com.github.kagkarlsson.scheduler.jdbc.PostgreSqlJdbcCustomization Maven / Gradle / Ivy

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Simple persistent scheduler for scheduled tasks, recurring or ad-hoc.

There is a newer version: 15.0.0

/**
 * Copyright (C) Gustav Karlsson
 *
 * 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 com.github.kagkarlsson.scheduler.jdbc;

import com.github.kagkarlsson.scheduler.task.Execution;

import java.time.Instant;
import java.util.List;

import static com.github.kagkarlsson.scheduler.StringUtils.truncate;

public class PostgreSqlJdbcCustomization extends DefaultJdbcCustomization {

    @Override
    public String getName() {
        return "PostgreSQL";
    }

    @Override
    public boolean supportsExplicitQueryLimitPart() {
        return true;
    }

    @Override
    public String getQueryLimitPart(int limit) {
        return " LIMIT " + limit;
    }

    @Override
    public boolean supportsLockAndFetch() {
        return true;
    }

    @Override
    public List lockAndFetch(JdbcTaskRepositoryContext ctx, Instant now, int limit) {
        final JdbcTaskRepository.UnresolvedFilter unresolvedFilter = new JdbcTaskRepository.UnresolvedFilter(ctx.taskResolver.getUnresolved());

        String selectForUpdateQuery =
            " UPDATE "+ctx.tableName+" st1 SET picked = ?, picked_by = ?, last_heartbeat = ?, version = version + 1 " +
                " WHERE (st1.task_name, st1.task_instance) IN (" +
                "   SELECT st2.task_name, st2.task_instance FROM "+ctx.tableName+" st2 " +
                "   WHERE picked = ? and execution_time <= ? " + unresolvedFilter.andCondition() + " order by execution_time asc FOR UPDATE SKIP LOCKED LIMIT ?)" +
                " RETURNING st1.*";

        return ctx.jdbcRunner.query(selectForUpdateQuery,
            ps -> {
                int index = 1;
                // Update
                ps.setBoolean(index++, true); // picked (new)
                ps.setString(index++, truncate(ctx.schedulerName.getName(), 50)); // picked_by
                setInstant(ps, index++, now); // last_heartbeat
                // Inner select
                ps.setBoolean(index++, false); // picked (old)
                setInstant(ps, index++, now); // execution_time
                index = unresolvedFilter.setParameters(ps, index);
                ps.setInt(index++, limit); // limit
            },
            ctx.resultSetMapper.get());
    }
}