r_Transaction Class Reference

Transactions can be started, committed, aborted, and checkpointed. More...

#include <transaction.hh>

Public Types
enum	r_TAStatus { active , inactive , comiting , aborting }
	possible states of the transaction More...
enum	r_TAMode { read_write , read_only }
	possible transaction modes More...

Public Member Functions
	r_Transaction (r_Database *db=NULL)
	create a new transaction object; if the db object is not provided, this class not thread-safe.
	~r_Transaction ()
	destructor, an active transaction is aborted
void	begin (r_TAMode mode=read_write)
	start the transaction
void	commit ()
	By default, a transaction is started in write mode.
void	abort ()
	The transaction is committed and changes are made persistent in the database.
r_TAStatus	get_status () const
	returns the current state
r_TAMode	get_mode () const
	returns current mode
r_Ref_Any	load_object (const r_OId &oid)
	load an object (internal use only)
void	add_object_list (GenRefType type, void *ref)
	adds a non-r_Object to the list of persistent objects
void	setDatabase (r_Database *database)
	sets the database reference that this transaction is using.
r_Database *	getDatabase ()
	returns the database used by this transaction

Static Public Attributes
static r_Transaction *	actual_transaction
	store a pointer to the actual transaction

Detailed Description

Transactions can be started, committed, aborted, and checkpointed.

It is important to note that all access, creation, modification, and deletion of persistent objects must be done within a transaction. Right now, only one transaction can be active at a time.

Member Enumeration Documentation

r_TAMode

enum r_Transaction::r_TAMode

possible transaction modes

Enumerator
read_write
read_only

r_TAStatus

enum r_Transaction::r_TAStatus

possible states of the transaction

Enumerator
active
inactive
comiting
aborting

Constructor & Destructor Documentation

r_Transaction()

r_Transaction::r_Transaction

(

r_Database *

db = NULL

)

create a new transaction object; if the db object is not provided, this class not thread-safe.

~r_Transaction()

r_Transaction::~r_Transaction

(

)

destructor, an active transaction is aborted

Member Function Documentation

abort()

void r_Transaction::abort

(

)

The transaction is committed and changes are made persistent in the database.

While committing, the following errors can occur:

abort transaction and forget changes within transaction

add_object_list()

void r_Transaction::add_object_list	(	GenRefType	type,
		void *	ref
	)

adds a non-r_Object to the list of persistent objects

begin()

void r_Transaction::begin

(

r_TAMode

mode = read_write

)

start the transaction

commit()

void r_Transaction::commit

(

)

By default, a transaction is started in write mode.

If the read_only mode is specified, no write operations are allowed within the transaction anymore. If any write operation occurs in read_only mode, the exception r_Error with kind r_Error_TransactionReadOnly will be raised and the transaction will be aborted. In order to achieve maximal performance, read-only transactions should be used whenever posssible, i.e., when no update operations occur within this transaction. commit transaction and make changes persistent

get_mode()

r_TAMode r_Transaction::get_mode

(

)

const

returns current mode

get_status()

r_TAStatus r_Transaction::get_status

(

)

const

returns the current state

getDatabase()

r_Database * r_Transaction::getDatabase

(

)

returns the database used by this transaction

load_object()

r_Ref_Any r_Transaction::load_object

(

const r_OId &

oid

)

load an object (internal use only)

setDatabase()

void r_Transaction::setDatabase

(

r_Database *

database

)

sets the database reference that this transaction is using.

if none is provided the default static database is used NOTE: The setDatabase method should be called before any other operation that uses the database

Member Data Documentation

actual_transaction

r_Transaction* r_Transaction::actual_transaction

static

store a pointer to the actual transaction

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

• transaction.hh