1adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik//=== FileOutputBuffer.h - File Output Buffer -------------------*- C++ -*-===// 2adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik// 3adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik// The LLVM Compiler Infrastructure 4adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik// 5adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik// This file is distributed under the University of Illinois Open Source 6adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik// License. See LICENSE.TXT for details. 7adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik// 8adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik//===----------------------------------------------------------------------===// 9adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik// 10adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik// Utility for creating a in-memory buffer that will be written to a file. 11adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik// 12adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik//===----------------------------------------------------------------------===// 13adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik 14adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik#ifndef LLVM_SUPPORT_FILEOUTPUTBUFFER_H 15adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik#define LLVM_SUPPORT_FILEOUTPUTBUFFER_H 16adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik 17adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik#include "llvm/ADT/SmallString.h" 18adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik#include "llvm/ADT/StringRef.h" 19adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik#include "llvm/Support/DataTypes.h" 206bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer#include "llvm/Support/FileSystem.h" 21adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik 22adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledziknamespace llvm { 23adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik/// FileOutputBuffer - This interface provides simple way to create an in-memory 246bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer/// buffer which will be written to a file. During the lifetime of these 25adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik/// objects, the content or existence of the specified file is undefined. That 26adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik/// is, creating an OutputBuffer for a file may immediately remove the file. 276bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer/// If the FileOutputBuffer is committed, the target file's content will become 286bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer/// the buffer content at the time of the commit. If the FileOutputBuffer is 29adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik/// not committed, the file will be deleted in the FileOutputBuffer destructor. 30adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzikclass FileOutputBuffer { 31adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzikpublic: 32adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik 33adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik enum { 34adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik F_executable = 1 /// set the 'x' bit on the resulting file 356bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer }; 36adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik 37adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik /// Factory method to create an OutputBuffer object which manages a read/write 38adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik /// buffer of the specified size. When committed, the buffer will be written 396bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer /// to the file at the specified path. 40cd81d94322a39503e4a3e87b6ee03d4fcb3465fbStephen Hines static std::error_code create(StringRef FilePath, size_t Size, 41cd81d94322a39503e4a3e87b6ee03d4fcb3465fbStephen Hines std::unique_ptr<FileOutputBuffer> &Result, 42cd81d94322a39503e4a3e87b6ee03d4fcb3465fbStephen Hines unsigned Flags = 0); 43adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik 44adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik /// Returns a pointer to the start of the buffer. 456bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer uint8_t *getBufferStart() { 466bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer return (uint8_t*)Region->data(); 47adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik } 486bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer 49adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik /// Returns a pointer to the end of the buffer. 506bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer uint8_t *getBufferEnd() { 516bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer return (uint8_t*)Region->data() + Region->size(); 52adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik } 536bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer 54adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik /// Returns size of the buffer. 55adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik size_t getBufferSize() const { 566bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer return Region->size(); 57adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik } 586bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer 59adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik /// Returns path where file will show up if buffer is committed. 60adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik StringRef getPath() const { 61adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik return FinalPath; 62adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik } 636bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer 646bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer /// Flushes the content of the buffer to its file and deallocates the 65adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik /// buffer. If commit() is not called before this object's destructor 66adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik /// is called, the file is deleted in the destructor. The optional parameter 67adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik /// is used if it turns out you want the file size to be smaller than 68adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik /// initially requested. 69cd81d94322a39503e4a3e87b6ee03d4fcb3465fbStephen Hines std::error_code commit(int64_t NewSmallerSize = -1); 706bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer 71adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik /// If this object was previously committed, the destructor just deletes 72adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik /// this object. If this object was not committed, the destructor 73adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik /// deallocates the buffer and the target file is never written. 74adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik ~FileOutputBuffer(); 75adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik 76fc601db2ed899d800ea0a50f7ecf7de2a820cbc1Craig Topperprivate: 77fc601db2ed899d800ea0a50f7ecf7de2a820cbc1Craig Topper FileOutputBuffer(const FileOutputBuffer &) LLVM_DELETED_FUNCTION; 78fc601db2ed899d800ea0a50f7ecf7de2a820cbc1Craig Topper FileOutputBuffer &operator=(const FileOutputBuffer &) LLVM_DELETED_FUNCTION; 796bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer 806bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer FileOutputBuffer(llvm::sys::fs::mapped_file_region *R, 816bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer StringRef Path, StringRef TempPath); 826bc86018d189e9ab62d30ef8190bac961dd22248Michael J. Spencer 8336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines std::unique_ptr<llvm::sys::fs::mapped_file_region> Region; 84adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik SmallString<128> FinalPath; 85adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik SmallString<128> TempPath; 86adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik}; 87adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik} // end namespace llvm 88adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik 89adfe2637b839efe041165f27c9ad57e3befb2be0Nick Kledzik#endif 90