// This software is released into the Public Domain. See copying.txt for details.
package org.openstreetmap.osmosis.apidb.v0_6;
import java.util.Collections;
import java.util.Date;
import org.openstreetmap.osmosis.apidb.common.DatabaseContext2;
import org.openstreetmap.osmosis.apidb.v0_6.impl.AllEntityDao;
import org.openstreetmap.osmosis.apidb.v0_6.impl.DeltaToDiffReader;
import org.openstreetmap.osmosis.apidb.v0_6.impl.SchemaVersionValidator;
import org.openstreetmap.osmosis.core.container.v0_6.ChangeContainer;
import org.openstreetmap.osmosis.core.database.DatabaseLoginCredentials;
import org.openstreetmap.osmosis.core.database.DatabasePreferences;
import org.openstreetmap.osmosis.core.lifecycle.ReleasableIterator;
import org.openstreetmap.osmosis.core.task.v0_6.ChangeSink;
import org.openstreetmap.osmosis.core.task.v0_6.RunnableChangeSource;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.support.TransactionCallbackWithoutResult;
/**
* A change source reading from database history tables. This aims to be suitable for running at
* regular intervals with database overhead proportional to changeset size.
*
* @author Brett Henderson
*/
public class ApidbChangeReader implements RunnableChangeSource {
private ChangeSink changeSink;
private DatabaseLoginCredentials loginCredentials;
private DatabasePreferences preferences;
private Date intervalBegin;
private Date intervalEnd;
private boolean fullHistory;
/**
* Creates a new instance.
*
* @param loginCredentials
* Contains all information required to connect to the database.
* @param preferences
* Contains preferences configuring database behaviour.
* @param intervalBegin
* Marks the beginning (inclusive) of the time interval to be checked.
* @param intervalEnd
* Marks the end (exclusive) of the time interval to be checked.
* @param fullHistory
* Specifies if full version history should be returned, or just a single change per
* entity for the interval.
*/
public ApidbChangeReader(DatabaseLoginCredentials loginCredentials, DatabasePreferences preferences,
Date intervalBegin, Date intervalEnd, boolean fullHistory) {
this.loginCredentials = loginCredentials;
this.preferences = preferences;
this.intervalBegin = intervalBegin;
this.intervalEnd = intervalEnd;
this.fullHistory = fullHistory;
}
/**
* {@inheritDoc}
*/
public void setChangeSink(ChangeSink changeSink) {
this.changeSink = changeSink;
}
/**
* Runs the task implementation. This is called by the run method within a transaction.
*
* @param dbCtx
* Used to access the database.
*/
protected void runImpl(DatabaseContext2 dbCtx) {
try {
AllEntityDao entityDao;
ReleasableIterator<ChangeContainer> reader;
changeSink.initialize(Collections.<String, Object>emptyMap());
new SchemaVersionValidator(loginCredentials, preferences)
.validateVersion(ApidbVersionConstants.SCHEMA_MIGRATIONS);
entityDao = new AllEntityDao(dbCtx.getJdbcTemplate());
reader = entityDao.getHistory(intervalBegin, intervalEnd);
if (!fullHistory) {
reader = new DeltaToDiffReader(reader);
}
try {
while (reader.hasNext()) {
changeSink.process(reader.next());
}
} finally {
reader.release();
}
changeSink.complete();
} finally {
changeSink.release();
}
}
/**
* Reads all data from the database and send it to the sink.
*/
public void run() {
final DatabaseContext2 dbCtx = new DatabaseContext2(loginCredentials);
try {
dbCtx.executeWithinTransaction(new TransactionCallbackWithoutResult() {
private DatabaseContext2 dbCtxInner = dbCtx;
@Override
protected void doInTransactionWithoutResult(TransactionStatus arg0) {
runImpl(dbCtxInner);
} });
} finally {
dbCtx.release();
}
}
}