Base class for MetaLog entities. More...

#include <MetaLogEntity.h>

Inheritance diagram for Hypertable::MetaLog::Entity:

Collaboration diagram for Hypertable::MetaLog::Entity:

Public Member Functions
	Entity (int32_t type)
	Constructor from entity type. More...

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

virtual	~Entity ()
	Destructor. More...

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

virtual const std::string	name ()=0
	Returns the name of the entity. 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...

Public Member Functions inherited from Hypertable::Serializable
virtual size_t	encoded_length () const
	Returns serialized object length. More...

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

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

Protected Member Functions
void	encode_entry (uint8_t **bufp)
	Encodes entity header plus serialized state. More...

Protected Member Functions inherited from Hypertable::Serializable
virtual uint8_t	encoding_version () const =0
	Returns encoding version. More...

virtual size_t	encoded_length_internal () const =0
	Returns internal serialized length. More...

virtual void	encode_internal (uint8_t **bufp) const =0
	Writes serialized representation of object to a buffer. More...

virtual void	decode_internal (uint8_t version, const uint8_t *bufp, size_t remainp)=0
	Reads serialized representation of object from a buffer. More...

Protected Attributes
std::mutex	m_mutex
	Mutex for serializing access to members More...

EntityHeader	header
	Entity header More...

Friends
class	Reader

class	Writer

std::ostream &	operator<< (std::ostream &os, Entity &entity)
	ostream shift function for Entity objects. More...

Detailed Description

Base class for MetaLog entities.

A MetaLog entitiy is associated with each application object that is to be persisted in the MetaLog. Entity objects are what get passed into and out of the read and write methods of the MetaLog API. Application objects can include a member that is derived from this class for the purpose of persisting its state. The application object class can also be derived from Entity allowing the application object itself to be passed directly into the Metalog APIs.

Definition at line 62 of file MetaLogEntity.h.

Constructor & Destructor Documentation

Entity::Entity ( int32_t type )

Constructor from entity type.

This method constructs a new entity, initializing the header member with type.

Parameters

type	Numeric entity type

Definition at line 40 of file MetaLogEntity.cc.

Entity::Entity ( const EntityHeader & header_ )

Constructor from entity header.

This method constructs an entity from an entity header (typically read and deserialized from a MetaLog). The header member is initialized with header_.

Parameters

header_ Entity header

Definition at line 42 of file MetaLogEntity.cc.

virtual Hypertable::MetaLog::Entity::~Entity ( )

inlinevirtual

Destructor.

Definition at line 81 of file MetaLogEntity.h.

Member Function Documentation

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

inlinevirtual

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 in Hypertable::Operation, Hypertable::BalancePlanAuthority, Hypertable::MetaLog::EntityRecover, Hypertable::MetaLogEntityRange, Hypertable::SystemState, Hypertable::MetaLogEntityRemoveOkLogs, Hypertable::RecoveredServers, Hypertable::RangeServerConnection, and Hypertable::MetaLog::EntityTaskAcknowledgeRelinquish.

Definition at line 91 of file MetaLogEntity.h.

virtual void Hypertable::MetaLog::Entity::display ( std::ostream & os )

inlinevirtual

Prints a textual representation of the entity state to an ostream.

Parameters

os	ostream on which to print entity state

Reimplemented in Hypertable::Operation, Hypertable::BalancePlanAuthority, Hypertable::MetaLogEntityRange, Hypertable::SystemState, Hypertable::MetaLogEntityRemoveOkLogs, Hypertable::RecoveredServers, Hypertable::RangeServerConnection, and Hypertable::MetaLog::EntityTaskAcknowledgeRelinquish.

Definition at line 142 of file MetaLogEntity.h.

void Entity::encode_entry ( uint8_t ** bufp )

protected

Encodes entity header plus serialized state.

This method first encodes the serialized state at *bufp plus EntityHeader::LENGTH bytes. It then computes the checksum of the serialized state with a call to fletcher32() and stores the result in header.checksum. It then encodes header at the beginning of the buffer. *bufp is left pointing to the end of the serialized state when the method returns.

Parameters

bufp	Address of destination buffer pointer (advanced by call)

Definition at line 45 of file MetaLogEntity.cc.

int64_t Hypertable::MetaLog::Entity::id ( ) const

inline

Returns the entity ID.

Returns: Entity ID from the

Definition at line 137 of file MetaLogEntity.h.

void Hypertable::MetaLog::Entity::lock ( )

inline

Locks the entity's mutex.

Definition at line 97 of file MetaLogEntity.h.

void Hypertable::MetaLog::Entity::mark_for_removal ( )

inline

Marks entity for removal.

To remove an entity from a MetaLog, the entity header gets written to the log with the EntityHeader::FLAG_REMOVE bit set in the flags field of the header. This method sets the EntityHeader::FLAG_REMOVE bit in the header and sets the header length and header checksum fields to zero. After a call to this method, the next time the entity is persisted to the log, it will be logically removed.

Definition at line 110 of file MetaLogEntity.h.

bool Hypertable::MetaLog::Entity::marked_for_removal ( )

inline

Checks if entity is marked for removal.

This method returns true if the EntityHeader::FLAG_REMOVE bit is set in the flags member of its header which means the next time it gets persisted, it will be logically removed removed.

See also: mark_for_removal()

Returns: true if entity is marked for removal, false otherwise

Definition at line 123 of file MetaLogEntity.h.

virtual const std::string Hypertable::MetaLog::Entity::name ( )

pure virtual

Returns the name of the entity.

This method returns the name of the entity which is used by tools that convert a MetaLog into a human readable representation

Returns: Name of the entity

void Hypertable::MetaLog::Entity::unlock ( )

inline

Unlocks the entity's mutex.

Definition at line 100 of file MetaLogEntity.h.

Friends And Related Function Documentation

std::ostream& operator<<	(	std::ostream &	os,
		Entity &	entity
	)

friend

ostream shift function for Entity objects.

This method writes a human readable representation of an Entity to a given ostream. It prints the header followed by the entity state.

Parameters

os	ostream on which to print entity
entity	Entity object to print

Returns: os

Definition at line 179 of file MetaLogEntity.h.

friend class Reader

friend

Definition at line 145 of file MetaLogEntity.h.

friend class Writer

friend

Definition at line 146 of file MetaLogEntity.h.

Member Data Documentation

EntityHeader Hypertable::MetaLog::Entity::header

protected

Entity header

Definition at line 165 of file MetaLogEntity.h.

std::mutex Hypertable::MetaLog::Entity::m_mutex

mutableprotected

Mutex for serializing access to members

Definition at line 162 of file MetaLogEntity.h.

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

/home/doug/src/hypertable/src/cc/Hypertable/Lib/MetaLogEntity.h
/home/doug/src/hypertable/src/cc/Hypertable/Lib/MetaLogEntity.cc

Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation