Decoder Class Reference

#include <OnixS/FIXEngine/FIX/FAST.h>

Public Member Functions
	Decoder (const std::string &xmlTemplates, const OnixS::FIX::Dictionary &fixDictionary, bool decodeEachMessageIndependently, InputDataTraits::Enum inputDataTraits)
	Decoder (const std::string &xmlTemplates, bool decodeEachMessageIndependently, InputDataTraits::Enum inputDataTraits)
	Decoder (ProtocolVersion::Enum baseVersionForGeneratedDictionary, const std::string &xmlTemplates, bool decodeEachMessageIndependently, InputDataTraits::Enum inputDataTraits)
	Decoder (ProtocolVersion::Enum baseVersionForGeneratedDictionary, const std::string &xmlTemplates, const std::string &genericFixDictionaryId, bool decodeEachMessageIndependently, InputDataTraits::Enum inputDataTraits)
	~Decoder ()
InputDataTraits::Enum	inputDataTraits () const
const OnixS::FIX::Message &	decode (const char *buffer, size_t bufferSize)
const OnixS::FIX::Message &	decode (const unsigned char *buffer, size_t bufferSize)
const OnixS::FIX::Message &	decode (const std::vector< char > &chunk)
const OnixS::FIX::Message &	decode (const OnixS::Sockets::Bytes &chunk)
bool	tryDecode (const char *buffer, size_t offset, size_t count, OnixS::FIX::Message *message, size_t *numberOfDecodedBytes)
bool	tryDecode (const unsigned char *buffer, size_t offset, size_t count, OnixS::FIX::Message *message, size_t *numberOfDecodedBytes)
void	reset ()
OnixS::FIX::Dictionary	fixDictionary () const
void	maximumNumberOfRepeatingGroupEntries (int value)
int	maximumNumberOfRepeatingGroupEntries () const

Static Public Member Functions
static bool	tryDecodeUnsignedInteger (const char *buffer, size_t bufferSize, unsigned int *value, size_t *fieldLength)
static bool	tryDecodeUnsignedInteger (const unsigned char *buffer, size_t bufferSize, unsigned int *value, size_t *fieldLength)
static void	generateFixDictionary (const std::string &fastTemplateXml, const std::string &fixDictionaryId, std::string *fixDictionaryXml)
static void	generateFixDictionary (ProtocolVersion::Enum baseVersion, const std::string &fastTemplateXml, const std::string &fixDictionaryId, std::string *fixDictionaryXml)

Detailed Description

Definition at line 129 of file FAST.h.

Constructor & Destructor Documentation

Decoder	(	const std::string &	xmlTemplates,
		const OnixS::FIX::Dictionary &	fixDictionary,
		bool	decodeEachMessageIndependently,
		InputDataTraits::Enum	inputDataTraits
	)

Creates a FAST to FIX Decoder.

Parameters

xmlTemplates	XML-based FAST templates.
fixDictionary	The customized FIX dictionary used for the decoded message.
decodeEachMessageIndependently	The option to reset the previous values dictionaries before decoding a new FAST stream chunk.
inputDataTraits	Traits of input data, has effect only when decodeEachMessageIndependently is false. See InputDataTraits::Enum for details.

Decoder	(	const std::string &	xmlTemplates,
		bool	decodeEachMessageIndependently,
		InputDataTraits::Enum	inputDataTraits
	)

Creates a FAST to FIX Decoder for the FIX dictionary-independent mode.

The generic FIX dictionary is created by the provided FAST-template content, it uses the FIX 4.0 as a base FIX dictionary and has a generic name.

Parameters

xmlTemplates	XML-based FAST templates.
decodeEachMessageIndependently	The option to reset the previous values dictionaries before decoding a new FAST stream chunk.
inputDataTraits	Traits of input data, has effect only when decodeEachMessageIndependently is false. See InputDataTraits::Enum for details.

Decoder	(	ProtocolVersion::Enum	baseVersionForGeneratedDictionary,
		const std::string &	xmlTemplates,
		bool	decodeEachMessageIndependently,
		InputDataTraits::Enum	inputDataTraits
	)

Creates a FAST to FIX Decoder for the FIX dictionary-independent mode.

The generic FIX dictionary is created by the provided FAST-template content, it uses the specified FIX dictionary as a base and has a generic name.

Parameters

baseVersionForGeneratedDictionary	This version of the FIX protocol becomes the base for the newly generated FIX dictionary.
xmlTemplates	XML-based FAST templates used to generate the FIX dictionary. This FIX dictionary takes a generic identifier generated on a base of the XML content and baseVersion
decodeEachMessageIndependently	The option to reset the previous values dictionaries before decoding a new FAST stream chunk.
inputDataTraits	Traits of input data, has effect only when decodeEachMessageIndependently is false. See InputDataTraits::Enum for details.

Decoder	(	ProtocolVersion::Enum	baseVersionForGeneratedDictionary,
		const std::string &	xmlTemplates,
		const std::string &	genericFixDictionaryId,
		bool	decodeEachMessageIndependently,
		InputDataTraits::Enum	inputDataTraits
	)

Creates a FAST to FIX Decoder for the FIX dictionary-independent mode.

The generic FIX dictionary is created by the provided FAST-template content, it uses the specified FIX dictionary as a base and has the specified name.

Note

The new FIX dictionary instance will be generated if and only if there is no a FIX dictionary with the same name.

Parameters

baseVersionForGeneratedDictionary	This version of the FIX protocol becomes the base for the newly generated FIX dictionary.
xmlTemplates	XML-based FAST templates.
genericFixDictionaryId	The identifier which is applied to the generic FIX dictionary. This FIX dictionary is generated using xmlTemplates and baseVersion.
decodeEachMessageIndependently	The option to reset the previous values dictionaries before decoding a new FAST stream chunk.
inputDataTraits	Traits of input data, has effect only when decodeEachMessageIndependently is false. See InputDataTraits::Enum for details.

~Decoder

(

)

The destructor.

Member Function Documentation

const OnixS::FIX::Message& decode	(	const char *	buffer,
		size_t	bufferSize
	)

Decodes the given FAST stream chunk into the corresponding FIX Message.

Parameters

buffer	The buffer that contains the FAST stream chunk to be decoded.
bufferSize	The size of the buffer.

Warning

The returned message is 'owned' by the Decoder.

The previously decoded message is freed by the Decoder when this method is called again.

Exceptions

An	exception if the message cannot be decoded.

Returns

the decoded FIX message.

const OnixS::FIX::Message& decode	(	const unsigned char *	buffer,
		size_t	bufferSize
	)

const OnixS::FIX::Message& decode

(

const std::vector< char > &

chunk

)

Decodes the given FAST stream chunk into the corresponding FIX Message.

Parameters

chunk

The FAST stream chunk to be decoded.

Warning

The returned message is 'owned' by the Decoder.

The previously decoded message is freed by the Decoder when this method is called again.

Exceptions

An	exception if the message cannot be decoded.

Returns

the decoded FIX message.

const OnixS::FIX::Message& decode

(

const OnixS::Sockets::Bytes &

chunk

)

OnixS::FIX::Dictionary fixDictionary

(

)

const

The FIX dictionary used by the decoder instance.

Returns

The FIX dictionary currently used by the decoder instance. If the decoder was initialized with the FIX dictionary-independent mode, the method returns a reference to the internally generated FIX dictionary.

static void generateFixDictionary ( const std::string &  fastTemplateXml, const std::string &  fixDictionaryId, std::string *  fixDictionaryXml  )

static

Generates the FIX dictionary XML.

Parameters

[in]	fastTemplateXml	The XML content of FAST template (the same as used to initialize Decoder).
[in]	fixDictionaryId	The output FIX dictionary identifier (see "id" attribute of "FIX" node).
[out]	fixDictionaryXml	The XML with the generated FIX dictionary.

static void generateFixDictionary ( ProtocolVersion::Enum  baseVersion, const std::string &  fastTemplateXml, const std::string &  fixDictionaryId, std::string *  fixDictionaryXml  )

static

Generates the FIX dictionary XML.

Parameters

[in]	fastTemplateXml	The XML content of the FAST template (the same as used to initialize the Decoder).
[in]	baseVersion	This version of the FIX protocol becomes the base for the newly generated FIX dictionary.
[in]	fixDictionaryId	The output FIX dictionary identifier (see "id" attribute of "FIX" node).
[out]	fixDictionaryXml	The XML with the generated FIX dictionary.

InputDataTraits::Enum inputDataTraits

(

)

const

Input data traits of the decoder.

Returns

Input data traits provided during the construction of the decoder.

void maximumNumberOfRepeatingGroupEntries

(

int

value

)

Manages the maximum number of repeating groups, allowed for decoded messages.

This parameter is used during the decoding and is useful to detect a broken data, which, in particular cases, can 'need' to allocate an unexpectedly huge number of entries (for instance - billions of entries, while normally there are just a few ones). This situation results in memory exhausting and (often) significantly decreases the overall system performance.

To prevent the memory exhausting and negative consequences of that, this parameter should be configured with the value, which is greater then the maximum possible number of entries in valid input data, but less then the maximum integer value (default one). In a lot of real cases the value of 10000 is good enough to detect broken data without the memory overloading.

Default is the maximum positive value for int type.

Parameters

value

The number of repeating groups, allowed for decoded messages.

int maximumNumberOfRepeatingGroupEntries

(

)

const

The maximum number of repeating groups, allowed for decoded messages.

Returns

The current number of repeating groups, allowed for decoded messages. The default value is the maximum positive value for int type.

void reset

(

)

Resets the state of the previous values dictionaries (sets the state of the previous values to undefined).

See also

decodeEachMessageIndependently.

bool tryDecode	(	const char *	buffer,
		size_t	offset,
		size_t	count,
		OnixS::FIX::Message *	message,
		size_t *	numberOfDecodedBytes
	)

Tries to decode the given FAST stream buffer into the corresponding FIX Message.

Parameters

[in]	buffer	The FAST stream chunk to be decoded.
[in]	offset	The index in the buffer at which decoding begins.
[in]	count	The number of bytes to analyze during the decoding.
[out]	message	The pointer to the decoded FIX Message.
[out]	numberOfDecodedBytes	The number of bytes that contained the encoded FIX Message.

Warning

The message should point to an existing object. This object is not owned by the Decoder and should be managed by a user.

Exceptions

An	exception if the decoding error is detected.

Returns

'true' if the given bytes could be decoded into a FIX message, otherwise - 'false'.

bool tryDecode	(	const unsigned char *	buffer,
		size_t	offset,
		size_t	count,
		OnixS::FIX::Message *	message,
		size_t *	numberOfDecodedBytes
	)

static bool tryDecodeUnsignedInteger ( const char *  buffer, size_t  bufferSize, unsigned int *  value, size_t *  fieldLength  )

static

Decodes the FAST-encoded unsigned integer.

Parameters

buffer	The buffer that contains the FAST stream chunk to be decoded.
bufferSize	The size of the buffer.
value	The decoded value.
fieldLength	The number of bytes that contained the encoded value.

Returns

'true' if the stop bit was found and the value was decoded, otherwise - 'false'.

static bool tryDecodeUnsignedInteger ( const unsigned char *  buffer, size_t  bufferSize, unsigned int *  value, size_t *  fieldLength  )

static

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

• OnixS/FIXEngine/FIX/FAST.h