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->headerSize);
  75                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Read %d bytes (%d wanted).', __METHOD__, __LINE__, strlen($data), $this->headerSize));
  76
  77                 // Have all requested bytes been read?
  78                 assert(strlen($data) == $this->headerSize);
  79                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  80
  81                 // Last character must be the separator
  82                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] data(-1)=%s', __METHOD__, __LINE__, dechex(ord(substr($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                 $this->header = explode(chr(self::SEPARATOR_HEADER_DATA), $data);
  99
 100                 // Check if the array has only 3 elements
 101                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] header(%d)=%s', __METHOD__, __LINE__, count($this->header), print_r($this->header, TRUE)));
 102                 assert(count($this->header) == 2);
 103                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 104
 105                 // Check magic
 106                 assert($this->header[0] == self::INDEX_MAGIC);
 107                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 108
 109                 // Check length of count
 110                 assert(strlen($this->header[1]) == self::LENGTH_COUNT);
 111                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 112
 113                 // Decode count
 114                 $this->header[1] = hex2bin($this->header[1]);
 115
 116                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 117         }
 118
 119         /**
 120          * Flushes the file header
 121          *
 122          * @return      void
 123          */
 124         private function flushFileHeader () {
 125                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 126
 127                 // Put all informations together
 128                 $header = sprintf('%s%s',
 129                         // Magic
 130                         self::INDEX_MAGIC,
 131
 132                         // Separator position<->entries
 133                         chr(self::SEPARATOR_HEADER_ENTRIES)
 134                 );
 135
 136                 // Write it to disk (header is always at seek position 0)
 137                 $this->writeData(0, $header);
 138
 139                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 140         }
 141
 142         /**
 143          * Analyzes entries in index file. This will count all found (and valid)
 144          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
 145          * only gaps are found, the file is considered as "virgin" (no entries).
 146          *
 147          * @return      void
 148          */
 149         private function analyzeFile () {
 150                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 151
 152                 // Make sure the file is initialized
 153                 assert($this->isFileInitialized());
 154
 155                 // Init counters and gaps array
 156                 $this->initGapsArray();
 157
 158                 // Output message (as this may take some time)
 159                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Analyzing file structure ... (this may take some time)', __METHOD__, __LINE__));
 160
 161                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 162         }
 163
 164         /**
 165          * Initializes this index
 166          *
 167          * @param       $fileName       File name of this index
 168          * @return      void
 169          */
 170         protected function initIndex ($fileName) {
 171                 // Get a file i/o pointer instance for index file
 172                 $pointerInstance = ObjectFactory::createObjectByConfiguredName('file_raw_input_output_class', array($fileName));
 173
 174                 // Get iterator instance
 175                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_io_iterator_class', array($pointerInstance));
 176
 177                 // Is the instance implementing the right interface?
 178                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 179
 180                 // Set iterator here
 181                 $this->setIteratorInstance($iteratorInstance);
 182
 183                 // Is the file's header initialized?
 184                 if (!$this->isFileHeaderInitialized()) {
 185                         // No, then create it (which may pre-allocate the index)
 186                         $this->createFileHeader();
 187
 188                         // And pre-allocate a bit
 189                         $this->preAllocateFile('index');
 190                 } // END - if
 191
 192                 // Load the file header
 193                 $this->readFileHeader();
 194
 195                 // Count all entries in file
 196                 $this->analyzeFile();
 197         }
 198 }
 199
 200 // [EOF]
 201 ?>