[INLONG-10803][SDK] Transform SQL support Round function (apache#10810)

* [INLONG-10803][SDK] Transform SQL support Round function

* [INLONG-10803][SDK] Transform SQL support Round function

---------

Co-authored-by: ZKpLo <14148880+zkplo@user.noreply.gitee.com>

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

@@ -0,0 +1,60 @@
+/*
+ * 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.operator.OperatorTools;
+import org.apache.inlong.sdk.transform.process.parser.ValueParser;
+
+import net.sf.jsqlparser.expression.Expression;
+import net.sf.jsqlparser.expression.Function;
+
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+import java.util.List;
+
+/**
+ * RoundFunction
+ * description: ROUND(x [,y]) -- Return the nearest integer to x, with optional parameter y indicating the number of decimal places to be rounded. If omitted, return the integer.
+ */
+public class RoundFunction implements ValueParser {
+
+    private ValueParser numberParser;
+    private ValueParser reservedDigitsParser;
+
+    public RoundFunction(Function expr) {
+        List<Expression> expressions = expr.getParameters().getExpressions();
+        numberParser = OperatorTools.buildParser(expressions.get(0));
+        if (expressions.size() == 2) {
+            reservedDigitsParser = OperatorTools.buildParser(expressions.get(1));
+        }
+    }
+
+    @Override
+    public Object parse(SourceData sourceData, int rowIndex, Context context) {
+        Object numberObj = numberParser.parse(sourceData, rowIndex, context);
+        BigDecimal number = OperatorTools.parseBigDecimal(numberObj);
+        if (reservedDigitsParser != null) {
+            Object reservedDigitsObj = reservedDigitsParser.parse(sourceData, rowIndex, context);
+            int reservedDigits = OperatorTools.parseBigDecimal(reservedDigitsObj).intValue();
+            return number.setScale(reservedDigits, RoundingMode.HALF_UP).doubleValue();
+        }
+        return Math.round(number.doubleValue());
+    }
+}

inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/operator/OperatorTools.java

@@ -34,6 +34,7 @@
 import org.apache.inlong.sdk.transform.process.function.LogFunction;
 import org.apache.inlong.sdk.transform.process.function.NowFunction;
 import org.apache.inlong.sdk.transform.process.function.PowerFunction;
+import org.apache.inlong.sdk.transform.process.function.RoundFunction;
 import org.apache.inlong.sdk.transform.process.function.SinFunction;
 import org.apache.inlong.sdk.transform.process.function.SinhFunction;
 import org.apache.inlong.sdk.transform.process.function.SqrtFunction;
@@ -129,6 +130,7 @@ public class OperatorTools {
         functionMap.put("second",
                 func -> new TimestampExtractFunction(TimestampExtractFunction.TimestampExtractFunctionType.SECOND,
                         func));
+        functionMap.put("round", RoundFunction::new);
         functionMap.put("from_unixtime", FromUnixTimeFunction::new);
         functionMap.put("unix_timestamp", UnixTimestampFunction::new);
         functionMap.put("to_timestamp", ToTimestampFunction::new);

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

@@ -41,6 +41,7 @@ public class TestTransformArithmeticFunctionsProcessor {
     private static final List<FieldInfo> dstFields = new ArrayList<>();
     private static final CsvSourceInfo csvSource;
     private static final KvSinkInfo kvSink;
+
     static {
         for (int i = 1; i < 5; i++) {
             FieldInfo field = new FieldInfo();
@@ -54,6 +55,36 @@ public class TestTransformArithmeticFunctionsProcessor {
         kvSink = new KvSinkInfo("UTF-8", dstFields);
     }
 
+    @Test
+    public void testRoundFunction() throws Exception {
+        String transformSql = "select round(numeric1) from source";
+        TransformConfig config = new TransformConfig(transformSql);
+        // case1: round(3.14159265358979323846)
+        TransformProcessor<String, String> processor = TransformProcessor
+                .create(config, SourceDecoderFactory.createCsvDecoder(csvSource),
+                        SinkEncoderFactory.createKvEncoder(kvSink));
+        List<String> output1 = processor.transform("3.14159265358979323846|4|6|8");
+        Assert.assertEquals(1, output1.size());
+        Assert.assertEquals(output1.get(0), "result=3");
+        // case2: round(3.5)
+        List<String> output2 = processor.transform("3.5|4|6|8");
+        Assert.assertEquals(1, output2.size());
+        Assert.assertEquals(output2.get(0), "result=4");
+
+        transformSql = "select round(numeric1,numeric2) from source";
+        config = new TransformConfig(transformSql);
+        // case3: round(3.14159265358979323846,10)
+        processor = TransformProcessor.create(config, SourceDecoderFactory.createCsvDecoder(csvSource),
+                SinkEncoderFactory.createKvEncoder(kvSink));
+        List<String> output3 = processor.transform("3.14159265358979323846|10|6|8");
+        Assert.assertEquals(1, output3.size());
+        Assert.assertEquals(output3.get(0), "result=3.1415926536");
+        // case4: round(13.14159265358979323846,-1)
+        List<String> output4 = processor.transform("13.14159265358979323846|-1|6|8");
+        Assert.assertEquals(1, output4.size());
+        Assert.assertEquals(output4.get(0), "result=10.0");
+    }
+
     @Test
     public void testPowerFunction() throws Exception {
         String transformSql = "select power(numeric1, numeric2) from source";