Reference-counted stream buffer. More...

#include <astreambuf.h>

Inheritance diagram for Concurrency::streams::streambuf< _CharType >:

Public Types
typedef details::basic_streambuf< _CharType >::traits	traits

typedef details::basic_streambuf< _CharType >::int_type	int_type

typedef details::basic_streambuf< _CharType >::pos_type	pos_type

typedef details::basic_streambuf< _CharType >::off_type	off_type

typedef details::basic_streambuf< _CharType >::char_type	char_type

Public Types inherited from Concurrency::streams::details::basic_streambuf< _CharType >
typedef _CharType	char_type

typedef ::concurrency::streams::char_traits< _CharType >	traits

typedef traits::int_type	int_type

typedef traits::pos_type	pos_type

typedef traits::off_type	off_type

Public Member Functions
	streambuf (_In_ const std::shared_ptr< details::basic_streambuf< _CharType >> &ptr)
	Constructor. More...

	streambuf ()
	Default constructor. More...

template<typename AlterCharType >
	streambuf (const streambuf< AlterCharType > &other)
	Converter Constructor. More...

concurrency::streams::basic_istream< _CharType >	create_istream () const
	Constructs an input stream head for this stream buffer. More...

concurrency::streams::basic_ostream< _CharType >	create_ostream () const
	Constructs an output stream for this stream buffer. More...

	operator bool () const
	Checks if the stream buffer has been initialized or not. More...

virtual	~streambuf ()
	Destructor More...

const std::shared_ptr< details::basic_streambuf< _CharType > > &	get_base () const

virtual bool	can_read () const
	`can_read` is used to determine whether a stream buffer will support read operations (get). More...

virtual bool	can_write () const
	`can_write` is used to determine whether a stream buffer will support write operations (put). More...

virtual bool	can_seek () const
	`can_seek` is used to determine whether a stream buffer supports seeking. More...

virtual bool	has_size () const
	`has_size` is used to determine whether a stream buffer supports size(). More...

virtual utility::size64_t	size () const
	Gets the total number of characters in the stream buffer, if known. Calls to `has_size` will determine whether the result of `size` can be relied on. More...

virtual size_t	buffer_size (std::ios_base::openmode direction=std::ios_base::in) const
	Gets the stream buffer size, if one has been set. More...

virtual void	set_buffer_size (size_t size, std::ios_base::openmode direction=std::ios_base::in)
	Sets the stream buffer implementation to buffer or not buffer. More...

virtual size_t	in_avail () const
	For any input stream, `in_avail` 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. More...

virtual bool	is_open () const
	Checks if the stream buffer is open. More...

virtual bool	is_eof () const
	`is_eof` is used to determine whether a read head has reached the end of the buffer. More...

virtual pplx::task< void >	close (std::ios_base::openmode mode=(std::ios_base::in\|std::ios_base::out))
	Closes the stream buffer, preventing further read or write operations. More...

virtual pplx::task< void >	close (std::ios_base::openmode mode, std::exception_ptr eptr)
	Closes the stream buffer with an exception. More...

virtual pplx::task< int_type >	putc (_CharType ch)
	Writes a single character to the stream. More...

virtual _CharType *	alloc (size_t count)
	Allocates a contiguous memory block and returns it. More...

virtual void	commit (size_t count)
	Submits a block already allocated by the stream buffer. More...

virtual bool	acquire (_Out_ _CharType *&ptr, _Out_ size_t &count)
	Gets a pointer to the next already allocated contiguous block of data. More...

virtual void	release (_Out_writes_(count) _CharType *ptr, _In_ size_t count)
	Releases a block of data acquired using ::acquire method. This frees the stream buffer to de-allocate the memory, if it so desires. Move the read position ahead by the count. More...

virtual pplx::task< size_t >	putn (const _CharType *ptr, size_t count)
	Writes a number of characters to the stream. More...

virtual pplx::task< size_t >	putn_nocopy (const _CharType *ptr, size_t count)
	Writes a number of characters to the stream. Note: callers must make sure the data to be written is valid until the returned task completes. More...

virtual pplx::task< int_type >	bumpc ()
	Reads a single character from the stream and advances the read position. More...

virtual details::basic_streambuf< _CharType >::int_type	sbumpc ()
	Reads a single character from the stream and advances the read position. More...

virtual pplx::task< int_type >	getc ()
	Reads a single character from the stream without advancing the read position. More...

virtual details::basic_streambuf< _CharType >::int_type	sgetc ()
	Reads a single character from the stream without advancing the read position. More...

pplx::task< int_type >	nextc ()
	Advances the read position, then returns the next character without advancing again. More...

pplx::task< int_type >	ungetc ()
	Retreats the read position, then returns the current character without advancing. More...

virtual pplx::task< size_t >	getn (_Out_writes_(count) _CharType *ptr, _In_ size_t count)
	Reads up to a given number of characters from the stream. More...

virtual size_t	scopy (_Out_writes_(count) _CharType *ptr, _In_ size_t count)
	Copies up to a given number of characters from the stream, synchronously. More...

virtual details::basic_streambuf< _CharType >::pos_type	getpos (std::ios_base::openmode direction) const
	Gets the current read or write position in the stream. More...

virtual details::basic_streambuf< _CharType >::pos_type	seekpos (typename details::basic_streambuf< _CharType >::pos_type pos, std::ios_base::openmode direction)
	Seeks to the given position. More...

virtual details::basic_streambuf< _CharType >::pos_type	seekoff (typename details::basic_streambuf< _CharType >::off_type offset, std::ios_base::seekdir way, std::ios_base::openmode mode)
	Seeks to a position given by a relative offset. More...

virtual pplx::task< void >	sync ()
	For output streams, flush any internally buffered data to the underlying medium. More...

virtual std::exception_ptr	exception () const
	Retrieves the stream buffer exception_ptr if it has been set. More...

Public Member Functions inherited from Concurrency::streams::details::basic_streambuf< _CharType >
virtual	~basic_streambuf ()
	Virtual constructor for stream buffers. More...

virtual pos_type	seekpos (pos_type pos, std::ios_base::openmode direction)=0
	Seeks to the given position. More...

virtual pos_type	seekoff (off_type offset, std::ios_base::seekdir way, std::ios_base::openmode mode)=0
	Seeks to a position given by a relative offset. More...

virtual _CharType *	alloc (_In_ size_t count)=0
	Allocates a contiguous memory block and returns it. More...

virtual void	commit (_In_ size_t count)=0
	Submits a block already allocated by the stream buffer. More...

Friends
template<typename _CharType2 >
class	streambuf

Detailed Description

template<typename _CharType>
class Concurrency::streams::streambuf< _CharType >

Reference-counted stream buffer.

Template Parameters

_CharType	The data type of the basic element of the `streambuf.`
_CharType2	The data type of the basic element of the `streambuf.`

Constructor & Destructor Documentation

template<typename _CharType>

Concurrency::streams::streambuf< _CharType >::streambuf ( _In_ const std::shared_ptr< details::basic_streambuf< _CharType >> & ptr )

inline

Constructor.

Parameters

ptr	A pointer to the concrete stream buffer implementation.

template<typename _CharType>

Concurrency::streams::streambuf< _CharType >::streambuf ( )

inline

Default constructor.

template<typename _CharType>

template<typename AlterCharType >

Concurrency::streams::streambuf< _CharType >::streambuf ( const streambuf< AlterCharType > & other )

inline

Converter Constructor.

Template Parameters

AlterCharType The data type of the basic element of the source streambuf.

Parameters

other The source buffer to be converted.

template<typename _CharType>

virtual Concurrency::streams::streambuf< _CharType >::~streambuf ( )

inlinevirtual

Destructor

Member Function Documentation

template<typename _CharType>

virtual bool Concurrency::streams::streambuf< _CharType >::acquire	(	_Out_ _CharType *&	ptr,
		_Out_ size_t &	count
	)

inlinevirtual

Gets a pointer to the next already allocated contiguous block of data.

Parameters

ptr	A reference to a pointer variable that will hold the address of the block on success.
count	The number of contiguous characters available at the address in 'ptr.'

Returns: true if the operation succeeded, false otherwise.

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 ::release method is called. If the end of the stream is reached, the function will return true, a null pointer, and a count of zero; a subsequent read will not succeed.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual _CharType* Concurrency::streams::streambuf< _CharType >::alloc ( size_t count )

inlinevirtual

Allocates a contiguous memory block and returns it.

Parameters

count The number of characters to allocate.

Returns: A pointer to a block to write to, null if the stream buffer implementation does not support alloc/commit.

template<typename _CharType>

virtual size_t Concurrency::streams::streambuf< _CharType >::buffer_size ( std::ios_base::openmode direction = std::ios_base::in ) const

inlinevirtual

Gets the stream buffer size, if one has been set.

Parameters

direction The direction of buffering (in or out)

Returns: The size of the internal buffer (for the given direction).

An implementation that does not support buffering will always return 0.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual pplx::task<int_type> Concurrency::streams::streambuf< _CharType >::bumpc ( )

inlinevirtual

Reads a single character from the stream and advances the read position.

Returns: The value of the character. EOF if the read fails.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual bool Concurrency::streams::streambuf< _CharType >::can_read ( ) const

inlinevirtual

can_read is used to determine whether a stream buffer will support read operations (get).

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual bool Concurrency::streams::streambuf< _CharType >::can_seek ( ) const

inlinevirtual

can_seek is used to determine whether a stream buffer supports seeking.

Returns: True if seeking is supported, false otherwise.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual bool Concurrency::streams::streambuf< _CharType >::can_write ( ) const

inlinevirtual

can_write is used to determine whether a stream buffer will support write operations (put).

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual pplx::task<void> Concurrency::streams::streambuf< _CharType >::close ( std::ios_base::openmode mode = (std::ios_base::in | std::ios_base::out) )

inlinevirtual

Closes the stream buffer, preventing further read or write operations.

Parameters

mode	The I/O mode (in or out) to close for.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual pplx::task<void> Concurrency::streams::streambuf< _CharType >::close	(	std::ios_base::openmode	mode,
		std::exception_ptr	eptr
	)

inlinevirtual

Closes the stream buffer with an exception.

Parameters

mode	The I/O mode (in or out) to close for.
eptr	Pointer to the exception.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual void Concurrency::streams::streambuf< _CharType >::commit ( size_t count )

inlinevirtual

Submits a block already allocated by the stream buffer.

Parameters

count The number of characters to be committed.

template<typename _CharType>

concurrency::streams::basic_istream<_CharType> Concurrency::streams::streambuf< _CharType >::create_istream ( ) const

inline

Constructs an input stream head for this stream buffer.

Returns: basic_istream.

template<typename _CharType>

concurrency::streams::basic_ostream<_CharType> Concurrency::streams::streambuf< _CharType >::create_ostream ( ) const

inline

Constructs an output stream for this stream buffer.

Returns: basic_ostream

template<typename _CharType>

virtual std::exception_ptr Concurrency::streams::streambuf< _CharType >::exception ( ) const

inlinevirtual

Retrieves the stream buffer exception_ptr if it has been set.

Returns: Pointer to the exception, if it has been set; otherwise, nullptr will be returned

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual pplx::task<int_type> Concurrency::streams::streambuf< _CharType >::getc ( )

inlinevirtual

Reads a single character from the stream without advancing the read position.

Returns: The value of the byte. EOF if the read fails.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual pplx::task<size_t> Concurrency::streams::streambuf< _CharType >::getn	(	_Out_writes_(count) _CharType *	ptr,
		_In_ size_t	count
	)

inlinevirtual

Reads up to a given number of characters from the stream.

Parameters

ptr	The address of the target memory area.
count	The maximum number of characters to read.

Returns: The number of characters read. O if the end of the stream is reached.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual details::basic_streambuf<_CharType>::pos_type Concurrency::streams::streambuf< _CharType >::getpos ( std::ios_base::openmode direction ) const

inlinevirtual

Gets the current read or write position in the stream.

Parameters

direction The I/O direction to seek (see remarks)

Returns: The current position. EOF if the operation fails.

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.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual bool Concurrency::streams::streambuf< _CharType >::has_size ( ) const

inlinevirtual

has_size is used to determine whether a stream buffer supports size().

Returns: True if the size API is supported, false otherwise.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual size_t Concurrency::streams::streambuf< _CharType >::in_avail ( ) const

inlinevirtual

For any input stream, in_avail 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.

Returns: Number of characters that are ready to read.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual bool Concurrency::streams::streambuf< _CharType >::is_eof ( ) const

inlinevirtual

is_eof is used to determine whether a read head has reached the end of the buffer.

Returns: True if at the end of the buffer, false otherwise.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual bool Concurrency::streams::streambuf< _CharType >::is_open ( ) const

inlinevirtual

Checks if the stream buffer is open.

No separation is made between open for reading and open for writing.

Returns: True if the stream buffer is open for reading or writing, false otherwise.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

pplx::task<int_type> Concurrency::streams::streambuf< _CharType >::nextc ( )

inlinevirtual

Advances the read position, then returns the next character without advancing again.

Returns: The value of the character. EOF if the read fails.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

Concurrency::streams::streambuf< _CharType >::operator bool ( ) const

inline

Checks if the stream buffer has been initialized or not.

template<typename _CharType>

virtual pplx::task<int_type> Concurrency::streams::streambuf< _CharType >::putc ( _CharType ch )

inlinevirtual

Writes a single character to the stream.

Parameters

ch	The character to write

Returns: The value of the character. EOF if the write operation fails

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual pplx::task<size_t> Concurrency::streams::streambuf< _CharType >::putn	(	const _CharType *	ptr,
		size_t	count
	)

inlinevirtual

Writes a number of characters to the stream.

Parameters

ptr	A pointer to the block of data to be written.
count	The number of characters to write.

Returns: The number of characters actually written, either 'count' or 0.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual pplx::task<size_t> Concurrency::streams::streambuf< _CharType >::putn_nocopy	(	const _CharType *	ptr,
		size_t	count
	)

inlinevirtual

Writes a number of characters to the stream. Note: callers must make sure the data to be written is valid until the returned task completes.

Parameters

ptr	A pointer to the block of data to be written.
count	The number of characters to write.

Returns: The number of characters actually written, either 'count' or 0.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual void Concurrency::streams::streambuf< _CharType >::release	(	_Out_writes_(count) _CharType *	ptr,
		_In_ size_t	count
	)

inlinevirtual

Releases a block of data acquired using ::acquire method. This frees the stream buffer to de-allocate the memory, if it so desires. Move the read position ahead by the count.

Parameters

ptr	A pointer to the block of data to be released.
count	The number of characters that were read.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual details::basic_streambuf<_CharType>::int_type Concurrency::streams::streambuf< _CharType >::sbumpc ( )

inlinevirtual

Reads a single character from the stream and advances the read position.

Returns: The value of the character. -1 if the read fails. -2 if an asynchronous read is required

This is a synchronous operation, but is guaranteed to never block.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual size_t Concurrency::streams::streambuf< _CharType >::scopy	(	_Out_writes_(count) _CharType *	ptr,
		_In_ size_t	count
	)

inlinevirtual

Copies up to a given number of characters from the stream, synchronously.

Parameters

ptr	The address of the target memory area.
count	The maximum number of characters to read.

Returns: The number of characters copied. O if the end of the stream is reached or an asynchronous read is required.

This is a synchronous operation, but is guaranteed to never block.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual details::basic_streambuf<_CharType>::pos_type Concurrency::streams::streambuf< _CharType >::seekoff	(	typename details::basic_streambuf< _CharType >::off_type	offset,
		std::ios_base::seekdir	way,
		std::ios_base::openmode	mode
	)

inlinevirtual

Seeks to a position given by a relative offset.

Parameters

offset	The relative position to seek to
way	The starting point (beginning, end, current) for the seek.
mode	The I/O direction to seek (see remarks)

Returns: The position. EOF if the operation fails.

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.

template<typename _CharType>

virtual details::basic_streambuf<_CharType>::pos_type Concurrency::streams::streambuf< _CharType >::seekpos	(	typename details::basic_streambuf< _CharType >::pos_type	pos,
		std::ios_base::openmode	direction
	)

inlinevirtual

Seeks to the given position.

Parameters

pos	The offset from the beginning of the stream.
direction	The I/O direction to seek (see remarks).

Returns: The position. EOF if the operation fails.

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.

template<typename _CharType>

virtual void Concurrency::streams::streambuf< _CharType >::set_buffer_size	(	size_t	size,
		std::ios_base::openmode	direction = `std::ios_base::in`
	)

inlinevirtual

Sets the stream buffer implementation to buffer or not buffer.

Parameters

size	The size to use for internal buffering, 0 if no buffering should be done.
direction	The direction of buffering (in or out)

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 method.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual details::basic_streambuf<_CharType>::int_type Concurrency::streams::streambuf< _CharType >::sgetc ( )

inlinevirtual

Reads a single character from the stream without advancing the read position.

Returns: The value of the character. EOF if the read fails. ::requires_async method if an asynchronous read is required

This is a synchronous operation, but is guaranteed to never block.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual utility::size64_t Concurrency::streams::streambuf< _CharType >::size ( ) const

inlinevirtual

Gets the total number of characters in the stream buffer, if known. Calls to has_size will determine whether the result of size can be relied on.

Returns: The total number of characters in the stream buffer.

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

virtual pplx::task<void> Concurrency::streams::streambuf< _CharType >::sync ( )

inlinevirtual

For output streams, flush any internally buffered data to the underlying medium.

Returns: true if the flush succeeds, false if not

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

template<typename _CharType>

pplx::task<int_type> Concurrency::streams::streambuf< _CharType >::ungetc ( )

inlinevirtual

Retreats the read position, then returns the current character without advancing.

Returns: The value of the character. EOF if the read fails. ::requires_async method if an asynchronous read is required

Implements Concurrency::streams::details::basic_streambuf< _CharType >.

The documentation for this class was generated from the following file:

include/cpprest/astreambuf.h

Public Types

Public Member Functions

Friends

Detailed Description

template<typename _CharType> class Concurrency::streams::streambuf< _CharType >

Constructor & Destructor Documentation

Member Function Documentation

template<typename _CharType>
class Concurrency::streams::streambuf< _CharType >