Circular stream buffer to be used with the standard library's stream classes. Reading from or writing behind the buffer's end continues at the buffer's beginning. More...

Inheritance diagram for Util::circularbuf:

Public Types
using	CharT = char
	Data type of a single character stored in the buffer. More...

Public Member Functions
	circularbuf (size_t size)
	Constructs a new `circularbuf` instance with a buffer of size `size`. The put area will span the entire buffer, the get area will be empty. More...

bool	empty ()
	Indicates whether characters can be read from the get area. Not const since `sync()` needs to be called to get correct size after a character has been written recently. More...

size_t	gsize ()
	Returns the size of the get area. Not const since `sync()` needs to be called to get correct size after a character has been written recently. More...

size_t	psize () const noexcept
	Returns the size of the put area. More...

pos_type	gtellp () const noexcept
	Indicates the get pointer's position within the get area. More...

pos_type	ptellp () const noexcept
	Indicates the put pointer's position within the put area. More...

void	clear ()
	Resets the put areas to the entire area of buffer. The get area will be empty. The get and put pointers will point to the beginning of their respective areas. Resets put_overflowed. More...

void	resize (size_t size)
	Resizes the size of buffer to `size`. The put area will span the entire buffer. If the buffer is enlarged, the get area will maintain its size. If the buffer is shrunk, the get area will span the entire buffer. If the original put (get) pointer falls behind the new put (get) area's length, it is set to the put (get) area's end, otherwise it will maintain its old position. More...

Private Member Functions
std::streamsize	avail_get_count () const noexcept
	Returns the amount of characters available to be read from the current get pointer position to the get area's end. More...

virtual pos_type	seekoff (off_type off, std::ios_base::seekdir dir, std::ios_base::openmode which=std::ios_base::in\|std::ios_base::out) override
	Sets the position of the pointer(s) specified by `which` to the position `pos` relative to `dir`. Takes the stream's circularity into account. More...

virtual pos_type	seekpos (pos_type pos, std::ios_base::openmode which=std::ios_base::in\|std::ios_base::out) override
	Sets the position of the pointer(s) specified by `which` to the absolute position `pos`. More...

template<typename T , std::enable_if_t< std::is_unsigned_v< T >, int > = 0>
pos_type	to_pos_type (const T value)
	Converts an unsigned, integral number type to `pos_type`. More...

Overridden
Overridden from standard library. Refer to documentation of `std::streambuf`.
virtual int_type	overflow (int_type c=traits_type::eof()) override
	Refer to documentation of `std::streambuf`. More...

virtual int_type	underflow () override
	Refer to documentation of `std::streambuf`. More...

virtual std::streamsize	showmanyc () override
	Refer to documentation of `std::streambuf`. More...

virtual int_type	pbackfail (int_type c=traits_type::eof()) override
	Refer to documentation of `std::streambuf`. More...

virtual int	sync () override
	Expands the get area to the size of the put area. Resets put_overflowed. More...

Private Attributes
std::vector< CharT >	buffer
	The buffer itself. More...

bool	put_overflowed
	Indicates wheter an overflow occurred writing to the buffer. If this was the case, subsequent calls to `sync()` have to enlarge the get area to the put area's size regardless of the current put pointer's position. More...

Detailed Description

Circular stream buffer to be used with the standard library's stream classes. Reading from or writing behind the buffer's end continues at the buffer's beginning.

Definition at line 19 of file circularbuf.h.

Member Typedef Documentation

◆ CharT

using Util::circularbuf::CharT = char

Data type of a single character stored in the buffer.

Definition at line 25 of file circularbuf.h.

Constructor & Destructor Documentation

◆ circularbuf()

Util::circularbuf::circularbuf ( size_t size )

Constructs a new circularbuf instance with a buffer of size size. The put area will span the entire buffer, the get area will be empty.

Parameters

size	Initial buffer size

Definition at line 8 of file circularbuf.cpp.

Member Function Documentation

◆ avail_get_count()

std::streamsize Util::circularbuf::avail_get_count ( ) const

privatenoexcept

Returns the amount of characters available to be read from the current get pointer position to the get area's end.

Returns: Amount of available characters

Definition at line 71 of file circularbuf.cpp.

◆ clear()

void Util::circularbuf::clear ( )

Resets the put areas to the entire area of buffer. The get area will be empty. The get and put pointers will point to the beginning of their respective areas. Resets put_overflowed.

Definition at line 44 of file circularbuf.cpp.

◆ empty()

bool Util::circularbuf::empty ( )

Indicates whether characters can be read from the get area. Not const since sync() needs to be called to get correct size after a character has been written recently.

Returns: Returns true if avail_get_count() returns 0, false otherwise.

Definition at line 15 of file circularbuf.cpp.

◆ gsize()

size_t Util::circularbuf::gsize ( )

Returns the size of the get area. Not const since sync() needs to be called to get correct size after a character has been written recently.

Returns: Get area size

Definition at line 22 of file circularbuf.cpp.

◆ gtellp()

circularbuf::pos_type Util::circularbuf::gtellp ( ) const

noexcept

Indicates the get pointer's position within the get area.

Returns: Returns the distance between the get area's beginning and the get pointer's position.

Definition at line 34 of file circularbuf.cpp.

◆ overflow()

circularbuf::int_type Util::circularbuf::overflow ( int_type c = traits_type::eof() )

overrideprivatevirtual

Refer to documentation of std::streambuf.

Definition at line 76 of file circularbuf.cpp.

◆ pbackfail()

circularbuf::int_type Util::circularbuf::pbackfail ( int_type c = traits_type::eof() )

overrideprivatevirtual

Refer to documentation of std::streambuf.

Definition at line 118 of file circularbuf.cpp.

◆ psize()

size_t Util::circularbuf::psize ( ) const

noexcept

Returns the size of the put area.

Returns: Put area size

Definition at line 29 of file circularbuf.cpp.

◆ ptellp()

circularbuf::pos_type Util::circularbuf::ptellp ( ) const

noexcept

Indicates the put pointer's position within the put area.

Returns: Returns the distance between the put area's beginning and the put pointer's position.

Definition at line 39 of file circularbuf.cpp.

◆ resize()

void Util::circularbuf::resize ( size_t size )

Resizes the size of buffer to size. The put area will span the entire buffer. If the buffer is enlarged, the get area will maintain its size. If the buffer is shrunk, the get area will span the entire buffer. If the original put (get) pointer falls behind the new put (get) area's length, it is set to the put (get) area's end, otherwise it will maintain its old position.

Parameters

size	New buffer size to apply

Exceptions

std::overflow_error is thrown if size does not fit into int.

Definition at line 52 of file circularbuf.cpp.

◆ seekoff()

circularbuf::pos_type Util::circularbuf::seekoff	(	off_type	off,
		std::ios_base::seekdir	dir,
		std::ios_base::openmode	which = `std::ios_base::in \| std::ios_base::out`
	)

overrideprivatevirtual

Sets the position of the pointer(s) specified by which to the position pos relative to dir. Takes the stream's circularity into account.

Parameters

off	Destiny position (relative to `dir`).
dir	Set position relative to stream's beginning (`std::ios_base::beg`), its end (`std::ios_base::end`) or the current position (`std::ios_base::cur`).
which	Combination of flags `std::ios_base::in` and `std::ios_base::out` specifying get or put pointers.

Returns: New position pos in case of success, -1 otherwise. If the get and the put pointers are both successfully moved, the new position of the get pointer is returned.

Definition at line 149 of file circularbuf.cpp.

◆ seekpos()

circularbuf::pos_type Util::circularbuf::seekpos	(	pos_type	pos,
		std::ios_base::openmode	which = `std::ios_base::in \| std::ios_base::out`
	)

overrideprivatevirtual

Sets the position of the pointer(s) specified by which to the absolute position pos.

Parameters

pos	Destiny position (absolute).
which	Combination of flags `std::ios_base::in` and `std::ios_base::out` specifying get or put pointers.

Returns: New position pos in case of success, -1 otherwise.

Definition at line 200 of file circularbuf.cpp.

◆ showmanyc()

std::streamsize Util::circularbuf::showmanyc ( )

overrideprivatevirtual

Refer to documentation of std::streambuf.

Definition at line 110 of file circularbuf.cpp.

◆ sync()

int Util::circularbuf::sync ( )

overrideprivatevirtual

Expands the get area to the size of the put area. Resets put_overflowed.

Returns: Returns 0.

Definition at line 139 of file circularbuf.cpp.

◆ to_pos_type()

template<typename T , std::enable_if_t< std::is_unsigned_v< T >, int > = 0>

pos_type Util::circularbuf::to_pos_type ( const T value )

inlineprivate

Converts an unsigned, integral number type to pos_type.

Template Parameters

T	Type to convert from

Parameters

value Value to convert

Returns: Returns the converted value.

Exceptions

std::overflow_error is thrown if value is larger than the maximal number storable in pos_type.

Definition at line 143 of file circularbuf.h.

◆ underflow()

circularbuf::int_type Util::circularbuf::underflow ( )

overrideprivatevirtual

Refer to documentation of std::streambuf.

Definition at line 95 of file circularbuf.cpp.

Member Data Documentation

◆ buffer

std::vector<CharT> Util::circularbuf::buffer

private

The buffer itself.

Definition at line 154 of file circularbuf.h.

◆ put_overflowed

bool Util::circularbuf::put_overflowed

private

Indicates wheter an overflow occurred writing to the buffer. If this was the case, subsequent calls to sync() have to enlarge the get area to the put area's size regardless of the current put pointer's position.

Definition at line 161 of file circularbuf.h.

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

Public Types

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

◆ CharT

Constructor & Destructor Documentation

◆ circularbuf()

Member Function Documentation

◆ avail_get_count()

◆ clear()

◆ empty()

◆ gsize()

◆ gtellp()

◆ overflow()

◆ pbackfail()

◆ psize()

◆ ptellp()

◆ resize()

◆ seekoff()

◆ seekpos()

◆ showmanyc()

◆ sync()

◆ to_pos_type()

◆ underflow()

Member Data Documentation

◆ buffer

◆ put_overflowed