Internal net_flow struct that encapsulates the Flow-protocol low-level DATA packet. More...

#include <low_lvl_packet.hpp>

Inheritance diagram for flow::net_flow::Data_packet:

Collaboration diagram for flow::net_flow::Data_packet:

Public Types
using	rexmit_id_t = uint8_t
	Type used to store the retransmission count in DATA and ACK packets. More...

Public Types inherited from flow::net_flow::Low_lvl_packet
using	Const_buffer = boost::asio::const_buffer
	Short-hand for boost.asio immutable buffer, which essentially is a pointer to and length of a memory area. More...

using	Const_buffer_sequence = std::vector< Const_buffer >
	Short-hand for sequence of immutable buffers; i.e., a sequence of 1 or more scattered areas in memory. More...

using	security_token_t = uint64_t
	Type used for `m_security_token` member of a couple different packet types. More...

using	rexmit_id_t = uint8_t
	Type used to store the retransmission count in DATA and ACK packets. More...

using	rcv_wnd_t = uint32_t
	Type used to store the size of `m_rcv_wnd` member in a couple of different packet types. More...

Public Types inherited from flow::util::Shared_ptr_alias_holder< boost::shared_ptr< Low_lvl_packet > >
using	Ptr = boost::shared_ptr< Low_lvl_packet >
	Short-hand for ref-counted pointer to mutable values of type `Target_type::element_type` (a-la `T*`). More...

using	Const_ptr = Const_target_ptr
	Short-hand for ref-counted pointer to immutable values of type `Target_type::element_type` (a-la `T const *`). More...

Public Member Functions
size_t	serialize_to_raw_data (Const_buffer_sequence *raw_bufs) const override
	Implements Low_lvl_packet API. More...

Public Member Functions inherited from flow::net_flow::Low_lvl_packet
virtual size_t	serialize_to_raw_data (Const_buffer_sequence *raw_bufs) const =0
	Serializes the current logical packet data from `*this` into the given `Const_buffer_sequence`, which is a sequence of pointers and lengths of existing scattered areas in memory, presumably for transmission over the wire to a compatible serializing Node. More...

size_t	serialize_to_raw_data_and_log (Const_buffer_sequence *raw_bufs) const
	Identical to serialize_to_raw_data() but adds log-level-appropriate logging after the operation. More...

Public Member Functions inherited from flow::util::Null_interface
virtual	~Null_interface ()=0
	Boring `virtual` destructor. More...

Public Member Functions inherited from flow::log::Log_context
	Log_context (Logger *logger=0)
	Constructs Log_context by storing the given pointer to a Logger and a null Component. More...

template<typename Component_payload >
	Log_context (Logger *logger, Component_payload component_payload)
	Constructs Log_context by storing the given pointer to a Logger and a new Component storing the specified generically typed payload (an `enum` value). More...

	Log_context (const Log_context &src)
	Copy constructor that stores equal `Logger*` and Component values as the source. More...

	Log_context (Log_context &&src)
	Move constructor that makes this equal to `src`, while the latter becomes as-if default-constructed. More...

Log_context &	operator= (const Log_context &src)
	Assignment operator that behaves similarly to the copy constructor. More...

Log_context &	operator= (Log_context &&src)
	Move assignment operator that behaves similarly to the move constructor. More...

void	swap (Log_context &other)
	Swaps Logger pointers and Component objects held by `*this` and `other`. More...

Logger *	get_logger () const
	Returns the stored Logger pointer, particularly as many `FLOW_LOG_*()` macros expect. More...

const Component &	get_log_component () const
	Returns reference to the stored Component object, particularly as many `FLOW_LOG_*()` macros expect. More...

Public Attributes
Sequence_number	m_seq_num
	The sequence number of the first byte in the payload; i.e., of `m_data.front()`, a/k/a `m_data[0]`. More...

rexmit_id_t	m_rexmit_id
	Retransmit counter of the DATA packet being sent. More...

uint16_t	m_data_size_raw
	This is the serialized version of `m_data.size()` (see m_data). More...

util::Blob	m_data
	The payload. More...

Public Attributes inherited from flow::net_flow::Low_lvl_packet
bool	m_opt_rexmit_on
	Option indicating whether this connection is using retransmission or not. More...

struct {
flow_port_t m_src_port
	Flow-protocol port # of socket in sending Node. More...

flow_port_t m_dst_port
	Flow-protocol port # of socket in receiving Node. More...

}	m_packed
	Packed group affected by `#pragma pack`.

const Function< std::ostream &(std::ostream &)>	m_type_ostream_manip
	`ostream` manipulator (argument to `ostream <<`) that will output packet's type ("ACK", "RST", etc.). More...

const Function< std::ostream &(std::ostream &)>	m_verbose_ostream_manip
	`ostream` manipulator (argument to `ostream <<`) that will output packet info suitable for DATA log level. More...

const Function< std::ostream &(std::ostream &)>	m_concise_ostream_manip
	`ostream` manipulator (argument to `ostream <<`) that will output packet info suitable for TRACE log level. More...

Static Public Attributes
static const uint8_t	S_RAW_TYPE_ID
	In serialized packet, the type ID byte identifying this as a DATA packet. Must not equal any other packet type's. More...

Private Member Functions
	Data_packet (log::Logger *logger_ptr)
	The implementation of Low_lvl_packet::create_uninit_packet() for this sub-type of Low_lvl_packet. More...

std::ostream &	to_ostream (std::ostream &os, bool verbose) const override
	Implements Low_lvl_packet API. More...

bool	deserialize_type_specific_data_from_raw_data_packet (Const_buffer raw_buf, bool prefer_no_move, util::Blob raw_packet) override
	Implements Low_lvl_packet API. More...

Friends
boost::shared_ptr< Data_packet >	Low_lvl_packet::create_uninit_packet (log::Logger *)
	Friend of Data_packet: For access to private constructor `Data_packet(Logger*)`.

Additional Inherited Members
Static Public Member Functions inherited from flow::net_flow::Low_lvl_packet
template<typename Low_lvl_packet_sub >
static boost::shared_ptr< Low_lvl_packet_sub >	create_uninit_packet (log::Logger *logger_ptr)
	Constructs packet with uninitialized (essentially random) values, of the Low_lvl_packet sub-type specified as the template parameter (Ack_packet, Rst_packet, etc.). More...

template<typename Low_lvl_packet_sub >
static Ptr	create_uninit_packet_base (log::Logger *logger_ptr)
	A simple convenience method that casts the result of create_uninit_packet() from `shared_ptr<T>`, where `T` is a sub-type of Low_lvl_packet, to `shared_ptr<Low_lvl_packet>` a/k/a Ptr. More...

static Ptr	create_from_raw_data_packet (log::Logger logger_ptr, util::Blob raw_packet, bool prefer_no_move)
	Constructs packet on the heap with values determined by the given raw binary data as presumably received from the wire and originally serialized by a compatible serializing Node. More...

static const std::string &	type_id_to_str (const std::type_index &type_id)
	Returns a brief (a few characters) string description of the given packet type given as `type_index(typeid(p))`, where `p` is a reference to an instance of a concrete Low_lvl_packet sub-type. More...

Static Public Member Functions inherited from flow::util::Shared_ptr_alias_holder< boost::shared_ptr< Low_lvl_packet > >
static Ptr	ptr_cast (const From_ptr &ptr_to_cast)
	Provides syntactic-sugary way to perform a `static_pointer_cast<>` from a compatible smart pointer type `From_ptr`, typically `From_ptr::element_type` being in the same class hierarchy as `Target_ptr::element_type`. More...

static Const_ptr	const_ptr_cast (const From_ptr &ptr_to_cast)
	Identical to ptr_cast() but adds `const`-ness (immutability) to the pointed-to type. More...

static Ptr	dynamic_ptr_cast (const From_ptr &ptr_to_cast)
	Equivalent to ptr_cast() but a `dynamic_pointer_cast` instead of static. More...

static Const_ptr	dynamic_const_ptr_cast (const From_ptr &ptr_to_cast)
	Identical to const_ptr_cast() but a `dynamic_pointer_cast` instead of static. More...

Protected Member Functions inherited from flow::net_flow::Low_lvl_packet
	Low_lvl_packet (log::Logger *logger_ptr)
	Constructs packet with uninitialized (essentially random) values. More...

size_t	serialize_common_header_to_raw_data (Const_buffer_sequence *raw_bufs) const
	Helper for serialize_to_raw_data() implementations in sub-types that encodes the header common to all packet types, starting with the packet type ID leading that header. More...

virtual std::ostream &	to_ostream (std::ostream &os, bool verbose=false) const
	Writes a multi-line representation of `*this` to an output stream. More...

Static Protected Member Functions inherited from flow::net_flow::Low_lvl_packet
static constexpr bool	native_is_big_endian ()
	Returns `true`, at compile time, if and only if the native memory representation is big-endian, meaning, for example, the value `uint32_t(1)` is stored as the bytes, in order, 0x00 0x00 0x00 0x01, and not the reverse. More...

Detailed Description

Internal net_flow struct that encapsulates the Flow-protocol low-level DATA packet.

See Low_lvl_packet doc header for information common to all low-level packets including this one.

Each DATA packet contains actual data payload packetized from the application-provided stream of bytes. It is identified by the sequence number (encoded in this object) of the first byte of that payload. An individual acknowledgment inside an Ack_packet refers to the Data_packet by that first sequence number. If Low_lvl_packet::m_opt_rexmit_on is true, then m_rexmit_id identifies which attempt at sending the payload with this sequence number and payload this packet represents: 0 is 1st attempt, 1 is 1st retry, 2 is 2nd retry, etc. If that option is off, then a lost packet is never retransmitted; and therefore m_rexmit_id is always 0.

Definition at line 892 of file low_lvl_packet.hpp.

Member Typedef Documentation

◆ rexmit_id_t

using flow::net_flow::Data_packet::rexmit_id_t = uint8_t

Type used to store the retransmission count in DATA and ACK packets.

Why 8 bits? This handles up 255 retransmissions, which is long after we'd kill the connection anyway.

Definition at line 902 of file low_lvl_packet.hpp.

Constructor & Destructor Documentation

◆ Data_packet()

flow::net_flow::Data_packet::Data_packet ( log::Logger * logger_ptr )

explicitprivate

The implementation of Low_lvl_packet::create_uninit_packet() for this sub-type of Low_lvl_packet.

Parameters

logger_ptr Logger to use subsequently.

Definition at line 88 of file low_lvl_packet.cpp.

Member Function Documentation

◆ deserialize_type_specific_data_from_raw_data_packet()

bool flow::net_flow::Data_packet::deserialize_type_specific_data_from_raw_data_packet	(	Const_buffer *	raw_buf,
		bool	prefer_no_move,
		util::Blob *	raw_packet
	)

overrideprivatevirtual

Implements Low_lvl_packet API.

See that super-method's doc header.

Parameters

raw_buf	See Low_lvl_packet::deserialize_type_specific_data_from_raw_data_packet().
prefer_no_move	See Low_lvl_packet::deserialize_type_specific_data_from_raw_data_packet().
raw_packet	See Low_lvl_packet::deserialize_type_specific_data_from_raw_data_packet().

Returns: See Low_lvl_packet::deserialize_type_specific_data_from_raw_data_packet().

Implements flow::net_flow::Low_lvl_packet.

Definition at line 655 of file low_lvl_packet.cpp.

References FLOW_LOG_TRACE, FLOW_LOG_WARNING, m_data, m_data_size_raw, flow::net_flow::Low_lvl_packet::m_opt_rexmit_on, m_rexmit_id, m_seq_num, flow::net_flow::Low_lvl_packet::m_type_ostream_manip, flow::net_flow::Sequence_number::set_metadata(), and flow::net_flow::Sequence_number::set_raw_num().

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◆ serialize_to_raw_data()

size_t flow::net_flow::Data_packet::serialize_to_raw_data ( Const_buffer_sequence * raw_bufs ) const

overridevirtual

Implements Low_lvl_packet API.

See that super-method's doc header.

Parameters

raw_bufs See Low_lvl_packet::serialize_to_raw_data().

Returns: See Low_lvl_packet::serialize_to_raw_data().

Implements flow::net_flow::Low_lvl_packet.

Definition at line 279 of file low_lvl_packet.cpp.

◆ to_ostream()

std::ostream & flow::net_flow::Data_packet::to_ostream	(	std::ostream &	os,
		bool	verbose
	)		const

overrideprivatevirtual

Implements Low_lvl_packet API.

See that super-method's doc header.

Parameters

os	See Low_lvl_packet::to_ostream().
verbose	See Low_lvl_packet::to_ostream().

Returns: os.

Reimplemented from flow::net_flow::Low_lvl_packet.

Definition at line 968 of file low_lvl_packet.cpp.

References flow::util::buffers_to_ostream(), and flow::net_flow::Low_lvl_packet::to_ostream().

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Member Data Documentation

◆ m_data

util::Blob flow::net_flow::Data_packet::m_data

The payload.

Cannot be empty().

As of this writing there is an important (for performance) subtlety about how this is originally filled in when deserializing a wire-arrived packet. See Data_packet::deserialize_type_specific_data_from_raw_data_packet().

Definition at line 933 of file low_lvl_packet.hpp.

Referenced by deserialize_type_specific_data_from_raw_data_packet().

◆ m_data_size_raw

uint16_t flow::net_flow::Data_packet::m_data_size_raw

mutable

This is the serialized version of m_data.size() (see m_data).

We send this value, even though it could be figured out from the overall serialized size, to ensure integrity (see the deserialization logic for details). This here is set to m_data.size(), when Low_lvl_packet::serialize_to_raw_data() needs to serialize that value. Outside serialization m_data.size() is used directly, and this value is meaningless.

Definition at line 925 of file low_lvl_packet.hpp.

Referenced by deserialize_type_specific_data_from_raw_data_packet().

◆ m_rexmit_id

rexmit_id_t flow::net_flow::Data_packet::m_rexmit_id

Retransmit counter of the DATA packet being sent.

Identifies which attempt we are acknowledging (0 = initial, 1 = first retransmit, 2 = second retransmit, ...). Always 0 if !m_opt_rexmit_on.

Definition at line 916 of file low_lvl_packet.hpp.

Referenced by deserialize_type_specific_data_from_raw_data_packet().

◆ m_seq_num

Sequence_number flow::net_flow::Data_packet::m_seq_num

The sequence number of the first byte in the payload; i.e., of m_data.front(), a/k/a m_data[0].

Note that m_data cannot be empty, so m_seq_num is always meaningful.

Definition at line 910 of file low_lvl_packet.hpp.

Referenced by deserialize_type_specific_data_from_raw_data_packet().

◆ S_RAW_TYPE_ID

const uint8_t flow::net_flow::Data_packet::S_RAW_TYPE_ID

static

In serialized packet, the type ID byte identifying this as a DATA packet. Must not equal any other packet type's.

Definition at line 944 of file low_lvl_packet.hpp.

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

net_flow/detail/low_lvl_packet.hpp
net_flow/detail/low_lvl_packet.cpp

Public Types

Public Member Functions

Public Attributes

Static Public Attributes

Private Member Functions

Friends

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ rexmit_id_t

Constructor & Destructor Documentation

◆ Data_packet()

Member Function Documentation

◆ deserialize_type_specific_data_from_raw_data_packet()

◆ serialize_to_raw_data()

◆ to_ostream()

Member Data Documentation

◆ m_data

◆ m_data_size_raw

◆ m_rexmit_id

◆ m_seq_num

◆ S_RAW_TYPE_ID