76 lines
2.1 KiB
C++
76 lines
2.1 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/. */
|
|
|
|
#ifndef mozilla_devtools_AutoMemMap_h
|
|
#define mozilla_devtools_AutoMemMap_h
|
|
|
|
#include <prio.h>
|
|
#include "mozilla/GuardObjects.h"
|
|
|
|
namespace mozilla {
|
|
namespace devtools {
|
|
|
|
// # AutoMemMap
|
|
//
|
|
// AutoMemMap is an RAII class to manage mapping a file to memory. It is a
|
|
// wrapper aorund managing opening and closing a file and calling PR_MemMap and
|
|
// PR_MemUnmap.
|
|
//
|
|
// Example usage:
|
|
//
|
|
// {
|
|
// AutoMemMap mm;
|
|
// if (NS_FAILED(mm.init("/path/to/desired/file"))) {
|
|
// // Handle the error however you see fit.
|
|
// return false;
|
|
// }
|
|
//
|
|
// doStuffWithMappedMemory(mm.address());
|
|
// }
|
|
// // The memory is automatically unmapped when the AutoMemMap leaves scope.
|
|
class MOZ_RAII AutoMemMap
|
|
{
|
|
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER;
|
|
|
|
PRFileInfo64 fileInfo;
|
|
PRFileDesc* fd;
|
|
PRFileMap* fileMap;
|
|
void* addr;
|
|
|
|
AutoMemMap(const AutoMemMap& aOther) = delete;
|
|
void operator=(const AutoMemMap& aOther) = delete;
|
|
|
|
public:
|
|
explicit AutoMemMap(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM)
|
|
: fd(nullptr)
|
|
, fileMap(nullptr)
|
|
, addr(nullptr)
|
|
{
|
|
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
|
|
};
|
|
~AutoMemMap();
|
|
|
|
// Initialize this AutoMemMap.
|
|
nsresult init(const char* filePath, int flags = PR_RDONLY, int mode = 0,
|
|
PRFileMapProtect prot = PR_PROT_READONLY);
|
|
|
|
// Get the size of the memory mapped file.
|
|
uint32_t size() const {
|
|
MOZ_ASSERT(fileInfo.size <= UINT32_MAX,
|
|
"Should only call size() if init() succeeded.");
|
|
return uint32_t(fileInfo.size);
|
|
}
|
|
|
|
// Get the mapped memory.
|
|
void* address() { MOZ_ASSERT(addr); return addr; }
|
|
const void* address() const { MOZ_ASSERT(addr); return addr; }
|
|
};
|
|
|
|
} // namespace devtools
|
|
} // namespace mozilla
|
|
|
|
#endif // mozilla_devtools_AutoMemMap_h
|