/**
* 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.apache.cassandra.db;
import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.*;
import org.apache.avro.Schema;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.config.KSMetaData;
import org.apache.cassandra.db.filter.QueryFilter;
import org.apache.cassandra.db.filter.QueryPath;
import org.apache.cassandra.db.migration.Migration;
import org.apache.cassandra.io.SerDeUtils;
import org.apache.cassandra.service.StorageService;
import org.apache.cassandra.utils.ByteBufferUtil;
import org.apache.cassandra.utils.UUIDGen;
import static com.google.common.base.Charsets.UTF_8;
public class DefsTable
{
// column name for the schema storing serialized keyspace definitions
// NB: must be an invalid keyspace name
public static final ByteBuffer DEFINITION_SCHEMA_COLUMN_NAME = ByteBufferUtil.bytes("Avro/Schema");
/** dumps current keyspace definitions to storage */
public static synchronized void dumpToStorage(UUID version) throws IOException
{
final ByteBuffer versionKey = Migration.toUTF8Bytes(version);
// build a list of keyspaces
Collection<String> ksnames = DatabaseDescriptor.getNonSystemTables();
// persist keyspaces under new version
RowMutation rm = new RowMutation(Table.SYSTEM_TABLE, versionKey);
long now = System.currentTimeMillis();
for (String ksname : ksnames)
{
KSMetaData ksm = DatabaseDescriptor.getTableDefinition(ksname);
rm.add(new QueryPath(Migration.SCHEMA_CF, null, ByteBuffer.wrap(ksm.name.getBytes(UTF_8))), SerDeUtils.serialize(ksm.deflate()), now);
}
// add the schema
rm.add(new QueryPath(Migration.SCHEMA_CF,
null,
DEFINITION_SCHEMA_COLUMN_NAME),
ByteBuffer.wrap(org.apache.cassandra.avro.KsDef.SCHEMA$.toString().getBytes(UTF_8)),
now);
rm.apply();
// apply new version
rm = new RowMutation(Table.SYSTEM_TABLE, Migration.LAST_MIGRATION_KEY);
rm.add(new QueryPath(Migration.SCHEMA_CF, null, Migration.LAST_MIGRATION_KEY),
ByteBuffer.wrap(UUIDGen.decompose(version)),
now);
rm.apply();
}
/** loads a version of keyspace definitions from storage */
public static synchronized Collection<KSMetaData> loadFromStorage(UUID version) throws IOException
{
DecoratedKey vkey = StorageService.getPartitioner().decorateKey(Migration.toUTF8Bytes(version));
Table defs = Table.open(Table.SYSTEM_TABLE);
ColumnFamilyStore cfStore = defs.getColumnFamilyStore(Migration.SCHEMA_CF);
QueryFilter filter = QueryFilter.getIdentityFilter(vkey, new QueryPath(Migration.SCHEMA_CF));
ColumnFamily cf = cfStore.getColumnFamily(filter);
IColumn avroschema = cf.getColumn(DEFINITION_SCHEMA_COLUMN_NAME);
if (avroschema == null)
// TODO: more polite way to handle this?
throw new RuntimeException("Cannot read system table! Are you upgrading a pre-release version?");
ByteBuffer value = avroschema.value();
Schema schema = Schema.parse(ByteBufferUtil.string(value));
// deserialize keyspaces using schema
Collection<KSMetaData> keyspaces = new ArrayList<KSMetaData>();
for (IColumn column : cf.getSortedColumns())
{
if (column.name().equals(DEFINITION_SCHEMA_COLUMN_NAME))
continue;
org.apache.cassandra.avro.KsDef ks = SerDeUtils.deserialize(schema, column.value(), new org.apache.cassandra.avro.KsDef());
keyspaces.add(KSMetaData.inflate(ks));
}
return keyspaces;
}
/** gets all the files that belong to a given column family. */
public static Set<File> getFiles(String table, final String cf)
{
Set<File> found = new HashSet<File>();
for (String path : DatabaseDescriptor.getAllDataFileLocationsForTable(table))
{
File[] dbFiles = new File(path).listFiles(new FileFilter()
{
public boolean accept(File pathname)
{
return pathname.getName().startsWith(cf + "-") && pathname.getName().endsWith(".db") && pathname.exists();
}
});
found.addAll(Arrays.asList(dbFiles));
}
return found;
}
}