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mongodb/util/mmap_win.cpp
2010-04-27 15:27:52 -04:00

120 lines
3.6 KiB
C++

// mmap_win.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 "pch.h"
#include "mmap.h"
#include <windows.h>
namespace mongo {
MemoryMappedFile::MemoryMappedFile() {
fd = 0;
maphandle = 0;
view = 0;
len = 0;
created();
}
void MemoryMappedFile::close() {
if ( view )
UnmapViewOfFile(view);
view = 0;
if ( maphandle )
CloseHandle(maphandle);
maphandle = 0;
if ( fd )
CloseHandle(fd);
fd = 0;
}
std::wstring toWideString(const char *s) {
std::basic_ostringstream<TCHAR> buf;
buf << s;
return buf.str();
}
unsigned mapped = 0;
void* MemoryMappedFile::map(const char *_filename, long &length, int options) {
/* big hack here: Babble uses db names with colons. doesn't seem to work on windows. temporary perhaps. */
char filename[256];
strncpy(filename, _filename, 255);
filename[255] = 0;
{
size_t len = strlen( filename );
for ( size_t i=len-1; i>=0; i-- ){
if ( filename[i] == '/' ||
filename[i] == '\\' )
break;
if ( filename[i] == ':' )
filename[i] = '_';
}
}
updateLength( filename, length );
std::wstring filenamew = toWideString(filename);
DWORD createOptions = FILE_ATTRIBUTE_NORMAL;
if ( options & SEQUENTIAL )
createOptions |= FILE_FLAG_SEQUENTIAL_SCAN;
fd = CreateFile(
filenamew.c_str(), GENERIC_WRITE | GENERIC_READ, FILE_SHARE_READ,
NULL, OPEN_ALWAYS, createOptions , NULL);
if ( fd == INVALID_HANDLE_VALUE ) {
out() << "Create/OpenFile failed " << filename << ' ' << GetLastError() << endl;
return 0;
}
mapped += length;
maphandle = CreateFileMapping(fd, NULL, PAGE_READWRITE, 0, length, NULL);
if ( maphandle == NULL ) {
out() << "CreateFileMapping failed " << filename << ' ' << GetLastError() << endl;
return 0;
}
view = MapViewOfFile(maphandle, FILE_MAP_ALL_ACCESS, 0, 0, 0);
if ( view == 0 ) {
out() << "MapViewOfFile failed " << filename << " " << errnoWithDescription() << " ";
out() << GetLastError();
out() << endl;
}
len = length;
return view;
}
void MemoryMappedFile::flush(bool sync) {
uassert(13056, "Async flushing not supported on windows", sync);
if (!view || !fd) return;
bool success = FlushViewOfFile(view, 0); // 0 means whole mapping
if (!success){
int err = GetLastError();
out() << "FlushViewOfFile failed " << err << endl;
}
success = FlushFileBuffers(fd);
if (!success){
int err = GetLastError();
out() << "FlushFileBuffers failed " << err << endl;
}
}
}