Add a task for refreshing the materialized views

baremaps-core/src/main/java/org/apache/baremaps/tasks/RefreshMaterializedViews.java

@@ -0,0 +1,71 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to you 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.apache.baremaps.tasks;
+
+import java.sql.SQLException;
+import javax.sql.DataSource;
+import org.apache.baremaps.postgres.graph.DatabaseMetadataRetriever;
+import org.apache.baremaps.postgres.graph.DependencyGraphBuilder;
+import org.apache.baremaps.postgres.graph.MaterializedViewRefresher;
+import org.apache.baremaps.workflow.Task;
+import org.apache.baremaps.workflow.WorkflowContext;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class RefreshMaterializedViews implements Task {
+
+  private static final Logger LOGGER = LoggerFactory.getLogger(RefreshMaterializedViews.class);
+
+  private Object database;
+
+  public RefreshMaterializedViews() {
+    // Default constructor
+  }
+
+  public RefreshMaterializedViews(Object database) {
+    this.database = database;
+  }
+
+  @Override
+  public void execute(WorkflowContext context) throws Exception {
+    DataSource dataSource = context.getDataSource(database);
+    try (var connection = dataSource.getConnection()) {
+      LOGGER.info("Connected to PostgreSQL database.");
+      var schema = "public";
+
+      // 1. Retrieve database objects (tables, views, materialized views).
+      var objects = DatabaseMetadataRetriever.getObjects(connection, schema);
+
+      // 2. Retrieve dependencies between database objects.
+      var dependencies = DatabaseMetadataRetriever.getDependencies(connection, schema, objects);
+
+      // 3. Build a directed graph of dependencies between the database objects.
+      var graph = DependencyGraphBuilder.buildGraph(connection, schema, objects, dependencies);
+
+      // 4. Perform a topological sort so that dependencies come before dependents.
+      var sorted = DependencyGraphBuilder.topologicalSort(graph);
+
+      // 5. Refresh materialized views, dropping and recreating indexes if present.
+      MaterializedViewRefresher.refreshMaterializedViews(connection, sorted);
+
+      LOGGER.info("Done refreshing materialized views.");
+    } catch (SQLException ex) {
+      LOGGER.error("Database error", ex);
+    }
+  }
+}

baremaps-core/src/main/java/org/apache/baremaps/workflow/Task.java

@@ -52,6 +52,7 @@
     @Type(value = ImportOsmPbf.class, name = "ImportOsmPbf"),
     @Type(value = ImportShapefile.class, name = "ImportShapefile"),
     @Type(value = LogMessage.class, name = "LogMessage"),
+    @Type(value = RefreshMaterializedViews.class, name = "RefreshMaterializedViews"),
     @Type(value = UpdateOsmDatabase.class, name = "UpdateOsmDatabase"),
 })
 public interface Task {

baremaps-postgres/src/main/java/org/apache/baremaps/postgres/graph/DatabaseMetadataRetriever.java

@@ -28,7 +28,7 @@
 /**
  * Utility class to retrieve metadata about tables, views, and materialized views.
  */
-class DatabaseMetadataRetriever {
+public class DatabaseMetadataRetriever {
 
   private static final Logger LOGGER =
       LoggerFactory.getLogger(DatabaseMetadataRetriever.class.getName());
@@ -208,15 +208,15 @@ public record DatabaseObject(
   /**
    * Record representing a dependency between two database objects.
    */
-  record DatabaseDependency(DatabaseObject source, DatabaseObject dependent) {
+  public record DatabaseDependency(DatabaseObject source, DatabaseObject dependent) {
 
   }
 
 
   /**
    * Record representing a database index.
    */
-  record DatabaseIndex(String indexName, String indexDef) {
+  public record DatabaseIndex(String indexName, String indexDef) {
   }
 
 }

baremaps-postgres/src/main/java/org/apache/baremaps/postgres/graph/DependencyGraphBuilder.java

@@ -33,7 +33,7 @@
 /**
  * Utility class to build a directed dependency graph among DatabaseObject items.
  */
-class DependencyGraphBuilder {
+public class DependencyGraphBuilder {
 
   private static final Logger LOGGER =
       LoggerFactory.getLogger(DependencyGraphBuilder.class.getName());

baremaps-postgres/src/main/java/org/apache/baremaps/postgres/graph/MaterializedViewRefresher.java

@@ -30,7 +30,7 @@
  * Utility class to refresh materialized views in topological order: 1) drop indexes, 2) refresh MV,
  * 3) recreate indexes.
  */
-class MaterializedViewRefresher {
+public class MaterializedViewRefresher {
 
   private static final Logger LOGGER =
       LoggerFactory.getLogger(MaterializedViewRefresher.class.getName());

basemap/refresh.js

@@ -19,30 +19,14 @@ import config from "./config.js";
 export default {
     "steps": [
         {
-            "id": "refresh-node",
+            "id": "refresh-materialized-views",
             "needs": [],
             "tasks": [
-                "layers/node/refresh.sql",
-                "layers/way/refresh.sql",
-                "layers/relation/refresh.sql",
-                "layers/member/refresh.sql",
-                "layers/amenity/refresh.sql",
-                "layers/ocean/refresh.sql",
-                "layers/highway/refresh.sql",
-                "layers/landuse/refresh.sql",
-                "layers/leisure/refresh.sql",
-                "layers/natural/refresh.sql",
-                "layers/point/refresh.sql",
-                "layers/railway/refresh.sql",
-                "layers/route/refresh.sql",
-                "layers/waterway/refresh.sql"
-            ].map(file => {
-                return {
-                    "type": "ExecuteSql",
-                    "file": file,
+                {
+                    "type": "RefreshMaterializedViews",
                     "database": config.database,
                 }
-            })
-        },
+            ]
+        }
     ]
 }