bit::Buffer Class Reference
["Data Buffers", "Data Buffers", "Data Buffers"]

#include <bit/buffer.h>

Inheritance diagram for bit::Buffer:

[legend]List of all members.

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Detailed Description

This class manages a packed bit (or octet) buffer.

Although this class manages bit oriented buffers, it attempts to optimize for octet (byte) based buffers.

The methods pack, unpack and clear provide a means of extracting bit segments from the buffer.

Todo:

create an overloaded = operator that copies memory if the buffer is the owner

Author:

Rick L. Vinyard, Jr.

Public Types
typedef BitPointer< Buffer >	pointer
typedef BitPointer< Buffer >	pointer
typedef BitPointer< Buffer >	pointer
Public Member Functions
bool	unpack (void *mem, size_t mem_octets, Location mem_loc, size_t buf_offset_bits, size_t extract_bits)
	Transfer data from the buffer area into the low order bits of a memory location.
Data	unpack (size_t buf_offset_bits, size_t extract_bits, Location mem_loc=END)
template<typename T>
bool	unpack (T &val, Location mem_loc, size_t buf_offset_bits, size_t extract_bits)
bool	pack (const void *mem, size_t mem_octets, Location mem_loc, size_t buf_offset, size_t buf_tgtsize, size_t n)
	Transfer data from the low order bits of a memory location into the low order bits of a segment of the buffer area.
bool	pack (Data d, size_t buf_offset, size_t buf_tgtsize, size_t n, Location mem_loc=END)
template<typename T>
bool	pack (const T &val, Location mem_loc, size_t offset, size_t destsize, size_t n)
bool	clear_bits (size_t offset, size_t bits)
size_t	size_max ()
	Gets the maximum size this buffer is allowed to grow.
void	set_size_max (size_t sizemax)
	Sets the maximum size that this buffer is allowed to grow.
virtual void	set_data (const void *newdata, size_t newsize, DataMode mode=COPY) throw (std::bad_alloc)
virtual bool	resize (size_t s) throw (std::bad_alloc)
sigc::signal< void >	signal_changed ()
	Signals a change to the data within the buffer.
bool	unpack (void *mem, size_t mem_octets, Location mem_loc, size_t buf_offset_bits, size_t extract_bits)
	Transfer data from the buffer area into the low order bits of a memory location.
Data::pointer	unpack (size_t buf_offset_bits, size_t extract_bits, Location mem_loc=END)
template<typename T>
bool	unpack (T &val, Location mem_loc, size_t buf_offset_bits, size_t extract_bits)
bool	pack (const void *mem, size_t mem_octets, Location mem_loc, size_t buf_offset, size_t buf_tgtsize, size_t n)
	Transfer data from the low order bits of a memory location into the low order bits of a segment of the buffer area.
bool	pack (Data::pointer d, size_t buf_offset, size_t buf_tgtsize, size_t n, Location mem_loc=END)
template<typename T>
bool	pack (const T &val, Location mem_loc, size_t offset, size_t destsize, size_t n)
bool	clear_bits (size_t offset, size_t bits)
size_t	size_max ()
	Gets the maximum size this buffer is allowed to grow.
void	set_size_max (size_t sizemax)
	Sets the maximum size that this buffer is allowed to grow.
virtual void	set_data (const void *newdata, size_t newsize, DataMode mode=COPY) throw (std::bad_alloc)
virtual bool	resize (size_t s) throw (std::bad_alloc)
sigc::signal< void >	signal_changed ()
	Signals a change to the data within the buffer.
bool	unpack (void *mem, size_t mem_octets, Location mem_loc, size_t buf_offset_bits, size_t extract_bits)
	Transfer data from the buffer area into the low order bits of a memory location.
Data::pointer	unpack (size_t buf_offset_bits, size_t extract_bits, Location mem_loc=END)
template<typename T>
bool	unpack (T &val, Location mem_loc, size_t buf_offset_bits, size_t extract_bits)
bool	pack (const void *mem, size_t mem_octets, Location mem_loc, size_t buf_offset, size_t buf_tgtsize, size_t n)
	Transfer data from the low order bits of a memory location into the low order bits of a segment of the buffer area.
bool	pack (Data::pointer d, size_t buf_offset, size_t buf_tgtsize, size_t n, Location mem_loc=END)
template<typename T>
bool	pack (const T &val, Location mem_loc, size_t offset, size_t destsize, size_t n)
bool	clear_bits (size_t offset, size_t bits)
size_t	size_max ()
	Gets the maximum size this buffer is allowed to grow.
void	set_size_max (size_t sizemax)
	Sets the maximum size that this buffer is allowed to grow.
virtual void	set_data (const void *newdata, size_t newsize, DataMode mode=COPY) throw (std::bad_alloc)
virtual bool	resize (size_t s) throw (std::bad_alloc)
sigc::signal< void >	signal_changed ()
	Signals a change to the data within the buffer.
Static Public Member Functions
static pointer	create (size_t initial_size=0, size_t sizemax=0)
static pointer	create (void *data, size_t size, size_t sizemax=0, DataMode mode=COPY)
static pointer	create (size_t initial_size=0, size_t sizemax=0)
static pointer	create (void *data, size_t size, size_t sizemax=0, DataMode mode=COPY)
static pointer	create (size_t initial_size=0, size_t sizemax=0)
static pointer	create (void *data, size_t size, size_t sizemax=0, DataMode mode=COPY)
Protected Member Functions
	Buffer (size_t initial_size=0, size_t sizemax=0)
	Construct a buffer of a given size that is allowed to dynamically grown as pack/unpack requests are made.
	Buffer (void *data, size_t size, size_t sizemax=0, DataMode mode=COPY)
	Construct a buffer that is a copy of external data.
bool	clear_bits (size_t offset, size_t bits, bool suppress)
	Utility method to clear bits and suppress calling the on_changed* methods.
virtual void	on_data_changed ()
	Buffer (size_t initial_size=0, size_t sizemax=0)
	Construct a buffer of a given size that is allowed to dynamically grown as pack/unpack requests are made.
	Buffer (void *data, size_t size, size_t sizemax=0, DataMode mode=COPY)
	Construct a buffer that is a copy of external data.
bool	clear_bits (size_t offset, size_t bits, bool suppress)
	Utility method to clear bits and suppress calling the on_changed* methods.
virtual void	on_data_changed ()
	Buffer (size_t initial_size=0, size_t sizemax=0)
	Construct a buffer of a given size that is allowed to dynamically grown as pack/unpack requests are made.
	Buffer (void *data, size_t size, size_t sizemax=0, DataMode mode=COPY)
	Construct a buffer that is a copy of external data.
bool	clear_bits (size_t offset, size_t bits, bool suppress)
	Utility method to clear bits and suppress calling the on_changed* methods.
virtual void	on_data_changed ()
Protected Attributes
size_t	m_size_max

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Member Function Documentation

bool bit::Buffer::unpack	(	void *	mem,
		size_t	mem_octets,
		Location	mem_loc,
		size_t	buf_offset_bits,
		size_t	extract_bits
	)

Transfer data from the buffer area into the low order bits of a memory location.

Parameters:

	mem	The memory location to transfer buffer data into
	mem_octets	The size of the memory location in octets
	buf_offset_bits	The offset from the beginning of the buffer in bits to begin extraction from
	bits	The size of the data to extract in bits

Returns:

true if transfer accomplished, false otherwise

Bit Buffer ================================================== |000000000011111111112222222222333333333344444444| |012345678901234567890123456789012345678901234567| ================================================== ^ buf_offset_bits = 14 ^ extract_bits = 20 ^

Memory Buffer ================================================== |000000000011111111112222222222333333333344444444| |012345678901234567890123456789012345678901234567| ================================================== ^ mem = start of memory address ^ mem_octets = 6 ^ ^ Resulting data ^ when mem_loc = END ^ Resulting data ^ when mem_loc = START

bool bit::Buffer::pack	(	const void *	mem,
		size_t	mem_octets,
		Location	mem_loc,
		size_t	buf_offset,
		size_t	buf_tgtsize,
		size_t	n
	)

Transfer data from the low order bits of a memory location into the low order bits of a segment of the buffer area.

Parameters:

	mem	The memory location to transfer from
	mem_octets	The size of the memory location in octets
	buf_offset	The offset from the start of the data buffer in bits
	buf_tgtsize	The size of the target area in the buffer in bits
	n	The size of the data to extract in bits

Returns:

true if transfer accomplished, false otherwise. If

Parameters:

	offset	+
	destsize	are greater than the size of the buffer and the buffer cannot be expanded to accommodate the request zero is returned.

Memory Buffer ================================================== |000000000011111111112222222222333333333344444444| |012345678901234567890123456789012345678901234567| ================================================== ^ mem = start of memory address ^ mem_octets = 6 ^ ^ n = 10 ^ when mem_loc = END ^ cpy out^ when mem_loc = END ^ n = 10 ^ when mem_loc = START ^ cpy out^ when mem_loc = START

Bit Buffer ================================================== |000000000011111111112222222222333333333344444444| |012345678901234567890123456789012345678901234567| ================================================== ^ buf_offset_bits = 14 ^ buf_tgtsize = 20 ^ ^ n = 10 ^ ^ cpy in ^

void bit::Buffer::set_size_max

(

size_t

sizemax

)

Sets the maximum size that this buffer is allowed to grow.

Note: if sizemax is set to a value less than the current buffer size the buffer will be truncated immediately.

bool bit::Buffer::unpack	(	void *	mem,
		size_t	mem_octets,
		Location	mem_loc,
		size_t	buf_offset_bits,
		size_t	extract_bits
	)

Transfer data from the buffer area into the low order bits of a memory location.

Parameters:

	mem	The memory location to transfer buffer data into
	mem_octets	The size of the memory location in octets
	buf_offset_bits	The offset from the beginning of the buffer in bits to begin extraction from
	bits	The size of the data to extract in bits

Returns:

true if transfer accomplished, false otherwise

Bit Buffer ================================================== |000000000011111111112222222222333333333344444444| |012345678901234567890123456789012345678901234567| ================================================== ^ buf_offset_bits = 14 ^ extract_bits = 20 ^

Memory Buffer ================================================== |000000000011111111112222222222333333333344444444| |012345678901234567890123456789012345678901234567| ================================================== ^ mem = start of memory address ^ mem_octets = 6 ^ ^ Resulting data ^ when mem_loc = END ^ Resulting data ^ when mem_loc = START

bool bit::Buffer::pack	(	const void *	mem,
		size_t	mem_octets,
		Location	mem_loc,
		size_t	buf_offset,
		size_t	buf_tgtsize,
		size_t	n
	)

Transfer data from the low order bits of a memory location into the low order bits of a segment of the buffer area.

Parameters:

	mem	The memory location to transfer from
	mem_octets	The size of the memory location in octets
	buf_offset	The offset from the start of the data buffer in bits
	buf_tgtsize	The size of the target area in the buffer in bits
	n	The size of the data to extract in bits

Returns:

true if transfer accomplished, false otherwise. If

Parameters:

	offset	+
	destsize	are greater than the size of the buffer and the buffer cannot be expanded to accommodate the request zero is returned.

Memory Buffer ================================================== |000000000011111111112222222222333333333344444444| |012345678901234567890123456789012345678901234567| ================================================== ^ mem = start of memory address ^ mem_octets = 6 ^ ^ n = 10 ^ when mem_loc = END ^ cpy out^ when mem_loc = END ^ n = 10 ^ when mem_loc = START ^ cpy out^ when mem_loc = START

Bit Buffer ================================================== |000000000011111111112222222222333333333344444444| |012345678901234567890123456789012345678901234567| ================================================== ^ buf_offset_bits = 14 ^ buf_tgtsize = 20 ^ ^ n = 10 ^ ^ cpy in ^

void bit::Buffer::set_size_max

(

size_t

sizemax

)

Sets the maximum size that this buffer is allowed to grow.

Note: if sizemax is set to a value less than the current buffer size the buffer will be truncated immediately.

bool bit::Buffer::unpack	(	void *	mem,
		size_t	mem_octets,
		Location	mem_loc,
		size_t	buf_offset_bits,
		size_t	extract_bits
	)

Transfer data from the buffer area into the low order bits of a memory location.

Parameters:

	mem	The memory location to transfer buffer data into
	mem_octets	The size of the memory location in octets
	buf_offset_bits	The offset from the beginning of the buffer in bits to begin extraction from
	bits	The size of the data to extract in bits

Returns:

true if transfer accomplished, false otherwise

Bit Buffer ================================================== |000000000011111111112222222222333333333344444444| |012345678901234567890123456789012345678901234567| ================================================== ^ buf_offset_bits = 14 ^ extract_bits = 20 ^

Memory Buffer ================================================== |000000000011111111112222222222333333333344444444| |012345678901234567890123456789012345678901234567| ================================================== ^ mem = start of memory address ^ mem_octets = 6 ^ ^ Resulting data ^ when mem_loc = END ^ Resulting data ^ when mem_loc = START

bool bit::Buffer::pack	(	const void *	mem,
		size_t	mem_octets,
		Location	mem_loc,
		size_t	buf_offset,
		size_t	buf_tgtsize,
		size_t	n
	)

Transfer data from the low order bits of a memory location into the low order bits of a segment of the buffer area.

Parameters:

	mem	The memory location to transfer from
	mem_octets	The size of the memory location in octets
	buf_offset	The offset from the start of the data buffer in bits
	buf_tgtsize	The size of the target area in the buffer in bits
	n	The size of the data to extract in bits

Returns:

true if transfer accomplished, false otherwise. If

Parameters:

	offset	+
	destsize	are greater than the size of the buffer and the buffer cannot be expanded to accommodate the request zero is returned.

Memory Buffer ================================================== |000000000011111111112222222222333333333344444444| |012345678901234567890123456789012345678901234567| ================================================== ^ mem = start of memory address ^ mem_octets = 6 ^ ^ n = 10 ^ when mem_loc = END ^ cpy out^ when mem_loc = END ^ n = 10 ^ when mem_loc = START ^ cpy out^ when mem_loc = START

Bit Buffer ================================================== |000000000011111111112222222222333333333344444444| |012345678901234567890123456789012345678901234567| ================================================== ^ buf_offset_bits = 14 ^ buf_tgtsize = 20 ^ ^ n = 10 ^ ^ cpy in ^

void bit::Buffer::set_size_max

(

size_t

sizemax

)

Sets the maximum size that this buffer is allowed to grow.

Note: if sizemax is set to a value less than the current buffer size the buffer will be truncated immediately.

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

• bit/buffer.h
• debian/libbit-dev/usr/include/bit-0.3/bit/buffer.h
• debian/tmp/usr/include/bit-0.3/bit/buffer.h
• buffer.cpp

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