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 for header data
  32          */
  33         const SEPARATOR_HEADER_DATA = 0x01;
  34
  35         /**
  36          * Separator header->entries
  37          */
  38         const SEPARATOR_HEADER_ENTRIES = 0x02;
  39
  40         /**
  41          * Separator hash->name
  42          */
  43         const SEPARATOR_HASH_NAME = 0x03;
  44
  45         /**
  46          * Length of name
  47          */
  48         const LENGTH_NAME = 10;
  49
  50         /**
  51          * Protected constructor
  52          *
  53          * @param       $className      Name of the class
  54          * @return      void
  55          */
  56         protected function __construct ($className) {
  57                 // Call parent constructor
  58                 parent::__construct($className);
  59
  60                 // Calculate header size
  61                 $this->setHeaderSize(
  62                         strlen(self::STACK_MAGIC) +
  63                         strlen(self::SEPARATOR_HEADER_DATA) +
  64                         self::LENGTH_COUNT +
  65                         strlen(self::SEPARATOR_HEADER_DATA) +
  66                         self::LENGTH_POSITION +
  67                         strlen(self::SEPARATOR_HEADER_ENTRIES)
  68                 );
  69
  70                 // Init counters and gaps array
  71                 $this->initCountersGapsArray();
  72         }
  73
  74         /**
  75          * Reads the file header
  76          *
  77          * @return      void
  78          */
  79         protected function readFileHeader () {
  80                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
  81
  82                 // First rewind to beginning as the header sits at the beginning ...
  83                 $this->getIteratorInstance()->rewind();
  84
  85                 // Then read it (see constructor for calculation)
  86                 $data = $this->getIteratorInstance()->read($this->getHeaderSize());
  87                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Read %d bytes (%d wanted).', __METHOD__, __LINE__, strlen($data), $this->getHeaderSize()));
  88
  89                 // Have all requested bytes been read?
  90                 assert(strlen($data) == $this->getHeaderSize());
  91                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  92
  93                 // Last character must be the separator
  94                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] data(-1)=%s', __METHOD__, __LINE__, dechex(ord(substr($data, -1, 1)))));
  95                 assert(substr($data, -1, 1) == chr(self::SEPARATOR_HEADER_ENTRIES));
  96                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  97
  98                 // Okay, then remove it
  99                 $data = substr($data, 0, -1);
 100
 101                 // And update seek position
 102                 $this->updateSeekPosition();
 103
 104                 /*
 105                  * Now split it:
 106                  *
 107                  * 0 => magic
 108                  * 1 => total entries
 109                  * 2 => current seek position
 110                  */
 111                 $header = explode(chr(self::SEPARATOR_HEADER_DATA), $data);
 112
 113                 // Set header here
 114                 $this->setHeader($header);
 115
 116                 // Check if the array has only 3 elements
 117                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] header(%d)=%s', __METHOD__, __LINE__, count($header), print_r($header, TRUE)));
 118                 assert(count($header) == 3);
 119                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 120
 121                 // Check magic
 122                 assert($header[0] == self::STACK_MAGIC);
 123                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 124
 125                 // Check length of count and seek position
 126                 assert(strlen($header[1]) == self::LENGTH_COUNT);
 127                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 128                 assert(strlen($header[2]) == self::LENGTH_POSITION);
 129                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 130
 131                 // Decode count and seek position
 132                 $header[1] = hex2bin($header[1]);
 133                 $header[2] = hex2bin($header[2]);
 134
 135                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 136         }
 137
 138         /**
 139          * Flushes the file header
 140          *
 141          * @return      void
 142          */
 143         private function flushFileHeader () {
 144                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 145
 146                 // Put all informations together
 147                 $header = sprintf('%s%s%s%s%s%s',
 148                         // Magic
 149                         self::STACK_MAGIC,
 150
 151                         // Separator magic<->count
 152                         chr(self::SEPARATOR_HEADER_DATA),
 153
 154                         // Total entries (will be zero) and pad it to 20 chars
 155                         str_pad($this->dec2hex($this->getCounter()), self::LENGTH_COUNT, '0', STR_PAD_LEFT),
 156
 157                         // Separator count<->seek position
 158                         chr(self::SEPARATOR_HEADER_DATA),
 159
 160                         // Position (will be zero)
 161                         str_pad($this->dec2hex($this->getSeekPosition(), 2), self::LENGTH_POSITION, '0', STR_PAD_LEFT),
 162
 163                         // Separator position<->entries
 164                         chr(self::SEPARATOR_HEADER_ENTRIES)
 165                 );
 166
 167                 // Write it to disk (header is always at seek position 0)
 168                 $this->writeData(0, $header);
 169
 170                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 171         }
 172
 173         /**
 174          * Analyzes entries in stack file. This will count all found (and valid)
 175          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
 176          * only gaps are found, the file is considered as "virgin" (no entries).
 177          *
 178          * @return      void
 179          */
 180         private function analyzeFile () {
 181                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 182
 183                 // Make sure the file is initialized
 184                 assert($this->isFileInitialized());
 185
 186                 // Init counters and gaps array
 187                 $this->initCountersGapsArray();
 188
 189                 // Output message (as this may take some time)
 190                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Analyzing file structure ... (this may take some time)', __METHOD__, __LINE__));
 191
 192                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 193         }
 194
 195         /**
 196          * Initializes this file-based stack.
 197          *
 198          * @param       $fileName       File name of this stack
 199          * @param       $type           Type of this stack (e.g. url_source for URL sources)
 200          * @return      void
 201          */
 202         protected function initFileStack ($fileName, $type) {
 203                 // Get a file i/o pointer instance for stack file
 204                 $pointerInstance = ObjectFactory::createObjectByConfiguredName('file_raw_input_output_class', array($fileName));
 205
 206                 // Get iterator instance
 207                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_io_iterator_class', array($pointerInstance));
 208
 209                 // Is the instance implementing the right interface?
 210                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 211
 212                 // Set iterator here
 213                 $this->setIteratorInstance($iteratorInstance);
 214
 215                 // Is the file's header initialized?
 216                 if (!$this->isFileHeaderInitialized()) {
 217                         // No, then create it (which may pre-allocate the stack)
 218                         $this->createFileHeader();
 219
 220                         // And pre-allocate a bit
 221                         $this->preAllocateFile('file_stack');
 222                 } // END - if
 223
 224                 // Load the file header
 225                 $this->readFileHeader();
 226
 227                 // Count all entries in file
 228                 $this->analyzeFile();
 229
 230                 /*
 231                  * Get stack index instance. This can be used for faster
 232                  * "defragmentation" and startup.
 233                  */
 234                 $indexInstance = FileStackIndexFactory::createFileStackIndexInstance($fileName, $type);
 235
 236                 // And set it here
 237                 $this->setIndexInstance($indexInstance);
 238         }
 239
 240         /**
 241          * Calculates minimum length for one entry
 242          *
 243          * @return      $length         Minimum length for one entry
 244          */
 245         protected function caluclateMinimumFileEntryLength () {
 246                 // Calulcate it
 247                 $length = self::getHashLength() + strlen(self::SEPARATOR_HASH_NAME) + self::LENGTH_NAME + 1;
 248
 249                 // Return it
 250                 return $length;
 251         }
 252
 253         /**
 254          * Adds a value to given stack
 255          *
 256          * @param       $stackerName    Name of the stack
 257          * @param       $value                  Value to add to this stacker
 258          * @return      void
 259          * @throws      FullStackerException    If the stack is full
 260          */
 261         protected function addValue ($stackerName, $value) {
 262                 // Do some tests
 263                 if ($this->isStackFull($stackerName)) {
 264                         // Stacker is full
 265                         throw new FullStackerException(array($this, $stackerName, $value), self::EXCEPTION_STACKER_IS_FULL);
 266                 } // END - if
 267
 268                 // Now add the value to the stack
 269                 $this->partialStub('stackerName=' . $stackerName . ',value[]=' . gettype($value));
 270         }
 271
 272         /**
 273          * Get last value from named stacker
 274          *
 275          * @param       $stackerName    Name of the stack
 276          * @return      $value                  Value of last added value
 277          * @throws      EmptyStackerException   If the stack is empty
 278          */
 279         protected function getLastValue ($stackerName) {
 280                 // Is the stack not yet initialized or full?
 281                 if ($this->isStackEmpty($stackerName)) {
 282                         // Throw an exception
 283                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 284                 } // END - if
 285
 286                 // Now get the last value
 287                 $this->partialStub('stackerName=' . $stackerName);
 288                 $value = NULL;
 289
 290                 // Return it
 291                 return $value;
 292         }
 293
 294         /**
 295          * Get first value from named stacker
 296          *
 297          * @param       $stackerName    Name of the stack
 298          * @return      $value                  Value of last added value
 299          * @throws      EmptyStackerException   If the stack is empty
 300          */
 301         protected function getFirstValue ($stackerName) {
 302                 // Is the stack not yet initialized or full?
 303                 if ($this->isStackEmpty($stackerName)) {
 304                         // Throw an exception
 305                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 306                 } // END - if
 307
 308                 // Now get the first value
 309                 $this->partialStub('stackerName=' . $stackerName);
 310                 $value = NULL;
 311
 312                 // Return it
 313                 return $value;
 314         }
 315
 316         /**
 317          * "Pops" last entry from stack
 318          *
 319          * @param       $stackerName    Name of the stack
 320          * @return      $value                  Value "poped" from array
 321          * @throws      EmptyStackerException   If the stack is empty
 322          */
 323         protected function popLast ($stackerName) {
 324                 // Is the stack not yet initialized or full?
 325                 if ($this->isStackEmpty($stackerName)) {
 326                         // Throw an exception
 327                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 328                 } // END - if
 329
 330                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 331                 $this->partialStub('stackerName=' . $stackerName);
 332                 return NULL;
 333         }
 334
 335         /**
 336          * "Pops" first entry from stack
 337          *
 338          * @param       $stackerName    Name of the stack
 339          * @return      $value                  Value "shifted" from array
 340          * @throws      EmptyStackerException   If the named stacker is empty
 341          */
 342         protected function popFirst ($stackerName) {
 343                 // Is the stack not yet initialized or full?
 344                 if ($this->isStackEmpty($stackerName)) {
 345                         // Throw an exception
 346                         throw new EmptyStackerException(array($this, $stackerName), self::EXCEPTION_STACKER_IS_EMPTY);
 347                 } // END - if
 348
 349                 // Now, remove the last entry, we don't care about the return value here, see elseif() block above
 350                 $this->partialStub('stackerName=' . $stackerName);
 351                 return NULL;
 352         }
 353
 354         /**
 355          * Checks whether the given stack is full
 356          *
 357          * @param       $stackerName    Name of the stack
 358          * @return      $isFull                 Whether the stack is full
 359          */
 360         protected function isStackFull ($stackerName) {
 361                 // File-based stacks will only run full if the disk space is low.
 362                 // @TODO Please implement this, returning FALSE
 363                 $isFull = FALSE;
 364
 365                 // Return result
 366                 return $isFull;
 367         }
 368
 369         /**
 370          * Checks whether the given stack is empty
 371          *
 372          * @param       $stackerName            Name of the stack
 373          * @return      $isEmpty                        Whether the stack is empty
 374          * @throws      NoStackerException      If given stack is missing
 375          */
 376         public function isStackEmpty ($stackerName) {
 377                 // So, is the stack empty?
 378                 $isEmpty = (($this->getStackCount($stackerName)) == 0);
 379
 380                 // Return result
 381                 return $isEmpty;
 382         }
 383
 384         /**
 385          * Initializes given stacker
 386          *
 387          * @param       $stackerName    Name of the stack
 388          * @param       $forceReInit    Force re-initialization
 389          * @return      void
 390          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 391          */
 392         public function initStack ($stackerName, $forceReInit = FALSE) {
 393                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 394         }
 395
 396         /**
 397          * Initializes all stacks
 398          *
 399          * @return      void
 400          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 401          */
 402         public function initStacks (array $stacks, $forceReInit = FALSE) {
 403                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 404         }
 405
 406         /**
 407          * Checks whether the given stack is initialized (set in array $stackers)
 408          *
 409          * @param       $stackerName    Name of the stack
 410          * @return      $isInitialized  Whether the stack is initialized
 411          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 412          */
 413         public function isStackInitialized ($stackerName) {
 414                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 415         }
 416
 417         /**
 418          * Getter for size of given stack (array count)
 419          *
 420          * @param       $stackerName    Name of the stack
 421          * @return      $count                  Size of stack (array count)
 422          */
 423         public function getStackCount ($stackerName) {
 424                 // Now, simply return the found count value, this must be up-to-date then!
 425                 return $this->getCounter();
 426         }
 427 }
 428
 429 // [EOF]
 430 ?>