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                 // Flush file header
 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->getIteratorInstance()->writeAtPosition(0, $header);
 249
 250                 // Update seek position
 251                 $this->updateSeekPosition();
 252
 253                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 254         }
 255
 256         /**
 257          * Pre-allocates file (if enabled) with some space for later faster write access.
 258          *
 259          * @return      void
 260          */
 261         private function preAllocateFile () {
 262                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 263
 264                 // Is it enabled?
 265                 if ($this->getConfigInstance()->getConfigEntry('file_stack_pre_allocate_enabled') != 'Y') {
 266                         // Not enabled
 267                         self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Not pre-allocating stack file.', __METHOD__, __LINE__));
 268
 269                         // Don't continue here.
 270                         return;
 271                 } // END - if
 272
 273                 // Message to user
 274                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Pre-allocating stack file ...', __METHOD__, __LINE__));
 275
 276                 /*
 277                  * Calculate minimum length for one entry:
 278                  * minimum length = hash length + separator + name + minimum entry size = ?? + 1 + 10 + 1 = ??
 279                  */
 280                 $minLengthEntry = self::getHashLength() + strlen(self::SEPARATOR_HASH_NAME) + self::COUNT_NAME + 1;
 281                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] minLengthEntry=%s', __METHOD__, __LINE__, $minLengthEntry));
 282
 283                 // Calulcate seek position
 284                 $seekPosition = $minLengthEntry * $this->getConfigInstance()->getConfigEntry('file_stack_pre_allocate_count');
 285                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] seekPosition=%s', __METHOD__, __LINE__, $seekPosition));
 286
 287                 // Now seek to the position
 288                 $seekStatus = $this->getIteratorInstance()->writeAtPosition($seekPosition, chr(0));
 289
 290                 // Did it work?
 291                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] seekStatus=%d', __METHOD__, __LINE__, $seekStatus));
 292
 293                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 294         }
 295
 296         /**
 297          * Initializes this file-based stack.
 298          *
 299          * @param       $fileName       File name of this stack
 300          * @return      void
 301          */
 302         protected function initFileStack ($fileName) {
 303                 // Get a file i/o pointer instance
 304                 $pointerInstance = ObjectFactory::createObjectByConfiguredName('file_raw_input_output_class', array($fileName));
 305
 306                 // Get iterator instance
 307                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_io_iterator_class', array($pointerInstance));
 308
 309                 // Is the instance implementing the right interface?
 310                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 311
 312                 // Set iterator here
 313                 $this->setIteratorInstance($iteratorInstance);
 314
 315                 // Is the file's header initialized?
 316                 if ($this->isFileHeaderInitialized()) {
 317                         // Then load it
 318                         $this->loadFileHeader();
 319                 } else {
 320                         // No, then create it (which may pre-allocate the stack)
 321                         $this->createFileHeader();
 322
 323                         // And pre-allocate a bit
 324                         $this->preAllocateFile();
 325                 }
 326         }
 327
 328         /**
 329          * Initializes given stacker
 330          *
 331          * @param       $stackerName    Name of the stack
 332          * @param       $forceReInit    Force re-initialization
 333          * @return      void
 334          * @throws      AlreadyInitializedStackerException      If the stack is already initialized
 335          */
 336         public function initStack ($stackerName, $forceReInit = FALSE) {
 337                 // Is the stack already initialized?
 338                 if (($forceReInit === FALSE) && ($this->isStackInitialized($stackerName))) {
 339                         // Then throw the exception
 340                         throw new AlreadyInitializedStackerException(array($this, $stackerName, $forceReInit), self::EXCEPTION_STACKER_ALREADY_INITIALIZED);
 341                 } // END - if
 342
 343                 // Initialize the given stack
 344                 $this->partialStub('stackerName=' . $stackerName . ',forceReInit=' . intval($forceReInit));
 345         }
 346
 347         /**
 348          * Checks whether the given stack is initialized (set in array $stackers)
 349          *
 350          * @param       $stackerName    Name of the stack
 351          * @return      $isInitialized  Whether the stack is initialized
 352          */
 353         public function isStackInitialized ($stackerName) {
 354                 // Is is there?
 355                 $this->partialStub('stackerName=' . $stackerName);
 356                 $isInitialized = TRUE;
 357
 358                 // Return result
 359                 return $isInitialized;
 360         }
 361
 362         /**
 363          * Getter for size of given stack (array count)
 364          *
 365          * @param       $stackerName    Name of the stack
 366          * @return      $count                  Size of stack (array count)
 367          * @throws      NoStackerException      If given stack is missing
 368          */
 369         public function getStackCount ($stackerName) {
 370                 // Is the stack not yet initialized?
 371                 if (!$this->isStackInitialized($stackerName)) {
 372                         // Throw an exception
 373                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 374                 } // END - if
 375
 376                 // Now, count the array of entries
 377                 $this->partialStub('stackerName=' . $stackerName);
 378                 $count = 0;
 379
 380                 // Return result
 381                 return $count;
 382         }
 383
 384         /**
 385          * Adds a value to given stack
 386          *
 387          * @param       $stackerName    Name of the stack
 388          * @param       $value                  Value to add to this stacker
 389          * @return      void
 390          * @throws      FullStackerException    Thrown if the stack is full
 391          */
 392         protected function addValue ($stackerName, $value) {
 393                 // Is the stack not yet initialized or full?
 394                 if (!$this->isStackInitialized($stackerName)) {
 395                         // Then do it here
 396                         $this->initStack($stackerName);
 397                 } elseif ($this->isStackFull($stackerName)) {
 398                         // Stacker is full
 399                         throw new FullStackerException(array($this, $stackerName, $value), self::EXCEPTION_STACKER_IS_FULL);
 400                 }
 401
 402                 // Now add the value to the stack
 403                 $this->partialStub('stackerName=' . $stackerName . ',value[]=' . gettype($value));
 404         }
 405
 406         /**
 407          * Get last value from named stacker
 408          *
 409          * @param       $stackerName    Name of the stack
 410          * @return      $value                  Value of last added value
 411          * @throws      NoStackerException      If the named stacker was not found
 412          * @throws      EmptyStackerException   If the named stacker is empty
 413          */
 414         protected function getLastValue ($stackerName) {
 415                 // Is the stack not yet initialized or full?
 416                 if (!$this->isStackInitialized($stackerName)) {
 417                         // Throw an exception
 418                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 419                 } elseif ($this->isStackEmpty($stackerName)) {
 420                         // Throw an exception
 421                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 422                 }
 423
 424                 // Now get the last value
 425                 $this->partialStub('stackerName=' . $stackerName);
 426                 $value = NULL;
 427
 428                 // Return it
 429                 return $value;
 430         }
 431
 432         /**
 433          * Get first value from named stacker
 434          *
 435          * @param       $stackerName    Name of the stack
 436          * @return      $value                  Value of last added value
 437          * @throws      NoStackerException      If the named stacker was not found
 438          * @throws      EmptyStackerException   If the named stacker is empty
 439          */
 440         protected function getFirstValue ($stackerName) {
 441                 // Is the stack not yet initialized or full?
 442                 if (!$this->isStackInitialized($stackerName)) {
 443                         // Throw an exception
 444                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 445                 } elseif ($this->isStackEmpty($stackerName)) {
 446                         // Throw an exception
 447                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 448                 }
 449
 450                 // Now get the first value
 451                 $this->partialStub('stackerName=' . $stackerName);
 452                 $value = NULL;
 453
 454                 // Return it
 455                 return $value;
 456         }
 457
 458         /**
 459          * "Pops" last entry from stack
 460          *
 461          * @param       $stackerName    Name of the stack
 462          * @return      $value                  Value "poped" from array
 463          * @throws      NoStackerException      If the named stacker was not found
 464          * @throws      EmptyStackerException   If the named stacker is empty
 465          */
 466         protected function popLast ($stackerName) {
 467                 // Is the stack not yet initialized or full?
 468                 if (!$this->isStackInitialized($stackerName)) {
 469                         // Throw an exception
 470                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 471                 } elseif ($this->isStackEmpty($stackerName)) {
 472                         // Throw an exception
 473                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 474                 }
 475
 476                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 477                 $this->partialStub('stackerName=' . $stackerName);
 478                 return NULL;
 479         }
 480
 481         /**
 482          * "Pops" first entry from stack
 483          *
 484          * @param       $stackerName    Name of the stack
 485          * @return      $value                  Value "shifted" from array
 486          * @throws      NoStackerException      If the named stacker was not found
 487          * @throws      EmptyStackerException   If the named stacker is empty
 488          */
 489         protected function popFirst ($stackerName) {
 490                 // Is the stack not yet initialized or full?
 491                 if (!$this->isStackInitialized($stackerName)) {
 492                         // Throw an exception
 493                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 494                 } elseif ($this->isStackEmpty($stackerName)) {
 495                         // Throw an exception
 496                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 497                 }
 498
 499                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 500                 $this->partialStub('stackerName=' . $stackerName);
 501                 return NULL;
 502         }
 503 }
 504
 505 // [EOF]
 506 ?>