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+<?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 {
+}