[#9529] feat(server): Add server-side REST interface for UDFs

api/src/main/java/org/apache/gravitino/Catalog.java

@@ -24,6 +24,7 @@
 import org.apache.gravitino.authorization.SupportsRoles;
 import org.apache.gravitino.credential.SupportsCredentials;
 import org.apache.gravitino.file.FilesetCatalog;
+import org.apache.gravitino.function.FunctionCatalog;
 import org.apache.gravitino.messaging.TopicCatalog;
 import org.apache.gravitino.model.ModelCatalog;
 import org.apache.gravitino.policy.SupportsPolicies;
@@ -237,6 +238,14 @@ default ModelCatalog asModelCatalog() throws UnsupportedOperationException {
     throw new UnsupportedOperationException("Catalog does not support model operations");
   }
 
+  /**
+   * @return the {@link FunctionCatalog} if the catalog supports function operations.
+   * @throws UnsupportedOperationException if the catalog does not support function operations.
+   */
+  default FunctionCatalog asFunctionCatalog() throws UnsupportedOperationException {
+    throw new UnsupportedOperationException("Catalog does not support function operations");
+  }
+
   /**
    * @return the {@link SupportsTags} if the catalog supports tag operations.
    * @throws UnsupportedOperationException if the catalog does not support tag operations.

api/src/main/java/org/apache/gravitino/exceptions/FunctionAlreadyExistsException.java

@@ -0,0 +1,50 @@
+/*
+ * 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.gravitino.exceptions;
+
+import com.google.errorprone.annotations.FormatMethod;
+import com.google.errorprone.annotations.FormatString;
+
+/** Exception thrown when a function with a specified name already exists. */
+public class FunctionAlreadyExistsException extends AlreadyExistsException {
+
+  /**
+   * Constructs a new exception with the specified detail message.
+   *
+   * @param message the detail message.
+   * @param args the arguments to the message.
+   */
+  @FormatMethod
+  public FunctionAlreadyExistsException(@FormatString String message, Object... args) {
+    super(message, args);
+  }
+
+  /**
+   * Constructs a new exception with the specified detail message and cause.
+   *
+   * @param cause the cause.
+   * @param message the detail message.
+   * @param args the arguments to the message.
+   */
+  @FormatMethod
+  public FunctionAlreadyExistsException(
+      Throwable cause, @FormatString String message, Object... args) {
+    super(cause, message, args);
+  }
+}

api/src/main/java/org/apache/gravitino/exceptions/NoSuchFunctionException.java

@@ -0,0 +1,49 @@
+/*
+ * 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.gravitino.exceptions;
+
+import com.google.errorprone.annotations.FormatMethod;
+import com.google.errorprone.annotations.FormatString;
+
+/** Exception thrown when a function with the specified name does not exist. */
+public class NoSuchFunctionException extends NotFoundException {
+
+  /**
+   * Constructs a new exception with the specified detail message.
+   *
+   * @param message the detail message.
+   * @param args the arguments to the message.
+   */
+  @FormatMethod
+  public NoSuchFunctionException(@FormatString String message, Object... args) {
+    super(message, args);
+  }
+
+  /**
+   * Constructs a new exception with the specified detail message and cause.
+   *
+   * @param cause the cause.
+   * @param message the detail message.
+   * @param args the arguments to the message.
+   */
+  @FormatMethod
+  public NoSuchFunctionException(Throwable cause, String message, Object... args) {
+    super(cause, message, args);
+  }
+}

api/src/main/java/org/apache/gravitino/exceptions/NoSuchFunctionVersionException.java

@@ -0,0 +1,49 @@
+/*
+ * 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.gravitino.exceptions;
+
+import com.google.errorprone.annotations.FormatMethod;
+import com.google.errorprone.annotations.FormatString;
+
+/** Exception thrown when a function with the specified version does not exist. */
+public class NoSuchFunctionVersionException extends NotFoundException {
+
+  /**
+   * Constructs a new exception with the specified detail message.
+   *
+   * @param message the detail message.
+   * @param args the arguments to the message.
+   */
+  @FormatMethod
+  public NoSuchFunctionVersionException(@FormatString String message, Object... args) {
+    super(message, args);
+  }
+
+  /**
+   * Constructs a new exception with the specified detail message and cause.
+   *
+   * @param cause the cause.
+   * @param message the detail message.
+   * @param args the arguments to the message.
+   */
+  @FormatMethod
+  public NoSuchFunctionVersionException(Throwable cause, String message, Object... args) {
+    super(cause, message, args);
+  }
+}

api/src/main/java/org/apache/gravitino/function/Function.java

@@ -0,0 +1,89 @@
+/*
+ * 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.gravitino.function;
+
+import javax.annotation.Nullable;
+import org.apache.gravitino.Auditable;
+import org.apache.gravitino.annotation.Evolving;
+import org.apache.gravitino.rel.types.Type;
+
+/** Represents a user-defined function registered in Gravitino. */
+@Evolving
+public interface Function extends Auditable {
+  /** An empty array of {@link FunctionColumn}. */
+  FunctionColumn[] EMPTY = new FunctionColumn[0];
+
+  /**
+   * @return The function name.
+   */
+  String name();
+
+  /**
+   * @return The function type.
+   */
+  FunctionType functionType();
+
+  /**
+   * @return Whether the function is deterministic.
+   */
+  boolean deterministic();
+
+  /**
+   * @return The optional comment of the function.
+   */
+  @Nullable
+  default String comment() {
+    return null;
+  }
+
+  /**
+   * The return type for scalar or aggregate functions.
+   *
+   * @return The return type, null if this is a table-valued function.
+   */
+  @Nullable
+  default Type returnType() {
+    return null;
+  }
+
+  /**
+   * The output columns for a table-valued function.
+   *
+   * @return The output columns of a table-valued function, or an empty array for scalar or
+   *     aggregate functions.
+   */
+  default FunctionColumn[] returnColumns() {
+    return EMPTY;
+  }
+
+  /**
+   * @return The definitions of the function.
+   */
+  FunctionDefinition[] definitions();
+
+  /**
+   * Returns the internal revision version of the function.
+   *
+   * <p>This version is a 0-based counter, where {@code 0} represents the initial definition of the
+   * function, and the value is incremented by 1 on each later alteration.
+   *
+   * @return The 0-based revision version of the function.
+   */
+  int version();
+}