com.atlassian.confluence.impl.hibernate

Class HibernateSessionManager5

java.lang.Object

com.atlassian.confluence.impl.hibernate.HibernateSessionManager5

public class HibernateSessionManager5
extends Object

Provides methods to manage objects in the current Hibernate Session. Methods will throw IllegalStateException if there is no active session on the executing thread. Replacement for HibernateSessionManager due to Hibernate 2 removal.

Since:

7.16.0

Constructor Summary

Constructors

Constructor and Description
HibernateSessionManager5(org.hibernate.SessionFactory sessionFactory, org.springframework.transaction.PlatformTransactionManager transactionManager)

Method Summary

Modifier and Type	Method and Description
<I,O> Iterable<O>	executeThenClearSession(Iterable<I> input, int batchSize, int expectedTotal, Function<I,O> task) Executes a bulk database update in a way that prevents excessive memory usage, by committing the transaction and clearing the session periodically.
int	executeThenClearSessionWithoutCommitOrFlush(int batchSize, int expectedTotal, Function<Integer,Integer> taskExecutor) Execute tasks in batches and clear session after every batch, re-using the existing transaction rather than nesting transactions.
<I,O> Iterable<O>	executeThenClearSessionWithoutCommitOrFlush(Iterable<I> input, int batchSize, int expectedTotal, Function<I,O> task) Executes a bulk database update in a way that prevents excessive memory usage, by clearing the session (but NOT committing or flushing) periodically.
<I,O> Iterable<O>	executeThenFlushAndClearSession(Iterable<I> input, int batchSize, int expectedTotal, Function<I,O> task) Reuses the current transaction, to avoid nested transaction issues.
org.springframework.transaction.support.TransactionTemplate	getTransactionTemplate()
boolean	withNewTransaction(Callable<Boolean> callable)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

HibernateSessionManager5

public HibernateSessionManager5(org.hibernate.SessionFactory sessionFactory,
                                org.springframework.transaction.PlatformTransactionManager transactionManager)

Method Detail

executeThenClearSession

public <I,O> Iterable<O> executeThenClearSession(Iterable<I> input,
                                                 int batchSize,
                                                 int expectedTotal,
                                                 Function<I,O> task)

Executes a bulk database update in a way that prevents excessive memory usage, by committing the transaction and clearing the session periodically. The provided task is executed once per input item. The commit and session-clearing is done once per batchSize items.

WARNING: the session clearing will discard any unflushed or uncommitted changes made higher in the stack. Batch operations using this method should generally be done in a separate thread or otherwise outside the scope of a request.

Type Parameters:

I - the type of the input items

O - the type of the resulting items, which can be Void

Parameters:

input - the list of items to process

task - the task to execute

batchSize - a transaction will be committed and the session will be cleared after this many input items

expectedTotal - the total number of items, used for logging. A value of 0 indicates expected total is not known.

Returns:

the output of the task

Throws:

IllegalStateException - if there is no active session

org.springframework.dao.DataAccessException - if there is a problem committing changes to the database

executeThenFlushAndClearSession

public <I,O> Iterable<O> executeThenFlushAndClearSession(Iterable<I> input,
                                                         int batchSize,
                                                         int expectedTotal,
                                                         Function<I,O> task)

Reuses the current transaction, to avoid nested transaction issues.

Since:

7.0.1

executeThenClearSessionWithoutCommitOrFlush

public <I,O> Iterable<O> executeThenClearSessionWithoutCommitOrFlush(Iterable<I> input,
                                                                     int batchSize,
                                                                     int expectedTotal,
                                                                     Function<I,O> task)

Executes a bulk database update in a way that prevents excessive memory usage, by clearing the session (but NOT committing or flushing) periodically. The provided task is executed once per input item. The session-clearing (But no commit) is done once per batchSize items.

WARNING: the session clearing will discard any unflushed or uncommitted changes made higher in the stack. Also, the existing transaction will not be committed in this method. Use this method only for the operations that do not write to database.

Type Parameters:

I - the type of the input items

O - the type of the resulting items, which can be Void

Parameters:

input - the list of items to process

batchSize - a transaction will be committed and the session will be cleared after this many input items

expectedTotal - the total number of items, used for logging. A value of 0 indicates expected total is not known.

task - the task to execute

Returns:

the output of the task

Throws:

IllegalStateException - if there is no active session

org.springframework.dao.DataAccessException - if there is a problem committing changes to the database

Since:

7.19.12

executeThenClearSessionWithoutCommitOrFlush

public int executeThenClearSessionWithoutCommitOrFlush(int batchSize,
                                                       int expectedTotal,
                                                       Function<Integer,Integer> taskExecutor)

Execute tasks in batches and clear session after every batch, re-using the existing transaction rather than nesting transactions. WARNING: the session clearing will discard any unflushed or uncommitted changes made higher in the stack. Use this method only for the operations that do not write to database. Also, the existing transaction will not be committed in this method.

Parameters:

batchSize - the positive number of tasks to execute in a batch, before any hibernate clears.

expectedTotal - the positive total number of tasks to be executed.

taskExecutor - the task executor. The taskExecutor should accept the batchSize to execute, and return how many tasks have been successfully executed.

Returns:

the number of tasks which were executed successfully.

withNewTransaction

public boolean withNewTransaction(Callable<Boolean> callable)

getTransactionTemplate

public org.springframework.transaction.support.TransactionTemplate getTransactionTemplate()