Recover entity used for sanity checking. More...

#include <MetaLogEntity.h>

Inheritance diagram for Hypertable::MetaLog::EntityRecover:

Collaboration diagram for Hypertable::MetaLog::EntityRecover:

Public Member Functions
	EntityRecover ()
	Constructor. More...

size_t	encoded_length () const override
	Returns serialized object length. More...

void	encode (uint8_t **bufp) const override
	Writes serialized representation of object to a buffer. More...

void	decode (const uint8_t *bufp, size_t remainp) override
	Reads serialized representation of object from a buffer. More...

void	decode (const uint8_t *bufp, size_t remainp, uint16_t definition_version) override
	Decodes serialized entity state. More...

const std::string	name () override
	Returns the name of the entity. More...

Public Member Functions inherited from Hypertable::MetaLog::Entity
	Entity (int32_t type)
	Constructor from entity type. More...

	Entity (const EntityHeader &header_)
	Constructor from entity header. More...

virtual	~Entity ()
	Destructor. More...

void	lock ()
	Locks the entity's mutex. More...

void	unlock ()
	Unlocks the entity's mutex. More...

void	mark_for_removal ()
	Marks entity for removal. More...

bool	marked_for_removal ()
	Checks if entity is marked for removal. More...

int64_t	id () const
	Returns the entity ID. More...

virtual void	display (std::ostream &os)
	Prints a textual representation of the entity state to an ostream. More...

Private Member Functions
uint8_t	encoding_version () const override
	Returns encoding version. More...

size_t	encoded_length_internal () const override
	Returns internal serialized length. More...

void	encode_internal (uint8_t **bufp) const override
	Writes serialized representation of object to a buffer. More...

void	decode_internal (uint8_t version, const uint8_t *bufp, size_t remainp) override
	Reads serialized representation of object from a buffer. More...

Additional Inherited Members
Protected Member Functions inherited from Hypertable::MetaLog::Entity
void	encode_entry (uint8_t **bufp)
	Encodes entity header plus serialized state. More...

Protected Attributes inherited from Hypertable::MetaLog::Entity
std::mutex	m_mutex
	Mutex for serializing access to members More...

EntityHeader	header
	Entity header More...

Detailed Description

Recover entity used for sanity checking.

When a MetaLog is opened for writing, a set of entities are provided which first get written to the new log (see Writer()). The log file is kept open by the MetaLog::Writer during the execution of the server and application object state changes are recorded in the log by updating the state of the associated entity object and appending the updated entity to the log file. To detect the situation when a server exits before the initially provided entities were completely written to the log, an EntityRecover object is written to the log after all of the initially provided entities. When the MetaLog::Reader reads a MetaLog file, it checks for this entity and if not found, it throws and Exception with error code Error::METALOG_MISSING_RECOVER_ENTITY.

Definition at line 207 of file MetaLogEntity.h.

Constructor & Destructor Documentation

Hypertable::MetaLog::EntityRecover::EntityRecover ( )

inline

Constructor.

Initializes parent Entity constructor with EntityType::RECOVER.

Definition at line 213 of file MetaLogEntity.h.

Member Function Documentation

void Hypertable::MetaLog::EntityRecover::decode	(	const uint8_t **	bufp,
		size_t *	remainp
	)

inlineoverridevirtual

Reads serialized representation of object from a buffer.

Parameters

bufp	Address of destination buffer pointer (advanced by call)
remainp	Address of integer holding amount of remaining buffer

See also: encode() for encoding format

Exceptions

Exception with code Error::PROTOCOL_ERROR if version being decoded is greater than that returned by encoding_version().

Reimplemented from Hypertable::Serializable.

Definition at line 219 of file MetaLogEntity.h.

void Hypertable::MetaLog::EntityRecover::decode	(	const uint8_t **	bufp,
		size_t *	remainp,
		uint16_t	definition_version
	)

inlineoverridevirtual

Decodes serialized entity state.

Parameters

bufp	Address of destination buffer pointer (advanced by call)
remainp	Address of integer holding amount of remaining buffer
definition_version	Version of MetaLog::Definition that was used to generate the log.

Reimplemented from Hypertable::MetaLog::Entity.

Definition at line 221 of file MetaLogEntity.h.

void Hypertable::MetaLog::EntityRecover::decode_internal	(	uint8_t	version,
		const uint8_t **	bufp,
		size_t *	remainp
	)

inlineoverrideprivatevirtual

Reads serialized representation of object from a buffer.

This function is to be overridden by derived classes and should decode the object per-se as encoded with encode_internal().

Parameters

version	Encoding version
bufp	Address of destination buffer pointer (advanced by call)
remainp	Address of integer holding amount of serialized encoding remaining

See also: encode_internal() for encoding format

Implements Hypertable::Serializable.

Definition at line 238 of file MetaLogEntity.h.

void Hypertable::MetaLog::EntityRecover::encode ( uint8_t ** bufp ) const

inlineoverridevirtual

Writes serialized representation of object to a buffer.

This function encodes a serialized representation of the object, starting with a header that includes the encoding version and the serialized length of the object. After the header, the object per-se is encoded with encode_internal().

Parameters

bufp	Address of destination buffer pointer (advanced by call)

Encoding is as follows:

Encoding	Description
1 byte	Encoding version as returned by encoding_version()
vint	Length of encoded object as returned by encoded_length_internal()
variable	Object encoded with encode_internal()