/*
* Copyright 2011 The Apache Software Foundation
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.lealone.hbase.metadata;
import java.util.List;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.util.Bytes;
import org.lealone.engine.MetaRecord;
import org.lealone.hbase.util.HBaseUtils;
import org.lealone.result.SimpleRow;
import org.lealone.value.Value;
import org.lealone.value.ValueInt;
import org.lealone.value.ValueString;
/**
*
* 在HBase中存放数据库的元数据(比如create sql、alter sql等)
*
* 此类不是线程安全的，只在Master端使用。
*
*/
public class MetaDataTable {
private final static byte[] TABLE_NAME = Bytes.toBytes(MetaDataAdmin.META_DATA_PREFIX + "meta_data_table");
//private final static byte[] ID = Bytes.toBytes("id");
private final static byte[] OBJECT_TYPE = Bytes.toBytes("type");
private final static byte[] SQL = Bytes.toBytes("sql");
private final HTable table;
public MetaDataTable() throws Exception {
MetaDataAdmin.createTableIfNotExists(TABLE_NAME);
table = new HTable(HBaseUtils.getConfiguration(), TABLE_NAME);
}
public void loadMetaRecords(List<MetaRecord> records) throws Exception {
MetaRecord rec;
for (Result r : table.getScanner(new Scan())) {
if (r.isEmpty())
continue;
rec = getMetaRecord(r);
records.add(rec);
}
}
public void addRecord(MetaRecord rec) {
try {
addMetaRecord(rec);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
public void removeRecord(int id) {
try {
MetaRecord rec = getMetaRecord(id);
if (rec != null) {
table.delete(new Delete(Bytes.toBytes(id)));
}
} catch (Exception e) {
throw new RuntimeException(e);
}
}
public void updateRecord(MetaRecord rec) {
try {
addRecord(rec);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
private void addMetaRecord(MetaRecord rec) throws Exception {
Put put = new Put(Bytes.toBytes(rec.getId()));
put.add(MetaDataAdmin.DEFAULT_COLUMN_FAMILY, OBJECT_TYPE, Bytes.toBytes(rec.getObjectType()));
put.add(MetaDataAdmin.DEFAULT_COLUMN_FAMILY, SQL, Bytes.toBytes(rec.getSQL()));
table.put(put);
}
private MetaRecord getMetaRecord(Result r) {
Value[] data = new Value[4];
//id
//data[0] = ValueInt.get(Bytes.toInt(r.getValue(MetaDataAdmin.DEFAULT_FAMILY, ID)));
data[0] = ValueInt.get(Bytes.toInt(r.getRow()));
//head 未使用
//data[1] = null;
//type
data[2] = ValueInt.get(Bytes.toInt(r.getValue(MetaDataAdmin.DEFAULT_COLUMN_FAMILY, OBJECT_TYPE)));
//sql
data[3] = ValueString.get(Bytes.toString(r.getValue(MetaDataAdmin.DEFAULT_COLUMN_FAMILY, SQL)));
return new MetaRecord(new SimpleRow(data));
}
private MetaRecord getMetaRecord(int id) {
try {
Result r = table.get(new Get(Bytes.toBytes(id)));
if (!r.isEmpty())
return getMetaRecord(r);
else
return null;
} catch (Exception e) {
throw new RuntimeException(e);
}
}
public void close() {
if (table != null) {
try {
table.close();
} catch (Exception e) {
//ignore
}
}
}
}