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 namespace mcld { 14 15 FileOutputBuffer::FileOutputBuffer(llvm::sys::fs::mapped_file_region* pRegion, 16 FileHandle& pFileHandle) 17 : m_pRegion(pRegion), m_FileHandle(pFileHandle) { 18 } 19 20 FileOutputBuffer::~FileOutputBuffer() { 21 // Unmap buffer, letting OS flush dirty pages to file on disk. 22 m_pRegion.reset(); 23 } 24 25 std::error_code 26 FileOutputBuffer::create(FileHandle& pFileHandle, 27 size_t pSize, 28 std::unique_ptr<FileOutputBuffer>& pResult) { 29 std::error_code ec; 30 31 // Resize the file before mapping the file region. 32 ec = llvm::sys::fs::resize_file(pFileHandle.handler(), pSize); 33 if (ec) 34 return ec; 35 36 std::unique_ptr<llvm::sys::fs::mapped_file_region> mapped_file( 37 new llvm::sys::fs::mapped_file_region(pFileHandle.handler(), 38 llvm::sys::fs::mapped_file_region::readwrite, pSize, 0, ec)); 39 if (ec) 40 return ec; 41 42 pResult.reset(new FileOutputBuffer(mapped_file.get(), pFileHandle)); 43 if (pResult) 44 mapped_file.release(); 45 46 return std::error_code(); 47 } 48 49 MemoryRegion FileOutputBuffer::request(size_t pOffset, size_t pLength) { 50 if (pOffset > getBufferSize() || (pOffset + pLength) > getBufferSize()) 51 return MemoryRegion(); 52 return MemoryRegion(getBufferStart() + pOffset, pLength); 53 } 54 55 llvm::StringRef FileOutputBuffer::getPath() const { 56 return m_FileHandle.path().native(); 57 } 58 59 } // namespace mcld 60
