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          * Protected constructor
  32          *
  33          * @param       $className      Name of the class
  34          * @return      void
  35          */
  36         protected function __construct ($className) {
  37                 // Call parent constructor
  38                 parent::__construct($className);
  39
  40                 // Calculate header size
  41                 $this->setHeaderSize(
  42                         strlen(self::STACK_MAGIC) +
  43                         strlen(chr(BaseFile::SEPARATOR_HEADER_DATA)) +
  44                         self::LENGTH_COUNT +
  45                         strlen(chr(BaseFile::SEPARATOR_HEADER_DATA)) +
  46                         self::LENGTH_POSITION +
  47                         strlen(chr(BaseFile::SEPARATOR_HEADER_ENTRIES))
  48                 );
  49
  50                 // Init counters and gaps array
  51                 $this->initCountersGapsArray();
  52         }
  53
  54         /**
  55          * Reads the file header
  56          *
  57          * @return      void
  58          * @todo        To hard assertions here, better rewrite them to exceptions
  59          */
  60         public function readFileHeader () {
  61                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
  62
  63                 // First rewind to beginning as the header sits at the beginning ...
  64                 $this->getIteratorInstance()->rewind();
  65
  66                 // Then read it (see constructor for calculation)
  67                 $data = $this->getIteratorInstance()->read($this->getHeaderSize());
  68                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Read %d bytes (%d wanted).', __METHOD__, __LINE__, strlen($data), $this->getHeaderSize()));
  69
  70                 // Have all requested bytes been read?
  71                 assert(strlen($data) == $this->getHeaderSize());
  72                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  73
  74                 // Last character must be the separator
  75                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] data(-1)=%s', __METHOD__, __LINE__, dechex(ord(substr($data, -1, 1)))));
  76                 assert(substr($data, -1, 1) == chr(BaseFile::SEPARATOR_HEADER_ENTRIES));
  77                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  78
  79                 // Okay, then remove it
  80                 $data = substr($data, 0, -1);
  81
  82                 // And update seek position
  83                 $this->updateSeekPosition();
  84
  85                 /*
  86                  * Now split it:
  87                  *
  88                  * 0 => magic
  89                  * 1 => total entries
  90                  * 2 => current seek position
  91                  */
  92                 $header = explode(chr(BaseFile::SEPARATOR_HEADER_DATA), $data);
  93
  94                 // Set header here
  95                 $this->setHeader($header);
  96
  97                 // Check if the array has only 3 elements
  98                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] header(%d)=%s', __METHOD__, __LINE__, count($header), print_r($header, TRUE)));
  99                 assert(count($header) == 3);
 100                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 101
 102                 // Check magic
 103                 assert($header[0] == self::STACK_MAGIC);
 104                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 105
 106                 // Check length of count and seek position
 107                 assert(strlen($header[1]) == self::LENGTH_COUNT);
 108                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 109                 assert(strlen($header[2]) == self::LENGTH_POSITION);
 110                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 111
 112                 // Decode count and seek position
 113                 $header[1] = hex2bin($header[1]);
 114                 $header[2] = hex2bin($header[2]);
 115
 116                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 117         }
 118
 119         /**
 120          * Flushes the file header
 121          *
 122          * @return      void
 123          */
 124         public function flushFileHeader () {
 125                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 126
 127                 // Put all informations together
 128                 $header = sprintf('%s%s%s%s%s%s',
 129                         // Magic
 130                         self::STACK_MAGIC,
 131
 132                         // Separator magic<->count
 133                         chr(BaseFile::SEPARATOR_HEADER_DATA),
 134
 135                         // Total entries (will be zero) and pad it to 20 chars
 136                         str_pad($this->dec2hex($this->getCounter()), self::LENGTH_COUNT, '0', STR_PAD_LEFT),
 137
 138                         // Separator count<->seek position
 139                         chr(BaseFile::SEPARATOR_HEADER_DATA),
 140
 141                         // Position (will be zero)
 142                         str_pad($this->dec2hex($this->getSeekPosition(), 2), self::LENGTH_POSITION, '0', STR_PAD_LEFT),
 143
 144                         // Separator position<->entries
 145                         chr(BaseFile::SEPARATOR_HEADER_ENTRIES)
 146                 );
 147
 148                 // Write it to disk (header is always at seek position 0)
 149                 $this->writeData(0, $header, FALSE);
 150
 151                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 152         }
 153
 154         /**
 155          * Initializes this file-based stack.
 156          *
 157          * @param       $fileName       File name of this stack
 158          * @param       $type           Type of this stack (e.g. url_source for URL sources)
 159          * @return      void
 160          * @todo        Currently the stack file is not cached, please implement a memory-handling class and if enough RAM is found, cache the whole stack file.
 161          */
 162         protected function initFileStack ($fileName, $type) {
 163                 // Get a stack file instance
 164                 $fileInstance = ObjectFactory::createObjectByConfiguredName('stack_file_class', array($fileName, $this));
 165
 166                 // Get iterator instance
 167                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_iterator_class', array($fileInstance));
 168
 169                 // Is the instance implementing the right interface?
 170                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 171
 172                 // Set iterator here
 173                 $this->setIteratorInstance($iteratorInstance);
 174
 175                 // Is the file's header initialized?
 176                 if (!$this->getIteratorInstance()->isFileHeaderInitialized()) {
 177                         // No, then create it (which may pre-allocate the stack)
 178                         $this->getIteratorInstance()->createFileHeader();
 179
 180                         // And pre-allocate a bit
 181                         $this->getIteratorInstance()->preAllocateFile('file_stack');
 182                 } // END - if
 183
 184                 // Load the file header
 185                 $this->readFileHeader();
 186
 187                 // Count all entries in file
 188                 $this->getIteratorInstance()->analyzeFile();
 189
 190                 /*
 191                  * Get stack index instance. This can be used for faster
 192                  * "defragmentation" and startup.
 193                  */
 194                 $indexInstance = FileStackIndexFactory::createFileStackIndexInstance($fileName, $type);
 195
 196                 // And set it here
 197                 $this->setIndexInstance($indexInstance);
 198         }
 199
 200         /**
 201          * Adds a value to given stack
 202          *
 203          * @param       $stackerName    Name of the stack
 204          * @param       $value                  Value to add to this stacker
 205          * @return      void
 206          * @throws      FullStackerException    If the stack is full
 207          */
 208         protected function addValue ($stackerName, $value) {
 209                 // Do some tests
 210                 if ($this->isStackFull($stackerName)) {
 211                         // Stacker is full
 212                         throw new FullStackerException(array($this, $stackerName, $value), self::EXCEPTION_STACKER_IS_FULL);
 213                 } // END - if
 214
 215                 // Now add the value to the stack
 216                 $this->partialStub('stackerName=' . $stackerName . ',value[]=' . gettype($value));
 217         }
 218
 219         /**
 220          * Get last value from named stacker
 221          *
 222          * @param       $stackerName    Name of the stack
 223          * @return      $value                  Value of last added value
 224          * @throws      EmptyStackerException   If the stack is empty
 225          */
 226         protected function getLastValue ($stackerName) {
 227                 // Is the stack not yet initialized or full?
 228                 if ($this->isStackEmpty($stackerName)) {
 229                         // Throw an exception
 230                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 231                 } // END - if
 232
 233                 // Now get the last value
 234                 $this->partialStub('stackerName=' . $stackerName);
 235                 $value = NULL;
 236
 237                 // Return it
 238                 return $value;
 239         }
 240
 241         /**
 242          * Get first value from named stacker
 243          *
 244          * @param       $stackerName    Name of the stack
 245          * @return      $value                  Value of last added value
 246          * @throws      EmptyStackerException   If the stack is empty
 247          */
 248         protected function getFirstValue ($stackerName) {
 249                 // Is the stack not yet initialized or full?
 250                 if ($this->isStackEmpty($stackerName)) {
 251                         // Throw an exception
 252                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 253                 } // END - if
 254
 255                 // Now get the first value
 256                 $this->partialStub('stackerName=' . $stackerName);
 257                 $value = NULL;
 258
 259                 // Return it
 260                 return $value;
 261         }
 262
 263         /**
 264          * "Pops" last entry from stack
 265          *
 266          * @param       $stackerName    Name of the stack
 267          * @return      $value                  Value "poped" from array
 268          * @throws      EmptyStackerException   If the stack is empty
 269          */
 270         protected function popLast ($stackerName) {
 271                 // Is the stack not yet initialized or full?
 272                 if ($this->isStackEmpty($stackerName)) {
 273                         // Throw an exception
 274                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 275                 } // END - if
 276
 277                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 278                 $this->partialStub('stackerName=' . $stackerName);
 279                 return NULL;
 280         }
 281
 282         /**
 283          * "Pops" first entry from stack
 284          *
 285          * @param       $stackerName    Name of the stack
 286          * @return      $value                  Value "shifted" from array
 287          * @throws      EmptyStackerException   If the named stacker is empty
 288          */
 289         protected function popFirst ($stackerName) {
 290                 // Is the stack not yet initialized or full?
 291                 if ($this->isStackEmpty($stackerName)) {
 292                         // Throw an exception
 293                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 294                 } // END - if
 295
 296                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 297                 $this->partialStub('stackerName=' . $stackerName);
 298                 return NULL;
 299         }
 300
 301         /**
 302          * Checks whether the given stack is full
 303          *
 304          * @param       $stackerName    Name of the stack
 305          * @return      $isFull                 Whether the stack is full
 306          */
 307         protected function isStackFull ($stackerName) {
 308                 // File-based stacks will only run full if the disk space is low.
 309                 // @TODO Please implement this, returning FALSE
 310                 $isFull = FALSE;
 311
 312                 // Return result
 313                 return $isFull;
 314         }
 315
 316         /**
 317          * Checks whether the given stack is empty
 318          *
 319          * @param       $stackerName            Name of the stack
 320          * @return      $isEmpty                        Whether the stack is empty
 321          * @throws      NoStackerException      If given stack is missing
 322          */
 323         public function isStackEmpty ($stackerName) {
 324                 // So, is the stack empty?
 325                 $isEmpty = (($this->getStackCount($stackerName)) == 0);
 326
 327                 // Return result
 328                 return $isEmpty;
 329         }
 330
 331         /**
 332          * Initializes given stacker
 333          *
 334          * @param       $stackerName    Name of the stack
 335          * @param       $forceReInit    Force re-initialization
 336          * @return      void
 337          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 338          */
 339         public function initStack ($stackerName, $forceReInit = FALSE) {
 340                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 341         }
 342
 343         /**
 344          * Initializes all stacks
 345          *
 346          * @return      void
 347          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 348          */
 349         public function initStacks (array $stacks, $forceReInit = FALSE) {
 350                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 351         }
 352
 353         /**
 354          * Checks whether the given stack is initialized (set in array $stackers)
 355          *
 356          * @param       $stackerName    Name of the stack
 357          * @return      $isInitialized  Whether the stack is initialized
 358          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 359          */
 360         public function isStackInitialized ($stackerName) {
 361                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 362         }
 363
 364         /**
 365          * Close a file source and set it's instance to null and the file name
 366          * to empty.
 367          *
 368          * @return      void
 369          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 370          */
 371         public function closeFile () {
 372                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 373         }
 374
 375         /**
 376          * Determines whether the EOF has been reached
 377          *
 378          * @return      $isEndOfFileReached             Whether the EOF has been reached
 379          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 380          */
 381         public function isEndOfFileReached () {
 382                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 383         }
 384
 385         /**
 386          * Getter for file name
 387          *
 388          * @return      $fileName       The current file name
 389          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 390          */
 391         public function getFileName () {
 392                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 393         }
 394
 395         /**
 396          * Getter for size of given stack (array count)
 397          *
 398          * @param       $stackerName    Name of the stack
 399          * @return      $count                  Size of stack (array count)
 400          */
 401         public function getStackCount ($stackerName) {
 402                 // Now, simply return the found count value, this must be up-to-date then!
 403                 return $this->getCounter();
 404         }
 405
 406         /**
 407          * Calculates minimum length for one entry/block
 408          *
 409          * @return      $length         Minimum length for one entry/block
 410          */
 411         public function calculateMinimumBlockLength () {
 412                 // Calulcate it
 413                 $length = self::getHashLength() + strlen(chr(BaseFile::SEPARATOR_HASH_NAME)) + self::LENGTH_NAME + 1 + strlen(chr(BaseFile::SEPARATOR_ENTRIES));
 414
 415                 // Return it
 416                 return $length;
 417         }
 418 }
 419
 420 // [EOF]
 421 ?>