io.druid.metadata.storage.postgresql.PostgreSQLConnector.java Source code

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Here is the source code for io.druid.metadata.storage.postgresql.PostgreSQLConnector.java

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/*
 * Druid - a distributed column store.
 * Copyright 2012 - 2015 Metamarkets Group Inc.
 *
 * 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.druid.metadata.storage.postgresql;

import com.google.common.base.Supplier;
import com.google.inject.Inject;
import com.metamx.common.logger.Logger;
import io.druid.metadata.MetadataStorageConnectorConfig;
import io.druid.metadata.MetadataStorageTablesConfig;
import io.druid.metadata.SQLMetadataConnector;
import org.apache.commons.dbcp2.BasicDataSource;
import org.skife.jdbi.v2.DBI;
import org.skife.jdbi.v2.Handle;
import org.skife.jdbi.v2.tweak.HandleCallback;
import org.skife.jdbi.v2.util.StringMapper;

import java.sql.SQLException;

public class PostgreSQLConnector extends SQLMetadataConnector {
    private static final Logger log = new Logger(PostgreSQLConnector.class);
    private static final String PAYLOAD_TYPE = "BYTEA";
    private static final String SERIAL_TYPE = "BIGSERIAL";

    private final DBI dbi;

    @Inject
    public PostgreSQLConnector(Supplier<MetadataStorageConnectorConfig> config,
            Supplier<MetadataStorageTablesConfig> dbTables) {
        super(config, dbTables);

        final BasicDataSource datasource = getDatasource();
        // PostgreSQL driver is classloader isolated as part of the extension
        // so we need to help JDBC find the driver
        datasource.setDriverClassLoader(getClass().getClassLoader());
        datasource.setDriverClassName("org.postgresql.Driver");

        this.dbi = new DBI(datasource);

        log.info("Configured PostgreSQL as metadata storage");
    }

    @Override
    protected String getPayloadType() {
        return PAYLOAD_TYPE;
    }

    @Override
    protected String getSerialType() {
        return SERIAL_TYPE;
    }

    @Override
    public boolean tableExists(final Handle handle, final String tableName) {
        return !handle.createQuery(
                "SELECT tablename FROM pg_catalog.pg_tables WHERE schemaname = 'public' AND tablename LIKE :tableName")
                .bind("tableName", tableName).map(StringMapper.FIRST).list().isEmpty();
    }

    @Override
    public Void insertOrUpdate(final String tableName, final String keyColumn, final String valueColumn,
            final String key, final byte[] value) throws Exception {
        return getDBI().withHandle(new HandleCallback<Void>() {
            @Override
            public Void withHandle(Handle handle) throws Exception {
                handle.createStatement(String.format("BEGIN;\n" + "LOCK TABLE %1$s IN SHARE ROW EXCLUSIVE MODE;\n"
                        + "WITH upsert AS (UPDATE %1$s SET %3$s=:value WHERE %2$s=:key RETURNING *)\n"
                        + "    INSERT INTO %1$s (%2$s, %3$s) SELECT :key, :value WHERE NOT EXISTS (SELECT * FROM upsert)\n;"
                        + "COMMIT;", tableName, keyColumn, valueColumn)).bind("key", key).bind("value", value)
                        .execute();
                return null;
            }
        });
    }

    @Override
    public DBI getDBI() {
        return dbi;
    }

    @Override
    protected boolean connectorIsTransientException(Throwable e) {
        if (e instanceof SQLException) {
            final String sqlState = ((SQLException) e).getSQLState();
            // limited to errors that are likely to be resolved within a few retries
            // retry on connection errors and insufficient resources
            // see http://www.postgresql.org/docs/current/static/errcodes-appendix.html for details
            return sqlState != null && (sqlState.startsWith("08") || sqlState.startsWith("53"));
        }
        return false;
    }
}