| // Copyright 2013 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "base/files/memory_mapped_file.h" |
| |
| #include "base/files/file_path.h" |
| #include "base/logging.h" |
| #include "base/sys_info.h" |
| |
| namespace base { |
| |
| const MemoryMappedFile::Region MemoryMappedFile::Region::kWholeFile( |
| base::LINKER_INITIALIZED); |
| |
| MemoryMappedFile::Region::Region(base::LinkerInitialized) : offset(0), size(0) { |
| } |
| |
| MemoryMappedFile::Region::Region() : offset(-1), size(-1) { |
| } |
| |
| MemoryMappedFile::Region::Region(int64 offset, int64 size) |
| : offset(offset), size(size) { |
| } |
| |
| bool MemoryMappedFile::Region::operator==( |
| const MemoryMappedFile::Region& other) const { |
| return other.offset == offset && other.size == size; |
| } |
| |
| bool MemoryMappedFile::Region::operator!=( |
| const MemoryMappedFile::Region& other) const { |
| return other.offset != offset || other.size != size; |
| } |
| |
| MemoryMappedFile::~MemoryMappedFile() { |
| CloseHandles(); |
| } |
| |
| #if !defined(OS_NACL) |
| bool MemoryMappedFile::Initialize(const FilePath& file_name) { |
| if (IsValid()) |
| return false; |
| |
| file_.Initialize(file_name, File::FLAG_OPEN | File::FLAG_READ); |
| |
| if (!file_.IsValid()) { |
| DLOG(ERROR) << "Couldn't open " << file_name.AsUTF8Unsafe(); |
| return false; |
| } |
| |
| if (!MapFileRegionToMemory(Region::kWholeFile)) { |
| CloseHandles(); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| bool MemoryMappedFile::Initialize(File file) { |
| return Initialize(file.Pass(), Region::kWholeFile); |
| } |
| |
| bool MemoryMappedFile::Initialize(File file, const Region& region) { |
| if (IsValid()) |
| return false; |
| |
| if (region != Region::kWholeFile) { |
| DCHECK_GE(region.offset, 0); |
| DCHECK_GT(region.size, 0); |
| } |
| |
| file_ = file.Pass(); |
| |
| if (!MapFileRegionToMemory(region)) { |
| CloseHandles(); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| bool MemoryMappedFile::IsValid() const { |
| return data_ != NULL; |
| } |
| |
| // static |
| void MemoryMappedFile::CalculateVMAlignedBoundaries(int64 start, |
| int64 size, |
| int64* aligned_start, |
| int64* aligned_size, |
| int32* offset) { |
| // Sadly, on Windows, the mmap alignment is not just equal to the page size. |
| const int64 mask = static_cast<int64>(SysInfo::VMAllocationGranularity()) - 1; |
| DCHECK_LT(mask, std::numeric_limits<int32>::max()); |
| *offset = start & mask; |
| *aligned_start = start & ~mask; |
| *aligned_size = (size + *offset + mask) & ~mask; |
| } |
| #endif |
| |
| } // namespace base |