Encodes empty optional fields with a single "presence" bit. More...

#include <dccl/codecs3/field_codec_presence.h>

Inheritance diagram for dccl::v3::PresenceBitCodec< WrappedType >:

[legend]

Public Types
using	Base = TypedFieldCodec< typename WrappedType::wire_type, typename WrappedType::field_type >

using	wrapped_type = WrappedType
	The codec type of the "wrapped" codec.

using	wire_type = typename Base::wire_type
	The wire_type of the "wrapped" codec.

using	field_type = typename Base::field_type
	The field_type of the "wrapped" codec.

Public Types inherited from dccl::TypedFieldCodec< WrappedType::wire_type, WrappedType::field_type >
using	wire_type = WrappedType::wire_type

using	field_type = WrappedType::field_type

Public Member Functions
wire_type	pre_encode (const field_type &field_value) override
	Convert from the FieldType representation (used in the Google Protobuf message) to the WireType representation (used with encode() and decode(), i.e. "on the wire").

field_type	post_decode (const wire_type &wire_value) override
	Convert from the WireType representation (used with encode() and decode(), i.e. "on the wire") to the FieldType representation (used in the Google Protobuf message).

void	validate () override
	Calls _inner_codec.validate()

Bitset	encode () override
	Encodes an empty field as a single 0 bit.

Bitset	encode (const wire_type &value) override
	Encodes a non-empty field, adding a 1 bit to the front for optional fields.

wire_type	decode (Bitset *bits) override
	Decodes a field, first evaluating the presence bit if necessary.

unsigned	size () override
	Size of an empty field (1 bit)

unsigned	size (const wire_type &wire_value) override
	Size of a non-empty field; gets size from "wrapped" codec, adds 1 for optional fields.

unsigned	max_size () override
	Calculate maximum size of the field in bits.

unsigned	min_size () override
	Calculate minimum size of the field in bits.

void	set_manager (FieldCodecManagerLocal *manager) override

Public Member Functions inherited from dccl::TypedFieldCodec< WrappedType::wire_type, WrappedType::field_type >
virtual Bitset	encode (const WrappedType::wire_type &wire_value)=0
	Encode a non-empty field.

virtual unsigned	size (const WrappedType::wire_type &wire_value)=0
	Calculate the size (in bits) of a non-empty field.

Public Member Functions inherited from dccl::FieldCodecBase
void	base_encode (Bitset *bits, const google::protobuf::Message &msg, MessagePart part, bool strict)
	Encode this part (body or head) of the base message.

void	base_size (unsigned *bit_size, const google::protobuf::Message &msg, MessagePart part)
	Calculate the size (in bits) of a part of the base message when it is encoded.

void	base_decode (Bitset bits, google::protobuf::Message msg, MessagePart part)
	Decode part of a message.

void	base_max_size (unsigned bit_size, const google::protobuf::Descriptor desc, MessagePart part)
	Calculate the maximum size of a message given its Descriptor alone (no data)

void	base_min_size (unsigned bit_size, const google::protobuf::Descriptor desc, MessagePart part)
	Calculate the minimum size of a message given its Descriptor alone (no data)

void	base_validate (const google::protobuf::Descriptor *desc, MessagePart part)
	Validate this part of the message to make sure all required extensions are set.

void	base_info (std::ostream os, const google::protobuf::Descriptor desc, MessagePart part)
	Get human readable information (size of fields, etc.) about this part of the DCCL message.

void	base_hash (std::size_t hash, const google::protobuf::Descriptor desc, MessagePart part)
	Provide a hash of the DCCL message definition to detect changes in the DCCL message.

void	field_pre_encode (dccl::any *wire_value, const dccl::any &field_value)
	Pre-encodes a non-repeated (i.e. optional or required) field by converting the FieldType representation (the Google Protobuf representation) into the WireType representation (the type used in the encoded DCCL message). This allows for type-converting codecs.

void	field_pre_encode_repeated (std::vector< dccl::any > *wire_values, const std::vector< dccl::any > &field_values)
	Pre-encodes a repeated field.

void	field_encode (Bitset bits, const dccl::any &field_value, const google::protobuf::FieldDescriptor field)
	Encode a non-repeated field.

void	field_encode_repeated (Bitset bits, const std::vector< dccl::any > &field_values, const google::protobuf::FieldDescriptor field)
	Encode a repeated field.

void	field_size (unsigned bit_size, const dccl::any &field_value, const google::protobuf::FieldDescriptor field)
	Calculate the size of a field.

void	field_size_repeated (unsigned bit_size, const std::vector< dccl::any > &field_values, const google::protobuf::FieldDescriptor field)
	Calculate the size of a repeated field.

void	field_decode (Bitset bits, dccl::any field_value, const google::protobuf::FieldDescriptor *field)
	Decode a non-repeated field.

void	field_decode_repeated (Bitset bits, std::vector< dccl::any > field_values, const google::protobuf::FieldDescriptor *field)
	Decode a repeated field.

void	field_post_decode (const dccl::any &wire_value, dccl::any *field_value)
	Post-decodes a non-repeated (i.e. optional or required) field by converting the WireType (the type used in the encoded DCCL message) representation into the FieldType representation (the Google Protobuf representation). This allows for type-converting codecs.

void	field_post_decode_repeated (const std::vector< dccl::any > &wire_values, std::vector< dccl::any > *field_values)
	Post-decodes a repeated field.

void	field_max_size (unsigned bit_size, const google::protobuf::FieldDescriptor field)
	Calculate the upper bound on this field's size (in bits)

void	field_min_size (unsigned bit_size, const google::protobuf::FieldDescriptor field)
	Calculate the lower bound on this field's size (in bits)

void	field_validate (bool b, const google::protobuf::FieldDescriptor field)
	Validate this field, checking that all required option extensions are set (e.g. (dccl.field).max and (dccl.field).min for arithmetic codecs)

void	field_info (std::ostream os, const google::protobuf::FieldDescriptor field)
	Write human readable information about the field and its bounds to the provided stream.

void	field_hash (std::size_t hash, const google::protobuf::FieldDescriptor field)
	Provide a hash for this field definition.

dccl::DCCLFieldOptions	dccl_field_options () const
	Get the DCCL field option extension value for the current field.

void	require (bool b, const std::string &description)
	Essentially an assertion to be used in the validate() virtual method.

DynamicConditions &	dynamic_conditions (const google::protobuf::FieldDescriptor *field)

FieldCodecManagerLocal &	manager ()

const FieldCodecManagerLocal &	manager () const

std::string	name () const
	the name of the codec used to identifier it in the .proto custom option extension

google::protobuf::FieldDescriptor::Type	field_type () const
	the type exposed to the user in the original and decoded Protobuf messages

google::protobuf::FieldDescriptor::CppType	wire_type () const
	the C++ type used "on the wire". This is the type visible after pre_encode and before post_decode functions are called.

const google::protobuf::FieldDescriptor *	this_field () const
	Returns the FieldDescriptor (field schema meta-data) for this field.

const google::protobuf::Descriptor *	this_descriptor () const
	Returns the Descriptor (message schema meta-data) for the immediate parent Message.

const google::protobuf::Message *	this_message ()

const google::protobuf::Message *	root_message ()

const google::protobuf::Descriptor *	root_descriptor () const

internal::MessageStackData &	message_data ()

const internal::MessageStackData &	message_data () const

bool	has_codec_group ()

std::string	codec_group ()

int	codec_version ()

MessagePart	part ()
	the part of the message currently being encoded (head or body)

bool	strict ()

void	set_force_use_required (bool force_required=true)
	Force the codec to always use the "required" field encoding, regardless of the FieldDescriptor setting. Useful when wrapping this codec in another that handles optional and repeated fields.

Additional Inherited Members
Static Public Member Functions inherited from dccl::FieldCodecBase
static std::string	codec_group (const google::protobuf::Descriptor *desc)

Protected Member Functions inherited from dccl::FieldCodecBase
bool	use_required ()
	Whether to use the required or optional encoding.

virtual std::string	info ()
	Write field specific information (in addition to general information such as sizes that are automatically written by this class for all fields.

virtual std::size_t	hash ()
	Generate a field specific hash to be combined with the descriptor hash.

virtual void	any_encode_repeated (Bitset *bits, const std::vector< dccl::any > &wire_values)

virtual void	any_decode_repeated (Bitset repeated_bits, std::vector< dccl::any > field_values)

virtual void	any_pre_encode_repeated (std::vector< dccl::any > *wire_values, const std::vector< dccl::any > &field_values)

virtual void	any_post_decode_repeated (const std::vector< dccl::any > &wire_values, std::vector< dccl::any > *field_values)

virtual unsigned	any_size_repeated (const std::vector< dccl::any > &wire_values)

virtual unsigned	max_size_repeated ()

virtual unsigned	min_size_repeated ()

void	check_repeat_settings () const

Detailed Description

template<typename WrappedType>
class dccl::v3::PresenceBitCodec< WrappedType >

Encodes empty optional fields with a single "presence" bit.

This class wraps an existing TypedFieldCodec, adding an extra "presence" bit to the LSB for optional fields. The field size is as follows:

Optional
- Empty: 1 bit
- Non-empty: size of WrappedType + 1
Required
- Empty: size of WrappedType
- Non-empty: size of WrappedType

Definition at line 44 of file field_codec_presence.h.

Member Typedef Documentation

◆ Base

template<typename WrappedType >

using dccl::v3::PresenceBitCodec< WrappedType >::Base = TypedFieldCodec<typename WrappedType::wire_type, typename WrappedType::field_type>

Definition at line 48 of file field_codec_presence.h.

◆ field_type

template<typename WrappedType >

using dccl::v3::PresenceBitCodec< WrappedType >::field_type = typename Base::field_type

The field_type of the "wrapped" codec.

Definition at line 57 of file field_codec_presence.h.

◆ wire_type

template<typename WrappedType >

using dccl::v3::PresenceBitCodec< WrappedType >::wire_type = typename Base::wire_type

The wire_type of the "wrapped" codec.

Definition at line 54 of file field_codec_presence.h.

◆ wrapped_type

template<typename WrappedType >

using dccl::v3::PresenceBitCodec< WrappedType >::wrapped_type = WrappedType

The codec type of the "wrapped" codec.

Definition at line 51 of file field_codec_presence.h.

Constructor & Destructor Documentation

◆ PresenceBitCodec()

template<typename WrappedType >

dccl::v3::PresenceBitCodec< WrappedType >::PresenceBitCodec ( )

inline

Definition at line 64 of file field_codec_presence.h.

Member Function Documentation

◆ decode()

template<typename WrappedType >

wire_type dccl::v3::PresenceBitCodec< WrappedType >::decode ( Bitset * bits )

inlineoverridevirtual

Decodes a field, first evaluating the presence bit if necessary.

Implements dccl::TypedFieldCodec< WrappedType::wire_type, WrappedType::field_type >.

Definition at line 100 of file field_codec_presence.h.

◆ encode() [1/2]

template<typename WrappedType >

Bitset dccl::v3::PresenceBitCodec< WrappedType >::encode ( )

inlineoverridevirtual

Encodes an empty field as a single 0 bit.

Implements dccl::TypedFieldCodec< WrappedType::wire_type, WrappedType::field_type >.

Definition at line 82 of file field_codec_presence.h.

◆ encode() [2/2]

template<typename WrappedType >

Bitset dccl::v3::PresenceBitCodec< WrappedType >::encode ( const wire_type & value )

inlineoverride

Encodes a non-empty field, adding a 1 bit to the front for optional fields.

Definition at line 88 of file field_codec_presence.h.

◆ max_size()

template<typename WrappedType >

unsigned dccl::v3::PresenceBitCodec< WrappedType >::max_size ( )

inlineoverridevirtual

Calculate maximum size of the field in bits.

Returns: Maximum size of this field (in bits).

Implements dccl::FieldCodecBase.

Definition at line 132 of file field_codec_presence.h.

◆ min_size()

template<typename WrappedType >

unsigned dccl::v3::PresenceBitCodec< WrappedType >::min_size ( )

inlineoverridevirtual

Calculate minimum size of the field in bits.

Returns: Minimum size of this field (in bits).

Implements dccl::FieldCodecBase.

Definition at line 146 of file field_codec_presence.h.

◆ post_decode()

template<typename WrappedType >

field_type dccl::v3::PresenceBitCodec< WrappedType >::post_decode ( const wire_type & wire_value )

inlineoverridevirtual

Convert from the WireType representation (used with encode() and decode(), i.e. "on the wire") to the FieldType representation (used in the Google Protobuf message).

Parameters

wire_value Value to convert

Returns: Converted value

Implements dccl::FieldCodecSelector< WireType, FieldType, Enable >.

Definition at line 73 of file field_codec_presence.h.

◆ pre_encode()

template<typename WrappedType >

wire_type dccl::v3::PresenceBitCodec< WrappedType >::pre_encode ( const field_type & field_value )

inlineoverridevirtual

Convert from the FieldType representation (used in the Google Protobuf message) to the WireType representation (used with encode() and decode(), i.e. "on the wire").

Parameters

field_value Value to convert

Returns: Converted value

Implements dccl::FieldCodecSelector< WireType, FieldType, Enable >.

Definition at line 67 of file field_codec_presence.h.

◆ set_manager()

template<typename WrappedType >

void dccl::v3::PresenceBitCodec< WrappedType >::set_manager ( FieldCodecManagerLocal * manager )

inlineoverridevirtual

Reimplemented from dccl::FieldCodecBase.

Definition at line 160 of file field_codec_presence.h.

◆ size() [1/2]

template<typename WrappedType >

unsigned dccl::v3::PresenceBitCodec< WrappedType >::size ( )

inlineoverridevirtual

Size of an empty field (1 bit)

Implements dccl::TypedFieldCodec< WrappedType::wire_type, WrappedType::field_type >.

Definition at line 119 of file field_codec_presence.h.

◆ size() [2/2]

template<typename WrappedType >

unsigned dccl::v3::PresenceBitCodec< WrappedType >::size ( const wire_type & wire_value )

inlineoverride

Size of a non-empty field; gets size from "wrapped" codec, adds 1 for optional fields.

Definition at line 126 of file field_codec_presence.h.

◆ validate()

template<typename WrappedType >

void dccl::v3::PresenceBitCodec< WrappedType >::validate ( )

inlineoverridevirtual

Calls _inner_codec.validate()

Reimplemented from dccl::FieldCodecBase.

Definition at line 79 of file field_codec_presence.h.

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

dccl/codecs3/field_codec_presence.h

Public Types

Public Member Functions

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ Base

◆ field_type

◆ wire_type

◆ wrapped_type

Constructor & Destructor Documentation

◆ PresenceBitCodec()

Member Function Documentation

◆ decode()

◆ encode() [1/2]

◆ encode() [2/2]

◆ max_size()

◆ min_size()

◆ post_decode()

◆ pre_encode()

◆ set_manager()

◆ size() [1/2]

◆ size() [2/2]

◆ validate()