Mypal/dom/heapsnapshot/AutoMemMap.cpp

64 lines
1.5 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "mozilla/devtools/AutoMemMap.h"
#include "mozilla/Unused.h"
#include "nsDebug.h"
namespace mozilla {
namespace devtools {
AutoMemMap::~AutoMemMap()
{
if (addr) {
Unused << NS_WARN_IF(PR_MemUnmap(addr, size()) != PR_SUCCESS);
addr = nullptr;
}
if (fileMap) {
Unused << NS_WARN_IF(PR_CloseFileMap(fileMap) != PR_SUCCESS);
fileMap = nullptr;
}
if (fd) {
Unused << NS_WARN_IF(PR_Close(fd) != PR_SUCCESS);
fd = nullptr;
}
}
nsresult
AutoMemMap::init(const char* filePath, int flags, int mode, PRFileMapProtect prot)
{
MOZ_ASSERT(!fd);
MOZ_ASSERT(!fileMap);
MOZ_ASSERT(!addr);
if (PR_GetFileInfo64(filePath, &fileInfo) != PR_SUCCESS)
return NS_ERROR_FILE_NOT_FOUND;
// Check if the file is too big to memmap.
if (fileInfo.size > int64_t(UINT32_MAX))
return NS_ERROR_INVALID_ARG;
auto length = uint32_t(fileInfo.size);
fd = PR_Open(filePath, flags, flags);
if (!fd)
return NS_ERROR_UNEXPECTED;
fileMap = PR_CreateFileMap(fd, fileInfo.size, prot);
if (!fileMap)
return NS_ERROR_UNEXPECTED;
addr = PR_MemMap(fileMap, 0, length);
if (!addr)
return NS_ERROR_UNEXPECTED;
return NS_OK;
}
} // namespace devtools
} // namespace mozilla