tes::PacketReader Class Reference

A utility class for dealing with reading packets. More...

#include <3espacketreader.h>

Inheritance diagram for tes::PacketReader:

Public Member Functions
	PacketReader (const PacketHeader &packet)
	Creates a new packet reader for the given packet and its CRC.
bool	checkCrc ()
	Calculates the CRC value, returning true if it matches. More...
CrcType	calculateCrc () const
	Caluclates the CRC for the packet.
uint16_t	bytesAvailable () const
	Returns the number of bytes available for writing in the payload. More...
size_t	readElement (uint8_t *bytes, size_t elementSize)
	Reads a single data element from the current position. More...
size_t	readArray (uint8_t *bytes, size_t elementSize, size_t elementCount)
	Reads an array of data items from the current position. More...
size_t	readRaw (uint8_t *bytes, size_t byteCount)
	Reads raw bytes from the packet at the current position up to byteCount. More...
template<typename T >
size_t	readElement (T &element)
	Reads a single data item from the packet. More...
template<typename T >
size_t	readArray (T *elements, size_t elementCount)
template<typename T >
PacketReader &	operator>> (T &val)
Public Member Functions inherited from tes::PacketStream< const PacketHeader >
	PacketStream (const PacketHeader &packet)
	Create a stream to read from beginning at packet. More...
uint32_t	marker () const
	Fetch the marker bytes in local endian. More...
uint16_t	versionMajor () const
	Fetch the major version bytes in local endian. More...
uint16_t	versionMinor () const
	Fetch the minor version bytes in local endian. More...
uint16_t	payloadSize () const
	Fetch the payload size bytes in local endian. More...
uint16_t	packetSize () const
	Returns the size of the packet plus payload, giving the full data packet size including the CRC. More...
uint16_t	routingId () const
	Fetch the routing ID bytes in local endian. More...
uint16_t	messageId () const
	Fetch the message ID bytes in local endian. More...
CrcType	crc () const
	Fetch the CRC bytes in local endian. More...
CrcType *	crcPtr ()
	Fetch a pointer to the CRC bytes. More...
const CrcType *	crcPtr () const
uint16_t	status () const
	Report the Status bits. More...
bool	isEop () const
	At end of packet/stream? More...
bool	isOk () const
	Status OK? More...
bool	isFail () const
	Fail bit set? More...
bool	isReadOnly () const
	Read only stream? More...
bool	isCrcValid () const
	CRC validated? More...
const PacketHeader &	packet () const
	Access the head of the packet buffer, for direct PacketHeader access. More...
uint16_t	tell () const
	Tell the current stream position. More...
bool	seek (int offset, SeekPos pos=Begin)
	Seek to the indicated position. More...
const uint8_t *	payload () const
	Direct payload pointer access. More...

Additional Inherited Members
Public Types inherited from tes::PacketStream< const PacketHeader >
enum	SeekPos
	Control values for seeking.
enum	Status
	Status bits.
typedef uint16_t	CrcType
	Defies the packet CRC type.
Protected Attributes inherited from tes::PacketStream< const PacketHeader >
const PacketHeader &	_packet
	Packet header and buffer start address.
uint16_t	_status
	Status bits.
uint16_t	_payloadPosition
	Payload cursor.

Detailed Description

A utility class for dealing with reading packets.

Bug:

Use the payloadOffset in various calculations herein. It was added after this class was written, but is currently only supported as being zero, so it's not an issue yet.

Member Function Documentation

bytesAvailable()

uint16_t tes::PacketReader::bytesAvailable ( ) const

inline

Returns the number of bytes available for writing in the payload.

Returns

The number of bytes available for writing.

checkCrc()

bool tes::PacketReader::checkCrc

(

)

Calculates the CRC value, returning true if it matches.

This also sets isCrcValid() on success.

Returns true immediately when isCrcValid() is already set.

Returns

True if the CRC is valid.

readArray()

size_t tes::PacketReader::readArray	(	uint8_t *	bytes,
		size_t	elementSize,
		size_t	elementCount
	)

Reads an array of data items from the current position.

This makes the same assumptions as readElement() and performs an endian swap per array element. Elements in the array are assumed to be contiguous in both source and destination locations.

Up to elementCount elements will be read depending on availability. Less may be read, but on success the number of bytes read will be a multiple of elementSize.

The reader position is advanced by the number of bytes read. Does not set the Fail bit on failure.

Parameters

bytes	Location to read into.
elementSize	Size of a single array element to read.
elementCount	The number of elements to attempt to read.

Returns

On success returns the number of whole elements read.

Referenced by tes::ServerInfoMessage::read(), tes::ObjectAttributes::read(), and readElement().

readElement() [1/2]

size_t tes::PacketReader::readElement	(	uint8_t *	bytes,
		size_t	elementSize
	)

Reads a single data element from the current position.

This assumes that a single data element of size elementSize is being read and may require an endian swap to the current platform endian.

The reader position is advanced by elementSize. Does not set the Fail bit on failure.

Parameters

bytes	Location to read into.
elementSize	Size of the data item being read at bytes.

Returns

elementSize on success, 0 otherwise.

Referenced by tes::MeshCreateMessage::read(), tes::ServerInfoMessage::read(), tes::MeshDestroyMessage::read(), tes::ControlMessage::read(), tes::MeshComponentMessage::read(), tes::CategoryNameMessage::read(), tes::Material::read(), tes::MeshFinaliseMessage::read(), tes::CollatedPacketMessage::read(), tes::ObjectAttributes::read(), tes::CreateMessage::read(), tes::DataMessage::read(), tes::UpdateMessage::read(), and tes::DestroyMessage::read().

readElement() [2/2]

template<typename T >

size_t tes::PacketReader::readElement ( T &  element )

inline

Reads a single data item from the packet.

This reads a number of bytes equal to sizeof(T) performing an endian swap if necessary.

Parameters

[out]

element

Set to the data read.

Returns

sizeof(T) on success, zero on failure.

References readArray().

readRaw()

size_t tes::PacketReader::readRaw	(	uint8_t *	bytes,
		size_t	byteCount
	)

Reads raw bytes from the packet at the current position up to byteCount.

No endian swap is performed on the data read.

The reader position is advanced by byteCount. Does not set the Fail bit on failure.

Parameters

bytes

Location to read into. byteCount Number of bytes to read.

Returns

The number of bytes read. This may be less than byteCount if there are insufficient data available.

Referenced by tes::CategoryNameMessage::read().

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

• 3espacketreader.h