/*
 * 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.cache;

import org.junit.Assert;
import org.junit.Assume;
import org.junit.BeforeClass;
import org.junit.Test;

import org.apache.cassandra.SchemaLoader;
import org.apache.cassandra.Util;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.db.ColumnFamilyStore;
import org.apache.cassandra.db.Keyspace;
import org.apache.cassandra.db.RowUpdateBuilder;
import org.apache.cassandra.db.marshal.AsciiType;
import org.apache.cassandra.exceptions.ConfigurationException;
import org.apache.cassandra.io.sstable.AbstractRowIndexEntry;
import org.apache.cassandra.io.sstable.format.SSTableReader;
import org.apache.cassandra.io.sstable.keycache.KeyCacheSupport;
import org.apache.cassandra.schema.ColumnMetadata;
import org.apache.cassandra.schema.KeyspaceParams;
import org.apache.cassandra.schema.TableMetadata;
import org.apache.cassandra.service.CacheService;
import org.apache.cassandra.utils.ByteBufferUtil;

import static org.apache.cassandra.utils.Clock.Global.currentTimeMillis;

public class AutoSavingCacheTest
{
    private static final String KEYSPACE1 = "AutoSavingCacheTest1";
    private static final String CF_STANDARD1 = "Standard1";

    @BeforeClass
    public static void defineSchema() throws ConfigurationException
    {
        DatabaseDescriptor.daemonInitialization();
        Assume.assumeTrue(KeyCacheSupport.isSupportedBy(DatabaseDescriptor.getSelectedSSTableFormat()));
        SchemaLoader.prepareServer();
        SchemaLoader.createKeyspace(KEYSPACE1,
                                    KeyspaceParams.simple(1),
                                    TableMetadata.builder(KEYSPACE1, CF_STANDARD1)
                                                 .addPartitionKeyColumn("pKey", AsciiType.instance)
                                                 .addRegularColumn("col1", AsciiType.instance));
    }

    @Test
    public void testSerializeAndLoadKeyCache0kB() throws Exception
    {
        DatabaseDescriptor.setColumnIndexCacheSize(0);
        doTestSerializeAndLoadKeyCache();
    }

    @Test
    public void testSerializeAndLoadKeyCache() throws Exception
    {
        DatabaseDescriptor.setColumnIndexCacheSize(8);
        doTestSerializeAndLoadKeyCache();
    }

    private static void doTestSerializeAndLoadKeyCache() throws Exception
    {
        ColumnFamilyStore cfs = Keyspace.open(KEYSPACE1).getColumnFamilyStore(CF_STANDARD1);
        cfs.truncateBlocking();
        for (int i = 0; i < 2; i++)
        {
            ColumnMetadata colDef = ColumnMetadata.regularColumn(cfs.metadata(), ByteBufferUtil.bytes("col1"), AsciiType.instance, ColumnMetadata.NO_UNIQUE_ID);
            RowUpdateBuilder rowBuilder = new RowUpdateBuilder(cfs.metadata(), currentTimeMillis(), "key1");
            rowBuilder.add(colDef, "val1");
            rowBuilder.build().apply();
            Util.flush(cfs);
        }

        Assert.assertEquals(2, cfs.getLiveSSTables().size());

        // preheat key cache
        for (SSTableReader sstable : cfs.getLiveSSTables())
            sstable.getPosition(Util.dk("key1"), SSTableReader.Operator.EQ);

        AutoSavingCache<KeyCacheKey, AbstractRowIndexEntry> keyCache = CacheService.instance.keyCache;

        // serialize to file
        keyCache.submitWrite(keyCache.size()).get();
        keyCache.clear();

        Assert.assertEquals(0, keyCache.size());

        // then load saved
        keyCache.loadSavedAsync().get();
        for (SSTableReader sstable : cfs.getLiveSSTables())
            Assert.assertNotNull(keyCache.get(new KeyCacheKey(cfs.metadata(), sstable.descriptor, ByteBufferUtil.bytes("key1"))));
    }
}
