1 files changed, 100 insertions, 0 deletions
diff --git a/indexlib/mmap_manager.cpp b/indexlib/mmap_manager.cpp
new file mode 100644
index 00000000..58ebd47e
--- /dev/null
+++ b/indexlib/mmap_manager.cpp
@@ -0,0 +1,100 @@
+
+/* This file is part of indexlib.
+ * Copyright (C) 2005 Luís Pedro Coelho <luis@luispedro.org>
+ *
+ * Indexlib is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation and available as file
+ * GPL_V2 which is distributed along with indexlib.
+ * 
+ * Indexlib 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
+ * 
+ * In addition, as a special exception, the copyright holders give
+ * permission to link the code of this program with any edition of
+ * the Qt library by Trolltech AS, Norway (or with modified versions
+ * of Qt that use the same license as Qt), and distribute linked
+ * combinations including the two.  You must obey the GNU General
+ * Public License in all respects for all of the code used other than
+ * Qt.  If you modify this file, you may extend this exception to
+ * your version of the file, but you are not obligated to do so.  If
+ * you do not wish to do so, delete this exception statement from
+ * your version.
+ */
+
+#include "mmap_manager.h"
+#include "logfile.h"
+#include "exception.h"
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <strings.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <cstring>
+#include "format.h"
+
+using indexlib::detail::errno_error;
+
+mmap_manager::mmap_manager( std::string filename )
+	:filename_( filename ),
+	 pagesize_( ( size_t )sysconf( _SC_PAGESIZE ) ),
+	 base_( 0 ),
+	 size_( 0 )
+{
+	fd_ = open( filename.c_str(), O_RDWR | O_CREAT, 0644 );
+	logfile() << format( "open( %s, O_RDWR) returned %s\n" ) % filename % fd_;
+	if ( fd_ > 0 ) {
+		struct stat st;
+		if ( fstat( fd_, &st ) == -1 ) {
+			throw errno_error( "stat()" );
+		}
+		if ( st.st_size ) map( st.st_size );
+	} else {
+		fd_ = open( filename.c_str(), O_RDWR );
+		if ( !fd_ ) throw errno_error( "open()" );
+	}
+
+}
+
+mmap_manager::~mmap_manager()
+{
+	unmap();
+	close( fd_ );
+}
+
+void mmap_manager::resize( unsigned ns ) {
+	if ( size() >= ns ) return;
+	unsigned old_size = size();
+	unmap();
+	ns = ( ns / pagesize_ + bool( ns % pagesize_ ) ) * pagesize_;
+	ftruncate( fd_, ns );
+	map( ns );
+	logfile() << format( "Going to bzero from %s to %s)\n" ) % old_size % size();
+	memset( rw_base( old_size ), 0, size() - old_size );
+}
+
+void mmap_manager::unmap() {
+	if ( !base_ ) return;
+	if ( munmap( base_, size_ ) == -1 ) {
+		throw errno_error( "munmap()" ); // This should be BUG
+	}
+	base_ = 0;
+	size_ = 0;
+}
+
+void mmap_manager::map( unsigned size ) {
+	base_ = mmap( 0, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd_, 0 );
+	if ( base_ == reinterpret_cast<void*>( -1 ) ) {
+		throw errno_error( "mmap()" );
+	}
+	size_ = size;
+}
+