Index: base/files/memory_mapped_file.cc |
diff --git a/base/files/memory_mapped_file.cc b/base/files/memory_mapped_file.cc |
index ace4e112628519137e7f56fbfb36f6176c2e8e83..e9656495844212d1fea11c16cabdca9118e1a540 100644 |
--- a/base/files/memory_mapped_file.cc |
+++ b/base/files/memory_mapped_file.cc |
@@ -6,9 +6,26 @@ |
#include "base/files/file_path.h" |
#include "base/logging.h" |
+#include "base/sys_info.h" |
namespace base { |
+const MemoryMappedFile::Region MemoryMappedFile::Region::kWholeFile; |
+ |
+MemoryMappedFile::Region::Region() : offset(0), size(0) { |
+} |
+ |
+MemoryMappedFile::Region::Region(int64 offset, int64 size) |
+ : offset(offset), size(size) { |
+ DCHECK_GE(offset, 0); |
+ DCHECK_GT(size, 0); |
+} |
+ |
+bool MemoryMappedFile::Region::operator==( |
+ const MemoryMappedFile::Region& other) const { |
+ return other.offset == offset && other.size == size; |
+} |
+ |
MemoryMappedFile::~MemoryMappedFile() { |
CloseHandles(); |
} |
@@ -24,7 +41,7 @@ bool MemoryMappedFile::Initialize(const FilePath& file_name) { |
return false; |
} |
- if (!MapFileToMemory()) { |
+ if (!MapFileRegionToMemory(Region::kWholeFile)) { |
CloseHandles(); |
return false; |
} |
@@ -33,12 +50,16 @@ bool MemoryMappedFile::Initialize(const FilePath& file_name) { |
} |
bool MemoryMappedFile::Initialize(File file) { |
+ return Initialize(file.Pass(), Region::kWholeFile); |
+} |
+ |
+bool MemoryMappedFile::Initialize(File file, const Region& region) { |
if (IsValid()) |
return false; |
file_ = file.Pass(); |
- if (!MapFileToMemory()) { |
+ if (!MapFileRegionToMemory(region)) { |
CloseHandles(); |
return false; |
} |
@@ -50,4 +71,18 @@ 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; |
+} |
+ |
} // namespace base |