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(self::SEPARATOR_HEADER_DATA) +
  44                         self::LENGTH_COUNT +
  45                         strlen(self::SEPARATOR_HEADER_DATA) +
  46                         self::LENGTH_POSITION +
  47                         strlen(self::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          */
  59         protected function readFileHeader () {
  60                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
  61
  62                 // First rewind to beginning as the header sits at the beginning ...
  63                 $this->getIteratorInstance()->rewind();
  64
  65                 // Then read it (see constructor for calculation)
  66                 $data = $this->getIteratorInstance()->read($this->getHeaderSize());
  67                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Read %d bytes (%d wanted).', __METHOD__, __LINE__, strlen($data), $this->getHeaderSize()));
  68
  69                 // Have all requested bytes been read?
  70                 assert(strlen($data) == $this->getHeaderSize());
  71                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  72
  73                 // Last character must be the separator
  74                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] data(-1)=%s', __METHOD__, __LINE__, dechex(ord(substr($data, -1, 1)))));
  75                 assert(substr($data, -1, 1) == chr(self::SEPARATOR_HEADER_ENTRIES));
  76                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  77
  78                 // Okay, then remove it
  79                 $data = substr($data, 0, -1);
  80
  81                 // And update seek position
  82                 $this->updateSeekPosition();
  83
  84                 /*
  85                  * Now split it:
  86                  *
  87                  * 0 => magic
  88                  * 1 => total entries
  89                  * 2 => current seek position
  90                  */
  91                 $header = explode(chr(self::SEPARATOR_HEADER_DATA), $data);
  92
  93                 // Set header here
  94                 $this->setHeader($header);
  95
  96                 // Check if the array has only 3 elements
  97                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] header(%d)=%s', __METHOD__, __LINE__, count($header), print_r($header, TRUE)));
  98                 assert(count($header) == 3);
  99                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 100
 101                 // Check magic
 102                 assert($header[0] == self::STACK_MAGIC);
 103                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 104
 105                 // Check length of count and seek position
 106                 assert(strlen($header[1]) == self::LENGTH_COUNT);
 107                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 108                 assert(strlen($header[2]) == self::LENGTH_POSITION);
 109                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 110
 111                 // Decode count and seek position
 112                 $header[1] = hex2bin($header[1]);
 113                 $header[2] = hex2bin($header[2]);
 114
 115                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 116         }
 117
 118         /**
 119          * Flushes the file header
 120          *
 121          * @return      void
 122          */
 123         protected function flushFileHeader () {
 124                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 125
 126                 // Put all informations together
 127                 $header = sprintf('%s%s%s%s%s%s',
 128                         // Magic
 129                         self::STACK_MAGIC,
 130
 131                         // Separator magic<->count
 132                         chr(self::SEPARATOR_HEADER_DATA),
 133
 134                         // Total entries (will be zero) and pad it to 20 chars
 135                         str_pad($this->dec2hex($this->getCounter()), self::LENGTH_COUNT, '0', STR_PAD_LEFT),
 136
 137                         // Separator count<->seek position
 138                         chr(self::SEPARATOR_HEADER_DATA),
 139
 140                         // Position (will be zero)
 141                         str_pad($this->dec2hex($this->getSeekPosition(), 2), self::LENGTH_POSITION, '0', STR_PAD_LEFT),
 142
 143                         // Separator position<->entries
 144                         chr(self::SEPARATOR_HEADER_ENTRIES)
 145                 );
 146
 147                 // Write it to disk (header is always at seek position 0)
 148                 $this->writeData(0, $header, FALSE);
 149
 150                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 151         }
 152
 153         /**
 154          * Analyzes entries in stack file. This will count all found (and valid)
 155          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
 156          * only gaps are found, the file is considered as "virgin" (no entries).
 157          *
 158          * @return      void
 159          */
 160         private function analyzeFile () {
 161                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 162
 163                 // Make sure the file is initialized
 164                 assert($this->isFileInitialized());
 165
 166                 // Init counters and gaps array
 167                 $this->initCountersGapsArray();
 168
 169                 // Output message (as this may take some time)
 170                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Analyzing file structure ... (this may take some time)', __METHOD__, __LINE__));
 171
 172                 // First rewind to the begining
 173                 $this->getIteratorInstance()->rewind();
 174
 175                 // Then try to load all entries
 176                 while ($this->getIteratorInstance()->valid()) {
 177                         // Go to next entry
 178                         $this->getIteratorInstance()->next();
 179
 180                         // Get current entry
 181                         $current = $this->getIteratorInstance()->current();
 182
 183                         // Simply output it
 184                         self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] current(%s)=%s', __METHOD__, __LINE__, strlen($current), print_r($current, TRUE)));
 185                 } // END - while
 186
 187                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 188         }
 189
 190         /**
 191          * Initializes this file-based stack.
 192          *
 193          * @param       $fileName       File name of this stack
 194          * @param       $type           Type of this stack (e.g. url_source for URL sources)
 195          * @return      void
 196          * @todo        Currently the stack file is not cached, please implement a memory-handling class and if enough RAM is found, cache the whole stack file.
 197          */
 198         protected function initFileStack ($fileName, $type) {
 199                 // Get a stack file instance
 200                 $fileInstance = ObjectFactory::createObjectByConfiguredName('stack_file_class', array($fileName));
 201
 202                 // Get iterator instance
 203                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_io_iterator_class', array($fileInstance, $this));
 204
 205                 // Is the instance implementing the right interface?
 206                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 207
 208                 // Set iterator here
 209                 $this->setIteratorInstance($iteratorInstance);
 210
 211                 // Is the file's header initialized?
 212                 if (!$this->isFileHeaderInitialized()) {
 213                         // No, then create it (which may pre-allocate the stack)
 214                         $this->createFileHeader();
 215
 216                         // And pre-allocate a bit
 217                         $this->preAllocateFile('file_stack');
 218                 } // END - if
 219
 220                 // Load the file header
 221                 $this->readFileHeader();
 222
 223                 // Count all entries in file
 224                 $this->analyzeFile();
 225
 226                 /*
 227                  * Get stack index instance. This can be used for faster
 228                  * "defragmentation" and startup.
 229                  */
 230                 $indexInstance = FileStackIndexFactory::createFileStackIndexInstance($fileName, $type);
 231
 232                 // And set it here
 233                 $this->setIndexInstance($indexInstance);
 234         }
 235
 236         /**
 237          * Adds a value to given stack
 238          *
 239          * @param       $stackerName    Name of the stack
 240          * @param       $value                  Value to add to this stacker
 241          * @return      void
 242          * @throws      FullStackerException    If the stack is full
 243          */
 244         protected function addValue ($stackerName, $value) {
 245                 // Do some tests
 246                 if ($this->isStackFull($stackerName)) {
 247                         // Stacker is full
 248                         throw new FullStackerException(array($this, $stackerName, $value), self::EXCEPTION_STACKER_IS_FULL);
 249                 } // END - if
 250
 251                 // Now add the value to the stack
 252                 $this->partialStub('stackerName=' . $stackerName . ',value[]=' . gettype($value));
 253         }
 254
 255         /**
 256          * Get last value from named stacker
 257          *
 258          * @param       $stackerName    Name of the stack
 259          * @return      $value                  Value of last added value
 260          * @throws      EmptyStackerException   If the stack is empty
 261          */
 262         protected function getLastValue ($stackerName) {
 263                 // Is the stack not yet initialized or full?
 264                 if ($this->isStackEmpty($stackerName)) {
 265                         // Throw an exception
 266                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 267                 } // END - if
 268
 269                 // Now get the last value
 270                 $this->partialStub('stackerName=' . $stackerName);
 271                 $value = NULL;
 272
 273                 // Return it
 274                 return $value;
 275         }
 276
 277         /**
 278          * Get first value from named stacker
 279          *
 280          * @param       $stackerName    Name of the stack
 281          * @return      $value                  Value of last added value
 282          * @throws      EmptyStackerException   If the stack is empty
 283          */
 284         protected function getFirstValue ($stackerName) {
 285                 // Is the stack not yet initialized or full?
 286                 if ($this->isStackEmpty($stackerName)) {
 287                         // Throw an exception
 288                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 289                 } // END - if
 290
 291                 // Now get the first value
 292                 $this->partialStub('stackerName=' . $stackerName);
 293                 $value = NULL;
 294
 295                 // Return it
 296                 return $value;
 297         }
 298
 299         /**
 300          * "Pops" last entry from stack
 301          *
 302          * @param       $stackerName    Name of the stack
 303          * @return      $value                  Value "poped" from array
 304          * @throws      EmptyStackerException   If the stack is empty
 305          */
 306         protected function popLast ($stackerName) {
 307                 // Is the stack not yet initialized or full?
 308                 if ($this->isStackEmpty($stackerName)) {
 309                         // Throw an exception
 310                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 311                 } // END - if
 312
 313                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 314                 $this->partialStub('stackerName=' . $stackerName);
 315                 return NULL;
 316         }
 317
 318         /**
 319          * "Pops" first entry from stack
 320          *
 321          * @param       $stackerName    Name of the stack
 322          * @return      $value                  Value "shifted" from array
 323          * @throws      EmptyStackerException   If the named stacker is empty
 324          */
 325         protected function popFirst ($stackerName) {
 326                 // Is the stack not yet initialized or full?
 327                 if ($this->isStackEmpty($stackerName)) {
 328                         // Throw an exception
 329                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 330                 } // END - if
 331
 332                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 333                 $this->partialStub('stackerName=' . $stackerName);
 334                 return NULL;
 335         }
 336
 337         /**
 338          * Checks whether the given stack is full
 339          *
 340          * @param       $stackerName    Name of the stack
 341          * @return      $isFull                 Whether the stack is full
 342          */
 343         protected function isStackFull ($stackerName) {
 344                 // File-based stacks will only run full if the disk space is low.
 345                 // @TODO Please implement this, returning FALSE
 346                 $isFull = FALSE;
 347
 348                 // Return result
 349                 return $isFull;
 350         }
 351
 352         /**
 353          * Checks whether the given stack is empty
 354          *
 355          * @param       $stackerName            Name of the stack
 356          * @return      $isEmpty                        Whether the stack is empty
 357          * @throws      NoStackerException      If given stack is missing
 358          */
 359         public function isStackEmpty ($stackerName) {
 360                 // So, is the stack empty?
 361                 $isEmpty = (($this->getStackCount($stackerName)) == 0);
 362
 363                 // Return result
 364                 return $isEmpty;
 365         }
 366
 367         /**
 368          * Initializes given stacker
 369          *
 370          * @param       $stackerName    Name of the stack
 371          * @param       $forceReInit    Force re-initialization
 372          * @return      void
 373          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 374          */
 375         public function initStack ($stackerName, $forceReInit = FALSE) {
 376                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 377         }
 378
 379         /**
 380          * Initializes all stacks
 381          *
 382          * @return      void
 383          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 384          */
 385         public function initStacks (array $stacks, $forceReInit = FALSE) {
 386                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 387         }
 388
 389         /**
 390          * Checks whether the given stack is initialized (set in array $stackers)
 391          *
 392          * @param       $stackerName    Name of the stack
 393          * @return      $isInitialized  Whether the stack is initialized
 394          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 395          */
 396         public function isStackInitialized ($stackerName) {
 397                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 398         }
 399
 400         /**
 401          * Getter for size of given stack (array count)
 402          *
 403          * @param       $stackerName    Name of the stack
 404          * @return      $count                  Size of stack (array count)
 405          */
 406         public function getStackCount ($stackerName) {
 407                 // Now, simply return the found count value, this must be up-to-date then!
 408                 return $this->getCounter();
 409         }
 410
 411         /**
 412          * Calculates minimum length for one entry/block
 413          *
 414          * @return      $length         Minimum length for one entry/block
 415          */
 416         public function caluclateMinimumBlockLength () {
 417                 // Calulcate it
 418                 $length = self::getHashLength() + strlen(chr(self::SEPARATOR_HASH_NAME)) + self::LENGTH_NAME + 1 + strlen(self::getBlockSeparator());
 419
 420                 // Return it
 421                 return $length;
 422         }
 423 }
 424
 425 // [EOF]
 426 ?>