update to MediaWiki 1.16.0

1 files changed, 374 insertions, 0 deletions

diff --git a/includes/Cdb_PHP.php b/includes/Cdb_PHP.php
new file mode 100644
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--- /dev/null
+++ b/includes/Cdb_PHP.php
@@ -0,0 +1,374 @@
+<?php
+
+/**
+ * This is a port of D.J. Bernstein's CDB to PHP. It's based on the copy that 
+ * appears in PHP 5.3. Changes are:
+ *    * Error returns replaced with exceptions
+ *    * Exception thrown if sizes or offsets are between 2GB and 4GB
+ *    * Some variables renamed
+ */
+
+/**
+ * Common functions for readers and writers
+ */
+class CdbFunctions {
+	/**
+	 * Take a modulo of a signed integer as if it were an unsigned integer.
+	 * $b must be less than 0x40000000 and greater than 0
+	 */
+	public static function unsignedMod( $a, $b ) {
+		if ( $a & 0x80000000 ) {
+			$m = ( $a & 0x7fffffff ) % $b + 2 * ( 0x40000000 % $b );
+			return $m % $b;
+		} else {
+			return $a % $b;
+		}
+	}
+	
+	/**
+	 * Shift a signed integer right as if it were unsigned
+	 */
+	public static function unsignedShiftRight( $a, $b ) {
+		if ( $b == 0 ) {
+			return $a;
+		}
+		if ( $a & 0x80000000 ) {
+			return ( ( $a & 0x7fffffff ) >> $b ) | ( 0x40000000 >> ( $b - 1 ) );
+		} else {
+			return $a >> $b;
+		}
+	}
+
+	/**
+	 * The CDB hash function.
+	 */
+	public static function hash( $s ) {
+		$h = 5381;
+		for ( $i = 0; $i < strlen( $s ); $i++ ) {
+			$h5 = ($h << 5) & 0xffffffff;
+			// Do a 32-bit sum
+			// Inlined here for speed
+			$sum = ($h & 0x3fffffff) + ($h5 & 0x3fffffff);
+			$h = 
+				(
+					( $sum & 0x40000000 ? 1 : 0 )
+					+ ( $h & 0x80000000 ? 2 : 0 )
+					+ ( $h & 0x40000000 ? 1 : 0 )
+					+ ( $h5 & 0x80000000 ? 2 : 0 )
+					+ ( $h5 & 0x40000000 ? 1 : 0 )
+				) << 30
+				| ( $sum & 0x3fffffff );
+			$h ^= ord( $s[$i] );
+			$h &= 0xffffffff;
+		}
+		return $h;
+	}
+}
+
+/**
+ * CDB reader class
+ */
+class CdbReader_PHP extends CdbReader {
+	/** The file handle */
+	var $handle;
+
+	/* number of hash slots searched under this key */
+	var $loop;
+
+	/* initialized if loop is nonzero */
+	var $khash;
+
+	/* initialized if loop is nonzero */
+	var $kpos;
+
+	/* initialized if loop is nonzero */
+	var $hpos;
+
+	/* initialized if loop is nonzero */
+	var $hslots;
+
+	/* initialized if findNext() returns true */
+	var $dpos;
+
+	/* initialized if cdb_findnext() returns 1 */
+	var $dlen; 
+
+	function __construct( $fileName ) {
+		$this->handle = fopen( $fileName, 'rb' );
+		if ( !$this->handle ) {
+			throw new MWException( 'Unable to open DB file "' . $fileName . '"' );
+		}
+		$this->findStart();
+	}
+
+	function close() {
+		if( isset($this->handle) )
+			fclose( $this->handle );
+		unset( $this->handle );
+	}
+
+	public function get( $key ) {
+		// strval is required
+		if ( $this->find( strval( $key ) ) ) {
+			return $this->read( $this->dlen, $this->dpos );
+		} else {
+			return false;
+		}
+	}
+
+	protected function match( $key, $pos ) {
+		$buf = $this->read( strlen( $key ), $pos );
+		return $buf === $key;
+	}
+
+	protected function findStart() {
+		$this->loop = 0;
+	}
+
+	protected function read( $length, $pos ) {
+		if ( fseek( $this->handle, $pos ) == -1 ) {
+			// This can easily happen if the internal pointers are incorrect
+			throw new MWException( __METHOD__.': seek failed, file may be corrupted.' );
+		}
+
+		if ( $length == 0 ) {
+			return '';
+		}
+
+		$buf = fread( $this->handle, $length );
+		if ( $buf === false || strlen( $buf ) !== $length ) {
+			throw new MWException( __METHOD__.': read from cdb file failed, file may be corrupted' );
+		}
+		return $buf;
+	}
+
+	/**
+	 * Unpack an unsigned integer and throw an exception if it needs more than 31 bits
+	 */
+	protected function unpack31( $s ) {
+		$data = unpack( 'V', $s );
+		if ( $data[1] > 0x7fffffff ) {
+			throw new MWException( __METHOD__.': error in CDB file, integer too big' );
+		}
+		return $data[1];
+	}
+
+	/**
+	 * Unpack a 32-bit signed integer
+	 */
+	protected function unpackSigned( $s ) {
+		$data = unpack( 'va/vb', $s );
+		return $data['a'] | ( $data['b'] << 16 );
+	}
+
+	protected function findNext( $key ) {
+		if ( !$this->loop ) {
+			$u = CdbFunctions::hash( $key );
+			$buf = $this->read( 8, ( $u << 3 ) & 2047 );
+			$this->hslots = $this->unpack31( substr( $buf, 4 ) );
+			if ( !$this->hslots ) {
+				return false;
+			}
+			$this->hpos = $this->unpack31( substr( $buf, 0, 4 ) );
+			$this->khash = $u;
+			$u = CdbFunctions::unsignedShiftRight( $u, 8 );
+			$u = CdbFunctions::unsignedMod( $u, $this->hslots );
+			$u <<= 3;
+			$this->kpos = $this->hpos + $u;
+		}
+
+		while ( $this->loop < $this->hslots ) {
+			$buf = $this->read( 8, $this->kpos );
+			$pos = $this->unpack31( substr( $buf, 4 ) );
+			if ( !$pos ) {
+				return false;
+			}
+			$this->loop += 1;
+			$this->kpos += 8;
+			if ( $this->kpos == $this->hpos + ( $this->hslots << 3 ) ) {
+				$this->kpos = $this->hpos;
+			}
+			$u = $this->unpackSigned( substr( $buf, 0, 4 ) );
+			if ( $u === $this->khash ) {
+				$buf = $this->read( 8, $pos );
+				$keyLen = $this->unpack31( substr( $buf, 0, 4 ) );
+				if ( $keyLen == strlen( $key ) && $this->match( $key, $pos + 8 ) ) {
+					// Found
+					$this->dlen = $this->unpack31( substr( $buf, 4 ) );
+					$this->dpos = $pos + 8 + $keyLen;
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+
+	protected function find( $key ) {
+		$this->findStart();
+		return $this->findNext( $key );
+	}
+}
+
+/**
+ * CDB writer class
+ */
+class CdbWriter_PHP extends CdbWriter {
+	var $handle, $realFileName, $tmpFileName;
+
+	var $hplist;
+	var $numEntries, $pos;
+
+	function __construct( $fileName ) {
+		$this->realFileName = $fileName;
+		$this->tmpFileName = $fileName . '.tmp.' . mt_rand( 0, 0x7fffffff );
+		$this->handle = fopen( $this->tmpFileName, 'wb' );
+		if ( !$this->handle ) {
+			throw new MWException( 'Unable to open DB file for write "' . $fileName . '"' );
+		}
+		$this->hplist = array();
+		$this->numentries = 0;
+		$this->pos = 2048; // leaving space for the pointer array, 256 * 8
+		if ( fseek( $this->handle, $this->pos ) == -1 ) {
+			throw new MWException( __METHOD__.': fseek failed' );
+		}
+	}
+
+	function __destruct() {
+		if ( isset( $this->handle ) ) {
+			$this->close();
+		}
+	}
+
+	public function set( $key, $value ) {
+		if ( strval( $key ) === '' ) {
+			// DBA cross-check hack
+			return;
+		}
+		$this->addbegin( strlen( $key ), strlen( $value ) );
+		$this->write( $key );
+		$this->write( $value );
+		$this->addend( strlen( $key ), strlen( $value ), CdbFunctions::hash( $key ) );
+	}
+
+	public function close() {
+		$this->finish();
+		if( isset($this->handle) )
+			fclose( $this->handle );
+		if ( wfIsWindows() && file_exists($this->realFileName) ) {
+			unlink( $this->realFileName );
+		}
+		if ( !rename( $this->tmpFileName, $this->realFileName ) ) {
+			throw new MWException( 'Unable to move the new CDB file into place.' );
+		}
+		unset( $this->handle );
+	}
+
+	protected function write( $buf ) {
+		$len = fwrite( $this->handle, $buf );
+		if ( $len !== strlen( $buf ) ) {
+			throw new MWException( 'Error writing to CDB file.' );
+		}
+	}
+
+	protected function posplus( $len ) {
+		$newpos = $this->pos + $len;
+		if ( $newpos > 0x7fffffff ) {
+			throw new MWException( 'A value in the CDB file is too large' );
+		}
+		$this->pos = $newpos;
+	}
+
+	protected function addend( $keylen, $datalen, $h ) {
+		$this->hplist[] = array(
+			'h' => $h,
+			'p' => $this->pos
+		);
+
+		$this->numentries++;
+		$this->posplus( 8 );
+		$this->posplus( $keylen );
+		$this->posplus( $datalen );
+	}
+
+	protected function addbegin( $keylen, $datalen ) {
+		if ( $keylen > 0x7fffffff ) {
+			throw new MWException( __METHOD__.': key length too long' );
+		}
+		if ( $datalen > 0x7fffffff ) {
+			throw new MWException( __METHOD__.': data length too long' );
+		}
+		$buf = pack( 'VV', $keylen, $datalen );
+		$this->write( $buf );
+	}
+
+	protected function finish() {
+		// Hack for DBA cross-check
+		$this->hplist = array_reverse( $this->hplist );
+
+		// Calculate the number of items that will be in each hashtable
+		$counts = array_fill( 0, 256, 0 );
+		foreach ( $this->hplist as $item ) {
+			++ $counts[ 255 & $item['h'] ];
+		}
+
+		// Fill in $starts with the *end* indexes
+		$starts = array();
+		$pos = 0;
+		for ( $i = 0; $i < 256; ++$i ) {
+			$pos += $counts[$i];
+			$starts[$i] = $pos;
+		}
+
+		// Excessively clever and indulgent code to simultaneously fill $packedTables
+		// with the packed hashtables, and adjust the elements of $starts 
+		// to actually point to the starts instead of the ends.
+		$packedTables = array_fill( 0, $this->numentries, false );
+		foreach ( $this->hplist as $item ) {
+			$packedTables[--$starts[255 & $item['h']]] = $item;
+		}
+
+		$final = '';
+		for ( $i = 0; $i < 256; ++$i ) {
+			$count = $counts[$i];
+
+			// The size of the hashtable will be double the item count.
+			// The rest of the slots will be empty.
+			$len = $count + $count;
+			$final .= pack( 'VV', $this->pos, $len );
+
+			$hashtable = array();
+			for ( $u = 0; $u < $len; ++$u ) {
+				$hashtable[$u] = array( 'h' => 0, 'p' => 0 );
+			}
+
+			// Fill the hashtable, using the next empty slot if the hashed slot
+			// is taken.
+			for ( $u = 0; $u < $count; ++$u ) {
+				$hp = $packedTables[$starts[$i] + $u];
+				$where = CdbFunctions::unsignedMod( 
+					CdbFunctions::unsignedShiftRight( $hp['h'], 8 ), $len );
+				while ( $hashtable[$where]['p'] )
+					if ( ++$where == $len )
+						$where = 0;
+				$hashtable[$where] = $hp;
+			}
+
+			// Write the hashtable
+			for ( $u = 0; $u < $len; ++$u ) {
+				$buf = pack( 'vvV', 
+					$hashtable[$u]['h'] & 0xffff,
+					CdbFunctions::unsignedShiftRight( $hashtable[$u]['h'], 16 ),
+					$hashtable[$u]['p'] );
+				$this->write( $buf );
+				$this->posplus( 8 );
+			}
+		}
+
+		// Write the pointer array at the start of the file
+		rewind( $this->handle );
+		if ( ftell( $this->handle ) != 0 ) {
+			throw new MWException( __METHOD__.': Error rewinding to start of file' );
+		}
+		$this->write( $final );
+	}
+}