inc/classes/main/file_directories/class_BaseFile.php

   1 <?php
   2 /**
   3  * A general file class
   4  *
   5  * @author              Roland Haeder <webmaster@ship-simu.org>
   6  * @version             0.0.0
   7  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2012 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 BaseFile extends BaseFrameworkSystem {
  25         /**
  26          * The current file we are working in
  27          */
  28         private $fileName = '';
  29
  30         /**
  31          * Back-buffer
  32          */
  33         private $backBuffer = '';
  34
  35         /**
  36          * Currently loaded block (will be returned by current())
  37          */
  38         private $currentBlock = '';
  39
  40         /**
  41          * Protected constructor
  42          *
  43          * @param       $className      Name of the class
  44 y        * @return      void
  45          */
  46         protected function __construct ($className) {
  47                 // Call parent constructor
  48                 parent::__construct($className);
  49
  50                 // Init counters and gaps array
  51                 $this->initCountersGapsArray();
  52         }
  53
  54         /**
  55          * Destructor for cleaning purposes, etc
  56          *
  57          * @return      void
  58          */
  59         public final function __destruct() {
  60                 // Try to close a file
  61                 $this->closeFile();
  62
  63                 // Call the parent destructor
  64                 parent::__destruct();
  65         }
  66
  67         /**
  68          * Getter for the file pointer
  69          *
  70          * @return      $filePointer    The file pointer which shall be a valid file resource
  71          * @throws      UnsupportedOperationException   If this method is called
  72          */
  73         public final function getPointer () {
  74                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
  75         }
  76
  77         /**
  78          * Setter for file name
  79          *
  80          * @param       $fileName       The new file name
  81          * @return      void
  82          */
  83         protected final function setFileName ($fileName) {
  84                 $fileName = (string) $fileName;
  85                 $this->fileName = $fileName;
  86         }
  87
  88         /**
  89          * Getter for file name
  90          *
  91          * @return      $fileName       The current file name
  92          */
  93         public final function getFileName () {
  94                 return $this->fileName;
  95         }
  96
  97         /**
  98          * Initializes the back-buffer by setting it to an empty string.
  99          *
 100          * @return      void
 101          */
 102         private function initBackBuffer () {
 103                 // Simply call the setter
 104                 $this->setBackBuffer('');
 105         }
 106
 107         /**
 108          * Setter for backBuffer field
 109          *
 110          * @param       $backBuffer             Characters to "store" in back-buffer
 111          * @return      void
 112          */
 113         private function setBackBuffer ($backBuffer) {
 114                 // Cast to string (so no arrays or objects)
 115                 $backBuffer = (string) $backBuffer;
 116
 117                 // ... and set it
 118                 $this->backBuffer = $backBuffer;
 119         }
 120
 121         /**
 122          * Getter for backBuffer field
 123          *
 124          * @return      $backBuffer             Characters "stored" in back-buffer
 125          */
 126         private function getBackBuffer () {
 127                 return $this->backBuffer;
 128         }
 129
 130         /**
 131          * Setter for currentBlock field
 132          *
 133          * @param       $currentBlock           Characters to set a currently loaded block
 134          * @return      void
 135          */
 136         private function setCurrentBlock ($currentBlock) {
 137                 // Cast to string (so no arrays or objects)
 138                 $currentBlock = (string) $currentBlock;
 139
 140                 // ... and set it
 141                 $this->currentBlock = $currentBlock;
 142         }
 143
 144         /**
 145          * Initializes this file class
 146          *
 147          * @param       $fileName       Name of this abstract file
 148          * @return      void
 149          */
 150         protected function initFile ($fileName) {
 151                 // Get a file i/o pointer instance
 152                 $pointerInstance = ObjectFactory::createObjectByConfiguredName('file_raw_input_output_class', array($fileName));
 153
 154                 // ... and set it here
 155                 $this->setPointerInstance($pointerInstance);
 156         }
 157
 158         /**
 159          * Close a file source and set it's instance to null and the file name
 160          * to empty
 161          *
 162          * @return      void
 163          * @todo        ~10% done?
 164          */
 165         public function closeFile () {
 166                 $this->partialStub('Unfinished method.');
 167
 168                 // Remove file name
 169                 $this->setFileName('');
 170         }
 171
 172         /**
 173          * Determines seek position
 174          *
 175          * @return      $seekPosition   Current seek position
 176          */
 177         public function determineSeekPosition () {
 178                 // Call pointer instance
 179                 return $this->getPointerInstance()->determineSeekPosition();
 180         }
 181
 182         /**
 183          * Seek to given offset (default) or other possibilities as fseek() gives.
 184          *
 185          * @param       $offset         Offset to seek to (or used as "base" for other seeks)
 186          * @param       $whence         Added to offset (default: only use offset to seek to)
 187          * @return      $status         Status of file seek: 0 = success, -1 = failed
 188          */
 189         public function seek ($offset, $whence = SEEK_SET) {
 190                 // Call pointer instance
 191                 return $this->getPointerInstance()->seek($offset, $whence);
 192         }
 193
 194         /**
 195          * Size of this file
 196          *
 197          * @return      $size   Size (in bytes) of file
 198          * @todo        Handle seekStatus
 199          */
 200         public function size () {
 201                 // Call pointer instance
 202                 return $this->getPointerInstance()->size();
 203         }
 204
 205         /**
 206          * Read data a file pointer
 207          *
 208          * @return      mixed   The result of fread()
 209          * @throws      NullPointerException    If the file pointer instance
 210          *                                                                      is not set by setPointer()
 211          * @throws      InvalidResourceException        If there is being set
 212          */
 213         public function readFromFile () {
 214                 // Call pointer instance
 215                 return $this->getPointerInstance()->readFromFile();
 216         }
 217
 218         /**
 219          * Reads given amount of bytes from file.
 220          *
 221          * @param       $bytes  Amount of bytes to read
 222          * @return      $data   Data read from file
 223          */
 224         public function read ($bytes) {
 225                 // Call pointer instance
 226                 return $this->getPointerInstance()->read($bytes);
 227         }
 228
 229         /**
 230          * Write data to a file pointer
 231          *
 232          * @param       $dataStream             The data stream we shall write to the file
 233          * @return      mixed                   Number of writes bytes or FALSE on error
 234          * @throws      NullPointerException    If the file pointer instance
 235          *                                                                      is not set by setPointer()
 236          * @throws      InvalidResourceException        If there is being set
 237          *                                                                                      an invalid file resource
 238          */
 239         public function writeToFile ($dataStream) {
 240                 // Call pointer instance
 241                 return $this->getPointerInstance()->writeToFile($dataStream);
 242         }
 243
 244         /**
 245          * Rewinds to the beginning of the file
 246          *
 247          * @return      $status         Status of this operation
 248          */
 249         public function rewind () {
 250                 // Call pointer instance
 251                 return $this->getPointerInstance()->rewind();
 252         }
 253
 254         /**
 255          * Determines whether the EOF has been reached
 256          *
 257          * @return      $isEndOfFileReached             Whether the EOF has been reached
 258          */
 259         public final function isEndOfFileReached () {
 260                 // Call pointer instance
 261                 return $this->getPointerInstance()->isEndOfFileReached();
 262         }
 263
 264         /**
 265          * Analyzes entries in index file. This will count all found (and valid)
 266          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
 267          * only gaps are found, the file is considered as "virgin" (no entries).
 268          *
 269          * @return      void
 270          */
 271         public function analyzeFile () {
 272                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 273
 274                 // Make sure the file is initialized
 275                 assert($this->isFileInitialized());
 276
 277                 // Init counters and gaps array
 278                 $this->initCountersGapsArray();
 279
 280                 // Output message (as this may take some time)
 281                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Analyzing file structure ... (this may take some time)', __METHOD__, __LINE__));
 282
 283                 // First rewind to the begining
 284                 $this->rewind();
 285
 286                 // Then try to load all entries
 287                 while ($this->valid()) {
 288                         // Go to next entry
 289                         $this->next();
 290
 291                         // Get current entry
 292                         $current = $this->current();
 293
 294                         // Simply output it
 295                         self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] current=%s', __METHOD__, __LINE__, print_r($current, TRUE)));
 296                 } // END - while
 297
 298                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 299         }
 300
 301         /**
 302          * Advances to next "block" of bytes
 303          *
 304          * @return      void
 305          * @todo        This method will load large but empty files in a whole
 306          */
 307         public function next () {
 308                 // Is there nothing to read?
 309                 if (!$this->valid()) {
 310                         // Nothing to read
 311                         return;
 312                 } // END - if
 313
 314                 // Make sure the block instance is set
 315                 assert($this->getBlockInstance() instanceof CalculatableBlock);
 316
 317                 // First calculate minimum block length
 318                 $length = $this->getBlockInstance()->caluclateMinimumBlockLength();
 319
 320                 // Short be more than zero!
 321                 assert($length > 0);
 322
 323                 // Wait until a entry/block separator has been found
 324                 $data = $this->getBackBuffer();
 325                 while ((!$this->isEndOfFileReached()) && (!$this->getBlockInstance()->isBlockSeparatorFound($data))) {
 326                         // Then read the block
 327                         $data .= $this->read($length);
 328                         //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('data()=' . strlen($data));
 329                 } // END - if
 330
 331                 // EOF reached?
 332                 if ($this->isEndOfFileReached()) {
 333                         // Set whole data as current block
 334                         //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('Calling setCurrentBlock(' . strlen($data) . ') ...');
 335                         $this->setCurrentBlock($data);
 336
 337                         // Then abort here silently
 338                         //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('EOF reached.');
 339                         return;
 340                 } // END - if
 341
 342                 /*
 343                  * Init back-buffer which is the data that has been found beyond the
 344                  * separator.
 345                  */
 346                 $this->initBackBuffer();
 347
 348                 // Separate data
 349                 $dataArray = explode(self::getBlockSeparator(), $data);
 350
 351                 // This array must contain two elements
 352                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('dataArray=' . print_r($dataArray, TRUE));
 353                 assert(count($dataArray) == 2);
 354
 355                 // Left part is the actual block, right one the back-buffer data
 356                 $this->setCurrentBlock($dataArray[0]);
 357                 $this->setBackBuffer($dataArray[1]);
 358         }
 359
 360         /**
 361          * Checks wether the current entry is valid (not at the end of the file).
 362          * This method will return TRUE if an emptied (nulled) entry has been found.
 363          *
 364          * @return      $isValid        Whether the next entry is valid
 365          */
 366         public function valid () {
 367                 // Make sure the block instance is set
 368                 assert($this->getBlockInstance() instanceof CalculatableBlock);
 369
 370                 // First calculate minimum block length
 371                 $length = $this->getBlockInstance()->caluclateMinimumBlockLength();
 372
 373                 // Short be more than zero!
 374                 assert($length > 0);
 375
 376                 // Get current seek position
 377                 $seekPosition = $this->key();
 378
 379                 // Then try to read it
 380                 $data = $this->read($length);
 381
 382                 // If some bytes could be read, all is fine
 383                 $isValid = ((is_string($data)) && (strlen($data) > 0));
 384
 385                 // Get header size
 386                 $headerSize = $this->getBlockInstance()->getHeaderSize();
 387
 388                 // Is the seek position at or beyond the header?
 389                 if ($seekPosition >= $headerSize) {
 390                         // Seek back to old position
 391                         $this->seek($seekPosition);
 392                 } else {
 393                         // Seek directly behind the header
 394                         $this->seek($headerSize);
 395                 }
 396
 397                 // Return result
 398                 return $isValid;
 399         }
 400 }
 401
 402 // [EOF]
 403 ?>