package org.apache.hadoop.hive.ql.hooks;
import java.util.Set;
import java.util.LinkedHashMap;
import java.util.Map;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.ql.session.SessionState;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.hive.ql.metadata.Hive;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.metadata.Partition;
import org.apache.hadoop.hive.ql.metadata.Table;
/**
* Implementation of a pre execute hook that updates the access
* times for all the inputs.
*/
public class UpdateInputAccessTimeHook {
private static final String LAST_ACCESS_TIME = "lastAccessTime";
public static class PreExec implements PreExecute {
Hive db;
public void run(SessionState sess, Set<ReadEntity> inputs,
Set<WriteEntity> outputs, UserGroupInformation ugi)
throws Exception {
if (db == null) {
try {
db = Hive.get(sess.getConf());
} catch (HiveException e) {
// ignore
db = null;
return;
}
}
int lastAccessTime = (int) (System.currentTimeMillis()/1000);
for(ReadEntity re: inputs) {
// Set the last query time
ReadEntity.Type typ = re.getType();
switch(typ) {
// It is possible that read and write entities contain a old version
// of the object, before it was modified by StatsTask.
// Get the latest versions of the object
case TABLE: {
Table t = db.getTable(re.getTable().getTableName());
t.setLastAccessTime(lastAccessTime);
db.alterTable(t.getTableName(), t);
break;
}
case PARTITION: {
Partition p = re.getPartition();
Table t = db.getTable(p.getTable().getTableName());
p = db.getPartition(t, p.getSpec(), false);
p.setLastAccessTime(lastAccessTime);
db.alterPartition(t.getTableName(), p);
t.setLastAccessTime(lastAccessTime);
db.alterTable(t.getTableName(), t);
break;
}
default:
// ignore dummy inputs
break;
}
}
}
}
}