[WIP] Implementation of IoTDB Function Runtime Interface.

server/src/main/java/org/apache/iotdb/db/query/udf/api/AbstractUDFRegister.java

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+/*
+ * 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.iotdb.db.query.udf.api;
+
+public abstract class AbstractUDFRegister {
+    private String language;
+
+    abstract void register(String functionName, String className, boolean writeToTemporaryLogFile);
+
+    abstract void deregister(String functionName);
+}

server/src/main/java/org/apache/iotdb/db/query/udf/api/UDFExecutorInterface.java

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+/*
+ * 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.iotdb.db.query.udf.api;
+
+import org.apache.iotdb.db.exception.query.QueryProcessException;
+import org.apache.iotdb.db.query.expression.Expression;
+import org.apache.iotdb.db.query.udf.api.access.Row;
+import org.apache.iotdb.db.query.udf.api.access.RowWindow;
+import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
+
+import java.util.Map;
+
+public interface UDFExecutorInterface {
+    void beforeStart(
+            long queryId,
+            float collectorMemoryBudgetInMB,
+            Map<Expression, TSDataType> expressionDataTypeMap)
+            throws QueryProcessException;
+
+    void execute(Row row, boolean isCurrentRowNull) throws QueryProcessException;
+
+    void execute(RowWindow rowWindow) throws QueryProcessException;
+
+    void terminate() throws QueryProcessException;
+    void beforeDestroy();
+
+
+
+}

server/src/main/java/org/apache/iotdb/db/query/udf/service/UDFManagementService.java

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+/*
+ * 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.iotdb.db.query.udf.service;
+
+import org.apache.iotdb.commons.exception.StartupException;
+import org.apache.iotdb.commons.service.IService;
+import org.apache.iotdb.commons.service.ServiceType;
+import org.apache.iotdb.db.query.udf.api.UDFExecutorInterface;
+
+import java.util.concurrent.ConcurrentHashMap;
+
+public class UDFManagementService implements IService {
+    private ConcurrentHashMap<String, UDFRegistrationInformation> registrationInformation;
+    private ConcurrentHashMap<String, UDFExecutorInterface> udfExecutors;
+
+    @Override
+    public void start() throws StartupException {
+
+    }
+
+    @Override
+    public void stop() {
+
+    }
+
+    @Override
+    public ServiceType getID() {
+        return null;
+    }
+}