MediaWiki 1.30.2

[autoinstallsdev/mediawiki.git] / vendor / wikimedia / cdb / src / Reader.php

diff --git a/vendor/wikimedia/cdb/src/Reader.php b/vendor/wikimedia/cdb/src/Reader.php
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+++ b/vendor/wikimedia/cdb/src/Reader.php
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+<?php
+
+namespace Cdb;
+
+/**
+ * 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 Reader {
+       /**
+        * The file handle
+        */
+       protected $handle;
+
+       /**
+        * Open a file and return a subclass instance
+        *
+        * @param string $fileName
+        *
+        * @return Reader
+        */
+       public static function open( $fileName ) {
+               return self::haveExtension() ?
+                       new Reader\DBA( $fileName ) :
+                       new Reader\PHP( $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 );
+
+       /**
+        * Check whether key exists
+        *
+        * @param string $key
+        */
+       abstract public function exists( $key );
+
+       /**
+        * Fetch first key
+        */
+       abstract public function firstkey();
+
+       /**
+        * Fetch next key
+        */
+       abstract public function nextkey();
+}