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         private 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          * Checks whether the file header is initialized
 121          *
 122          * @return      $isInitialized  Whether the file header is initialized
 123          */
 124         private function isFileHeaderInitialized () {
 125                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 126                 // Default is not initialized
 127                 $isInitialized = FALSE;
 128
 129                 // Is the file initialized?
 130                 if ($this->isFileInitialized()) {
 131                         // Some bytes has been written, so rewind to start of it.
 132                         $rewindStatus = $this->getIteratorInstance()->rewind();
 133                         //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] rewindStatus=%s', __METHOD__, __LINE__, $rewindStatus));
 134
 135                         // Is the rewind() call successfull?
 136                         if ($rewindStatus != 1) {
 137                                 // Something bad happened
 138                                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Could not rewind().', __METHOD__, __LINE__));
 139                         } // END - if
 140
 141                         // Read file header
 142                         $this->readFileHeader();
 143
 144                         // The above method does already check the header
 145                         $isInitialized = TRUE;
 146                 } // END - if
 147
 148                 // Return result
 149                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] isInitialized=%d - EXIT!', __METHOD__, __LINE__, intval($isInitialized)));
 150                 return $isInitialized;
 151         }
 152
 153         /**
 154          * Flushes the file header
 155          *
 156          * @return      void
 157          */
 158         private function flushFileHeader () {
 159                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 160
 161                 // Put all informations together
 162                 $header = sprintf('%s%s',
 163                         // Magic
 164                         self::INDEX_MAGIC,
 165
 166                         // Separator position<->entries
 167                         chr(self::SEPARATOR_HEADER_ENTRIES)
 168                 );
 169
 170                 // Write it to disk (header is always at seek position 0)
 171                 $this->writeData(0, $header);
 172
 173                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 174         }
 175
 176         /**
 177          * Analyzes entries in index file. This will count all found (and valid)
 178          * entries, mark invalid as damaged and count gaps ("fragmentation"). If
 179          * only gaps are found, the file is considered as "virgin" (no entries).
 180          *
 181          * @return      void
 182          */
 183         private function analyzeFile () {
 184                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 185
 186                 // Make sure the file is initialized
 187                 assert($this->isFileInitialized());
 188
 189                 // Init counters and gaps array
 190                 $this->initGapsArray();
 191
 192                 // Output message (as this may take some time)
 193                 self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Analyzing file structure ... (this may take some time)', __METHOD__, __LINE__));
 194
 195                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 196         }
 197
 198         /**
 199          * Initializes this index
 200          *
 201          * @param       $fileName       File name of this index
 202          * @return      void
 203          */
 204         protected function initIndex ($fileName) {
 205                 // Get a file i/o pointer instance for index file
 206                 $pointerInstance = ObjectFactory::createObjectByConfiguredName('file_raw_input_output_class', array($fileName));
 207
 208                 // Get iterator instance
 209                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_io_iterator_class', array($pointerInstance));
 210
 211                 // Is the instance implementing the right interface?
 212                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 213
 214                 // Set iterator here
 215                 $this->setIteratorInstance($iteratorInstance);
 216
 217                 // Is the file's header initialized?
 218                 if (!$this->isFileHeaderInitialized()) {
 219                         // No, then create it (which may pre-allocate the index)
 220                         $this->createFileHeader();
 221
 222                         // And pre-allocate a bit
 223                         $this->preAllocateFile('index');
 224                 } // END - if
 225
 226                 // Load the file header
 227                 $this->readFileHeader();
 228
 229                 // Count all entries in file
 230                 $this->analyzeFile();
 231         }
 232 }
 233
 234 // [EOF]
 235 ?>