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