inc/classes/main/index/class_BaseIndex.php

   1 <?php
   2 /**
   3  * A general index class
   4  *
   5  * @author              Roland Haeder <webmaster@ship-simu.org>
   6  * @version             0.0.0
   7  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2015 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 BaseIndex extends BaseFrameworkSystem {
  25         /**
  26          * Magic for this index
  27          */
  28         const INDEX_MAGIC = 'INDEXv0.1';
  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
  41         /**
  42          * Reads the file header
  43          *
  44          * @return      void
  45          */
  46         public function readFileHeader () {
  47                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
  48
  49                 // First rewind to beginning as the header sits at the beginning ...
  50                 $this->getIteratorInstance()->rewind();
  51
  52                 // Then read it (see constructor for calculation)
  53                 $data = $this->getIteratorInstance()->read($this->getIteratorInstance()->getHeaderSize());
  54                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Read %d bytes (%d wanted).', __METHOD__, __LINE__, strlen($data), $this->getIteratorInstance()->getHeaderSize()));
  55
  56                 // Have all requested bytes been read?
  57                 assert(strlen($data) == $this->getIteratorInstance()->getHeaderSize());
  58                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  59
  60                 // Last character must be the separator
  61                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] data(-1)=%s', __METHOD__, __LINE__, dechex(ord(substr($data, -1, 1)))));
  62                 assert(substr($data, -1, 1) == chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES));
  63                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  64
  65                 // Okay, then remove it
  66                 $data = substr($data, 0, -1);
  67
  68                 // And update seek position
  69                 $this->getIteratorInstance()->updateSeekPosition();
  70
  71                 /*
  72                  * Now split it:
  73                  *
  74                  * 0 => magic
  75                  * 1 => total entries
  76                  */
  77                 $header = explode(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA), $data);
  78
  79                 // Set it here
  80                 $this->getIteratorInstance()->setHeader($header);
  81
  82                 // Check if the array has only 3 elements
  83                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] header(%d)=%s', __METHOD__, __LINE__, count($header), print_r($header, TRUE)));
  84                 assert(count($header) == 2);
  85                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  86
  87                 // Check magic
  88                 assert($header[0] == self::INDEX_MAGIC);
  89                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  90
  91                 // Check length of count
  92                 assert(strlen($header[1]) == BaseBinaryFile::LENGTH_COUNT);
  93                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  94
  95                 // Decode count
  96                 $header[1] = hex2bin($header[1]);
  97
  98                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
  99         }
 100
 101         /**
 102          * Flushes the file header
 103          *
 104          * @return      void
 105          */
 106         public function flushFileHeader () {
 107                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 108
 109                 // Put all informations together
 110                 $header = sprintf('%s%s%s%s',
 111                         // Magic
 112                         self::INDEX_MAGIC,
 113
 114                         // Separator header data
 115                         chr(BaseBinaryFile::SEPARATOR_HEADER_DATA),
 116
 117                         // Total entries
 118                         str_pad($this->dec2hex($this->getIteratorInstance()->getCounter()), BaseBinaryFile::LENGTH_COUNT, '0', STR_PAD_LEFT),
 119
 120                         // Separator header<->entries
 121                         chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES)
 122                 );
 123
 124                 // Write it to disk (header is always at seek position 0)
 125                 $this->getIteratorInstance()->writeData(0, $header, FALSE);
 126
 127                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 128         }
 129
 130         /**
 131          * Initializes this index
 132          *
 133          * @param       $fileName       File name of this index
 134          * @return      void
 135          * @todo        Currently the index file is not cached, please implement a memory-handling class and if enough RAM is found, cache the whole index file.
 136          */
 137         protected function initIndex ($fileName) {
 138                 // Append index file extension
 139                 $fileName .= $this->getConfigInstance()->getConfigEntry('index_extension');
 140
 141                 // Get a file i/o pointer instance for index file
 142                 $fileInstance = ObjectFactory::createObjectByConfiguredName('index_file_class', array($fileName, $this));
 143
 144                 // Get iterator instance
 145                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_iterator_class', array($fileInstance));
 146
 147                 // Is the instance implementing the right interface?
 148                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 149
 150                 // Set iterator here
 151                 $this->setIteratorInstance($iteratorInstance);
 152
 153                 // Calculate header size
 154                 $this->getIteratorInstance()->setHeaderSize(
 155                         strlen(self::INDEX_MAGIC) +
 156                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA)) +
 157                         BaseBinaryFile::LENGTH_COUNT +
 158                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES))
 159                 );
 160
 161                 // Init counters and gaps array
 162                 $this->getIteratorInstance()->initCountersGapsArray();
 163
 164                 // Is the file's header initialized?
 165                 if (!$this->getIteratorInstance()->isFileHeaderInitialized()) {
 166                         // No, then create it (which may pre-allocate the index)
 167                         $this->getIteratorInstance()->createFileHeader();
 168
 169                         // And pre-allocate a bit
 170                         $this->getIteratorInstance()->preAllocateFile('index');
 171                 } // END - if
 172
 173                 // Load the file header
 174                 $this->readFileHeader();
 175
 176                 // Count all entries in file
 177                 $this->getIteratorInstance()->analyzeFile();
 178         }
 179
 180         /**
 181          * Calculates minimum length for one entry/block
 182          *
 183          * @return      $length         Minimum length for one entry/block
 184          */
 185         public function calculateMinimumBlockLength () {
 186                 // Calulcate it
 187                 $length = BaseBinaryFile::LENGTH_TYPE + strlen(chr(BaseBinaryFile::SEPARATOR_TYPE_POSITION)) + BaseBinaryFile::LENGTH_POSITION + strlen(chr(BaseBinaryFile::SEPARATOR_ENTRIES));
 188
 189                 // Return it
 190                 return $length;
 191         }
 192
 193         /**
 194          * Determines whether the EOF has been reached
 195          *
 196          * @return      $isEndOfFileReached             Whether the EOF has been reached
 197          * @throws      UnsupportedOperationException   If this method is called
 198          */
 199         public function isEndOfFileReached () {
 200                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 201         }
 202
 203         /**
 204          * Getter for file name
 205          *
 206          * @return      $fileName       The current file name
 207          * @throws      UnsupportedOperationException   If this method is called
 208          */
 209         public function getFileName () {
 210                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 211         }
 212
 213         /**
 214          * Initializes counter for valid entries, arrays for damaged entries and
 215          * an array for gap seek positions. If you call this method on your own,
 216          * please re-analyze the file structure. So you are better to call
 217          * analyzeFile() instead of this method.
 218          *
 219          * @return      void
 220          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 221          */
 222         public function initCountersGapsArray () {
 223                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 224         }
 225
 226         /**
 227          * Getter for header size
 228          *
 229          * @return      $totalEntries   Size of file header
 230          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 231          */
 232         public final function getHeaderSize () {
 233                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 234         }
 235
 236         /**
 237          * Setter for header size
 238          *
 239          * @param       $headerSize             Size of file header
 240          * @return      void
 241          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 242          */
 243         public final function setHeaderSize ($headerSize) {
 244                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 245         }
 246
 247         /**
 248          * Getter for header array
 249          *
 250          * @return      $totalEntries   Size of file header
 251          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 252          */
 253         public final function getHeader () {
 254                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 255         }
 256
 257         /**
 258          * Setter for header
 259          *
 260          * @param       $header         Array for a file header
 261          * @return      void
 262          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 263          */
 264         public final function setHeader (array $header) {
 265                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 266         }
 267
 268         /**
 269          * Updates seekPosition attribute from file to avoid to much access on file.
 270          *
 271          * @return      void
 272          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 273          */
 274         public function updateSeekPosition () {
 275                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 276         }
 277
 278         /**
 279          * Getter for total entries
 280          *
 281          * @return      $totalEntries   Total entries in this file
 282          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 283          */
 284         public final function getCounter () {
 285                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 286         }
 287
 288         /**
 289          * "Getter" for file size
 290          *
 291          * @return      $fileSize       Size of currently loaded file
 292          */
 293         public function getFileSize () {
 294                 // Call iterator's method
 295                 return $this->getIteratorInstance()->getFileSize();
 296         }
 297 }
 298
 299 // [EOF]
 300 ?>