|
| 1 | +/* |
| 2 | + * Copyright 2016 the original author or authors. |
| 3 | + * |
| 4 | + * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | + * you may not use this file except in compliance with the License. |
| 6 | + * You may obtain a copy of the License at |
| 7 | + * |
| 8 | + * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | + * |
| 10 | + * Unless required by applicable law or agreed to in writing, software |
| 11 | + * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | + * See the License for the specific language governing permissions and |
| 14 | + * limitations under the License. |
| 15 | + */ |
| 16 | + |
| 17 | +package io.zonky.test.db.flyway; |
| 18 | + |
| 19 | +import com.google.common.cache.CacheBuilder; |
| 20 | +import com.google.common.cache.CacheLoader; |
| 21 | +import com.google.common.cache.LoadingCache; |
| 22 | +import com.opentable.db.postgres.embedded.DatabasePreparer; |
| 23 | +import com.opentable.db.postgres.embedded.PreparedDbProvider; |
| 24 | +import org.apache.commons.lang3.ArrayUtils; |
| 25 | +import org.flywaydb.core.Flyway; |
| 26 | +import org.postgresql.ds.PGSimpleDataSource; |
| 27 | + |
| 28 | +import javax.sql.DataSource; |
| 29 | +import java.sql.SQLException; |
| 30 | +import java.util.Objects; |
| 31 | +import java.util.concurrent.Semaphore; |
| 32 | + |
| 33 | +import static com.google.common.base.Preconditions.checkState; |
| 34 | + |
| 35 | +/** |
| 36 | + * Default implementation of {@link FlywayDataSourceContext} that is used for deferred initialization of the embedded database. |
| 37 | + * Note that this target source is dynamic and supports hot reloading while the application is running. |
| 38 | + * <p/> |
| 39 | + * For the reloading of the underlying data source is used cacheable {@link com.opentable.db.postgres.embedded.DatabasePreparer}, |
| 40 | + * which can utilize a special template database to effective copy data into multiple independent databases. |
| 41 | + * |
| 42 | + * @see io.zonky.test.db.postgres.FlywayEmbeddedPostgresDataSourceFactoryBean |
| 43 | + * @see OptimizedFlywayTestExecutionListener |
| 44 | + * @see <a href="https://www.postgresql.org/docs/9.6/static/manage-ag-templatedbs.html">Template Databases</a> |
| 45 | + */ |
| 46 | +public class DefaultFlywayDataSourceContext implements FlywayDataSourceContext { |
| 47 | + |
| 48 | + protected static final LoadingCache<Integer, Semaphore> CONNECTION_SEMAPHORES = CacheBuilder.newBuilder() |
| 49 | + .build(new CacheLoader<Integer, Semaphore>() { |
| 50 | + public Semaphore load(Integer key) { |
| 51 | + return new Semaphore(100); // the maximum number of simultaneous connections to the database |
| 52 | + } |
| 53 | + }); |
| 54 | + |
| 55 | + protected static final ThreadLocal<DataSource> preparerDataSourceHolder = new ThreadLocal<>(); |
| 56 | + |
| 57 | + protected volatile DataSource dataSource; |
| 58 | + |
| 59 | + @Override |
| 60 | + public Class<?> getTargetClass() { |
| 61 | + return DataSource.class; |
| 62 | + } |
| 63 | + |
| 64 | + @Override |
| 65 | + public boolean isStatic() { |
| 66 | + return false; |
| 67 | + } |
| 68 | + |
| 69 | + @Override |
| 70 | + public Object getTarget() throws Exception { |
| 71 | + DataSource dataSource = preparerDataSourceHolder.get(); |
| 72 | + |
| 73 | + if (dataSource == null) { |
| 74 | + dataSource = this.dataSource; |
| 75 | + } |
| 76 | + |
| 77 | + checkState(dataSource != null, "dataSource is not initialized yet"); |
| 78 | + return dataSource; |
| 79 | + } |
| 80 | + |
| 81 | + @Override |
| 82 | + public void releaseTarget(Object target) throws Exception { |
| 83 | + // nothing to do |
| 84 | + } |
| 85 | + |
| 86 | + @Override |
| 87 | + public void reload(Flyway flyway) throws Exception { |
| 88 | + FlywayDatabasePreparer preparer = new FlywayDatabasePreparer(flyway); |
| 89 | + PreparedDbProvider provider = PreparedDbProvider.forPreparer(preparer); |
| 90 | + |
| 91 | + PGSimpleDataSource dataSource = ((PGSimpleDataSource) provider.createDataSource()); |
| 92 | + Semaphore semaphore = CONNECTION_SEMAPHORES.get(dataSource.getPortNumber()); |
| 93 | + this.dataSource = new BlockingDataSourceWrapper(dataSource, semaphore); |
| 94 | + } |
| 95 | + |
| 96 | + protected FlywayConfigSnapshot createConfigSnapshot(Flyway flyway) { |
| 97 | + FlywayConfigSnapshot configSnapshot = new FlywayConfigSnapshot(flyway); |
| 98 | + checkState(ArrayUtils.isNotEmpty(configSnapshot.getSchemas()), |
| 99 | + "org.flywaydb.core.Flyway#schemaNames must be specified"); |
| 100 | + return configSnapshot; |
| 101 | + } |
| 102 | + |
| 103 | + protected class FlywayDatabasePreparer implements DatabasePreparer { |
| 104 | + |
| 105 | + private final FlywayConfigSnapshot configSnapshot; |
| 106 | + private final Flyway flyway; |
| 107 | + |
| 108 | + public FlywayDatabasePreparer(Flyway flyway) { |
| 109 | + this.configSnapshot = createConfigSnapshot(flyway); |
| 110 | + this.flyway = flyway; |
| 111 | + } |
| 112 | + |
| 113 | + @Override |
| 114 | + public void prepare(DataSource ds) throws SQLException { |
| 115 | + preparerDataSourceHolder.set(ds); |
| 116 | + try { |
| 117 | + flyway.migrate(); |
| 118 | + } finally { |
| 119 | + preparerDataSourceHolder.remove(); |
| 120 | + } |
| 121 | + } |
| 122 | + |
| 123 | + @Override |
| 124 | + public boolean equals(Object o) { |
| 125 | + if (this == o) return true; |
| 126 | + if (o == null || getClass() != o.getClass()) return false; |
| 127 | + FlywayDatabasePreparer that = (FlywayDatabasePreparer) o; |
| 128 | + return Objects.equals(configSnapshot, that.configSnapshot); |
| 129 | + } |
| 130 | + |
| 131 | + @Override |
| 132 | + public int hashCode() { |
| 133 | + return Objects.hash(configSnapshot); |
| 134 | + } |
| 135 | + } |
| 136 | +} |
0 commit comments