cppcoro/include/cppcoro/readable_file.hpp

66 lines
2.0 KiB
C++

///////////////////////////////////////////////////////////////////////////////
// Copyright (c) Lewis Baker
// Licenced under MIT license. See LICENSE.txt for details.
///////////////////////////////////////////////////////////////////////////////
#ifndef CPPCORO_READABLE_FILE_HPP_INCLUDED
#define CPPCORO_READABLE_FILE_HPP_INCLUDED
#include <cppcoro/file.hpp>
#include <cppcoro/file_read_operation.hpp>
#include <cppcoro/cancellation_token.hpp>
namespace cppcoro
{
class readable_file : virtual public file
{
public:
/// Read some data from the file.
///
/// Reads \a byteCount bytes from the file starting at \a offset
/// into the specified \a buffer.
///
/// \param offset
/// The offset within the file to start reading from.
/// If the file has been opened using file_buffering_mode::unbuffered
/// then the offset must be a multiple of the file-system's sector size.
///
/// \param buffer
/// The buffer to read the file contents into.
/// If the file has been opened using file_buffering_mode::unbuffered
/// then the address of the start of the buffer must be a multiple of
/// the file-system's sector size.
///
/// \param byteCount
/// The number of bytes to read from the file.
/// If the file has been opeend using file_buffering_mode::unbuffered
/// then the byteCount must be a multiple of the file-system's sector size.
///
/// \param ct
/// An optional cancellation_token that can be used to cancel the
/// read operation before it completes.
///
/// \return
/// An object that represents the read-operation.
/// This object must be co_await'ed to start the read operation.
[[nodiscard]]
file_read_operation read(
std::uint64_t offset,
void* buffer,
std::size_t byteCount) const noexcept;
[[nodiscard]]
file_read_operation_cancellable read(
std::uint64_t offset,
void* buffer,
std::size_t byteCount,
cancellation_token ct) const noexcept;
protected:
using file::file;
};
}
#endif