Lightweight cursor for parsing a big-endian byte buffer without copies. More...

#include <wire.h>

Collaboration diagram for profinet::wire::Reader:

Public Member Functions
	Reader (const std::uint8_t *data, std::size_t len)
	Construct a reader over a raw pointer/length pair.

	Reader (std::span< const std::uint8_t > bytes)
	Construct a reader over a byte span.

	Reader (const std::vector< std::uint8_t > &v)
	Construct a reader over an existing byte vector.

std::size_t	Remaining () const
	Number of bytes not yet consumed.

std::size_t	Position () const
	Current read offset from the start of the buffer.

const std::uint8_t *	Cursor () const
	Pointer to the next unread byte.

void	Need (std::size_t n) const
	Assert that at least `n` bytes remain.

std::uint8_t	U8 ()
	Read and consume one byte.

std::uint16_t	U16 ()
	Read and consume a big-endian 16-bit value.

std::uint32_t	U32 ()
	Read and consume a big-endian 32-bit value.

std::uint16_t	U16LittleEndian ()
	Read and consume a little-endian 16-bit value.

std::uint32_t	U32LittleEndian ()
	Read and consume a little-endian 32-bit value.

std::vector< std::uint8_t >	ReadBytes (std::size_t n)
	Read and consume a variable-length byte range.

template<std::size_t N>
std::array< std::uint8_t, N >	Fixed ()
	Read and consume a fixed-size byte array.

void	Skip (std::size_t n)
	Advance the read position without returning the skipped bytes.

void	SkipTo (std::size_t offset)
	Move the read position to an absolute byte offset.

Private Attributes
const std::uint8_t *	data
	Pointer to the start of the underlying buffer (not owned).

std::size_t	len
	Total length of the underlying buffer in bytes.

std::size_t	pos = 0
	Current read offset from the start of the buffer.

Detailed Description

Lightweight cursor for parsing a big-endian byte buffer without copies.

Every read method advances the internal position and throws std::out_of_range if the buffer doesn't have enough remaining bytes.

Definition at line 191 of file wire.h.

Constructor & Destructor Documentation

◆ Reader() [1/3]

profinet::wire::Reader::Reader	(	const std::uint8_t *	data,
		std::size_t	len
	)

inline

Construct a reader over a raw pointer/length pair.

Parameters

data	Pointer to the first byte of the buffer. Must outlive the Reader.
len	Number of bytes available starting at Data.

Definition at line 197 of file wire.h.

◆ Reader() [2/3]

profinet::wire::Reader::Reader ( std::span< const std::uint8_t > bytes )

inlineexplicit

Construct a reader over a byte span.

Parameters

bytes Span containing the bytes to read. Must outlive the Reader.

Definition at line 204 of file wire.h.

◆ Reader() [3/3]

profinet::wire::Reader::Reader ( const std::vector< std::uint8_t > & v )

inlineexplicit

Construct a reader over an existing byte vector.

Parameters

v	Vector to read from. Must outlive the Reader.

Definition at line 211 of file wire.h.

Member Function Documentation

◆ Cursor()

const std::uint8_t * profinet::wire::Reader::Cursor ( ) const

inline

Pointer to the next unread byte.

Returns: Pointer into the underlying buffer at the current position.

Definition at line 232 of file wire.h.

References data, and pos.

Referenced by profinet::wire::TEST().

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◆ Fixed()

template<std::size_t N>

std::array< std::uint8_t, N > profinet::wire::Reader::Fixed ( )

inline

Read and consume a fixed-size byte array.

Template Parameters

N	Number of bytes to read.

Returns: A copy of the next N bytes as a fixed-size array.

Definition at line 316 of file wire.h.

References data, Need(), and pos.

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◆ Need()

void profinet::wire::Reader::Need ( std::size_t n ) const

inline

Assert that at least n bytes remain.

Parameters

n	Number of bytes required.

Throws std::out_of_range if fewer than n bytes remain.

Definition at line 240 of file wire.h.

References Remaining().

Referenced by Fixed(), ReadBytes(), Skip(), profinet::wire::TEST(), profinet::wire::TEST(), U16(), U16LittleEndian(), U32(), U32LittleEndian(), and U8().

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◆ Position()

std::size_t profinet::wire::Reader::Position ( ) const

inline

Current read offset from the start of the buffer.

Returns: Number of bytes already consumed.

Definition at line 225 of file wire.h.

References pos.

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◆ ReadBytes()

std::vector< std::uint8_t > profinet::wire::Reader::ReadBytes ( std::size_t n )

inline

Read and consume a variable-length byte range.

Parameters

n	Number of bytes to read.

Returns: A copy of the next n bytes.

Definition at line 304 of file wire.h.

References data, Need(), and pos.

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◆ Remaining()

std::size_t profinet::wire::Reader::Remaining ( ) const

inline

Number of bytes not yet consumed.

Returns: Byte count remaining between the current position and the end of the buffer.

Definition at line 218 of file wire.h.

References len, and pos.

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◆ Skip()

void profinet::wire::Reader::Skip ( std::size_t n )

inline

Advance the read position without returning the skipped bytes.

Parameters

n	Number of bytes to skip.

Definition at line 330 of file wire.h.

References Need(), and pos.

Referenced by profinet::dcp::DCPDeviceDescription::DCPDeviceDescription(), profinet::rt::ParseEthernetFrame(), profinet::blocks::ParseModuleDiffBlock(), profinet::blocks::ParseMultipleBlockHeader(), profinet::dcp::ParseSetResponse(), profinet::blocks::ParseWriteMultipleResponse(), profinet::dcp::ReadResponse(), profinet::dcp::ReceiveHello(), profinet::dcp::RecvSetResponse(), profinet::SkipVlanTags(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), TEST_F(), TEST_F(), and TEST_F().

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◆ SkipTo()

void profinet::wire::Reader::SkipTo ( std::size_t offset )

inline

Move the read position to an absolute byte offset.

Parameters

offset Zero-based byte offset from the start of the buffer.

The requested offset must be within the buffer. Moving to exactly the end of the buffer is valid and leaves no bytes remaining.

Exceptions

std::out_of_range if offset is greater than the buffer length.

Definition at line 343 of file wire.h.

References len, and pos.

Referenced by profinet::rpc::RPCCon::ApplicationReady(), profinet::rpc::RPCCon::EpmLookup(), profinet::sim::VirtualProfinetRpcDevice::HandleControl(), profinet::AlarmListener::HandleLayer2Frame(), profinet::PNBlockHeader::Parse(), profinet::ParseAlarmItem(), profinet::sim::VirtualProfinetRpcDevice::ParseArIdentity(), profinet::diagnosis::ParseDiagnosisBlock(), profinet::diagnosis::ParseDiagnosisSimple(), profinet::rpc::ParseEpmTower(), profinet::rt::ParseEthernetFrame(), profinet::blocks::ParsePdPortDataReal(), profinet::rpc::raw::ParseRawRpcHeader(), profinet::blocks::ParseWriteMultipleResponse(), profinet::rpc::PeekBlockHeader(), profinet::cyclic::CyclicController::ProcessInputFrame(), profinet::SkipVlanTags(), profinet::CyclicCaptureTests::TEST(), profinet::dcp::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), profinet::rpc::TEST_F(), and profinet::rpc::TEST_F().

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◆ U16()

std::uint16_t profinet::wire::Reader::U16 ( )

inline

Read and consume a big-endian 16-bit value.

Returns: The decoded value.

Definition at line 258 of file wire.h.

References data, Need(), and pos.

Referenced by profinet::dcp::DCPDeviceDescription::DCPDeviceDescription(), profinet::rpc::RPCCon::ApplicationReady(), profinet::rt::RTFrame::FromBytes(), profinet::sim::VirtualProfinetRpcDevice::HandleControl(), profinet::AlarmListener::HandleLayer2Frame(), profinet::EthernetHeader::Parse(), profinet::EthernetVLANHeader::Parse(), profinet::PNDCPHeader::Parse(), profinet::PNDCPBlockRequest::Parse(), profinet::PNDCPBlock::Parse(), profinet::PNRPCHeader::Parse(), profinet::PNIODHeader::Parse(), profinet::PNBlockHeader::Parse(), profinet::PNARBlockRequest::Parse(), profinet::PNIODReleaseBlock::Parse(), profinet::PNInM0::Parse(), profinet::IOCRAPIObject::Parse(), profinet::PNIOCRBlockRes::Parse(), profinet::PNIOCRBlockReqHeader::Parse(), profinet::PNAlarmCRBlockReq::Parse(), profinet::PNAlarmCRBlockRes::Parse(), profinet::PNAlarmNotificationPDU::Parse(), profinet::PNRTAHeader::Parse(), profinet::PNIODWriteRes::Parse(), profinet::ParseAlarmItem(), profinet::ParseAlarmNotification(), profinet::sim::VirtualProfinetRpcDevice::ParseArIdentity(), profinet::blocks::ParseBlockHeader(), profinet::diagnosis::ParseDiagnosisBlock(), profinet::diagnosis::ParseDiagnosisSimple(), profinet::rpc::ParseEpmTower(), profinet::rt::ParseEthernetFrame(), profinet::blocks::ParseModuleDiffBlock(), profinet::blocks::ParseMultipleBlockHeader(), profinet::blocks::ParsePdPortDataReal(), profinet::blocks::ParsePortStatistics(), profinet::rpc::raw::ParseRawRpcHeader(), profinet::blocks::ParseRealIdentificationData(), profinet::dcp::ParseSetResponse(), profinet::blocks::ParseWriteMultipleResponse(), profinet::rpc::PeekBlockHeader(), profinet::cyclic::CyclicController::ProcessInputFrame(), profinet::dcp::ReadResponse(), profinet::dcp::ReceiveHello(), profinet::dcp::RecvSetResponse(), profinet::SkipVlanTags(), profinet::CyclicCaptureTests::TEST(), profinet::dcp::TEST(), profinet::TEST(), profinet::TEST(), profinet::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), TEST_F(), profinet::device::TEST_F(), profinet::device::TEST_F(), profinet::device::TEST_F(), and profinet::rpc::UuidBytesToString().

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◆ U16LittleEndian()

std::uint16_t profinet::wire::Reader::U16LittleEndian ( )

inline

Read and consume a little-endian 16-bit value.

Returns: The decoded value.

Definition at line 279 of file wire.h.

References data, Need(), and pos.

Referenced by profinet::rpc::RPCCon::EpmLookup(), profinet::rpc::ParseEpmTower(), profinet::rpc::raw::ParseRawRpcHeader(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::rpc::TEST_F(), profinet::rpc::TEST_F(), and profinet::rpc::UuidBytesToString().

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◆ U32()

std::uint32_t profinet::wire::Reader::U32 ( )

inline

Read and consume a big-endian 32-bit value.

Returns: The decoded value.

Definition at line 268 of file wire.h.

References data, Need(), and pos.

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◆ U32LittleEndian()

std::uint32_t profinet::wire::Reader::U32LittleEndian ( )

inline

Read and consume a little-endian 32-bit value.

Returns: The decoded value.

Definition at line 291 of file wire.h.

References data, Need(), and pos.

Referenced by profinet::rpc::RPCCon::ApplicationReady(), profinet::rpc::RPCCon::EpmLookup(), profinet::rpc::raw::ParseRawRpcHeader(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::rpc::TEST_F(), profinet::rpc::TEST_F(), and profinet::rpc::UuidBytesToString().

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◆ U8()

std::uint8_t profinet::wire::Reader::U8 ( )

inline

Read and consume one byte.

Returns: The byte at the current position.

Definition at line 250 of file wire.h.

References data, Need(), and pos.

Referenced by profinet::dcp::DCPDeviceDescription::DCPDeviceDescription(), profinet::rt::RTFrame::FromBytes(), profinet::PNDCPHeader::Parse(), profinet::PNDCPBlockRequest::Parse(), profinet::PNDCPBlock::Parse(), profinet::PNRPCHeader::Parse(), profinet::PNBlockHeader::Parse(), profinet::PNInM0::Parse(), profinet::PNRTAHeader::Parse(), profinet::blocks::ParseBlockHeader(), profinet::rpc::raw::ParseRawRpcHeader(), profinet::TEST(), profinet::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), profinet::wire::TEST(), and profinet::wire::TEST().

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Member Data Documentation

◆ data

const std::uint8_t* profinet::wire::Reader::data

private

Pointer to the start of the underlying buffer (not owned).

Definition at line 355 of file wire.h.

Referenced by Cursor(), Fixed(), ReadBytes(), U16(), U16LittleEndian(), U32(), U32LittleEndian(), and U8().

◆ len

std::size_t profinet::wire::Reader::len

private

Total length of the underlying buffer in bytes.

Definition at line 358 of file wire.h.

Referenced by Remaining(), and SkipTo().

◆ pos

std::size_t profinet::wire::Reader::pos = 0

private

Current read offset from the start of the buffer.

Definition at line 361 of file wire.h.

Referenced by Cursor(), Fixed(), Position(), ReadBytes(), Remaining(), Skip(), SkipTo(), U16(), U16LittleEndian(), U32(), U32LittleEndian(), and U8().

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

include/profinet/wire.h

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Reader() [1/3]

◆ Reader() [2/3]

◆ Reader() [3/3]

Member Function Documentation

◆ Cursor()

◆ Fixed()

◆ Need()

◆ Position()

◆ ReadBytes()

◆ Remaining()

◆ Skip()

◆ SkipTo()

◆ U16()

◆ U16LittleEndian()

◆ U32()

◆ U32LittleEndian()

◆ U8()

Member Data Documentation

◆ data

◆ len

◆ pos