gecko-dev/xpcom/io/FileUtilsWin.cpp

64 lines
1.9 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "FileUtilsWin.h"
#include <windows.h>
#include <psapi.h>
#include "nsWindowsHelpers.h"
namespace {
// Scoped type used by HandleToFilename
struct ScopedMappedViewTraits
{
typedef void* type;
static void* empty() { return nullptr; }
static void release(void* ptr) { UnmapViewOfFile(ptr); }
};
typedef mozilla::Scoped<ScopedMappedViewTraits> ScopedMappedView;
} // anonymous namespace
namespace mozilla {
bool
HandleToFilename(HANDLE aHandle, const LARGE_INTEGER& aOffset,
nsAString& aFilename)
{
aFilename.Truncate();
// This implementation is nice because it uses fully documented APIs that
// are available on all Windows versions that we support.
nsAutoHandle fileMapping(CreateFileMapping(aHandle, nullptr, PAGE_READONLY,
0, 1, nullptr));
if (!fileMapping) {
return false;
}
ScopedMappedView view(MapViewOfFile(fileMapping, FILE_MAP_READ,
aOffset.HighPart, aOffset.LowPart, 1));
if (!view) {
return false;
}
nsAutoString mappedFilename;
DWORD len = 0;
SetLastError(ERROR_SUCCESS);
do {
mappedFilename.SetLength(mappedFilename.Length() + MAX_PATH);
len = GetMappedFileNameW(GetCurrentProcess(), view,
wwc(mappedFilename.BeginWriting()),
mappedFilename.Length());
} while (!len && GetLastError() == ERROR_INSUFFICIENT_BUFFER);
if (!len) {
return false;
}
mappedFilename.Truncate(len);
return NtPathToDosPath(mappedFilename, aFilename);
}
} // namespace mozilla