com.atlassian.confluence.impl.journal
Class DefaultJournalService

java.lang.Object
  com.atlassian.confluence.impl.journal.DefaultJournalService

All Implemented Interfaces:

JournalService

public class DefaultJournalService
extends Object
implements JournalService

This is the default implementation of JournalService.

Since:

5.6

Constructor Summary

DefaultJournalService(JournalManager journalManager)

Method Summary

int	countEntries(JournalIdentifier journalId) Counts the number of entries in a journal.
long	enqueue(JournalEntry entry) Adds the given entry to a journal.
Iterable<JournalEntry>	peek(JournalIdentifier journalId, int maxEntries) Return a copy of journal entries that are waiting to be processed.
<V> V	processEntries(JournalIdentifier journalId, int maxEntries, com.google.common.base.Function<Iterable<JournalEntry>,EntryProcessorResult<V>> entryProcessor) Processes journal entries that were added since the last time this method was called for this journal on this cluster node.
void	reset(JournalIdentifier journalId) Resets the state of the journal so that all entries currently in the journal will be skipped.
void	waitForRecentEntriesToBecomeVisible() Waits long enough to ensure that entries added before calling this method will be available to subsequent call to JournalService.processEntries(com.atlassian.confluence.api.model.journal.JournalIdentifier, int, com.google.common.base.Function).

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultJournalService

public DefaultJournalService(JournalManager journalManager)

Method Detail

enqueue

public long enqueue(@Nonnull
                    JournalEntry entry)
             throws ServiceException

Description copied from interface: JournalService

Adds the given entry to a journal.

New journal is automatically created if a journal with the given name does not exists.

Specified by:

enqueue in interface JournalService

Parameters:

entry - entry to persist

Returns:

id generated for the entry

Throws:

ServiceException - if the entry could not be persisted

processEntries

public <V> V processEntries(@Nonnull
                            JournalIdentifier journalId,
                            int maxEntries,
                            @Nonnull
                            com.google.common.base.Function<Iterable<JournalEntry>,EntryProcessorResult<V>> entryProcessor)
                 throws ServiceException

Description copied from interface: JournalService

Processes journal entries that were added since the last time this method was called for this journal on this cluster node.

This method does not return entries that were added immediately before calling this method. Use JournalService.waitForRecentEntriesToBecomeVisible() for ensuring these entries will be included.

This method can miss some entries due to identifier assignment and entry insertion not being an atomic operation. The risk of missed entries can be reduced by creating new entries as close to transaction commit as possible.

If entryProcessor throws an exception, the same entries will be returned again when this method is next called for this journal on this cluster node.

New journal is automatically created if a journal with the given name does not exists.

Specified by:

processEntries in interface JournalService

Parameters:

journalId - only entries with this journal id will be returned

maxEntries - maximum number of entries to process

entryProcessor - function that will process entries that were added since the last time

Returns:

result of entryProcessor

Throws:

ServiceException - if entries could not be fetched or the journal state could not be saved

waitForRecentEntriesToBecomeVisible

public void waitForRecentEntriesToBecomeVisible()
                                         throws InterruptedException

Description copied from interface: JournalService

Waits long enough to ensure that entries added before calling this method will be available to subsequent call to JournalService.processEntries(com.atlassian.confluence.api.model.journal.JournalIdentifier, int, com.google.common.base.Function).

Specified by:

waitForRecentEntriesToBecomeVisible in interface JournalService

Throws:

InterruptedException - if the thread got interrupted

peek

public Iterable<JournalEntry> peek(@Nonnull
                                   JournalIdentifier journalId,
                                   int maxEntries)
                            throws ServiceException

Description copied from interface: JournalService

Return a copy of journal entries that are waiting to be processed.

Specified by:

peek in interface JournalService

Parameters:

journalId - only entries with this journal id will be returned

maxEntries - maximum number of entries to return

Returns:

a copy of journal entries that are waiting to be processed

Throws:

ServiceException - if entries could not be fetched

reset

public void reset(@Nonnull
                  JournalIdentifier journalId)
           throws ServiceException

Description copied from interface: JournalService

Resets the state of the journal so that all entries currently in the journal will be skipped.

Specified by:

reset in interface JournalService

Parameters:

journalId - identifier of the journal to reset

Throws:

ServiceException - if the reset fails

countEntries

public int countEntries(@Nonnull
                        JournalIdentifier journalId)
                 throws ServiceException

Description copied from interface: JournalService

Counts the number of entries in a journal.

Specified by:

countEntries in interface JournalService

Parameters:

journalId - identifier of the journal

Throws:

ServiceException - if entries could not be counted