1 //===- FileOutputBuffer.cpp ------------------------------------------------===//
2 //
3 // The MCLinker Project
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 #include <mcld/Support/FileOutputBuffer.h>
10 #include <mcld/Support/FileHandle.h>
11 #include <mcld/Support/Path.h>
12
13 using namespace mcld;
14 using llvm::sys::fs::mapped_file_region;
15
FileOutputBuffer(llvm::sys::fs::mapped_file_region * pRegion,FileHandle & pFileHandle)16 FileOutputBuffer::FileOutputBuffer(llvm::sys::fs::mapped_file_region* pRegion,
17 FileHandle& pFileHandle)
18 : m_pRegion(pRegion), m_FileHandle(pFileHandle)
19 {
20 }
21
~FileOutputBuffer()22 FileOutputBuffer::~FileOutputBuffer()
23 {
24 // Unmap buffer, letting OS flush dirty pages to file on disk.
25 m_pRegion.reset(0);
26 }
27
create(FileHandle & pFileHandle,size_t pSize,std::unique_ptr<FileOutputBuffer> & pResult)28 std::error_code FileOutputBuffer::create(FileHandle& pFileHandle,
29 size_t pSize, std::unique_ptr<FileOutputBuffer>& pResult)
30 {
31 std::error_code ec;
32 std::unique_ptr<mapped_file_region> mapped_file(new mapped_file_region(
33 pFileHandle.handler(),
34 false,
35 mapped_file_region::readwrite,
36 pSize,
37 0,
38 ec));
39
40 if (ec)
41 return ec;
42
43 pResult.reset(new FileOutputBuffer(mapped_file.get(), pFileHandle));
44 if (pResult)
45 mapped_file.release();
46 return std::error_code();
47 }
48
request(size_t pOffset,size_t pLength)49 MemoryRegion FileOutputBuffer::request(size_t pOffset, size_t pLength)
50 {
51 if (pOffset > getBufferSize() || (pOffset + pLength) > getBufferSize())
52 return MemoryRegion();
53 return MemoryRegion(getBufferStart() + pOffset, pLength);
54 }
55
getPath() const56 llvm::StringRef FileOutputBuffer::getPath() const
57 {
58 return m_FileHandle.path().native();
59 }
60