option to use main memory instead of memory mapped files

really only for testing
though i guess is kind of cool if you want to use the db purely for an in memory cache
scons --mm to build

SConstruct

@@ -32,6 +32,15 @@ AddOption( "--32",
            action="store",
            help="whether to force 32 bit" )
 
+
+AddOption( "--mm",
+           dest="mm",
+           type="string",
+           nargs=0,
+           action="store",
+           help="use main memory instead of memory mapped files" )
+
+
 AddOption( "--release",
            dest="release",
            type="string",
@@ -73,7 +82,9 @@ commonFiles += Split( "client/connpool.cpp client/dbclient.cpp client/model.cpp"
 
 #mmap stuff
 
-if os.sys.platform == "win32":
+if GetOption( "mm" ) != None:
+    commonFiles += [ "util/mmap_mm.cpp" ]
+elif os.sys.platform == "win32":
     commonFiles += [ "util/mmap_win.cpp" ]
 else:
     commonFiles += [ "util/mmap_posix.cpp" ]

util/mmap_mm.cpp

@@ -0,0 +1,50 @@
+// mmap_mm.cpp
+
+/**
+ *    Copyright (C) 2008 10gen Inc.
+ *
+ *    This program is free software: you can redistribute it and/or  modify
+ *    it under the terms of the GNU Affero General Public License, version 3,
+ *    as published by the Free Software Foundation.
+ *
+ *    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 Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "stdafx.h"
+#include "mmap.h"
+
+namespace mongo {
+
+    MemoryMappedFile::MemoryMappedFile() {
+        fd = 0;
+        maphandle = 0;
+        view = 0;
+        len = 0;
+    }
+
+    void MemoryMappedFile::close() {
+        if ( view )
+            delete( view );
+        view = 0;
+        len = 0;
+    }
+
+    void* MemoryMappedFile::map(const char *filename, int length) {
+        path p( filename );
+
+        view = malloc( length );
+        return view;
+    }
+
+    void MemoryMappedFile::flush(bool sync) {
+    }
+    
+
+} 
+