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          * Gets currently read data
 146          *
 147          * @return      $current        Currently read data
 148          */
 149         public function getCurrentBlock () {
 150                 // Return it
 151                 return $this->currentBlock;
 152         }
 153
 154         /**
 155          * Initializes this file class
 156          *
 157          * @param       $fileName       Name of this abstract file
 158          * @return      void
 159          */
 160         protected function initFile ($fileName) {
 161                 // Get a file i/o pointer instance
 162                 $pointerInstance = ObjectFactory::createObjectByConfiguredName('file_raw_input_output_class', array($fileName));
 163
 164                 // ... and set it here
 165                 $this->setPointerInstance($pointerInstance);
 166         }
 167
 168         /**
 169          * Close a file source and set it's instance to null and the file name
 170          * to empty
 171          *
 172          * @return      void
 173          * @todo        ~10% done?
 174          */
 175         public function closeFile () {
 176                 $this->partialStub('Unfinished method.');
 177
 178                 // Remove file name
 179                 $this->setFileName('');
 180         }
 181
 182         /**
 183          * Determines seek position
 184          *
 185          * @return      $seekPosition   Current seek position
 186          */
 187         public function determineSeekPosition () {
 188                 // Call pointer instance
 189                 return $this->getPointerInstance()->determineSeekPosition();
 190         }
 191
 192         /**
 193          * Seek to given offset (default) or other possibilities as fseek() gives.
 194          *
 195          * @param       $offset         Offset to seek to (or used as "base" for other seeks)
 196          * @param       $whence         Added to offset (default: only use offset to seek to)
 197          * @return      $status         Status of file seek: 0 = success, -1 = failed
 198          */
 199         public function seek ($offset, $whence = SEEK_SET) {
 200                 // Call pointer instance
 201                 return $this->getPointerInstance()->seek($offset, $whence);
 202         }
 203
 204         /**
 205          * Size of this file
 206          *
 207          * @return      $size   Size (in bytes) of file
 208          * @todo        Handle seekStatus
 209          */
 210         public function size () {
 211                 // Call pointer instance
 212                 return $this->getPointerInstance()->size();
 213         }
 214
 215         /**
 216          * Read data a file pointer
 217          *
 218          * @return      mixed   The result of fread()
 219          * @throws      NullPointerException    If the file pointer instance
 220          *                                                                      is not set by setPointer()
 221          * @throws      InvalidResourceException        If there is being set
 222          */
 223         public function readFromFile () {
 224                 // Call pointer instance
 225                 return $this->getPointerInstance()->readFromFile();
 226         }
 227
 228         /**
 229          * Reads given amount of bytes from file.
 230          *
 231          * @param       $bytes  Amount of bytes to read
 232          * @return      $data   Data read from file
 233          */
 234         public function read ($bytes) {
 235                 // Call pointer instance
 236                 return $this->getPointerInstance()->read($bytes);
 237         }
 238
 239         /**
 240          * Write data to a file pointer
 241          *
 242          * @param       $dataStream             The data stream we shall write to the file
 243          * @return      mixed                   Number of writes bytes or FALSE on error
 244          * @throws      NullPointerException    If the file pointer instance
 245          *                                                                      is not set by setPointer()
 246          * @throws      InvalidResourceException        If there is being set
 247          *                                                                                      an invalid file resource
 248          */
 249         public function writeToFile ($dataStream) {
 250                 // Call pointer instance
 251                 return $this->getPointerInstance()->writeToFile($dataStream);
 252         }
 253
 254         /**
 255          * Rewinds to the beginning of the file
 256          *
 257          * @return      $status         Status of this operation
 258          */
 259         public function rewind () {
 260                 // Call pointer instance
 261                 return $this->getPointerInstance()->rewind();
 262         }
 263
 264         /**
 265          * Determines whether the EOF has been reached
 266          *
 267          * @return      $isEndOfFileReached             Whether the EOF has been reached
 268          */
 269         public final function isEndOfFileReached () {
 270                 // Call pointer instance
 271                 return $this->getPointerInstance()->isEndOfFileReached();
 272         }
 273
 274         /**
 275          * Analyzes entries in index file. This will count all found (and valid)
 276          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
 277          * only gaps are found, the file is considered as "virgin" (no entries).
 278          *
 279          * @return      void
 280          */
 281         public function analyzeFile () {
 282                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 283
 284                 // Make sure the file is initialized
 285                 assert($this->isFileInitialized());
 286
 287                 // Init counters and gaps array
 288                 $this->initCountersGapsArray();
 289
 290                 // Output message (as this may take some time)
 291                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Analyzing file structure ... (this may take some time)', __METHOD__, __LINE__));
 292
 293                 // First rewind to the begining
 294                 $this->rewind();
 295
 296                 // Then try to load all entries
 297                 while ($this->valid()) {
 298                         // Go to next entry
 299                         $this->next();
 300
 301                         // Get current entry
 302                         $current = $this->getCurrentBlock();
 303
 304                         // Simply output it
 305                         self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] current=%s', __METHOD__, __LINE__, print_r($current, TRUE)));
 306                 } // END - while
 307
 308                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 309         }
 310
 311         /**
 312          * Advances to next "block" of bytes
 313          *
 314          * @return      void
 315          * @todo        This method will load large but empty files in a whole
 316          */
 317         public function next () {
 318                 // Is there nothing to read?
 319                 if (!$this->valid()) {
 320                         // Nothing to read
 321                         return;
 322                 } // END - if
 323
 324                 // Make sure the block instance is set
 325                 assert($this->getBlockInstance() instanceof CalculatableBlock);
 326
 327                 // First calculate minimum block length
 328                 $length = $this->getBlockInstance()->caluclateMinimumBlockLength();
 329
 330                 // Short be more than zero!
 331                 assert($length > 0);
 332
 333                 // Wait until a entry/block separator has been found
 334                 $data = $this->getBackBuffer();
 335                 while ((!$this->isEndOfFileReached()) && (!$this->getBlockInstance()->isBlockSeparatorFound($data))) {
 336                         // Then read the block
 337                         $data .= $this->read($length);
 338                         //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('data()=' . strlen($data));
 339                 } // END - if
 340
 341                 // EOF reached?
 342                 if ($this->isEndOfFileReached()) {
 343                         // Set whole data as current block
 344                         //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('Calling setCurrentBlock(' . strlen($data) . ') ...');
 345                         $this->setCurrentBlock($data);
 346
 347                         // Then abort here silently
 348                         //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('EOF reached.');
 349                         return;
 350                 } // END - if
 351
 352                 /*
 353                  * Init back-buffer which is the data that has been found beyond the
 354                  * separator.
 355                  */
 356                 $this->initBackBuffer();
 357
 358                 // Separate data
 359                 $dataArray = explode(self::getBlockSeparator(), $data);
 360
 361                 // This array must contain two elements
 362                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('dataArray=' . print_r($dataArray, TRUE));
 363                 assert(count($dataArray) == 2);
 364
 365                 // Left part is the actual block, right one the back-buffer data
 366                 $this->setCurrentBlock($dataArray[0]);
 367                 $this->setBackBuffer($dataArray[1]);
 368         }
 369
 370         /**
 371          * Checks wether the current entry is valid (not at the end of the file).
 372          * This method will return TRUE if an emptied (nulled) entry has been found.
 373          *
 374          * @return      $isValid        Whether the next entry is valid
 375          */
 376         public function valid () {
 377                 // Make sure the block instance is set
 378                 assert($this->getBlockInstance() instanceof CalculatableBlock);
 379
 380                 // First calculate minimum block length
 381                 $length = $this->getBlockInstance()->caluclateMinimumBlockLength();
 382
 383                 // Short be more than zero!
 384                 assert($length > 0);
 385
 386                 // Get current seek position
 387                 $seekPosition = $this->key();
 388
 389                 // Then try to read it
 390                 $data = $this->read($length);
 391
 392                 // If some bytes could be read, all is fine
 393                 $isValid = ((is_string($data)) && (strlen($data) > 0));
 394
 395                 // Get header size
 396                 $headerSize = $this->getBlockInstance()->getHeaderSize();
 397
 398                 // Is the seek position at or beyond the header?
 399                 if ($seekPosition >= $headerSize) {
 400                         // Seek back to old position
 401                         $this->seek($seekPosition);
 402                 } else {
 403                         // Seek directly behind the header
 404                         $this->seek($headerSize);
 405                 }
 406
 407                 // Return result
 408                 return $isValid;
 409         }
 410
 411         /**
 412          * Gets current seek position ("key").
 413          *
 414          * @return      $key    Current key in iteration
 415          */
 416         public function key () {
 417                 // Call pointer instance
 418                 return $this->getPointerInstance()->determineSeekPosition();
 419         }
 420 }
 421
 422 // [EOF]
 423 ?>