Package liquibase.changelog

Class FastCheckService

java.lang.Object

liquibase.changelog.FastCheckService

All Implemented Interfaces:

SingletonObject

public class FastCheckService
extends Object
implements SingletonObject

Service to perform a fast check of the historyService to determine if there is no unrun changesets without obtaining an exclusive write lock.

Method Summary

Modifier and Type	Method	Description
void	clearCache()	Clear fastCheck cache
boolean	isUpToDateFastCheck(List<ChangeSetFilter> changesetFilters, Database database, DatabaseChangeLog databaseChangeLog, Contexts contexts, LabelExpression labelExpression)	Performs check of the historyService to determine if there is no unrun changesets without obtaining an exclusive write lock.

Methods inherited from class java.lang.Object

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

Method Details

isUpToDateFastCheck

public boolean isUpToDateFastCheck(List<ChangeSetFilter> changesetFilters,
 Database database,
 DatabaseChangeLog databaseChangeLog,
 Contexts contexts,
 LabelExpression labelExpression)
                            throws LiquibaseException

Performs check of the historyService to determine if there is no unrun changesets without obtaining an exclusive write lock. This allows multiple peer services to boot in parallel in the common case where there are no changelogs to run.

If we see that there is nothing in the changelog to run and this returns true, then regardless of the lock status we already know we are "done" and can finish up without waiting for the lock.

But, if there are changelogs that might have to be ran and this returns false, you MUST get a lock and do a real check to know what changesets actually need to run.

NOTE: to reduce the number of queries to the databasehistory table, this method will cache the "fast check" results within this instance under the assumption that the total changesets will not change within this instance.

Throws:

LiquibaseException

clearCache

public void clearCache()

Clear fastCheck cache