inc/main/classes/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 - 2017 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 group->hash
  32          */
  33         const SEPARATOR_GROUP_HASH = 0x01;
  34
  35         /**
  36          * Separator hash->gap position
  37          */
  38         const SEPARATOR_HASH_GAP_POSITION = 0x02;
  39
  40         /**
  41          * Separator gap position->length
  42          */
  43         const SEPARATOR_GAP_LENGTH = 0x03;
  44
  45         /**
  46          * Protected constructor
  47          *
  48          * @param       $className      Name of the class
  49          * @return      void
  50          */
  51         protected function __construct ($className) {
  52                 // Call parent constructor
  53                 parent::__construct($className);
  54         }
  55
  56         /**
  57          * Reads the file header
  58          *
  59          * @return      void
  60          */
  61         public function readFileHeader () {
  62                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
  63
  64                 // First rewind to beginning as the header sits at the beginning ...
  65                 $this->getIteratorInstance()->rewind();
  66
  67                 // Then read it (see constructor for calculation)
  68                 $data = $this->getIteratorInstance()->read($this->getIteratorInstance()->getHeaderSize());
  69                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Read %d bytes (%d wanted).', __METHOD__, __LINE__, strlen($data), $this->getIteratorInstance()->getHeaderSize()));
  70
  71                 // Have all requested bytes been read?
  72                 assert(strlen($data) == $this->getIteratorInstance()->getHeaderSize());
  73                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  74
  75                 // Last character must be the separator
  76                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] data(-1)=%s', __METHOD__, __LINE__, dechex(ord(substr($data, -1, 1)))));
  77                 assert(substr($data, -1, 1) == chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES));
  78                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
  79
  80                 // Okay, then remove it
  81                 $data = substr($data, 0, -1);
  82
  83                 // And update seek position
  84                 $this->getIteratorInstance()->updateSeekPosition();
  85
  86                 /*
  87                  * Now split it:
  88                  *
  89                  * 0 => magic
  90                  * 1 => total entries
  91                  */
  92                 $header = explode(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA), $data);
  93
  94                 // Set it here
  95                 $this->getIteratorInstance()->setHeader($header);
  96
  97                 // Check if the array has only 3 elements
  98                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] header(%d)=%s', __METHOD__, __LINE__, count($header), print_r($header, TRUE)));
  99                 assert(count($header) == 2);
 100                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 101
 102                 // Check magic
 103                 assert($header[0] == self::INDEX_MAGIC);
 104                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 105
 106                 // Check length of count
 107                 assert(strlen($header[1]) == BaseBinaryFile::LENGTH_COUNT);
 108                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] Passed assert().', __METHOD__, __LINE__));
 109
 110                 // Decode count
 111                 $header[1] = hex2bin($header[1]);
 112
 113                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 114         }
 115
 116         /**
 117          * Flushes the file header
 118          *
 119          * @return      void
 120          */
 121         public function flushFileHeader () {
 122                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] CALLED!', __METHOD__, __LINE__));
 123
 124                 // Put all informations together
 125                 $header = sprintf('%s%s%s%s',
 126                         // Magic
 127                         self::INDEX_MAGIC,
 128
 129                         // Separator header data
 130                         chr(BaseBinaryFile::SEPARATOR_HEADER_DATA),
 131
 132                         // Total entries
 133                         str_pad($this->dec2hex($this->getIteratorInstance()->getCounter()), BaseBinaryFile::LENGTH_COUNT, '0', STR_PAD_LEFT),
 134
 135                         // Separator header<->entries
 136                         chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES)
 137                 );
 138
 139                 // Write it to disk (header is always at seek position 0)
 140                 $this->getIteratorInstance()->writeData(0, $header, FALSE);
 141
 142                 //* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] EXIT!', __METHOD__, __LINE__));
 143         }
 144
 145         /**
 146          * Initializes this index
 147          *
 148          * @param       $fileName       File name of this index
 149          * @return      void
 150          * @todo        Currently the index file is not cached, please implement a memory-handling class and if enough RAM is found, cache the whole index file.
 151          */
 152         protected function initIndex ($fileName) {
 153                 // Append index file extension
 154                 $fileName .= $this->getConfigInstance()->getConfigEntry('index_extension');
 155
 156                 // Get a file i/o pointer instance for index file
 157                 $fileInstance = ObjectFactory::createObjectByConfiguredName('index_file_class', array($fileName, $this));
 158
 159                 // Get iterator instance
 160                 $iteratorInstance = ObjectFactory::createObjectByConfiguredName('file_iterator_class', array($fileInstance));
 161
 162                 // Is the instance implementing the right interface?
 163                 assert($iteratorInstance instanceof SeekableWritableFileIterator);
 164
 165                 // Set iterator here
 166                 $this->setIteratorInstance($iteratorInstance);
 167
 168                 // Calculate header size
 169                 $this->getIteratorInstance()->setHeaderSize(
 170                         strlen(self::INDEX_MAGIC) +
 171                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_DATA)) +
 172                         BaseBinaryFile::LENGTH_COUNT +
 173                         strlen(chr(BaseBinaryFile::SEPARATOR_HEADER_ENTRIES))
 174                 );
 175
 176                 // Init counters and gaps array
 177                 $this->getIteratorInstance()->initCountersGapsArray();
 178
 179                 // Is the file's header initialized?
 180                 if (!$this->getIteratorInstance()->isFileHeaderInitialized()) {
 181                         // No, then create it (which may pre-allocate the index)
 182                         $this->getIteratorInstance()->createFileHeader();
 183
 184                         // And pre-allocate a bit
 185                         $this->getIteratorInstance()->preAllocateFile('index');
 186                 } // END - if
 187
 188                 // Load the file header
 189                 $this->readFileHeader();
 190
 191                 // Count all entries in file
 192                 $this->getIteratorInstance()->analyzeFile();
 193         }
 194
 195         /**
 196          * Calculates minimum length for one entry/block
 197          *
 198          * @return      $length         Minimum length for one entry/block
 199          */
 200         public function calculateMinimumBlockLength () {
 201                 // Calulcate it
 202                 $length = BaseBinaryFile::LENGTH_TYPE + strlen(chr(BaseBinaryFile::SEPARATOR_TYPE_POSITION)) + BaseBinaryFile::LENGTH_POSITION + strlen(chr(BaseBinaryFile::SEPARATOR_ENTRIES));
 203
 204                 // Return it
 205                 return $length;
 206         }
 207
 208         /**
 209          * Determines whether the EOF has been reached
 210          *
 211          * @return      $isEndOfFileReached             Whether the EOF has been reached
 212          * @throws      UnsupportedOperationException   If this method is called
 213          */
 214         public function isEndOfFileReached () {
 215                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 216         }
 217
 218         /**
 219          * Getter for file name
 220          *
 221          * @return      $fileName       The current file name
 222          * @throws      UnsupportedOperationException   If this method is called
 223          */
 224         public function getFileName () {
 225                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 226         }
 227
 228         /**
 229          * Initializes counter for valid entries, arrays for damaged entries and
 230          * an array for gap seek positions. If you call this method on your own,
 231          * please re-analyze the file structure. So you are better to call
 232          * analyzeFile() instead of this method.
 233          *
 234          * @return      void
 235          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 236          */
 237         public function initCountersGapsArray () {
 238                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 239         }
 240
 241         /**
 242          * Getter for header size
 243          *
 244          * @return      $totalEntries   Size of file header
 245          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 246          */
 247         public final function getHeaderSize () {
 248                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 249         }
 250
 251         /**
 252          * Setter for header size
 253          *
 254          * @param       $headerSize             Size of file header
 255          * @return      void
 256          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 257          */
 258         public final function setHeaderSize ($headerSize) {
 259                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 260         }
 261
 262         /**
 263          * Getter for header array
 264          *
 265          * @return      $totalEntries   Size of file header
 266          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 267          */
 268         public final function getHeader () {
 269                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 270         }
 271
 272         /**
 273          * Setter for header
 274          *
 275          * @param       $header         Array for a file header
 276          * @return      void
 277          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 278          */
 279         public final function setHeader (array $header) {
 280                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 281         }
 282
 283         /**
 284          * Updates seekPosition attribute from file to avoid to much access on file.
 285          *
 286          * @return      void
 287          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 288          */
 289         public function updateSeekPosition () {
 290                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 291         }
 292
 293         /**
 294          * Getter for total entries
 295          *
 296          * @return      $totalEntries   Total entries in this file
 297          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 298          */
 299         public final function getCounter () {
 300                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 301         }
 302
 303         /**
 304          * "Getter" for file size
 305          *
 306          * @return      $fileSize       Size of currently loaded file
 307          */
 308         public function getFileSize () {
 309                 // Call iterator's method
 310                 return $this->getIteratorInstance()->getFileSize();
 311         }
 312
 313         /**
 314          * Writes data at given position
 315          *
 316          * @param       $seekPosition   Seek position
 317          * @param       $data                   Data to be written
 318          * @param       $flushHeader    Whether to flush the header (default: flush)
 319          * @return      void
 320          * @throws      UnsupportedOperationException   This method is not (and maybe never will be) supported
 321          */
 322         public function writeData ($seekPosition, $data, $flushHeader = TRUE) {
 323                 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput(sprintf('[%s:%d:] seekPosition=%s,data[]=%s,flushHeader=%d', __METHOD__, __LINE__, $seekPosition, gettype($data), intval($flushHeader)));
 324                 throw new UnsupportedOperationException(array($this, __FUNCTION__, $this->getIteratorInstance()->getPointerInstance()), self::EXCEPTION_UNSPPORTED_OPERATION);
 325         }
 326
 327         /**
 328          * Writes given value to the file and returns a hash and gap position for it
 329          *
 330          * @param       $groupId        Group identifier
 331          * @param       $value          Value to be added to the stack
 332          * @return      $data           Hash and gap position
 333          * @throws      UnsupportedOperationException   If this method is called
 334          */
 335         public function writeValueToFile ($groupId, $value) {
 336                 self::createDebugInstance(__CLASS__)->debugOutput('[' . __METHOD__ . ':' . __LINE__ . '] groupId=' . $groupId . ',value[' . gettype($value) . ']=' . print_r($value, TRUE));
 337                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 338         }
 339
 340         /**
 341          * Writes given raw data to the file and returns a gap position and length
 342          *
 343          * @param       $groupId        Group identifier
 344          * @param       $hash           Hash from encoded value
 345          * @param       $encoded        Encoded value to be written to the file
 346          * @return      $data           Gap position and length of the raw data
 347          */
 348         public function writeDataToFreeGap ($groupId, $hash, $encoded) {
 349                 self::createDebugInstance(__CLASS__)->debugOutput('[' . __METHOD__ . ':' . __LINE__ . '] groupId=' . $groupId . ',hash=' . $hash . ',encoded()=' . strlen($encoded));
 350                 throw new UnsupportedOperationException(array($this, __FUNCTION__), self::EXCEPTION_UNSPPORTED_OPERATION);
 351         }
 352 }
 353
 354 // [EOF]
 355 ?>