KeyValueStoreProvider.java

/*
 * Copyright 2013 David Tinker
 *
 * Licensed 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 io.qdb.server.repo;

import com.google.inject.Inject;
import io.qdb.kvstore.KeyValueStore;
import io.qdb.kvstore.KeyValueStoreBuilder;
import io.qdb.server.model.*;

import javax.inject.Named;
import javax.inject.Provider;
import javax.inject.Singleton;
import java.io.File;
import java.io.IOException;

/**
 * Creates the key value store for server meta data.
 */
@Singleton
public class KeyValueStoreProvider implements Provider<KeyValueStore<String, ModelObject>> {

    private final VersionProvider versionProvider;
    private final KeyValueStoreListener listener;
    private final String dataDir;
    private final int txLogSizeM;
    private final int snapshotCount;
    private final int snapshotIntervalSecs;

    private KeyValueStore<String, ModelObject> store;

    @Inject
    public KeyValueStoreProvider(VersionProvider versionProvider, KeyValueStoreListener listener,
                @Named("dataDir") String dataDir,
                @Named("txLogSizeM") int txLogSizeM,
                @Named("snapshotCount") int snapshotCount,
                @Named("snapshotIntervalSecs") int snapshotIntervalSecs) {
        this.versionProvider = versionProvider;
        this.listener = listener;
        this.dataDir = dataDir;
        this.txLogSizeM = txLogSizeM;
        this.snapshotCount = snapshotCount;
        this.snapshotIntervalSecs = snapshotIntervalSecs;
    }

    @Override
    @SuppressWarnings("unchecked")
    public KeyValueStore<String, ModelObject> get() {
        if (store == null) {
            try {
                store = new KeyValueStoreBuilder<String, ModelObject>()
                        .dir(new File(dataDir, "meta-data"))
                        .versionProvider(versionProvider)
                        .listener(listener)
                        .txLogSizeM(txLogSizeM)
                        .snapshotCount(snapshotCount)
                        .snapshotIntervalSecs(snapshotIntervalSecs)
                        .alias("user", User.class)
                        .alias("database", Database.class)
                        .alias("queue", Queue.class)
                        .alias("output", Output.class)
                        .create();
            } catch (IOException e) {
                throw new IllegalStateException(e.toString(), e);
            }
        }
        return store;
    }
}