
  37          */
  38         const SEPARATOR_COUNT_SEEK_POS = 0x02;
  39
  40         /**
  41          * Separator position->entries
  42          */
  43         const SEPARATOR_SEEK_POS_ENTRIES = 0x03;
  44
  45         /**
  46          * Separator hash->name
  47          */
  48         const SEPARATOR_HASH_NAME = 0x04;
  49
  50         /**
  51          * Length of name
  52          */
  53         const COUNT_NAME = 10;
  54
  55         /**
  56          * Length of count
  57          */
  58         const COUNT_LENGTH = 20;
  59
  60         /**
  61          * Length of position
  62          */
  63         const COUNT_POSITION = 20;
  64
  65         /**
  66          * Counter for total entries
  67          */
  68         private $totalEntries = 0;
  69
  70         /**
  71          * Current seek position
  72          */
  73         private $seekPosition = 0;
  74
  75         /**
  76          * Protected constructor
  77          *
  78          * @param       $className      Name of the class
  79          * @return      void
  80          */
  81         protected function __construct ($className) {
  82                 // Call parent constructor
  83                 parent::__construct($className);
  84         }
  85
  86         /**
  87          * Getter for total entries
  88          *
  89          * @return      $totalEntries   Total entries in this stack
  90          */
  91         private function getCounter () {
  92                 // Get it
  93                 return $this->totalEntries;
  94         }
  95
  96         /**
  97          * Increment counter
  98          *
  99          * @return      void
 100          */
 101         private function incrementCounter () {
 102                 // Get it
 103                 $this->totalEntries++;
 104         }
 105
 106         /**
 107          * Getter for seek position
 108          *
 109          * @return      $seekPosition   Current seek position (stored here in object)
 110          */
 111         private function getSeekPosition () {
 112                 // Get it
 113                 return $this->seekPosition;
 114         }
 115
 116         /**
 117          * Setter for seek position
 118          *
 119          * @param       $seekPosition   Current seek position (stored here in object)
 120          * @return      void
 121          */
 122         private function setSeekPosition ($seekPosition) {
 123                 // And set it
 124                 $this->seekPosition = $seekPosition;
 125         }
 126
 127         /**
 128          * Updates seekPosition attribute from file to avoid to much access on file.
 129          *
 130          * @return      void
 131          */
 132         private function updateSeekPosition () {
 133                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 134
 135                 // Get key (= seek position)
 136                 $seekPosition = $this->getIteratorInstance()->key();
 137                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Setting seekPosition=%s', __METHOD__, __LINE__, $seekPosition));
 138
 139                 // And set it here
 140                 $this->setSeekPosition($seekPosition);
 141
 142                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 143         }
 144
 145         /**
 146          * Checks whether the file header is initialized
 147          *
 148          * @return      $isInitialized  Whether the file header is initialized
 149          */
 150         private function isFileHeaderInitialized () {
 151                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 152                 // Default is not initialized
 153                 $isInitialized = FALSE;
 154
 155                 // Is the file initialized?
 156                 if ($this->isFileInitialized()) {
 157                         // Some bytes has been written, so rewind to start of it.
 158                         $rewindStatus = $this->getIteratorInstance()->rewind();
 159                         /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] rewindStatus=%s', __METHOD__, __LINE__, $rewindStatus));
 160
 161                         // Is the rewind() call successfull?
 162                         if ($rewindStatus != 1) {
 163                                 // Something bad happened
 164                                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Could not rewind().', __METHOD__, __LINE__));
 165                         } // END - if
 166
 167                         // Read file header
 168                         $this->readFileHeader();
 169                 } // END - if
 170
 171                 // Return result
 172                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] isInitialized=%d - EXIT!', __METHOD__, __LINE__, intval($isInitialized)));
 173                 return $isInitialized;
 174         }
 175
 176         /**
 177          * Checks whether the file-based stack has been initialized
 178          *
 179          * @return      $isInitialized          Whether the file's size is zero
 180          */
 181         private function isFileInitialized () {
 182                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 183
 184                 // Get it from iterator which holds the pointer instance. If FALSE is returned
 185                 $fileSize = $this->getIteratorInstance()->size();
 186                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] fileSize=%s', __METHOD__, __LINE__, $fileSize));
 187
 188                 /*
 189                  * The returned file size should not be FALSE or NULL as this means
 190                  * that the pointer class does not work correctly.
 191                  */
 192                 assert(is_int($fileSize));
 193
 194                 // Is more than 0 returned?
 195                 $isInitialized = ($fileSize > 0);
 196
 197                 // Return result
 198                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] isInitialized=%d - EXIT!', __METHOD__, __LINE__, intval($isInitialized)));
 199                 return $isInitialized;
 200         }
 201
 202         /**
 203          * Creates the file-stack's header
 204          *
 205          * @return      void
 206          */
 207         private function createFileHeader () {
 208                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 209                 // The file's header should not be initialized here
 210                 assert(!$this->isFileHeaderInitialized());
 211
 212                 // Simple flush file header which will create it.
 213                 $this->flushFileHeader();
 214
 215                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!!', __METHOD__, __LINE__));
 216         }
 217
 218         /**
 219          * Flushes the file header
 220          *
 221          * @return      void
 222          */
 223         private function flushFileHeader () {
 224                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 225
 226                 // Put all informations together
 227                 $header = sprintf('%s%s%s%s%s%s',
 228                         // Magic
 229                         self::STACK_MAGIC,
 230
 231                         // Separator magic<->count
 232                         chr(self::SEPARATOR_MAGIC_COUNT),
 233
 234                         // Total entries (will be zero) and pad it to 20 chars
 235                         str_pad($this->dec2hex($this->getCounter()), self::COUNT_LENGTH, '0', STR_PAD_LEFT),
 236
 237                         // Separator count<->seek position
 238                         chr(self::SEPARATOR_COUNT_SEEK_POS),
 239
 240                         // Position (will be zero)
 241                         str_pad($this->dec2hex($this->getSeekPosition(), 2), self::COUNT_POSITION, '0', STR_PAD_LEFT),
 242
 243                         // Separator position<->entries
 244                         chr(self::SEPARATOR_SEEK_POS_ENTRIES)
 245                 );
 246
 247                 // Write it to disk (header is always at seek position 0)
 248                 $this->writeData(0, $header);
 249
 250                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 251         }
 252
 253         /**
 254          * Writes data at given position
 255          *
 256          * @param       $seekPosition   Seek position
 257          * @param       $data                   Data to be written
 258          * @return      void
 259          */
 260         private function writeData ($seekPosition, $data) {
 261                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] seekPosition=%s,data()=%s - CALLED!', __METHOD__, __LINE__, $seekPosition, strlen($data)));
 262
 263                 // Write data at given position
 264                 $this->getIteratorInstance()->writeAtPosition($seekPosition, $data);
 265
 266                 // Update seek position
 267                 $this->updateSeekPosition();
 268
 269                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 270         }
 271
 272         /**
 273          * Pre-allocates file (if enabled) with some space for later faster write access.
 274          *
 275          * @return      void
 276          */
 277         private function preAllocateFile () {
 278                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 279
 280                 // Is it enabled?
 281                 if ($this->getConfigInstance()->getConfigEntry('file_stack_pre_allocate_enabled') != 'Y') {
 282                         // Not enabled
 283                         self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Not pre-allocating stack file.', __METHOD__, __LINE__));
 284
 285                         // Don't continue here.
 286                         return;
 287                 } // END - if
 288
 289                 // Message to user
 290                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Pre-allocating stack file ...', __METHOD__, __LINE__));
 291
 292                 /*
 293                  * Calculate minimum length for one entry:
 294                  * minimum length = hash length + separator + name + minimum entry size = ?? + 1 + 10 + 1 = ??
 295                  */
 296                 $minLengthEntry = self::getHashLength() + strlen(self::SEPARATOR_HASH_NAME) + self::COUNT_NAME + 1;
 297                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] minLengthEntry=%s', __METHOD__, __LINE__, $minLengthEntry));
 298
 299                 // Calulcate seek position
 300                 $seekPosition = $minLengthEntry * $this->getConfigInstance()->getConfigEntry('file_stack_pre_allocate_count');
 301                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] seekPosition=%s', __METHOD__, __LINE__, $seekPosition));
 302
 303                 // Now simply write a NUL there. This will pre-allocate the file.
 304                 $this->writeData($seekPosition, chr(0));
 305
 306                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 307         }
 308
 309         /**
 310          * Initializes this file-based stack.
 311          *
 312          * @param       $fileName       File name of this stack
 313          * @return      void
 314          */
 315         protected function initFileStack ($fileName) {
 316                 // Get a file i/o pointer instance
 317                 $pointerInstance = ObjectFactory::createObjectByConfiguredName('file_raw_input_output_class', array($fileName));
 318
 319                 // Get iterator instance
 320                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_io_iterator_class', array($pointerInstance));
 321
 322                 // Is the instance implementing the right interface?
 323                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 324
 325                 // Set iterator here
 326                 $this->setIteratorInstance($iteratorInstance);
 327
 328                 // Is the file's header initialized?
 329                 if ($this->isFileHeaderInitialized()) {
 330                         // Then load it
 331                         $this->loadFileHeader();
 332                 } else {
 333                         // No, then create it (which may pre-allocate the stack)
 334                         $this->createFileHeader();
 335
 336                         // And pre-allocate a bit
 337                         $this->preAllocateFile();
 338                 }
 339         }
 340
 341         /**
 342          * Initializes given stacker
 343          *
 344          * @param       $stackerName    Name of the stack
 345          * @param       $forceReInit    Force re-initialization
 346          * @return      void
 347          * @throws      AlreadyInitializedStackerException      If the stack is already initialized
 348          */
 349         public function initStack ($stackerName, $forceReInit = FALSE) {
 350                 // Is the stack already initialized?
 351                 if (($forceReInit === FALSE) && ($this->isStackInitialized($stackerName))) {
 352                         // Then throw the exception
 353                         throw new AlreadyInitializedStackerException(array($this, $stackerName, $forceReInit), self::EXCEPTION_STACKER_ALREADY_INITIALIZED);
 354                 } // END - if
 355
 356                 // Initialize the given stack
 357                 $this->partialStub('stackerName=' . $stackerName . ',forceReInit=' . intval($forceReInit));
 358         }
 359
 360         /**
 361          * Checks whether the given stack is initialized (set in array $stackers)
 362          *
 363          * @param       $stackerName    Name of the stack
 364          * @return      $isInitialized  Whether the stack is initialized
 365          */
 366         public function isStackInitialized ($stackerName) {
 367                 // Is is there?
 368                 $this->partialStub('stackerName=' . $stackerName);
 369                 $isInitialized = TRUE;
 370
 371                 // Return result
 372                 return $isInitialized;
 373         }
 374
 375         /**
 376          * Getter for size of given stack (array count)
 377          *
 378          * @param       $stackerName    Name of the stack
 379          * @return      $count                  Size of stack (array count)
 380          * @throws      NoStackerException      If given stack is missing
 381          */
 382         public function getStackCount ($stackerName) {
 383                 // Is the stack not yet initialized?
 384                 if (!$this->isStackInitialized($stackerName)) {
 385                         // Throw an exception
 386                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 387                 } // END - if
 388
 389                 // Now, count the array of entries
 390                 $this->partialStub('stackerName=' . $stackerName);
 391                 $count = 0;
 392
 393                 // Return result
 394                 return $count;
 395         }
 396
 397         /**
 398          * Adds a value to given stack
 399          *
 400          * @param       $stackerName    Name of the stack
 401          * @param       $value                  Value to add to this stacker
 402          * @return      void
 403          * @throws      FullStackerException    Thrown if the stack is full
 404          */
 405         protected function addValue ($stackerName, $value) {
 406                 // Is the stack not yet initialized or full?
 407                 if (!$this->isStackInitialized($stackerName)) {
 408                         // Then do it here
 409                         $this->initStack($stackerName);
 410                 } elseif ($this->isStackFull($stackerName)) {
 411                         // Stacker is full
 412                         throw new FullStackerException(array($this, $stackerName, $value), self::EXCEPTION_STACKER_IS_FULL);
 413                 }
 414
 415                 // Now add the value to the stack
 416                 $this->partialStub('stackerName=' . $stackerName . ',value[]=' . gettype($value));
 417         }
 418
 419         /**
 420          * Get last value from named stacker
 421          *
 422          * @param       $stackerName    Name of the stack
 423          * @return      $value                  Value of last added value
 424          * @throws      NoStackerException      If the named stacker was not found
 425          * @throws      EmptyStackerException   If the named stacker is empty
 426          */
 427         protected function getLastValue ($stackerName) {
 428                 // Is the stack not yet initialized or full?
 429                 if (!$this->isStackInitialized($stackerName)) {
 430                         // Throw an exception
 431                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 432                 } elseif ($this->isStackEmpty($stackerName)) {
 433                         // Throw an exception
 434                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 435                 }
 436
 437                 // Now get the last value
 438                 $this->partialStub('stackerName=' . $stackerName);
 439                 $value = NULL;
 440
 441                 // Return it
 442                 return $value;
 443         }
 444
 445         /**
 446          * Get first value from named stacker
 447          *
 448          * @param       $stackerName    Name of the stack
 449          * @return      $value                  Value of last added value
 450          * @throws      NoStackerException      If the named stacker was not found
 451          * @throws      EmptyStackerException   If the named stacker is empty
 452          */
 453         protected function getFirstValue ($stackerName) {
 454                 // Is the stack not yet initialized or full?
 455                 if (!$this->isStackInitialized($stackerName)) {
 456                         // Throw an exception
 457                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 458                 } elseif ($this->isStackEmpty($stackerName)) {
 459                         // Throw an exception
 460                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 461                 }
 462
 463                 // Now get the first value
 464                 $this->partialStub('stackerName=' . $stackerName);
 465                 $value = NULL;
 466
 467                 // Return it
 468                 return $value;
 469         }
 470
 471         /**
 472          * "Pops" last entry from stack
 473          *
 474          * @param       $stackerName    Name of the stack
 475          * @return      $value                  Value "poped" from array
 476          * @throws      NoStackerException      If the named stacker was not found
 477          * @throws      EmptyStackerException   If the named stacker is empty
 478          */
 479         protected function popLast ($stackerName) {
 480                 // Is the stack not yet initialized or full?
 481                 if (!$this->isStackInitialized($stackerName)) {
 482                         // Throw an exception
 483                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 484                 } elseif ($this->isStackEmpty($stackerName)) {
 485                         // Throw an exception
 486                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 487                 }
 488
 489                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 490                 $this->partialStub('stackerName=' . $stackerName);
 491                 return NULL;
 492         }
 493
 494         /**
 495          * "Pops" first entry from stack
 496          *
 497          * @param       $stackerName    Name of the stack
 498          * @return      $value                  Value "shifted" from array
 499          * @throws      NoStackerException      If the named stacker was not found
 500          * @throws      EmptyStackerException   If the named stacker is empty
 501          */
 502         protected function popFirst ($stackerName) {
 503                 // Is the stack not yet initialized or full?
 504                 if (!$this->isStackInitialized($stackerName)) {
 505                         // Throw an exception
 506                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 507                 } elseif ($this->isStackEmpty($stackerName)) {
 508                         // Throw an exception
 509                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 510                 }
 511
 512                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 513                 $this->partialStub('stackerName=' . $stackerName);
 514                 return NULL;
 515         }
 516 }
 517
 518 // [EOF]
 519 ?>