/usr/include/cpprest/filestream.h is in libcpprest-dev 2.9.1-1.
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* Copyright (C) Microsoft. All rights reserved.
* Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
*
* =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
*
* Asynchronous File streams
*
* For the latest on this and related APIs, please see: https://github.com/Microsoft/cpprestsdk
*
* =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
****/
#pragma once
#ifndef _CASA_FILE_STREAMS_H
#define _CASA_FILE_STREAMS_H
#include "cpprest/details/fileio.h"
#include "cpprest/astreambuf.h"
#include "cpprest/streams.h"
#include <assert.h>
#ifndef _CONCRT_H
#ifndef _LWRCASE_CNCRRNCY
#define _LWRCASE_CNCRRNCY
// Note to reader: we're using lower-case namespace names everywhere, but the 'Concurrency' namespace
// is capitalized for historical reasons. The alias let's us pretend that style issue doesn't exist.
namespace Concurrency { }
namespace concurrency = Concurrency;
#endif
#endif
namespace Concurrency { namespace streams
{
// Forward declarations
template<typename _CharType> class file_buffer;
namespace details {
// This operation queue is NOT thread safe
class async_operation_queue
{
pplx::task<void> m_lastOperation;
public:
async_operation_queue()
{
m_lastOperation = pplx::task_from_result();
}
// It only accepts functors that take no argument and return pplx::task<T>
// This function may execute op inline, thus it could throw immediately
template <typename Func>
auto enqueue_operation(Func &&op) -> decltype(op())
{
decltype(op()) res; // res is task<T> , which always has default constructor
if (m_lastOperation.is_done())
{
res = op(); // Exceptions are expected to be thrown directly without catching
if (res.is_done())
return res;
}
else
{
res = m_lastOperation.then([=] {
return op(); // It will cause task unwrapping
});
}
m_lastOperation = res.then([&] (decltype(op())) {
// This empty task is necessary for keeping the rest of the operations on the list running
// even when the previous operation gets error.
// Don't observe exception here.
});
return res;
}
void wait() const
{
m_lastOperation.wait();
}
};
/// <summary>
/// Private stream buffer implementation for file streams.
/// The class itself should not be used in application code, it is used by the stream definitions farther down in the header file.
/// </summary>
template<typename _CharType>
class basic_file_buffer : public details::streambuf_state_manager<_CharType>
{
public:
typedef typename basic_streambuf<_CharType>::traits traits;
typedef typename basic_streambuf<_CharType>::int_type int_type;
typedef typename basic_streambuf<_CharType>::pos_type pos_type;
typedef typename basic_streambuf<_CharType>::off_type off_type;
virtual ~basic_file_buffer()
{
if( this->can_read() )
{
this->_close_read().wait();
}
if (this->can_write())
{
this->_close_write().wait();
}
}
protected:
/// <summary>
/// <c>can_seek</c> is used to determine whether a stream buffer supports seeking.
/// </summary>
virtual bool can_seek() const { return this->is_open(); }
/// <summary>
/// <c>has_size<c/> is used to determine whether a stream buffer supports size().
/// </summary>
virtual bool has_size() const { return this->is_open(); }
virtual utility::size64_t size() const
{
if (!this->is_open())
return 0;
return _get_size(m_info, sizeof(_CharType));
}
/// <summary>
/// Gets the stream buffer size, if one has been set.
/// </summary>
/// <param name="direction">The direction of buffering (in or out)</param>
/// <remarks>An implementation that does not support buffering will always return '0'.</remarks>
virtual size_t buffer_size(std::ios_base::openmode direction = std::ios_base::in) const
{
if ( direction == std::ios_base::in )
return m_info->m_buffer_size;
else
return 0;
}
/// <summary>
/// Sets the stream buffer implementation to buffer or not buffer.
/// </summary>
/// <param name="size">The size to use for internal buffering, 0 if no buffering should be done.</param>
/// <param name="direction">The direction of buffering (in or out)</param>
/// <remarks>An implementation that does not support buffering will silently ignore calls to this function and it will not have
/// any effect on what is returned by subsequent calls to buffer_size().</remarks>
virtual void set_buffer_size(size_t size, std::ios_base::openmode direction = std::ios_base::in)
{
if ( direction == std::ios_base::out ) return;
m_info->m_buffer_size = size;
if ( size == 0 && m_info->m_buffer != nullptr )
{
delete m_info->m_buffer;
m_info->m_buffer = nullptr;
}
}
/// <summary>
/// For any input stream, <c>in_avail</c> returns the number of characters that are immediately available
/// to be consumed without blocking. May be used in conjunction with <cref="::sbumpc method"/> to read data without
/// incurring the overhead of using tasks.
/// </summary>
virtual size_t in_avail() const
{
pplx::extensibility::scoped_recursive_lock_t lck(m_info->m_lock);
return _in_avail_unprot();
}
size_t _in_avail_unprot() const
{
if ( !this->is_open() ) return 0;
if ( m_info->m_buffer == nullptr || m_info->m_buffill == 0 ) return 0;
if ( m_info->m_bufoff > m_info->m_rdpos || (m_info->m_bufoff+m_info->m_buffill) < m_info->m_rdpos ) return 0;
msl::safeint3::SafeInt<size_t> rdpos(m_info->m_rdpos);
msl::safeint3::SafeInt<size_t> buffill(m_info->m_buffill);
msl::safeint3::SafeInt<size_t> bufpos = rdpos - m_info->m_bufoff;
return buffill - bufpos;
}
_file_info * _close_stream()
{
// indicate that we are no longer open
auto fileInfo = m_info;
m_info = nullptr;
return fileInfo;
}
static pplx::task<void> _close_file(_In_ _file_info * fileInfo)
{
pplx::task_completion_event<void> result_tce;
auto callback = new _filestream_callback_close(result_tce);
if ( !_close_fsb_nolock(&fileInfo, callback) )
{
delete callback;
return pplx::task_from_result();
}
return pplx::create_task(result_tce);
}
// Workaround GCC compiler bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58972
void _invoke_parent_close_read()
{
streambuf_state_manager<_CharType>::_close_read();
}
pplx::task<void> _close_read()
{
return m_readOps.enqueue_operation([this]
{
_invoke_parent_close_read();
if (this->can_write())
{
return pplx::task_from_result();
}
else
{
// Neither heads are open. Close the underlying device
// to indicate that we are no longer open
auto fileInfo = _close_stream();
return _close_file(fileInfo);
}
});
}
pplx::task<void> _close_write()
{
streambuf_state_manager<_CharType>::_close_write();
if (this->can_read())
{
// Read head is still open. Just flush the write data
return flush_internal();
}
else
{
// Neither heads are open. Close the underlying device
// We need to flush all writes if the file was opened for writing.
return flush_internal().then([=](pplx::task<void> flushTask) -> pplx::task<void>
{
// swallow exception from flush
try
{
flushTask.wait();
}
catch(...)
{
}
// indicate that we are no longer open
auto fileInfo = this->_close_stream();
return this->_close_file(fileInfo);
});
}
}
/// <summary>
/// Writes a single byte to an output stream.
/// </summary>
/// <param name="ch">The byte to write</param>
/// <returns>A <c>task</c> that holds the value of the byte written. This is EOF if the write operation fails.</returns>
virtual pplx::task<int_type> _putc(_CharType ch)
{
auto result_tce = pplx::task_completion_event<size_t>();
auto callback = new _filestream_callback_write<size_t>(m_info, result_tce);
// Potentially we should consider deprecating this API, it is TERRIBLY inefficient.
std::shared_ptr<_CharType> sharedCh;
try
{
sharedCh = std::make_shared<_CharType>(ch);
} catch (const std::bad_alloc &)
{
delete callback;
throw;
}
size_t written = _putn_fsb(m_info, callback, sharedCh.get(), 1, sizeof(_CharType));
if (written == sizeof(_CharType))
{
delete callback;
return pplx::task_from_result<int_type>(ch);
}
return pplx::create_task(result_tce).then([sharedCh](size_t)
{
return static_cast<int_type>(*sharedCh);
});
}
/// <summary>
/// Allocates a contiguous memory block and returns it.
/// </summary>
/// <param name="count">The number of characters to allocate.</param>
/// <returns>A pointer to a block to write to, null if the stream buffer implementation does not support alloc/commit.</returns>
_CharType* _alloc(size_t)
{
return nullptr;
}
/// <summary>
/// Submits a block already allocated by the stream buffer.
/// </summary>
/// <param name="ptr">Count of characters to be commited.</param>
void _commit(size_t)
{
}
/// <summary>
/// Gets a pointer to the next already allocated contiguous block of data.
/// </summary>
/// <param name="ptr">A reference to a pointer variable that will hold the address of the block on success.</param>
/// <param name="count">The number of contiguous characters available at the address in 'ptr.'</param>
/// <returns><c>true</c> if the operation succeeded, <c>false</c> otherwise.</returns>
/// <remarks>
/// A return of false does not necessarily indicate that a subsequent read operation would fail, only that
/// there is no block to return immediately or that the stream buffer does not support the operation.
/// The stream buffer may not de-allocate the block until <see cref="::release method" /> is called.
/// If the end of the stream is reached, the function will return <c>true</c>, a null pointer, and a count of zero;
/// a subsequent read will not succeed.
/// </remarks>
virtual bool acquire(_Out_ _CharType*& ptr, _Out_ size_t& count)
{
ptr = nullptr;
count = 0;
return false;
}
/// <summary>
/// Releases a block of data acquired using <see cref="::acquire method"/>. This frees the stream buffer to de-allocate the
/// memory, if it so desires. Move the read position ahead by the count.
/// </summary>
/// <param name="ptr">A pointer to the block of data to be released.</param>
/// <param name="count">The number of characters that were read.</param>
virtual void release(_Out_writes_ (count) _CharType *, _In_ size_t count)
{
(void)(count);
}
/// <summary>
/// Writes a number of characters to the stream.
/// </summary>
/// <param name="ptr">A pointer to the block of data to be written.</param>
/// <param name="count">The number of characters to write.</param>
/// <returns>A <c>task</c> that holds the number of characters actually written, either 'count' or 0.</returns>
virtual pplx::task<size_t> _putn(const _CharType *ptr, size_t count)
{
auto result_tce = pplx::task_completion_event<size_t>();
auto callback = new _filestream_callback_write<size_t>(m_info, result_tce);
size_t written = _putn_fsb(m_info, callback, ptr, count, sizeof(_CharType));
if ( written != 0 && written != -1 )
{
delete callback;
written = written/sizeof(_CharType);
return pplx::task_from_result<size_t>(written);
}
return pplx::create_task(result_tce);
}
// Temporarily needed until the deprecated putn is removed.
virtual pplx::task<size_t> _putn(const _CharType *ptr, size_t count, bool copy)
{
if (copy)
{
auto sharedData = std::make_shared<std::vector<_CharType>>(ptr, ptr + count);
return _putn(ptr, count).then([sharedData](size_t size)
{
return size;
});
}
else
{
return _putn(ptr, count);
}
}
/// <summary>
/// Reads a single byte from the stream and advance the read position.
/// </summary>
/// <returns>A <c>task</c> that holds the value of the byte read. This is EOF if the read fails.</returns>
virtual pplx::task<int_type> _bumpc()
{
return m_readOps.enqueue_operation([this]()-> pplx::task<int_type> {
if ( _in_avail_unprot() > 0 )
{
pplx::extensibility::scoped_recursive_lock_t lck(m_info->m_lock);
// Check again once the lock is held.
if ( _in_avail_unprot() > 0 )
{
auto bufoff = m_info->m_rdpos - m_info->m_bufoff;
_CharType ch = m_info->m_buffer[bufoff*sizeof(_CharType)];
m_info->m_rdpos += 1;
return pplx::task_from_result<int_type>(ch);
}
}
auto result_tce = pplx::task_completion_event<int_type>();
auto callback = new _filestream_callback_bumpc(m_info, result_tce);
size_t ch = _getn_fsb(m_info, callback, &callback->m_ch, 1, sizeof(_CharType));
if ( ch == sizeof(_CharType) )
{
pplx::extensibility::scoped_recursive_lock_t lck(m_info->m_lock);
m_info->m_rdpos += 1;
_CharType ch1 = (_CharType)callback->m_ch;
delete callback;
return pplx::task_from_result<int_type>(ch1);
}
return pplx::create_task(result_tce);
});
}
/// <summary>
/// Reads a single byte from the stream and advance the read position.
/// </summary>
/// <returns>The value of the byte. EOF if the read fails. <see cref="::requires_async method" /> if an asynchronous read is required</returns>
/// <remarks>This is a synchronous operation, but is guaranteed to never block.</remarks>
virtual int_type _sbumpc()
{
m_readOps.wait();
if ( m_info->m_atend ) return traits::eof();
if ( _in_avail_unprot() == 0 ) return traits::requires_async();
pplx::extensibility::scoped_recursive_lock_t lck(m_info->m_lock);
if ( _in_avail_unprot() == 0 ) return traits::requires_async();
auto bufoff = m_info->m_rdpos - m_info->m_bufoff;
_CharType ch = m_info->m_buffer[bufoff*sizeof(_CharType)];
m_info->m_rdpos += 1;
return (int_type)ch;
}
pplx::task<int_type> _getcImpl()
{
if ( _in_avail_unprot() > 0 )
{
pplx::extensibility::scoped_recursive_lock_t lck(m_info->m_lock);
// Check again once the lock is held.
if ( _in_avail_unprot() > 0 )
{
auto bufoff = m_info->m_rdpos - m_info->m_bufoff;
_CharType ch = m_info->m_buffer[bufoff*sizeof(_CharType)];
return pplx::task_from_result<int_type>(ch);
}
}
auto result_tce = pplx::task_completion_event<int_type>();
auto callback = new _filestream_callback_getc(m_info, result_tce);
size_t ch = _getn_fsb(m_info, callback, &callback->m_ch, 1, sizeof(_CharType));
if ( ch == sizeof(_CharType) )
{
pplx::extensibility::scoped_recursive_lock_t lck(m_info->m_lock);
_CharType ch1 = (_CharType)callback->m_ch;
delete callback;
return pplx::task_from_result<int_type>(ch1);
}
return pplx::create_task(result_tce);
}
/// <summary>
/// Reads a single byte from the stream without advancing the read position.
/// </summary>
/// <returns>The value of the byte. EOF if the read fails.</returns>
pplx::task<int_type> _getc()
{
return m_readOps.enqueue_operation([this]()-> pplx::task<int_type> {
return _getcImpl();
});
}
/// <summary>
/// Reads a single byte from the stream without advancing the read position.
/// </summary>
/// <returns>The value of the byte. EOF if the read fails. <see cref="::requires_async method" /> if an asynchronous read is required</returns>
/// <remarks>This is a synchronous operation, but is guaranteed to never block.</remarks>
int_type _sgetc()
{
m_readOps.wait();
if ( m_info->m_atend ) return traits::eof();
if ( _in_avail_unprot() == 0 ) return traits::requires_async();
pplx::extensibility::scoped_recursive_lock_t lck(m_info->m_lock);
if ( _in_avail_unprot() == 0 ) return traits::requires_async();
auto bufoff = m_info->m_rdpos - m_info->m_bufoff;
_CharType ch = m_info->m_buffer[bufoff*sizeof(_CharType)];
return (int_type)ch;
}
/// <summary>
/// Advances the read position, then return the next character without advancing again.
/// </summary>
/// <returns>A <c>task</c> that holds the value of the byte, which is EOF if the read fails.</returns>
virtual pplx::task<int_type> _nextc()
{
return m_readOps.enqueue_operation([this]()-> pplx::task<int_type> {
_seekrdpos_fsb(m_info, m_info->m_rdpos+1, sizeof(_CharType));
if ( m_info->m_atend )
return pplx::task_from_result(basic_file_buffer<_CharType>::traits::eof());
return this->_getcImpl();
});
}
/// <summary>
/// Retreats the read position, then return the current character without advancing.
/// </summary>
/// <returns>A <c>task</c> that holds the value of the byte. The value is EOF if the read fails, <c>requires_async</c> if an asynchronous read is required</returns>
virtual pplx::task<int_type> _ungetc()
{
return m_readOps.enqueue_operation([this]()-> pplx::task<int_type> {
if ( m_info->m_rdpos == 0 )
return pplx::task_from_result<int_type>(basic_file_buffer<_CharType>::traits::eof());
_seekrdpos_fsb(m_info, m_info->m_rdpos-1, sizeof(_CharType));
return this->_getcImpl();
});
}
/// <summary>
/// Reads up to a given number of characters from the stream.
/// </summary>
/// <param name="ptr">The address of the target memory area</param>
/// <param name="count">The maximum number of characters to read</param>
/// <returns>A <c>task</c> that holds the number of characters read. This number is O if the end of the stream is reached, EOF if there is some error.</returns>
virtual pplx::task<size_t> _getn(_Out_writes_ (count) _CharType *ptr, _In_ size_t count)
{
return m_readOps.enqueue_operation([=] ()-> pplx::task<size_t>{
if ( m_info->m_atend || count == 0 )
return pplx::task_from_result<size_t>(0);
if ( _in_avail_unprot() >= count )
{
pplx::extensibility::scoped_recursive_lock_t lck(m_info->m_lock);
// Check again once the lock is held.
if ( _in_avail_unprot() >= count )
{
auto bufoff = m_info->m_rdpos - m_info->m_bufoff;
std::memcpy((void *)ptr, this->m_info->m_buffer+bufoff*sizeof(_CharType), count*sizeof(_CharType));
m_info->m_rdpos += count;
return pplx::task_from_result<size_t>(count);
}
}
auto result_tce = pplx::task_completion_event<size_t>();
auto callback = new _filestream_callback_read(m_info, result_tce);
size_t read = _getn_fsb(m_info, callback, ptr, count, sizeof(_CharType));
if ( read != 0 && read != -1)
{
delete callback;
pplx::extensibility::scoped_recursive_lock_t lck(m_info->m_lock);
m_info->m_rdpos += read/sizeof(_CharType);
return pplx::task_from_result<size_t>(read/sizeof(_CharType));
}
return pplx::create_task(result_tce);
});
}
/// <summary>
/// Reads up to a given number of characters from the stream.
/// </summary>
/// <param name="ptr">The address of the target memory area</param>
/// <param name="count">The maximum number of characters to read</param>
/// <returns>The number of characters read. O if the end of the stream is reached or an asynchronous read is required.</returns>
/// <remarks>This is a synchronous operation, but is guaranteed to never block.</remarks>
size_t _sgetn(_Out_writes_ (count) _CharType *ptr, _In_ size_t count)
{
m_readOps.wait();
if ( m_info->m_atend ) return 0;
if ( count == 0 || in_avail() == 0 ) return 0;
pplx::extensibility::scoped_recursive_lock_t lck(m_info->m_lock);
size_t available = _in_avail_unprot();
size_t copy = (count < available) ? count : available;
auto bufoff = m_info->m_rdpos - m_info->m_bufoff;
std::memcpy((void *)ptr, this->m_info->m_buffer+bufoff*sizeof(_CharType), copy*sizeof(_CharType));
m_info->m_rdpos += copy;
m_info->m_atend = (copy < count);
return copy;
}
/// <summary>
/// Copies up to a given number of characters from the stream.
/// </summary>
/// <param name="ptr">The address of the target memory area</param>
/// <param name="count">The maximum number of characters to copy</param>
/// <returns>The number of characters copied. O if the end of the stream is reached or an asynchronous read is required.</returns>
/// <remarks>This is a synchronous operation, but is guaranteed to never block.</remarks>
virtual size_t _scopy(_CharType *, size_t)
{
return 0;
}
/// <summary>
/// Gets the current read or write position in the stream.
/// </summary>
/// <param name="direction">The I/O direction to seek (see remarks)</param>
/// <returns>The current position. EOF if the operation fails.</returns>
/// <remarks>Some streams may have separate write and read cursors.
/// For such streams, the direction parameter defines whether to move the read or the write cursor.</remarks>
virtual pos_type getpos(std::ios_base::openmode mode) const
{
return const_cast<basic_file_buffer*>(this)->seekoff(0, std::ios_base::cur, mode);
}
/// <summary>
/// Seeks to the given position.
/// </summary>
/// <param name="pos">The offset from the beginning of the stream</param>
/// <param name="direction">The I/O direction to seek (see remarks)</param>
/// <returns>The position. EOF if the operation fails.</returns>
/// <remarks>Some streams may have separate write and read cursors.
/// For such streams, the direction parameter defines whether to move the read or the write cursor.</remarks>
virtual pos_type seekpos(pos_type pos, std::ios_base::openmode mode)
{
if ( mode == std::ios_base::in )
{
m_readOps.wait();
return (pos_type)_seekrdpos_fsb(m_info, size_t(pos), sizeof(_CharType));
}
else if ( (m_info->m_mode & std::ios::ios_base::app) == 0 )
{
return (pos_type)_seekwrpos_fsb(m_info, size_t(pos), sizeof(_CharType));
}
return (pos_type)Concurrency::streams::char_traits<_CharType>::eof();
}
/// <summary>
/// Seeks to a position given by a relative offset.
/// </summary>
/// <param name="offset">The relative position to seek to</param>
/// <param name="way">The starting point (beginning, end, current) for the seek.</param>
/// <param name="mode">The I/O direction to seek (see remarks)</param>
/// <returns>The position. EOF if the operation fails.</returns>
/// <remarks>Some streams may have separate write and read cursors.
/// For such streams, the mode parameter defines whether to move the read or the write cursor.</remarks>
virtual pos_type seekoff(off_type offset, std::ios_base::seekdir way, std::ios_base::openmode mode)
{
if ( mode == std::ios_base::in )
{
m_readOps.wait();
switch ( way )
{
case std::ios_base::beg:
return (pos_type)_seekrdpos_fsb(m_info, size_t(offset), sizeof(_CharType));
case std::ios_base::cur:
return (pos_type)_seekrdpos_fsb(m_info, size_t(m_info->m_rdpos+offset), sizeof(_CharType));
case std::ios_base::end:
return (pos_type)_seekrdtoend_fsb(m_info, int64_t(offset), sizeof(_CharType));
default:
// Fail on invalid input (_S_ios_seekdir_end)
assert(false);
}
}
else if ( (m_info->m_mode & std::ios::ios_base::app) == 0 )
{
switch ( way )
{
case std::ios_base::beg:
return (pos_type)_seekwrpos_fsb(m_info, size_t(offset), sizeof(_CharType));
case std::ios_base::cur:
return (pos_type)_seekwrpos_fsb(m_info, size_t(m_info->m_wrpos+offset), sizeof(_CharType));
case std::ios_base::end:
return (pos_type)_seekwrpos_fsb(m_info, size_t(-1), sizeof(_CharType));
default:
// Fail on invalid input (_S_ios_seekdir_end)
assert(false);
}
}
return (pos_type)traits::eof();
}
/// <summary>
/// For output streams, flush any internally buffered data to the underlying medium.
/// </summary>
virtual pplx::task<bool> _sync()
{
return flush_internal().then([](){return true;});
}
private:
template<typename _CharType1> friend class ::concurrency::streams::file_buffer;
pplx::task<void> flush_internal()
{
pplx::task_completion_event<void> result_tce;
auto callback = utility::details::make_unique<_filestream_callback_write_b>(m_info, result_tce);
if ( !_sync_fsb(m_info, callback.get()) )
{
return pplx::task_from_exception<void>(std::runtime_error("failure to flush stream"));
}
callback.release();
return pplx::create_task(result_tce);
}
basic_file_buffer(_In_ _file_info *info) : streambuf_state_manager<_CharType>(info->m_mode), m_info(info) { }
#if !defined(__cplusplus_winrt)
static pplx::task<std::shared_ptr<basic_streambuf<_CharType>>> open(
const utility::string_t &_Filename,
std::ios_base::openmode _Mode = std::ios_base::out,
#ifdef _WIN32
int _Prot = (int)std::ios_base::_Openprot
#else
int _Prot = 0 // unsupported on Linux, for now
#endif
)
{
auto result_tce = pplx::task_completion_event<std::shared_ptr<basic_streambuf<_CharType>>>();
auto callback = new _filestream_callback_open(result_tce);
_open_fsb_str(callback, _Filename.c_str(), _Mode, _Prot);
return pplx::create_task(result_tce);
}
#else
static pplx::task<std::shared_ptr<basic_streambuf<_CharType>>> open(
::Windows::Storage::StorageFile^ file,
std::ios_base::openmode _Mode = std::ios_base::out)
{
auto result_tce = pplx::task_completion_event<std::shared_ptr<basic_streambuf<_CharType>>>();
auto callback = new _filestream_callback_open(result_tce);
_open_fsb_stf_str(callback, file, _Mode, 0);
return pplx::create_task(result_tce);
}
#endif
class _filestream_callback_open : public details::_filestream_callback
{
public:
_filestream_callback_open(const pplx::task_completion_event<std::shared_ptr<basic_streambuf<_CharType>>> &op) : m_op(op) { }
virtual void on_opened(_In_ _file_info *info)
{
m_op.set(std::shared_ptr<basic_file_buffer<_CharType>>(new basic_file_buffer<_CharType>(info)));
delete this;
}
virtual void on_error(const std::exception_ptr & e)
{
m_op.set_exception(e);
delete this;
}
private:
pplx::task_completion_event<std::shared_ptr<basic_streambuf<_CharType>>> m_op;
};
class _filestream_callback_close : public details::_filestream_callback
{
public:
_filestream_callback_close(const pplx::task_completion_event<void> &op) : m_op(op) { }
virtual void on_closed()
{
m_op.set();
delete this;
}
virtual void on_error(const std::exception_ptr & e)
{
m_op.set_exception(e);
delete this;
}
private:
pplx::task_completion_event<void> m_op;
};
template<typename ResultType>
class _filestream_callback_write : public details::_filestream_callback
{
public:
_filestream_callback_write(_In_ _file_info *info, const pplx::task_completion_event<ResultType> &op) : m_info(info), m_op(op) { }
virtual void on_completed(size_t result)
{
m_op.set((ResultType)result / sizeof(_CharType));
delete this;
}
virtual void on_error(const std::exception_ptr & e)
{
m_op.set_exception(e);
delete this;
}
private:
_file_info *m_info;
pplx::task_completion_event<ResultType> m_op;
};
class _filestream_callback_write_b : public details::_filestream_callback
{
public:
_filestream_callback_write_b(_In_ _file_info *info, const pplx::task_completion_event<void> &op) : m_info(info), m_op(op) { }
virtual void on_completed(size_t)
{
m_op.set();
delete this;
}
virtual void on_error(const std::exception_ptr & e)
{
m_op.set_exception(e);
delete this;
}
private:
_file_info *m_info;
pplx::task_completion_event<void> m_op;
};
class _filestream_callback_read : public details::_filestream_callback
{
public:
_filestream_callback_read(_In_ _file_info *info, const pplx::task_completion_event<size_t> &op) : m_info(info), m_op(op) { }
virtual void on_completed(size_t result)
{
result = result / sizeof(_CharType);
m_info->m_rdpos += result;
m_op.set(result);
delete this;
}
virtual void on_error(const std::exception_ptr & e)
{
m_op.set_exception(e);
delete this;
}
private:
_file_info *m_info;
pplx::task_completion_event<size_t> m_op;
};
class _filestream_callback_bumpc : public details::_filestream_callback
{
public:
_filestream_callback_bumpc(_In_ _file_info *info, const pplx::task_completion_event<int_type> &op) : m_ch(0), m_info(info), m_op(op) { }
virtual void on_completed(size_t result)
{
if ( result == sizeof(_CharType) )
{
m_info->m_rdpos += 1;
m_op.set(m_ch);
}
else
{
m_op.set(traits::eof());
}
delete this;
}
virtual void on_error(const std::exception_ptr & e)
{
m_op.set_exception(e);
delete this;
}
int_type m_ch;
private:
_file_info *m_info;
pplx::task_completion_event<int_type> m_op;
};
class _filestream_callback_getc : public details::_filestream_callback
{
public:
_filestream_callback_getc(_In_ _file_info *info, const pplx::task_completion_event<int_type> &op) : m_ch(0), m_info(info), m_op(op) { }
virtual void on_completed(size_t result)
{
if ( result == sizeof(_CharType) )
{
m_op.set(m_ch);
}
else
{
m_op.set(traits::eof());
}
delete this;
}
int_type m_ch;
virtual void on_error(const std::exception_ptr & e)
{
m_op.set_exception(e);
delete this;
}
private:
_file_info *m_info;
pplx::task_completion_event<int_type> m_op;
};
_file_info *m_info;
async_operation_queue m_readOps;
};
} // namespace details
/// <summary>
/// Stream buffer for file streams.
/// </summary>
/// <typeparam name="_CharType">
/// The data type of the basic element of the <c>file_buffer</c>.
/// </typeparam>
template<typename _CharType>
class file_buffer
{
public:
#if !defined(__cplusplus_winrt)
/// <summary>
/// Open a new stream buffer representing the given file.
/// </summary>
/// <param name="file_name">The name of the file</param>
/// <param name="mode">The opening mode of the file</param>
/// <param name="prot">The file protection mode</param>
/// <returns>A <c>task</c> that returns an opened stream buffer on completion.</returns>
static pplx::task<streambuf<_CharType>> open(
const utility::string_t &file_name,
std::ios_base::openmode mode = std::ios_base::out,
#ifdef _WIN32
int prot = _SH_DENYRD
#else
int prot = 0 // unsupported on Linux
#endif
)
{
auto bfb = details::basic_file_buffer<_CharType>::open(file_name, mode, prot);
return bfb.then([](pplx::task<std::shared_ptr<details::basic_streambuf<_CharType>>> op) -> streambuf<_CharType>
{
return streambuf<_CharType>(op.get());
});
}
#else
/// <summary>
/// Open a new stream buffer representing the given file.
/// </summary>
/// <param name="file">The StorageFile instance</param>
/// <param name="mode">The opening mode of the file</param>
/// <param name="prot">The file protection mode</param>
/// <returns>A <c>task</c> that returns an opened stream buffer on completion.</returns>
static pplx::task<streambuf<_CharType>> open(
::Windows::Storage::StorageFile^ file,
std::ios_base::openmode mode = std::ios_base::out)
{
auto bfb = details::basic_file_buffer<_CharType>::open(file, mode);
return bfb.then([](pplx::task<std::shared_ptr<details::basic_streambuf<_CharType>>> op) -> streambuf<_CharType>
{
return streambuf<_CharType>(op.get());
});
}
#endif
};
/// <summary>
/// File stream class containing factory functions for file streams.
/// </summary>
/// <typeparam name="_CharType">
/// The data type of the basic element of the <c>file_stream</c>.
/// </typeparam>
template<typename _CharType>
class file_stream
{
public:
#if !defined(__cplusplus_winrt)
/// <summary>
/// Open a new input stream representing the given file.
/// The file should already exist on disk, or an exception will be thrown.
/// </summary>
/// <param name="file_name">The name of the file</param>
/// <param name="mode">The opening mode of the file</param>
/// <param name="prot">The file protection mode</param>
/// <returns>A <c>task</c> that returns an opened input stream on completion.</returns>
static pplx::task<streams::basic_istream<_CharType>> open_istream(
const utility::string_t &file_name,
std::ios_base::openmode mode = std::ios_base::in,
#ifdef _WIN32
int prot = (int) std::ios_base::_Openprot
#else
int prot = 0
#endif
)
{
mode |= std::ios_base::in;
return streams::file_buffer<_CharType>::open(file_name, mode, prot)
.then([](streams::streambuf<_CharType> buf) -> basic_istream<_CharType>
{
return basic_istream<_CharType>(buf);
});
}
/// <summary>
/// Open a new ouput stream representing the given file.
/// If the file does not exist, it will be create unless the folder or directory
/// where it is to be found also does not exist.
/// </summary>
/// <param name="file_name">The name of the file</param>
/// <param name="mode">The opening mode of the file</param>
/// <param name="prot">The file protection mode</param>
/// <returns>A <c>task</c> that returns an opened output stream on completion.</returns>
static pplx::task<streams::basic_ostream<_CharType>> open_ostream(
const utility::string_t &file_name,
std::ios_base::openmode mode = std::ios_base::out,
#ifdef _WIN32
int prot = (int) std::ios_base::_Openprot
#else
int prot = 0
#endif
)
{
mode |= std::ios_base::out;
return streams::file_buffer<_CharType>::open(file_name, mode, prot)
.then([](streams::streambuf<_CharType> buf) -> basic_ostream<_CharType>
{
return basic_ostream<_CharType>(buf);
});
}
#else
/// <summary>
/// Open a new input stream representing the given file.
/// The file should already exist on disk, or an exception will be thrown.
/// </summary>
/// <param name="file">The StorageFile reference representing the file</param>
/// <param name="mode">The opening mode of the file</param>
/// <returns>A <c>task</c> that returns an opened input stream on completion.</returns>
static pplx::task<streams::basic_istream<_CharType>> open_istream(
::Windows::Storage::StorageFile^ file,
std::ios_base::openmode mode = std::ios_base::in)
{
mode |= std::ios_base::in;
return streams::file_buffer<_CharType>::open(file, mode)
.then([](streams::streambuf<_CharType> buf) -> basic_istream<_CharType>
{
return basic_istream<_CharType>(buf);
});
}
/// <summary>
/// Open a new ouput stream representing the given file.
/// If the file does not exist, it will be create unless the folder or directory
/// where it is to be found also does not exist.
/// </summary>
/// <param name="file">The StorageFile reference representing the file</param>
/// <param name="mode">The opening mode of the file</param>
/// <returns>A <c>task</c> that returns an opened output stream on completion.</returns>
static pplx::task<streams::basic_ostream<_CharType>> open_ostream(
::Windows::Storage::StorageFile^ file,
std::ios_base::openmode mode = std::ios_base::out)
{
mode |= std::ios_base::out;
return streams::file_buffer<_CharType>::open(file, mode)
.then([](streams::streambuf<_CharType> buf) -> basic_ostream<_CharType>
{
return basic_ostream<_CharType>(buf);
});
}
#endif
};
typedef file_stream<uint8_t> fstream;
}} // namespace concurrency::streams
#endif
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