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 = 0x00;
  34
  35         /**
  36          * Separator position->entries
  37          */
  38         const SEPARATOR_SEEK_POS_ENTRIES = 0xff;
  39
  40         /**
  41          * Separator hash->name
  42          */
  43         const SEPARATOR_HASH_NAME = 0x05;
  44
  45         /**
  46          * Length of name
  47          */
  48         const COUNT_NAME = 10;
  49
  50         /**
  51          * Length of count
  52          */
  53         const COUNT_LENGTH = 20;
  54
  55         /**
  56          * Length of position
  57          */
  58         const COUNT_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          * Protected constructor
  72          *
  73          * @param       $className      Name of the class
  74          * @return      void
  75          */
  76         protected function __construct ($className) {
  77                 // Call parent constructor
  78                 parent::__construct($className);
  79         }
  80
  81         /**
  82          * Getter for total entries
  83          *
  84          * @return      $totalEntries   Total entries in this stack
  85          */
  86         private function getCounter () {
  87                 // Get it
  88                 return $this->totalEntries;
  89         }
  90
  91         /**
  92          * Increment counter
  93          *
  94          * @return      void
  95          */
  96         private function incrementCounter () {
  97                 // Get it
  98                 $this->totalEntries++;
  99         }
 100
 101         /**
 102          * Getter for seek position
 103          *
 104          * @return      $seekPosition   Current seek position (stored here in object)
 105          */
 106         private function getSeekPosition () {
 107                 // Get it
 108                 return $this->seekPosition;
 109         }
 110
 111         /**
 112          * Setter for seek position
 113          *
 114          * @param       $seekPosition   Current seek position (stored here in object)
 115          * @return      void
 116          */
 117         private function setSeekPosition ($seekPosition) {
 118                 // And set it
 119                 $this->seekPosition = $seekPosition;
 120         }
 121
 122         /**
 123          * Updates seekPosition attribute from file to avoid to much access on file.
 124          *
 125          * @return      void
 126          */
 127         private function updateSeekPosition () {
 128                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 129
 130                 // Get key (= seek position)
 131                 $seekPosition = $this->getIteratorInstance()->key();
 132                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Setting seekPosition=%s', __METHOD__, __LINE__, $seekPosition));
 133
 134                 // And set it here
 135                 $this->setSeekPosition($seekPosition);
 136
 137                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 138         }
 139
 140         /**
 141          * Checks whether the file header is initialized
 142          *
 143          * @return      $isInitialized  Whether the file header is initialized
 144          */
 145         private function isFileHeaderInitialized () {
 146                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 147                 // Default is not initialized
 148                 $isInitialized = FALSE;
 149
 150                 // Is the file initialized?
 151                 if ($this->isFileInitialized()) {
 152                         // Some bytes has been written, so rewind to start of it.
 153                         $rewindStatus = $this->getIteratorInstance()->rewind();
 154                         /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] rewindStatus=%s', __METHOD__, __LINE__, $rewindStatus));
 155
 156                         // Is the rewind() call successfull?
 157                         if ($rewindStatus != 1) {
 158                                 // Something bad happened
 159                                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Could not rewind().', __METHOD__, __LINE__));
 160                         } // END - if
 161
 162                         // Read file header
 163                         $this->readFileHeader();
 164                 } // END - if
 165
 166                 // Return result
 167                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] isInitialized=%d - EXIT!', __METHOD__, __LINE__, intval($isInitialized)));
 168                 return $isInitialized;
 169         }
 170
 171         /**
 172          * Checks whether the file-based stack has been initialized
 173          *
 174          * @return      $isInitialized          Whether the file's size is zero
 175          */
 176         private function isFileInitialized () {
 177                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 178
 179                 // Get it from iterator which holds the pointer instance. If FALSE is returned
 180                 $fileSize = $this->getIteratorInstance()->size();
 181                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] fileSize=%s', __METHOD__, __LINE__, $fileSize));
 182
 183                 /*
 184                  * The returned file size should not be FALSE or NULL as this means
 185                  * that the pointer class does not work correctly.
 186                  */
 187                 assert(is_int($fileSize));
 188
 189                 // Is more than 0 returned?
 190                 $isInitialized = ($fileSize > 0);
 191
 192                 // Return result
 193                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] isInitialized=%d - EXIT!', __METHOD__, __LINE__, intval($isInitialized)));
 194                 return $isInitialized;
 195         }
 196
 197         /**
 198          * Creates the file-stack's header
 199          *
 200          * @return      void
 201          */
 202         private function createFileHeader () {
 203                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 204                 // The file's header should not be initialized here
 205                 assert(!$this->isFileHeaderInitialized());
 206
 207                 // Flush file header
 208                 $this->flushFileHeader();
 209
 210                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!!', __METHOD__, __LINE__));
 211         }
 212
 213         /**
 214          * Flushes the file header
 215          *
 216          * @return      void
 217          */
 218         private function flushFileHeader () {
 219                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 220
 221                 // Put all informations together
 222                 $header = sprintf('%s%s%s%s%s',
 223                         // Magic
 224                         self::STACK_MAGIC,
 225
 226                         // Separator magic<->count
 227                         chr(self::SEPARATOR_MAGIC_COUNT),
 228
 229                         // Total entries (will be zero) and pad it to 20 chars
 230                         str_pad($this->dec2hex($this->getCounter()), self::COUNT_LENGTH, '0', STR_PAD_LEFT),
 231
 232                         // Position (will be zero)
 233                         str_pad($this->dec2hex(0, 2), self::COUNT_POSITION, '0', STR_PAD_LEFT),
 234
 235                         // Separator position<->entries
 236                         chr(self::SEPARATOR_SEEK_POS_ENTRIES)
 237                 );
 238
 239                 // Write it to disk (header is always at seek position 0)
 240                 $this->getIteratorInstance()->writeAtPosition(0, $header);
 241
 242                 // Update seek position
 243                 $this->updateSeekPosition();
 244
 245                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 246         }
 247
 248         /**
 249          * Pre-allocates file (if enabled) with some space for later faster write access.
 250          *
 251          * @return      void
 252          */
 253         private function preAllocateFile () {
 254                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 255
 256                 // Is it enabled?
 257                 if ($this->getConfigInstance()->getConfigEntry('file_stack_pre_allocate_enabled') != 'Y') {
 258                         // Not enabled
 259                         self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Not pre-allocating stack file.', __METHOD__, __LINE__));
 260
 261                         // Don't continue here.
 262                         return;
 263                 } // END - if
 264
 265                 // Message to user
 266                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Pre-allocating stack file ...', __METHOD__, __LINE__));
 267
 268                 /*
 269                  * Calculate minimum length for one entry:
 270                  * minimum length = hash length + separator + name + minimum entry size = ?? + 1 + 10 + 1 = ??
 271                  */
 272                 $minLengthEntry = self::getHashLength() + strlen(self::SEPARATOR_HASH_NAME) + self::COUNT_NAME + 1;
 273                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] minLengthEntry=%s', __METHOD__, __LINE__, $minLengthEntry));
 274
 275                 // Calulcate seek position
 276                 $seekPosition = $minLengthEntry * $this->getConfigInstance()->getConfigEntry('file_stack_pre_allocate_count');
 277                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] seekPosition=%s', __METHOD__, __LINE__, $seekPosition));
 278
 279                 // Now seek to the position
 280                 $seekStatus = $this->getIteratorInstance()->writeAtPosition($seekPosition, chr(0));
 281
 282                 // Did it work?
 283                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] seekStatus=%d', __METHOD__, __LINE__, $seekStatus));
 284
 285                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 286         }
 287
 288         /**
 289          * Initializes this file-based stack.
 290          *
 291          * @param       $fileName       File name of this stack
 292          * @return      void
 293          */
 294         protected function initFileStack ($fileName) {
 295                 // Get a file i/o pointer instance
 296                 $pointerInstance = ObjectFactory::createObjectByConfiguredName('file_raw_input_output_class', array($fileName));
 297
 298                 // Get iterator instance
 299                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_io_iterator_class', array($pointerInstance));
 300
 301                 // Is the instance implementing the right interface?
 302                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 303
 304                 // Set iterator here
 305                 $this->setIteratorInstance($iteratorInstance);
 306
 307                 // Is the file's header initialized?
 308                 if ($this->isFileHeaderInitialized()) {
 309                         // Then load it
 310                         $this->loadFileHeader();
 311                 } else {
 312                         // No, then create it (which may pre-allocate the stack)
 313                         $this->createFileHeader();
 314
 315                         // And pre-allocate a bit
 316                         $this->preAllocateFile();
 317                 }
 318         }
 319
 320         /**
 321          * Initializes given stacker
 322          *
 323          * @param       $stackerName    Name of the stack
 324          * @param       $forceReInit    Force re-initialization
 325          * @return      void
 326          * @throws      AlreadyInitializedStackerException      If the stack is already initialized
 327          */
 328         public function initStack ($stackerName, $forceReInit = FALSE) {
 329                 // Is the stack already initialized?
 330                 if (($forceReInit === FALSE) && ($this->isStackInitialized($stackerName))) {
 331                         // Then throw the exception
 332                         throw new AlreadyInitializedStackerException(array($this, $stackerName, $forceReInit), self::EXCEPTION_STACKER_ALREADY_INITIALIZED);
 333                 } // END - if
 334
 335                 // Initialize the given stack
 336                 $this->partialStub('stackerName=' . $stackerName . ',forceReInit=' . intval($forceReInit));
 337         }
 338
 339         /**
 340          * Checks whether the given stack is initialized (set in array $stackers)
 341          *
 342          * @param       $stackerName    Name of the stack
 343          * @return      $isInitialized  Whether the stack is initialized
 344          */
 345         public function isStackInitialized ($stackerName) {
 346                 // Is is there?
 347                 $this->partialStub('stackerName=' . $stackerName);
 348                 $isInitialized = TRUE;
 349
 350                 // Return result
 351                 return $isInitialized;
 352         }
 353
 354         /**
 355          * Getter for size of given stack (array count)
 356          *
 357          * @param       $stackerName    Name of the stack
 358          * @return      $count                  Size of stack (array count)
 359          * @throws      NoStackerException      If given stack is missing
 360          */
 361         public function getStackCount ($stackerName) {
 362                 // Is the stack not yet initialized?
 363                 if (!$this->isStackInitialized($stackerName)) {
 364                         // Throw an exception
 365                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 366                 } // END - if
 367
 368                 // Now, count the array of entries
 369                 $this->partialStub('stackerName=' . $stackerName);
 370                 $count = 0;
 371
 372                 // Return result
 373                 return $count;
 374         }
 375
 376         /**
 377          * Adds a value to given stack
 378          *
 379          * @param       $stackerName    Name of the stack
 380          * @param       $value                  Value to add to this stacker
 381          * @return      void
 382          * @throws      FullStackerException    Thrown if the stack is full
 383          */
 384         protected function addValue ($stackerName, $value) {
 385                 // Is the stack not yet initialized or full?
 386                 if (!$this->isStackInitialized($stackerName)) {
 387                         // Then do it here
 388                         $this->initStack($stackerName);
 389                 } elseif ($this->isStackFull($stackerName)) {
 390                         // Stacker is full
 391                         throw new FullStackerException(array($this, $stackerName, $value), self::EXCEPTION_STACKER_IS_FULL);
 392                 }
 393
 394                 // Now add the value to the stack
 395                 $this->partialStub('stackerName=' . $stackerName . ',value[]=' . gettype($value));
 396         }
 397
 398         /**
 399          * Get last value from named stacker
 400          *
 401          * @param       $stackerName    Name of the stack
 402          * @return      $value                  Value of last added value
 403          * @throws      NoStackerException      If the named stacker was not found
 404          * @throws      EmptyStackerException   If the named stacker is empty
 405          */
 406         protected function getLastValue ($stackerName) {
 407                 // Is the stack not yet initialized or full?
 408                 if (!$this->isStackInitialized($stackerName)) {
 409                         // Throw an exception
 410                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 411                 } elseif ($this->isStackEmpty($stackerName)) {
 412                         // Throw an exception
 413                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 414                 }
 415
 416                 // Now get the last value
 417                 $this->partialStub('stackerName=' . $stackerName);
 418                 $value = NULL;
 419
 420                 // Return it
 421                 return $value;
 422         }
 423
 424         /**
 425          * Get first value from named stacker
 426          *
 427          * @param       $stackerName    Name of the stack
 428          * @return      $value                  Value of last added value
 429          * @throws      NoStackerException      If the named stacker was not found
 430          * @throws      EmptyStackerException   If the named stacker is empty
 431          */
 432         protected function getFirstValue ($stackerName) {
 433                 // Is the stack not yet initialized or full?
 434                 if (!$this->isStackInitialized($stackerName)) {
 435                         // Throw an exception
 436                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 437                 } elseif ($this->isStackEmpty($stackerName)) {
 438                         // Throw an exception
 439                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 440                 }
 441
 442                 // Now get the first value
 443                 $this->partialStub('stackerName=' . $stackerName);
 444                 $value = NULL;
 445
 446                 // Return it
 447                 return $value;
 448         }
 449
 450         /**
 451          * "Pops" last entry from stack
 452          *
 453          * @param       $stackerName    Name of the stack
 454          * @return      $value                  Value "poped" from array
 455          * @throws      NoStackerException      If the named stacker was not found
 456          * @throws      EmptyStackerException   If the named stacker is empty
 457          */
 458         protected function popLast ($stackerName) {
 459                 // Is the stack not yet initialized or full?
 460                 if (!$this->isStackInitialized($stackerName)) {
 461                         // Throw an exception
 462                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 463                 } elseif ($this->isStackEmpty($stackerName)) {
 464                         // Throw an exception
 465                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 466                 }
 467
 468                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 469                 $this->partialStub('stackerName=' . $stackerName);
 470                 return NULL;
 471         }
 472
 473         /**
 474          * "Pops" first entry from stack
 475          *
 476          * @param       $stackerName    Name of the stack
 477          * @return      $value                  Value "shifted" from array
 478          * @throws      NoStackerException      If the named stacker was not found
 479          * @throws      EmptyStackerException   If the named stacker is empty
 480          */
 481         protected function popFirst ($stackerName) {
 482                 // Is the stack not yet initialized or full?
 483                 if (!$this->isStackInitialized($stackerName)) {
 484                         // Throw an exception
 485                         throw new NoStackerException(array($this, $stackerName), self::EXCEPTION_NO_STACKER_FOUND);
 486                 } elseif ($this->isStackEmpty($stackerName)) {
 487                         // Throw an exception
 488                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 489                 }
 490
 491                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 492                 $this->partialStub('stackerName=' . $stackerName);
 493                 return NULL;
 494         }
 495 }
 496
 497 // [EOF]
 498 ?>