CacheTransactionSynchronization (hibernate-core JavaDocs)

All Known Implementing Classes:

AbstractCacheTransactionSynchronization, StandardCacheTransactionSynchronization
```
public interface CacheTransactionSynchronization
```
Defines a context object that a RegionFactory is asked to create (RegionFactory.createTransactionContext(org.hibernate.engine.spi.SharedSessionContractImplementor)}) when a Hibernate Session is created. It's lifecycle is that of the Session. It receives "transactional event callbacks" around joining and completing resource transactions. This allows the cache impl to book-keep data related to current transaction, such as and process it in unique ways. E.g. this allows an impl to perform batch updates if Hibernate is configured to use JDBC-only transactions, and therefore information cannot be retrieved from the JTA transaction assigned to current thread. While transactional semantics might be fully implemented by the cache provider, Hibernate may require different transactional semantics: In order to prevent inconsistent reads, 2LC should not expose entities that are modified in any concurrently executing transactions, and force DB load instead. Native transactional implementation may provide looser semantics and 2LC implementation has to adapt to these.

ImplNote:

Even though a JTA transaction may involve more than one Session the CacheTransactionContext is specific to each Session since the distinction is generally unimportant. However, a provider is free to attempt to scope these CacheTransactionContext instances in such a way that they may be associated with more than one Session at a time. This SPI is designed to not require this of the caching impl, but it certainly allows the provider to do it

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`long`	`getCurrentTransactionStartTimestamp()` What is the start time of this context object?
`void`	`transactionCompleted(boolean successful)` Callback that the underling resource transaction to which the owning Session was joined is in the "completed" stage.
`void`	`transactionCompleting()` Callback that the underling resource transaction to which the owning Session was joined is in the beginning stages of completing.
`void`	`transactionJoined()` Callback that owning Session has become joined to a resource transaction.
`default void`	`transactionResumed()` Currently not used.
`default void`	`transactionSuspended()` Currently not used.

- Method Detail
  - getCurrentTransactionStartTimestamp
```
long getCurrentTransactionStartTimestamp()
```
    What is the start time of this context object?
    
    ApiNote:
    
    If not currently joined to a transaction, the timestamp from the last transaction is safe to use. If not ever/yet joined to a transaction, a timestamp at the time the Session/CacheTransactionSynchronization were created should be returned.
    
    ImplSpec:
    
    This "timestamp" need not be related to timestamp in the Java Date/millisecond sense. It just needs to be an incrementing value.
  - transactionJoined
```
void transactionJoined()
```
    Callback that owning Session has become joined to a resource transaction.
    
    ApiNote:
    
    Implementors can consider this the effective start of a transaction.
  - transactionCompleting
```
void transactionCompleting()
```
    Callback that the underling resource transaction to which the owning Session was joined is in the beginning stages of completing. Note that this is only called for successful "begin completion" of the underlying resource transaction (not rolling-back, marked-for-rollback, etc)
  - transactionCompleted
```
void transactionCompleted(boolean successful)
```
    Callback that the underling resource transaction to which the owning Session was joined is in the "completed" stage. This method is called regardless of success or failure of the transaction - the outcome is passed as a boolean.
    
    Parameters:
    
    successful - Was the resource transaction successful?
  - transactionSuspended
```
default void transactionSuspended()
```
    Currently not used. Here for future expansion
    
    ImplNote:
    
    Currently not used. JTA defines no standard means to be notified when a transaction is suspended nor resumed. Such a feature is proposed.
  - transactionResumed
```
default void transactionResumed()
```
    Currently not used. Here for future expansion
    
    ImplNote:
    
    Currently not used. JTA defines no standard means to be notified when a transaction is suspended nor resumed

Interface CacheTransactionSynchronization

Method Summary

Method Detail

getCurrentTransactionStartTimestamp

transactionJoined

transactionCompleting

transactionCompleted

transactionSuspended

transactionResumed