esphome::packet_interface::PacketBuffer Class Reference

A buffer class that efficiently represents a composite buffer with three sections: More...

#include <packet_buffer.h>

Public Member Functions
	PacketBuffer ()=default
	PacketBuffer (const PacketBuffer &)=delete
PacketBuffer &	operator= (const PacketBuffer &)=delete
	PacketBuffer (PacketBuffer &&)=default
PacketBuffer &	operator= (PacketBuffer &&)=default
	PacketBuffer (const uint8_t *data, size_t length)
	Construct from a single buffer.
	PacketBuffer (const std::vector< uint8_t > &vec)
	Construct from a vector.
	PacketBuffer (std::vector< uint8_t > &&)=delete
	PacketBuffer (const uint8_t *pre_data, size_t pre_length, const uint8_t *post_data, size_t post_length)
	Construct with pre and post buffers.
	PacketBuffer (const uint8_t *pre_data, size_t pre_length, const PacketBuffer *mid_buffer, const uint8_t *post_data, size_t post_length)
	Construct with pre, mid, and post buffers.
size_t	size () const
	Get the total size of the buffer.
bool	empty () const
	Check if the buffer is empty.
bool	is_contiguous () const
	Check if all the data is held in the pre-buffer, so it can be read as one span.
std::span< const uint8_t >	as_span () const
	Get the data as one span.
uint8_t	operator[] (size_t index) const
	Access a byte at a specific position.
size_t	copy_to (uint8_t *dest, size_t count, size_t offset=0) const
	Copy data from the buffer to a destination pointer.

Detailed Description

A buffer class that efficiently represents a composite buffer with three sections:

• pre_buffer: A pointer to uint8_t data with a length
• mid_buffer: A reference to another PacketBuffer (optional)
• post_buffer: A pointer to uint8_t data with a length

This allows efficient zero-copy composition of buffers without allocating new memory.

WARNING: PacketBuffer holds raw pointers to data. The user must ensure that the data remains valid for the lifetime of the PacketBuffer instance. Storing PacketBuffer instances beyond the scope of the data they reference will lead to dangling pointers and undefined behavior, so to keep a packet, copy it with copy_to() into a buffer allocated in setup().

Definition at line 24 of file packet_buffer.h.

Constructor & Destructor Documentation

PacketBuffer() [1/8]

esphome::packet_interface::PacketBuffer::PacketBuffer ( )

default

PacketBuffer() [2/8]

esphome::packet_interface::PacketBuffer::PacketBuffer ( const PacketBuffer & )

delete

PacketBuffer() [3/8]

esphome::packet_interface::PacketBuffer::PacketBuffer ( PacketBuffer && )

default

PacketBuffer() [4/8]

esphome::packet_interface::PacketBuffer::PacketBuffer ( const uint8_t * data, size_t length )

inline

Construct from a single buffer.

Definition at line 39 of file packet_buffer.h.

PacketBuffer() [5/8]

esphome::packet_interface::PacketBuffer::PacketBuffer ( const std::vector< uint8_t > & vec )

inlineexplicit

Construct from a vector.

Definition at line 44 of file packet_buffer.h.

PacketBuffer() [6/8]

esphome::packet_interface::PacketBuffer::PacketBuffer ( std::vector< uint8_t > && )

explicitdelete

PacketBuffer() [7/8]

esphome::packet_interface::PacketBuffer::PacketBuffer ( const uint8_t * pre_data, size_t pre_length, const uint8_t * post_data, size_t post_length )

inline

Construct with pre and post buffers.

Definition at line 51 of file packet_buffer.h.

PacketBuffer() [8/8]

esphome::packet_interface::PacketBuffer::PacketBuffer ( const uint8_t * pre_data, size_t pre_length, const PacketBuffer * mid_buffer, const uint8_t * post_data, size_t post_length )

inline

Construct with pre, mid, and post buffers.

Definition at line 57 of file packet_buffer.h.

Member Function Documentation

as_span()

std::span< const uint8_t > esphome::packet_interface::PacketBuffer::as_span ( ) const

inline

Get the data as one span.

Only valid when is_contiguous() is true.

Definition at line 89 of file packet_buffer.h.

copy_to()

size_t esphome::packet_interface::PacketBuffer::copy_to ( uint8_t * dest, size_t count, size_t offset = 0 ) const

inline

Copy data from the buffer to a destination pointer.

Parameters

dest	Destination pointer
count	Number of bytes to copy
offset	Offset in the source buffer to start copying from

Returns

Number of bytes actually copied

Definition at line 120 of file packet_buffer.h.

empty()

bool esphome::packet_interface::PacketBuffer::empty ( ) const

inline

Check if the buffer is empty.

Definition at line 79 of file packet_buffer.h.

is_contiguous()

bool esphome::packet_interface::PacketBuffer::is_contiguous ( ) const

inline

Check if all the data is held in the pre-buffer, so it can be read as one span.

Definition at line 84 of file packet_buffer.h.

operator=() [1/2]

PacketBuffer & esphome::packet_interface::PacketBuffer::operator= ( const PacketBuffer & )

delete

operator=() [2/2]

PacketBuffer & esphome::packet_interface::PacketBuffer::operator= ( PacketBuffer && )

default

operator[]()

uint8_t esphome::packet_interface::PacketBuffer::operator[] ( size_t index ) const

inline

Access a byte at a specific position.

Parameters

index

The position to access

Returns

The byte at the specified position, or 0 past the end

Definition at line 96 of file packet_buffer.h.

size()

size_t esphome::packet_interface::PacketBuffer::size ( ) const

inline

Get the total size of the buffer.

Definition at line 68 of file packet_buffer.h.

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

• esphome/components/packet_interface/packet_buffer.h