Move DataSourceServiceImpl to core module

core/src/main/java/org/opensearch/sql/datasource/DataSourceService.java

@@ -7,34 +7,37 @@
 
 import java.util.Set;
 import org.opensearch.sql.datasource.model.DataSource;
-import org.opensearch.sql.storage.StorageEngine;
+import org.opensearch.sql.datasource.model.DataSourceMetadata;
 
 /**
- * DataSource Service manages datasources.
+ * DataSource Service manage {@link DataSource}.
  */
 public interface DataSourceService {
 
   /**
-   * Returns all datasource objects.
+   * Returns all DataSource objects.
    *
-   * @return DataSource datasources.
+   * @return set of {@link DataSource}.
    */
   Set<DataSource> getDataSources();
 
   /**
-   * Returns DataSource with corresponding to the datasource name.
+   * Returns {@link DataSource} with corresponding to the DataSource name.
    *
-   * @param dataSourceName Name of the datasource.
-   * @return DataSource datasource.
+   * @param dataSourceName Name of the {@link DataSource}.
+   * @return {@link DataSource}.
    */
   DataSource getDataSource(String dataSourceName);
 
   /**
-   * Default opensearch engine is not defined in datasources config.
-   * So the registration of default datasource happens separately.
+   * Register {@link DataSource} defined by {@link DataSourceMetadata}.
    *
-   * @param storageEngine StorageEngine.
+   * @param dataSourceMetadata {@link DataSourceMetadata}.
    */
-  void registerDefaultOpenSearchDataSource(StorageEngine storageEngine);
+  void addDataSource(DataSourceMetadata dataSourceMetadata);
 
+  /**
+   * remove all the registered {@link DataSource}.
+   */
+  void clear();
 }

core/src/main/java/org/opensearch/sql/datasource/DataSourceServiceImpl.java

@@ -0,0 +1,94 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.sql.datasource;
+
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Collectors;
+import org.apache.commons.lang3.StringUtils;
+import org.opensearch.sql.datasource.model.DataSource;
+import org.opensearch.sql.datasource.model.DataSourceMetadata;
+import org.opensearch.sql.datasource.model.DataSourceType;
+import org.opensearch.sql.storage.DataSourceFactory;
+
+/**
+ * Default implementation of {@link DataSourceService}. It is per-jvm single instance.
+ *
+ * <p>{@link DataSourceService} is constructed by the list of {@link DataSourceFactory} at service
+ * bootstrap time. The set of {@link DataSourceFactory} is immutable. Client could add {@link
+ * DataSource} defined by {@link DataSourceMetadata} at any time. {@link DataSourceService} use
+ * {@link DataSourceFactory} to create {@link DataSource}.
+ */
+public class DataSourceServiceImpl implements DataSourceService {
+
+  private static String DATASOURCE_NAME_REGEX = "[@*A-Za-z]+?[*a-zA-Z_\\-0-9]*";
+
+  private final ConcurrentHashMap<String, DataSource> dataSourceMap;
+
+  private final Map<DataSourceType, DataSourceFactory> dataSourceFactoryMap;
+
+  /**
+   * Construct from the set of {@link DataSourceFactory} at bootstrap time.
+   */
+  public DataSourceServiceImpl(Set<DataSourceFactory> dataSourceFactories) {
+    dataSourceFactoryMap =
+        dataSourceFactories.stream()
+            .collect(Collectors.toMap(DataSourceFactory::getDataSourceType, f -> f));
+    dataSourceMap = new ConcurrentHashMap<>();
+  }
+
+  @Override
+  public Set<DataSource> getDataSources() {
+    return new HashSet<>(dataSourceMap.values());
+  }
+
+  @Override
+  public DataSource getDataSource(String dataSourceName) {
+    if (!dataSourceMap.containsKey(dataSourceName)) {
+      throw new IllegalArgumentException(
+          String.format("DataSource with name %s doesn't exist.", dataSourceName));
+    }
+    return dataSourceMap.get(dataSourceName);
+  }
+
+  @Override
+  public void addDataSource(DataSourceMetadata metadata) {
+    validateDataSource(metadata);
+    dataSourceMap.put(
+        metadata.getName(),
+        dataSourceFactoryMap.get(metadata.getConnector()).createDataSource(metadata));
+  }
+
+  @Override
+  public void clear() {
+    dataSourceMap.clear();
+  }
+
+  /**
+   * This can be moved to a different validator class when we introduce more connectors.
+   *
+   * @param metadata {@link DataSourceMetadata}.
+   */
+  private void validateDataSource(DataSourceMetadata metadata) {
+    if (StringUtils.isEmpty(metadata.getName())) {
+      throw new IllegalArgumentException(
+          "Missing Name Field from a DataSource. Name is a required parameter.");
+    }
+    if (!metadata.getName().matches(DATASOURCE_NAME_REGEX)) {
+      throw new IllegalArgumentException(
+          String.format(
+              "DataSource Name: %s contains illegal characters. Allowed characters: a-zA-Z0-9_-*@.",
+              metadata.getName()));
+    }
+    if (Objects.isNull(metadata.getProperties())) {
+      throw new IllegalArgumentException(
+          "Missing properties field in catalog configuration. Properties are required parameters.");
+    }
+  }
+}

core/src/main/java/org/opensearch/sql/datasource/model/DataSource.java

@@ -12,14 +12,17 @@
 import lombok.RequiredArgsConstructor;
 import org.opensearch.sql.storage.StorageEngine;
 
+/**
+ * Each user configured datasource mapping to one instance of DataSource per JVM.
+ */
 @Getter
 @RequiredArgsConstructor
 @EqualsAndHashCode
 public class DataSource {
 
   private final String name;
 
-  private final ConnectorType connectorType;
+  private final DataSourceType connectorType;
 
   @EqualsAndHashCode.Exclude
   private final StorageEngine storageEngine;

core/src/main/java/org/opensearch/sql/datasource/model/DataSourceMetadata.java

@@ -5,26 +5,44 @@
 
 package org.opensearch.sql.datasource.model;
 
+
+import static org.opensearch.sql.analysis.DataSourceSchemaIdentifierNameResolver.DEFAULT_DATASOURCE_NAME;
+
 import com.fasterxml.jackson.annotation.JsonFormat;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
+import com.google.common.collect.ImmutableMap;
 import java.util.Map;
+import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.Setter;
+import org.opensearch.sql.datasource.DataSourceService;
 
 @JsonIgnoreProperties(ignoreUnknown = true)
 @Getter
 @Setter
+@EqualsAndHashCode
 public class DataSourceMetadata {
 
   @JsonProperty(required = true)
   private String name;
 
   @JsonProperty(required = true)
   @JsonFormat(with = JsonFormat.Feature.ACCEPT_CASE_INSENSITIVE_PROPERTIES)
-  private ConnectorType connector;
+  private DataSourceType connector;
 
   @JsonProperty(required = true)
   private Map<String, String> properties;
 
+  /**
+   * Default OpenSearch {@link DataSourceMetadata}. Which is used to register default OpenSearch
+   * {@link DataSource} to {@link DataSourceService}.
+   */
+  public static DataSourceMetadata defaultOpenSearchDataSourceMetadata() {
+    DataSourceMetadata dataSourceMetadata = new DataSourceMetadata();
+    dataSourceMetadata.setName(DEFAULT_DATASOURCE_NAME);
+    dataSourceMetadata.setConnector(DataSourceType.OPENSEARCH);
+    dataSourceMetadata.setProperties(ImmutableMap.of());
+    return dataSourceMetadata;
+  }
 }

core/src/main/java/org/opensearch/sql/datasource/model/ConnectorType.java → core/src/main/java/org/opensearch/sql/datasource/model/DataSourceType.java

@@ -5,6 +5,6 @@
 
 package org.opensearch.sql.datasource.model;
 
-public enum ConnectorType {
+public enum DataSourceType {
   PROMETHEUS,OPENSEARCH
 }

core/src/main/java/org/opensearch/sql/storage/DataSourceFactory.java

@@ -0,0 +1,31 @@
+/*
+ *
+ *  * Copyright OpenSearch Contributors
+ *  * SPDX-License-Identifier: Apache-2.0
+ *
+ */
+
+package org.opensearch.sql.storage;
+
+import org.opensearch.sql.datasource.DataSourceService;
+import org.opensearch.sql.datasource.model.DataSource;
+import org.opensearch.sql.datasource.model.DataSourceMetadata;
+import org.opensearch.sql.datasource.model.DataSourceType;
+
+/**
+ * {@link DataSourceFactory} is used to create {@link DataSource} from {@link DataSourceMetadata}.
+ * Each data source define {@link DataSourceFactory} and register to {@link DataSourceService}.
+ * {@link DataSourceFactory} is one instance per JVM . Each {@link DataSourceType} mapping to one
+ * {@link DataSourceFactory}.
+ */
+public interface DataSourceFactory {
+  /**
+   * Get {@link DataSourceType}.
+   */
+  DataSourceType getDataSourceType();
+
+  /**
+   * Create {@link DataSource}.
+   */
+  DataSource createDataSource(DataSourceMetadata metadata);
+}

core/src/test/java/org/opensearch/sql/analysis/AnalyzerTestBase.java

@@ -22,10 +22,10 @@
 import org.opensearch.sql.config.TestConfig;
 import org.opensearch.sql.data.type.ExprType;
 import org.opensearch.sql.datasource.DataSourceService;
-import org.opensearch.sql.datasource.model.ConnectorType;
 import org.opensearch.sql.datasource.model.DataSource;
+import org.opensearch.sql.datasource.model.DataSourceMetadata;
+import org.opensearch.sql.datasource.model.DataSourceType;
 import org.opensearch.sql.exception.ExpressionEvaluationException;
-import org.opensearch.sql.expression.DSL;
 import org.opensearch.sql.expression.Expression;
 import org.opensearch.sql.expression.ReferenceExpression;
 import org.opensearch.sql.expression.env.Environment;
@@ -144,9 +144,7 @@ protected Environment<Expression, ExprType> typeEnv() {
   @Bean
   protected Analyzer analyzer(ExpressionAnalyzer expressionAnalyzer,
                       DataSourceService dataSourceService,
-                      StorageEngine storageEngine,
                       Table table) {
-    dataSourceService.registerDefaultOpenSearchDataSource(storageEngine);
     BuiltinFunctionRepository functionRepository = BuiltinFunctionRepository.getInstance();
     functionRepository.register("prometheus", new FunctionResolver() {
 
@@ -195,7 +193,7 @@ private class DefaultDataSourceService implements DataSourceService {
 
     private StorageEngine storageEngine = storageEngine();
     private final DataSource dataSource
-        = new DataSource("prometheus", ConnectorType.PROMETHEUS, storageEngine);
+        = new DataSource("prometheus", DataSourceType.PROMETHEUS, storageEngine);
 
 
     @Override
@@ -209,8 +207,13 @@ public DataSource getDataSource(String dataSourceName) {
     }
 
     @Override
-    public void registerDefaultOpenSearchDataSource(StorageEngine storageEngine) {
-      this.storageEngine = storageEngine;
+    public void addDataSource(DataSourceMetadata metadata) {
+      throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void clear() {
+      throw new UnsupportedOperationException();
     }
   }