[INLONG-10979][SDK] Transform support PI() function

inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/PiFunction.java

@@ -0,0 +1,40 @@
+/*
+ * 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.inlong.sdk.transform.process.function;
+
+import org.apache.inlong.sdk.transform.decode.SourceData;
+import org.apache.inlong.sdk.transform.process.Context;
+import org.apache.inlong.sdk.transform.process.parser.ValueParser;
+
+import net.sf.jsqlparser.expression.Function;
+/**
+ * PiFunction
+ * returns the mathematical constant PI
+ */
+@TransformFunction(names = {"pi"})
+public class PiFunction implements ValueParser {
+
+    public PiFunction(Function expr) {
+    }
+
+    @Override
+    public Object parse(SourceData sourceData, int rowIndex, Context context) {
+        return String.valueOf(Math.PI);
+    }
+
+}

inlong-sdk/transform-sdk/src/test/java/org/apache/inlong/sdk/transform/process/TestTransformArithmeticFunctionsProcessor.java

@@ -711,4 +711,17 @@ public void testHexFunction() throws Exception {
         Assert.assertEquals(output5.get(0), "result=616263");
     }
 
+    @Test
+    public void testPiFunction() throws Exception {
+        String transformSql1 = "select pi() from source";
+        TransformConfig config1 = new TransformConfig(transformSql1);
+        TransformProcessor<String, String> processor1 = TransformProcessor
+                .create(config1, SourceDecoderFactory.createCsvDecoder(csvSource),
+                        SinkEncoderFactory.createKvEncoder(kvSink));
+        // case: pi()
+        List<String> output1 = processor1.transform("1007|4|6|8", new HashMap<>());
+        Assert.assertEquals(1, output1.size());
+        Assert.assertEquals(output1.get(0), "result=3.141592653589793");
+    }
+
 }