ReadIfExists Method (query, tx, timeout, modifiers)

Read (according to the modifiers) any matching object from the space, returning null if there currently is none. Equivalent to read, except that blocking is done only if necessary to wait for transactional state to settle.

Declaration Syntax

Visual Basic

Visual C++

T ReadIfExists<T>(
	IQuery<T> query,
	ITransaction tx,
	long timeout,
	ReadModifiers modifiers
)

Function ReadIfExists(Of T) ( _
	query As IQuery(Of T), _
	tx As ITransaction, _
	timeout As Long, _
	modifiers As ReadModifiers _
) As T

generic<typename T>
T ReadIfExists(
	IQuery<T>^ query, 
	ITransaction^ tx, 
	long long timeout, 
	ReadModifiers modifiers
)

J# supports the use of generic APIs, but not the declaration of new ones.

Generic Template Parameters

T: Type of object to read.

Parameters

query (IQuery<(Of <(<'T>)>)>): The query used for matching.

tx (ITransaction): The transaction (if any) under which to work.

timeout (Int64): How long the client is willing to wait for a transactionally proper matching object.

modifiers (ReadModifiers): The modifier(s) to define behaviour of locks.

Return Value

A copy of the object read from the space (null if no match was found).

Exceptions

Exception	Condition
UnusableEntryException	A serialized field of the object being read cannot be deserialized.
TransactionException	Transaction error occured.
InactiveSpaceException	The space is in backup mode and therefore is not active.
SqlQueryException	The query template is an illegal SqlQuery.

Assembly: GigaSpaces.Core (Module: GigaSpaces.Core) Version: 16.2.0.0 (16.2.1)