1 files changed, 94 insertions, 0 deletions
diff --git a/util/mmap_posix.cpp b/util/mmap_posix.cpp
new file mode 100644
index 0000000..1237220
--- /dev/null
+++ b/util/mmap_posix.cpp
@@ -0,0 +1,94 @@
+// mmap_posix.cpp
+
+/*    Copyright 2009 10gen Inc.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#include "stdafx.h"
+#include "mmap.h"
+#include "file_allocator.h"
+
+#include <errno.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+namespace mongo {
+
+    MemoryMappedFile::MemoryMappedFile() {
+        fd = 0;
+        maphandle = 0;
+        view = 0;
+        len = 0;
+        created();
+    }
+
+    void MemoryMappedFile::close() {
+        if ( view )
+            munmap(view, len);
+        view = 0;
+
+        if ( fd )
+            ::close(fd);
+        fd = 0;
+    }
+
+#ifndef O_NOATIME
+#define O_NOATIME 0
+#endif
+
+    void* MemoryMappedFile::map(const char *filename, long &length) {
+        // length may be updated by callee.
+        theFileAllocator().allocateAsap( filename, length );
+        len = length;
+
+        massert( 10446 ,  (string)"mmap() can't map area of size 0 [" + filename + "]" , length > 0 );
+
+        
+        fd = open(filename, O_RDWR | O_NOATIME);
+        if ( fd <= 0 ) {
+            out() << "couldn't open " << filename << ' ' << OUTPUT_ERRNO << endl;
+            return 0;
+        }
+
+        off_t filelen = lseek(fd, 0, SEEK_END);
+        if ( filelen != length ){
+            cout << "wanted length: " << length << " filelen: " << filelen << endl;
+            cout << sizeof(size_t) << endl;
+            massert( 10447 ,  "file size allocation failed", filelen == length );
+        }
+        lseek( fd, 0, SEEK_SET );
+        
+        view = mmap(NULL, length, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+        if ( view == MAP_FAILED ) {
+            out() << "  mmap() failed for " << filename << " len:" << length << " " << OUTPUT_ERRNO << endl;
+            if ( errno == ENOMEM ){
+                out() << "     mmap failed with out of memory, if you're using 32-bits, then you probably need to upgrade to 64" << endl;
+            }
+            return 0;
+        }
+        return view;
+    }
+
+    void MemoryMappedFile::flush(bool sync) {
+        if ( view == 0 || fd == 0 )
+            return;
+        if ( msync(view, len, sync ? MS_SYNC : MS_ASYNC) )
+            problem() << "msync " << OUTPUT_ERRNO << endl;
+    }
+    
+
+} // namespace mongo
+