org.ambraproject.service.migration.Migrations.java Source code

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Here is the source code for org.ambraproject.service.migration.Migrations.java

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/*
 * Copyright (c) 2006-2014 by Public Library of Science
 *
 * http://plos.org
 * http://ambraproject.org
 *
 * 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 org.ambraproject.service.migration;

import com.google.common.collect.ImmutableCollection;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import java.util.Arrays;
import java.util.Collection;
import java.util.SortedMap;

/**
 * Static class for declaring non-legacy migrations.
 */
class Migrations {
    private Migrations() {
        throw new AssertionError("Not instantiable");
    }

    private static final ImmutableCollection<SchemaMigration> MIGRATIONS = ImmutableList
            .copyOf(new SchemaMigration[] {

                    // New migrations may be added to the end of this array.
                    //
                    // For migrations that only require running one or more SQL scripts, add a line like this:
                    //      new ScriptMigration(1001, "migration_1001_part1.sql", "migration_1001_part2.sql"),
                    //
                    // For migrations that require more complex procedural logic on a Session, add an object like this:
                    //      new SchemaMigration(1001) {
                    //        @Override protected void execute(Session session) throws SQLException {
                    //          // Do stuff
                    //        }
                    //      },
                    new ScriptMigration(1001, "migrate_ambra_1001.sql"),
                    new ScriptMigration(1002, "migrate_ambra_1002.sql"),
                    new ScriptMigration(1003, "migrate_ambra_1003.sql"),
                    new ScriptMigration(1004, "migrate_ambra_1004.sql"),
                    new ScriptMigration(1005, "migrate_ambra_1005.sql"),
                    new ScriptMigration(1006, "migrate_ambra_1006.sql"),
                    new ScriptMigration(1007, "migrate_ambra_1007.sql"),
                    new ScriptMigration(1008, "migrate_ambra_1008.sql"),
                    new ScriptMigration(1009, "migrate_ambra_1009.sql"),
                    new ScriptMigration(1010, "migrate_ambra_1010.sql") });

    /**
     * Get all migrations (legacy and non-legacy) necessary to migrate the database schema from its earliest version to
     * the present version.
     *
     * @return the ordered list of all migrations
     */
    static ImmutableList<Migration> getAllMigrations() {
        Collection<Migration> migrations = Lists.newArrayList();
        migrations.addAll(Arrays.asList(LegacyMigration.values()));
        migrations.addAll(MIGRATIONS);
        return sort(migrations);
    }

    /**
     * Sort migrations by version, checking that each version is unique and conforms to convention.
     *
     * @param migrations distinct migration objects
     * @return the migrations, sorted by version
     * @throws RuntimeException if a migration violates the numbering convention
     */
    private static ImmutableList<Migration> sort(Iterable<? extends Migration> migrations) {
        SortedMap<Integer, Migration> map = Maps.newTreeMap();
        for (Migration migration : migrations) {
            int version = migration.getVersion();

            // Validate that version number matches convention
            if (version <= SchemaMigration.THRESHOLD && !(migration instanceof LegacyMigration)) {
                String message = String.format(
                        "Illegal migration version: %d; non-legacy migrations must have version > %d", version,
                        SchemaMigration.THRESHOLD);
                throw new RuntimeException(message);
            }

            if (map.put(version, migration) != null) {
                throw new RuntimeException("Collision on migration version: " + version);
            }
        }
        return ImmutableList.copyOf(map.values());
    }

}