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Diffstat (limited to 'includes/utils/Cdb.php')
-rw-r--r-- | includes/utils/Cdb.php | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/includes/utils/Cdb.php b/includes/utils/Cdb.php new file mode 100644 index 00000000..3ceb620f --- /dev/null +++ b/includes/utils/Cdb.php @@ -0,0 +1,163 @@ +<?php +/** + * Native CDB file reader and writer. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * http://www.gnu.org/copyleft/gpl.html + * + * @file + */ + +/** + * Read from a CDB file. + * Native and pure PHP implementations are provided. + * http://cr.yp.to/cdb.html + */ +abstract class CdbReader { + /** + * The file handle + */ + protected $handle; + + /** + * Open a file and return a subclass instance + * + * @param string $fileName + * + * @return CdbReader + */ + public static function open( $fileName ) { + return self::haveExtension() ? + new CdbReaderDBA( $fileName ) : + new CdbReaderPHP( $fileName ); + } + + /** + * Returns true if the native extension is available + * + * @return bool + */ + public static function haveExtension() { + if ( !function_exists( 'dba_handlers' ) ) { + return false; + } + $handlers = dba_handlers(); + if ( !in_array( 'cdb', $handlers ) || !in_array( 'cdb_make', $handlers ) ) { + return false; + } + + return true; + } + + /** + * Create the object and open the file + * + * @param string $fileName + */ + abstract public function __construct( $fileName ); + + /** + * Close the file. Optional, you can just let the variable go out of scope. + */ + abstract public function close(); + + /** + * Get a value with a given key. Only string values are supported. + * + * @param string $key + */ + abstract public function get( $key ); +} + +/** + * Write to a CDB file. + * Native and pure PHP implementations are provided. + */ +abstract class CdbWriter { + /** + * The file handle + */ + protected $handle; + + /** + * File we'll be writing to when we're done + * @var string + */ + protected $realFileName; + + /** + * File we write to temporarily until we're done + * @var string + */ + protected $tmpFileName; + + /** + * Open a writer and return a subclass instance. + * The user must have write access to the directory, for temporary file creation. + * + * @param string $fileName + * + * @return CdbWriterDBA|CdbWriterPHP + */ + public static function open( $fileName ) { + return CdbReader::haveExtension() ? + new CdbWriterDBA( $fileName ) : + new CdbWriterPHP( $fileName ); + } + + /** + * Create the object and open the file + * + * @param string $fileName + */ + abstract public function __construct( $fileName ); + + /** + * Set a key to a given value. The value will be converted to string. + * @param string $key + * @param string $value + */ + abstract public function set( $key, $value ); + + /** + * Close the writer object. You should call this function before the object + * goes out of scope, to write out the final hashtables. + */ + abstract public function close(); + + /** + * If the object goes out of scope, close it for sanity + */ + public function __destruct() { + if ( isset( $this->handle ) ) { + $this->close(); + } + } + + /** + * Are we running on Windows? + * @return bool + */ + protected function isWindows() { + return substr( php_uname(), 0, 7 ) == 'Windows'; + } +} + +/** + * Exception for Cdb errors. + * This explicitly doesn't subclass MWException to encourage reuse. + */ +class CdbException extends Exception { +} |