Defines class that represents a transport packet header. More...

#include <TransportHeader.h>

Collaboration diagram for OpenDDS::DCPS::TransportHeader:

Public Types
enum	{ BYTE_ORDER_FLAG, FIRST_FRAGMENT_FLAG, LAST_FRAGMENT_FLAG }

Public Member Functions
	TransportHeader ()
	Default constructor. More...

	TransportHeader (ACE_Message_Block &buffer)
	Construct with values extracted from a buffer. More...

TransportHeader &	operator= (ACE_Message_Block &buffer)
	Assignment from an ACE_Message_Block. More...

void	incomplete (ACE_Message_Block &)

bool	swap_bytes () const
	Determine if the serializer should swap bytes. More...

bool	valid () const
	Determine if this is a valid packet header. More...

bool	init (ACE_Message_Block *buffer)
	Demarshal transport packet from ACE_Message_Block. More...

bool	first_fragment ()

bool	last_fragment ()

void	last_fragment (bool frag)

const SequenceNumber &	sequence ()

Static Public Member Functions
static size_t	get_max_serialized_size ()
	Similar to IDL compiler generated methods. More...

static ACE_UINT32	get_length (const char *marshaled_transport_header)

Public Attributes
ACE_CDR::Octet	protocol_ [6]
	The protocol of the packet being transmitted. More...

bool	byte_order_
	Flags: marshaled as a single byte (ACE_CDR::Octet) More...

bool	first_fragment_

bool	last_fragment_

ACE_CDR::Octet	reserved_
	Reserved for future use (provides padding for preamble). More...

ACE_UINT32	length_

SequenceNumber	sequence_

ACE_INT64	source_

Static Public Attributes
static const ACE_CDR::Octet	DCPS_PROTOCOL [6]

Detailed Description

Defines class that represents a transport packet header.

The TransportHeader is the transport packet header. Each packet sent by the transport will always start with a transport packet header, followed by one or more data samples (all belonging to the same transport packet).

Definition at line 36 of file TransportHeader.h.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

Constants for bit masking the marshaled flags byte. This needs to match the 'Flags' above.

Enumerator
BYTE_ORDER_FLAG
FIRST_FRAGMENT_FLAG
LAST_FRAGMENT_FLAG

Definition at line 66 of file TransportHeader.h.

66 { BYTE_ORDER_FLAG, FIRST_FRAGMENT_FLAG, LAST_FRAGMENT_FLAG };

OpenDDS::DCPS::TransportHeader::LAST_FRAGMENT_FLAG

Definition: TransportHeader.h:66

OpenDDS::DCPS::TransportHeader::FIRST_FRAGMENT_FLAG

Definition: TransportHeader.h:66

OpenDDS::DCPS::TransportHeader::BYTE_ORDER_FLAG

Definition: TransportHeader.h:66

Constructor & Destructor Documentation

◆ TransportHeader() [1/2]

ACE_INLINE OpenDDS::DCPS::TransportHeader::TransportHeader ( )

Default constructor.

Definition at line 19 of file TransportHeader.inl.

References ACE_CDR_BYTE_ORDER, ACE_INLINE, DBG_ENTRY_LVL, DCPS_PROTOCOL, and protocol_.

   : byte_order_(ACE_CDR_BYTE_ORDER)
   , first_fragment_(false)
   , last_fragment_(false)
   , reserved_(0)
   , length_(0)
   , sequence_()
   , source_(0)
 {
   DBG_ENTRY_LVL("TransportHeader","TransportHeader",6);
 
   std::copy(&DCPS_PROTOCOL[0], &DCPS_PROTOCOL[6], this->protocol_);
 }

◆ TransportHeader() [2/2]

ACE_INLINE OpenDDS::DCPS::TransportHeader::TransportHeader ( ACE_Message_Block & buffer )

explicit

Construct with values extracted from a buffer.

Definition at line 34 of file TransportHeader.inl.

References ACE_CDR_BYTE_ORDER, ACE_INLINE, DBG_ENTRY_LVL, and init().

   : byte_order_(ACE_CDR_BYTE_ORDER)
   , first_fragment_(false)
   , last_fragment_(false)
   , reserved_(0)
   , length_(0)
   , sequence_()
   , source_(0)
 {
   DBG_ENTRY_LVL("TransportHeader","TransportHeader",6);
   this->init(&buffer);
 }

Member Function Documentation

◆ first_fragment()

bool OpenDDS::DCPS::TransportHeader::first_fragment ( )

inline

Definition at line 90 of file TransportHeader.h.

90 { return this->first_fragment_; }

OpenDDS::DCPS::TransportHeader::first_fragment_

bool first_fragment_

Definition: TransportHeader.h:61

◆ get_length()

ACE_UINT32 OpenDDS::DCPS::TransportHeader::get_length ( const char * marshaled_transport_header )

static

Definition at line 49 of file TransportHeader.cpp.

References OPENDDS_END_VERSIONED_NAMESPACE_DECL, protocol_, and reserved_.

Referenced by OpenDDS::DCPS::ShmemReceiveStrategy::receive_bytes().

 {
   const TransportHeader* hdr = 0;
   static const unsigned int OFFSET = sizeof(hdr->protocol_) +
                                      1 /*flags*/ +
                                      sizeof(hdr->reserved_);
   return *reinterpret_cast<const ACE_UINT32*>(marshaled_header + OFFSET);
 }

◆ get_max_serialized_size()

ACE_INLINE size_t OpenDDS::DCPS::TransportHeader::get_max_serialized_size ( )

static

Similar to IDL compiler generated methods.

Definition at line 57 of file TransportHeader.inl.

References ACE_INLINE, length_, protocol_, reserved_, sequence_, and source_.

Referenced by OpenDDS::DCPS::UdpDataLink::open(), and OpenDDS::DCPS::TransportSendStrategy::TransportSendStrategy().

 {
   // Representation takes no extra space for encoding.
   const TransportHeader* hdr = 0;
   return sizeof(hdr->protocol_) +
          1 /*flags*/ +
          sizeof(hdr->reserved_) +
          sizeof(hdr->length_) +
          sizeof(hdr->sequence_) +
          sizeof(hdr->source_);
 }

◆ incomplete()

void OpenDDS::DCPS::TransportHeader::incomplete ( ACE_Message_Block & )

inline

Definition at line 48 of file TransportHeader.h.

48 {}

◆ init()

ACE_INLINE bool OpenDDS::DCPS::TransportHeader::init ( ACE_Message_Block * buffer )

Demarshal transport packet from ACE_Message_Block.

Definition at line 91 of file TransportHeader.inl.

References byte_order_, BYTE_ORDER_FLAG, DBG_ENTRY_LVL, first_fragment_, FIRST_FRAGMENT_FLAG, OpenDDS::DCPS::Encoding::KIND_UNALIGNED_CDR, last_fragment_, LAST_FRAGMENT_FLAG, length_, OPENDDS_END_VERSIONED_NAMESPACE_DECL, OpenDDS::DCPS::Serializer::read_octet_array(), reserved_, sequence_, source_, swap_bytes(), and OpenDDS::DCPS::Serializer::swap_bytes().

Referenced by operator=(), and TransportHeader().

 {
   DBG_ENTRY_LVL("TransportHeader","init",6);
 
   Serializer reader(buffer, Encoding::KIND_UNALIGNED_CDR);
 
   if (!reader.read_octet_array(this->protocol_, sizeof(this->protocol_)))
     return false;
 
   ACE_CDR::Octet flags;
   if (!(reader >> ACE_InputCDR::to_octet(flags)))
     return false;
 
   this->byte_order_= flags & (1 << BYTE_ORDER_FLAG);
   this->first_fragment_ = flags & (1 << FIRST_FRAGMENT_FLAG);
   this->last_fragment_ = flags & (1 << LAST_FRAGMENT_FLAG);
 
   if (!(reader >> ACE_InputCDR::to_octet(this->reserved_)))
     return false;
 
   reader.swap_bytes(swap_bytes());
 
   return (reader >> this->length_) &&
          (reader >> this->sequence_) &&
          (reader >> this->source_);
 }

◆ last_fragment() [1/2]

bool OpenDDS::DCPS::TransportHeader::last_fragment ( )

inline

Definition at line 91 of file TransportHeader.h.

91 { return this->last_fragment_; }

OpenDDS::DCPS::TransportHeader::last_fragment_

bool last_fragment_

Definition: TransportHeader.h:62

◆ last_fragment() [2/2]

void OpenDDS::DCPS::TransportHeader::last_fragment ( bool frag )

inline

Definition at line 92 of file TransportHeader.h.

92 { this->last_fragment_ = frag; }

OpenDDS::DCPS::TransportHeader::last_fragment_

bool last_fragment_

Definition: TransportHeader.h:62

◆ operator=()

ACE_INLINE TransportHeader & OpenDDS::DCPS::TransportHeader::operator= ( ACE_Message_Block & buffer )

Assignment from an ACE_Message_Block.

Definition at line 49 of file TransportHeader.inl.

References ACE_INLINE, DBG_ENTRY_LVL, and init().

 {
   DBG_ENTRY_LVL("TransportHeader","operator=",6);
   this->init(&buffer);
   return *this;
 }

◆ sequence()

const SequenceNumber& OpenDDS::DCPS::TransportHeader::sequence ( )

inline

Definition at line 93 of file TransportHeader.h.

References OpenDDS_Dcps_Export, OPENDDS_END_VERSIONED_NAMESPACE_DECL, OpenDDS::DCPS::operator<<(), and value.

93 { return this->sequence_; }

OpenDDS::DCPS::TransportHeader::sequence_

SequenceNumber sequence_

Definition: TransportHeader.h:78

◆ swap_bytes()

ACE_INLINE bool OpenDDS::DCPS::TransportHeader::swap_bytes ( ) const

Determine if the serializer should swap bytes.

Definition at line 71 of file TransportHeader.inl.

References ACE_CDR_BYTE_ORDER, ACE_INLINE, byte_order_, and DBG_ENTRY_LVL.

Referenced by init(), OpenDDS::DCPS::ReliableSession::nak_received(), OpenDDS::DCPS::ReliableSession::nakack_received(), OpenDDS::DCPS::MulticastDataLink::sample_received(), OpenDDS::DCPS::MulticastSession::syn_received(), and OpenDDS::DCPS::MulticastSession::synack_received().

 {
   DBG_ENTRY_LVL("TransportHeader","swap_bytes",6);
 
   return this->byte_order_ != ACE_CDR_BYTE_ORDER;
 }

◆ valid()

ACE_INLINE bool OpenDDS::DCPS::TransportHeader::valid ( void ) const

Determine if this is a valid packet header.

Definition at line 80 of file TransportHeader.inl.

References ACE_INLINE, DBG_ENTRY_LVL, DCPS_PROTOCOL, and protocol_.

 {
   DBG_ENTRY_LVL("TransportHeader","valid",6);
 
   // Currently we do not support compatibility with other
   // versions of the protocol:
   return std::equal(&DCPS_PROTOCOL[0], &DCPS_PROTOCOL[6], this->protocol_);
 }

Member Data Documentation

◆ byte_order_

bool OpenDDS::DCPS::TransportHeader::byte_order_

Flags: marshaled as a single byte (ACE_CDR::Octet)

Definition at line 60 of file TransportHeader.h.

Referenced by init(), OpenDDS::DCPS::operator<<(), and swap_bytes().

◆ DCPS_PROTOCOL

const ACE_CDR::Octet OpenDDS::DCPS::TransportHeader::DCPS_PROTOCOL

static

Initial value:

=

{ 0x44, 0x43, 0x50, 0x53, 0x02, 0x00 }

Definition at line 37 of file TransportHeader.h.

Referenced by OpenDDS::DCPS::ShmemSendStrategy::send_bytes_i(), TransportHeader(), and valid().

◆ first_fragment_

bool OpenDDS::DCPS::TransportHeader::first_fragment_

Definition at line 61 of file TransportHeader.h.

Referenced by OpenDDS::DCPS::TransportSendStrategy::get_packet_elems_from_queue(), init(), OpenDDS::DCPS::operator<<(), OpenDDS::DCPS::MulticastSession::reassemble(), and OpenDDS::DCPS::TransportSendStrategy::send().

◆ last_fragment_

bool OpenDDS::DCPS::TransportHeader::last_fragment_

Definition at line 62 of file TransportHeader.h.

Referenced by OpenDDS::DCPS::TransportSendStrategy::get_packet_elems_from_queue(), init(), OpenDDS::DCPS::operator<<(), and OpenDDS::DCPS::TransportSendStrategy::send().

◆ length_

ACE_UINT32 OpenDDS::DCPS::TransportHeader::length_

The size of the message following this header, not including the bytes used by this TransportHeader.

Definition at line 73 of file TransportHeader.h.

Referenced by OpenDDS::DCPS::TransportSendStrategy::adjust_packet_after_send(), OpenDDS::DCPS::TransportSendStrategy::clear(), OpenDDS::DCPS::TransportSendStrategy::current_space_available(), OpenDDS::DCPS::TransportSendStrategy::do_remove_sample(), get_max_serialized_size(), OpenDDS::DCPS::TransportSendStrategy::get_packet_elems_from_queue(), init(), OpenDDS::DCPS::UdpDataLink::open(), OpenDDS::DCPS::operator<<(), OpenDDS::DCPS::TransportSendStrategy::perform_work(), OpenDDS::DCPS::TransportSendStrategy::resume_send(), OpenDDS::DCPS::TransportSendStrategy::send(), and OpenDDS::DCPS::TransportSendStrategy::send_stop().

◆ protocol_

ACE_CDR::Octet OpenDDS::DCPS::TransportHeader::protocol_[6]

The protocol of the packet being transmitted.

Definition at line 57 of file TransportHeader.h.

Referenced by get_length(), get_max_serialized_size(), OpenDDS::DCPS::operator<<(), TransportHeader(), and valid().

◆ reserved_

ACE_CDR::Octet OpenDDS::DCPS::TransportHeader::reserved_

Reserved for future use (provides padding for preamble).

Definition at line 69 of file TransportHeader.h.

Referenced by get_length(), get_max_serialized_size(), init(), and OpenDDS::DCPS::operator<<().

◆ sequence_

SequenceNumber OpenDDS::DCPS::TransportHeader::sequence_

The sequence number of the packet identified by this header; this value is guaranteed to be a monotonically increasing number per transport instance.

Definition at line 78 of file TransportHeader.h.

Referenced by OpenDDS::DCPS::BestEffortSession::check_header(), OpenDDS::DCPS::ReliableSession::check_header(), OpenDDS::DCPS::UdpReceiveStrategy::check_header(), get_max_serialized_size(), init(), OpenDDS::DCPS::operator<<(), OpenDDS::DCPS::TransportSendStrategy::prepare_header(), OpenDDS::DCPS::BestEffortSession::ready_to_deliver(), OpenDDS::DCPS::ReliableSession::ready_to_deliver(), OpenDDS::DCPS::MulticastSession::reassemble(), OpenDDS::DCPS::ReliableSession::record_header_received(), OpenDDS::DCPS::TransportSendStrategy::send_packet(), and OpenDDS::DCPS::MulticastSession::syn_received().

◆ source_

ACE_INT64 OpenDDS::DCPS::TransportHeader::source_

A transport-specific identification number which uniquely identifies the source of the packet.

Definition at line 82 of file TransportHeader.h.

Referenced by OpenDDS::DCPS::ReliableSession::check_header(), OpenDDS::DCPS::MulticastDataLink::check_header(), get_max_serialized_size(), init(), OpenDDS::DCPS::ReliableSession::nak_received(), OpenDDS::DCPS::ReliableSession::nakack_received(), OpenDDS::DCPS::operator<<(), OpenDDS::DCPS::MulticastDataLink::ready_to_deliver(), OpenDDS::DCPS::MulticastDataLink::reassemble(), OpenDDS::DCPS::BestEffortSession::record_header_received(), OpenDDS::DCPS::ReliableSession::record_header_received(), OpenDDS::DCPS::MulticastDataLink::sample_received(), OpenDDS::DCPS::TransportSendStrategy::set_header_source(), OpenDDS::DCPS::MulticastSession::syn_received(), and OpenDDS::DCPS::MulticastSession::synack_received().

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

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Static Public Attributes

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

Constructor & Destructor Documentation

◆ TransportHeader() [1/2]

◆ TransportHeader() [2/2]

Member Function Documentation

◆ first_fragment()

◆ get_length()

◆ get_max_serialized_size()

◆ incomplete()

◆ init()

◆ last_fragment() [1/2]

◆ last_fragment() [2/2]

◆ operator=()

◆ sequence()

◆ swap_bytes()

◆ valid()

Member Data Documentation

◆ byte_order_

◆ DCPS_PROTOCOL

◆ first_fragment_

◆ last_fragment_

◆ length_

◆ protocol_

◆ reserved_

◆ sequence_

◆ source_