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 - 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 BaseIndex extends BaseFrameworkSystem {
  25         /**
  26          * Magic for this index
  27          */
  28         const INDEX_MAGIC = 'INDEXv0.1';
  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          * Protected constructor
  42          *
  43          * @param       $className      Name of the class
  44          * @return      void
  45          */
  46         protected function __construct ($className) {
  47                 // Call parent constructor
  48                 parent::__construct($className);
  49
  50                 // Calculate header size
  51                 $this->setHeaderSize(
  52                         strlen(self::INDEX_MAGIC) +
  53                         strlen(self::SEPARATOR_HEADER_DATA) +
  54                         self::LENGTH_COUNT +
  55                         strlen(self::SEPARATOR_HEADER_ENTRIES)
  56                 );
  57
  58                 // Init counters and gaps array
  59                 $this->initCountersGapsArray();
  60         }
  61
  62         /**
  63          * Reads the file header
  64          *
  65          * @return      void
  66          */
  67         protected function readFileHeader () {
  68                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
  69
  70                 // First rewind to beginning as the header sits at the beginning ...
  71                 $this->getIteratorInstance()->rewind();
  72
  73                 // Then read it (see constructor for calculation)
  74                 $data = $this->getIteratorInstance()->read($this->getHeaderSize());
  75                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Read %d bytes (%d wanted).', __METHOD__, __LINE__, strlen($data), $this->getHeaderSize()));
  76
  77                 // Have all requested bytes been read?
  78                 assert(strlen($data) == $this->getHeaderSize());
  79                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  80
  81                 // Last character must be the separator
  82                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] data(-1)=%s', __METHOD__, __LINE__, dechex(ord(substr($data, -1, 1)))));
  83                 assert(substr($data, -1, 1) == chr(self::SEPARATOR_HEADER_ENTRIES));
  84                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  85
  86                 // Okay, then remove it
  87                 $data = substr($data, 0, -1);
  88
  89                 // And update seek position
  90                 $this->updateSeekPosition();
  91
  92                 /*
  93                  * Now split it:
  94                  *
  95                  * 0 => magic
  96                  * 1 => total entries
  97                  */
  98                 $header = explode(chr(self::SEPARATOR_HEADER_DATA), $data);
  99
 100                 // Set it here
 101                 $this->setHeader($header);
 102
 103                 // Check if the array has only 3 elements
 104                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] header(%d)=%s', __METHOD__, __LINE__, count($header), print_r($header, TRUE)));
 105                 assert(count($header) == 2);
 106                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 107
 108                 // Check magic
 109                 assert($header[0] == self::INDEX_MAGIC);
 110                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 111
 112                 // Check length of count
 113                 assert(strlen($header[1]) == self::LENGTH_COUNT);
 114                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 115
 116                 // Decode count
 117                 $header[1] = hex2bin($header[1]);
 118
 119                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 120         }
 121
 122         /**
 123          * Flushes the file header
 124          *
 125          * @return      void
 126          */
 127         protected function flushFileHeader () {
 128                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 129
 130                 // Put all informations together
 131                 $header = sprintf('%s%s%s%s',
 132                         // Magic
 133                         self::INDEX_MAGIC,
 134
 135                         // Separator header data
 136                         chr(self::SEPARATOR_HEADER_DATA),
 137
 138                         // Total entries
 139                         str_pad($this->dec2hex($this->getCounter()), self::LENGTH_COUNT, '0', STR_PAD_LEFT),
 140
 141                         // Separator header<->entries
 142                         chr(self::SEPARATOR_HEADER_ENTRIES)
 143                 );
 144
 145                 // Write it to disk (header is always at seek position 0)
 146                 $this->writeData(0, $header, FALSE);
 147
 148                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 149         }
 150
 151         /**
 152          * Analyzes entries in index file. This will count all found (and valid)
 153          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
 154          * only gaps are found, the file is considered as "virgin" (no entries).
 155          *
 156          * @return      void
 157          */
 158         private function analyzeFile () {
 159                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 160
 161                 // Make sure the file is initialized
 162                 assert($this->isFileInitialized());
 163
 164                 // Init counters and gaps array
 165                 $this->initCountersGapsArray();
 166
 167                 // Output message (as this may take some time)
 168                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Analyzing file structure ... (this may take some time)', __METHOD__, __LINE__));
 169
 170                 // First rewind to the begining
 171                 $this->getIteratorInstance()->rewind();
 172
 173                 // Then try to load all entries
 174                 while ($this->getIteratorInstance()->next()) {
 175                         // Get current entry
 176                         $current = $this->getIteratorInstance()->current();
 177
 178                         // Simply output it
 179                         self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] current=%s', __METHOD__, __LINE__, print_r($current, TRUE)));
 180                 } // END - while
 181
 182                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 183         }
 184
 185         /**
 186          * Calculates minimum length for one entry
 187          *
 188          * @return      $length         Minimum length for one entry
 189          */
 190         protected function caluclateMinimumFileEntryLength () {
 191                 // Calulcate it
 192                 // @TODO Not finished yet
 193                 $length = 0;
 194
 195                 // Return it
 196                 return $length;
 197         }
 198
 199         /**
 200          * Initializes this index
 201          *
 202          * @param       $fileName       File name of this index
 203          * @return      void
 204          * @todo        Currently the index file is not cached, please implement a memory-handling class and if enough RAM is found, cache the whole index file.
 205          */
 206         protected function initIndex ($fileName) {
 207                 // Append index file extension
 208                 $fileName .= $this->getConfigInstance()->getConfigEntry('index_extension');
 209
 210                 // Get a file i/o pointer instance for index file
 211                 $fileInstance = ObjectFactory::createObjectByConfiguredName('index_file_class', array($fileName));
 212
 213                 // Get iterator instance
 214                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_io_iterator_class', array($fileInstance));
 215
 216                 // Is the instance implementing the right interface?
 217                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 218
 219                 // Set iterator here
 220                 $this->setIteratorInstance($iteratorInstance);
 221
 222                 // Is the file's header initialized?
 223                 if (!$this->isFileHeaderInitialized()) {
 224                         // No, then create it (which may pre-allocate the index)
 225                         $this->createFileHeader();
 226
 227                         // And pre-allocate a bit
 228                         $this->preAllocateFile('index');
 229                 } // END - if
 230
 231                 // Load the file header
 232                 $this->readFileHeader();
 233
 234                 // Count all entries in file
 235                 $this->analyzeFile();
 236         }
 237 }
 238
 239 // [EOF]
 240 ?>