fileio.h

/***
* ==++==
*
* Copyright (c) Microsoft Corporation. All rights reserved.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* ==--==
* =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
*
* fileio.h
*
* Asynchronous I/O: stream buffer implementation details
*
* We're going to some lengths to avoid exporting C++ class member functions and implementation details across
* module boundaries, and the factoring requires that we keep the implementation details away from the main header
* files. The supporting functions, which are in this file, use C-like signatures to avoid as many issues as
* possible.
*
* For the latest on this and related APIs, please see http://casablanca.codeplex.com.
*
* =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
****/
#pragma once

#ifdef _WIN32
#include <cstdint>
#endif

#include "pplx/pplxtasks.h"
#include "cpprest/details/basic_types.h"

namespace Concurrency { namespace streams
{
namespace details
{
    struct _file_info
    {
        _ASYNCRTIMP _file_info(std::ios_base::openmode mode, size_t buffer_size) :
            m_rdpos(0),
            m_wrpos(0),
            m_atend(false),
            m_buffer_size(buffer_size),
            m_buffer(nullptr),
            m_bufoff(0),
            m_bufsize(0),
            m_buffill(0),
            m_mode(mode)
        {
        }

        // Positional data

        size_t m_rdpos;
        size_t m_wrpos;
        bool   m_atend;

        // Input buffer

        size_t m_buffer_size;  // The intended size of the buffer to read into.
        char   *m_buffer;

        size_t m_bufoff;       // File position that the start of the buffer represents.
        msl::safeint3::SafeInt<size_t> m_bufsize;    // Buffer allocated size, as actually allocated.
        size_t m_buffill;      // Amount of file data actually in the buffer

        std::ios_base::openmode m_mode;

        pplx::extensibility::recursive_lock_t m_lock;
    };


    class _filestream_callback
    {
    public:
        virtual void on_opened(_In_ details::_file_info *) { }
        virtual void on_closed() { }
        virtual void on_error(const std::exception_ptr &) { }
        virtual void on_completed(size_t) { }
    protected:
        virtual ~_filestream_callback() {}
    };

}
}}

extern "C"
{
#if !defined(__cplusplus_winrt)
_ASYNCRTIMP bool __cdecl _open_fsb_str(_In_ concurrency::streams::details::_filestream_callback *callback, const utility::char_t *filename, std::ios_base::openmode mode, int prot);
#endif

#if defined(__cplusplus_winrt)
_ASYNCRTIMP bool __cdecl _open_fsb_stf_str(_In_ concurrency::streams::details::_filestream_callback *callback, ::Windows::Storage::StorageFile^ file, std::ios_base::openmode mode, int prot);
#endif

_ASYNCRTIMP bool __cdecl _close_fsb_nolock(_In_ concurrency::streams::details::_file_info **info, _In_ concurrency::streams::details::_filestream_callback *callback);
_ASYNCRTIMP bool __cdecl _close_fsb(_In_ concurrency::streams::details::_file_info **info, _In_ concurrency::streams::details::_filestream_callback *callback);


_ASYNCRTIMP size_t __cdecl _putn_fsb(_In_ concurrency::streams::details::_file_info *info, _In_ concurrency::streams::details::_filestream_callback *callback, const void *ptr, size_t count, size_t char_size);

_ASYNCRTIMP size_t __cdecl _getn_fsb(_In_ concurrency::streams::details::_file_info *info, _In_ concurrency::streams::details::_filestream_callback *callback, _Out_writes_ (count) void *ptr, _In_ size_t count, size_t char_size);

_ASYNCRTIMP bool __cdecl _sync_fsb(_In_ concurrency::streams::details::_file_info *info, _In_ concurrency::streams::details::_filestream_callback *callback);

_ASYNCRTIMP utility::size64_t __cdecl _get_size(_In_ concurrency::streams::details::_file_info *info, size_t char_size);

_ASYNCRTIMP size_t __cdecl _seekrdpos_fsb(_In_ concurrency::streams::details::_file_info *info, size_t pos, size_t char_size);

_ASYNCRTIMP size_t __cdecl _seekrdtoend_fsb(_In_ concurrency::streams::details::_file_info *info, int64_t offset, size_t char_size);

_ASYNCRTIMP size_t __cdecl _seekwrpos_fsb(_In_ concurrency::streams::details::_file_info *info, size_t pos, size_t char_size);
}