llvm-6502/include/llvm/Support/FileOutputBuffer.h
Michael J. Spencer 6bc86018d1 [Support] Make FileOutputBuffer work on Windows.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169167 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-03 22:09:52 +00:00

93 lines
3.3 KiB
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//=== FileOutputBuffer.h - File Output Buffer -------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Utility for creating a in-memory buffer that will be written to a file.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_FILEOUTPUTBUFFER_H
#define LLVM_SUPPORT_FILEOUTPUTBUFFER_H
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/FileSystem.h"
namespace llvm {
class error_code;
/// FileOutputBuffer - This interface provides simple way to create an in-memory
/// buffer which will be written to a file. During the lifetime of these
/// objects, the content or existence of the specified file is undefined. That
/// is, creating an OutputBuffer for a file may immediately remove the file.
/// If the FileOutputBuffer is committed, the target file's content will become
/// the buffer content at the time of the commit. If the FileOutputBuffer is
/// not committed, the file will be deleted in the FileOutputBuffer destructor.
class FileOutputBuffer {
public:
enum {
F_executable = 1 /// set the 'x' bit on the resulting file
};
/// Factory method to create an OutputBuffer object which manages a read/write
/// buffer of the specified size. When committed, the buffer will be written
/// to the file at the specified path.
static error_code create(StringRef FilePath, size_t Size,
OwningPtr<FileOutputBuffer> &Result,
unsigned Flags = 0);
/// Returns a pointer to the start of the buffer.
uint8_t *getBufferStart() {
return (uint8_t*)Region->data();
}
/// Returns a pointer to the end of the buffer.
uint8_t *getBufferEnd() {
return (uint8_t*)Region->data() + Region->size();
}
/// Returns size of the buffer.
size_t getBufferSize() const {
return Region->size();
}
/// Returns path where file will show up if buffer is committed.
StringRef getPath() const {
return FinalPath;
}
/// Flushes the content of the buffer to its file and deallocates the
/// buffer. If commit() is not called before this object's destructor
/// is called, the file is deleted in the destructor. The optional parameter
/// is used if it turns out you want the file size to be smaller than
/// initially requested.
error_code commit(int64_t NewSmallerSize = -1);
/// If this object was previously committed, the destructor just deletes
/// this object. If this object was not committed, the destructor
/// deallocates the buffer and the target file is never written.
~FileOutputBuffer();
private:
FileOutputBuffer(const FileOutputBuffer &) LLVM_DELETED_FUNCTION;
FileOutputBuffer &operator=(const FileOutputBuffer &) LLVM_DELETED_FUNCTION;
FileOutputBuffer(llvm::sys::fs::mapped_file_region *R,
StringRef Path, StringRef TempPath);
OwningPtr<llvm::sys::fs::mapped_file_region> Region;
SmallString<128> FinalPath;
SmallString<128> TempPath;
};
} // end namespace llvm
#endif