[INLONG-11035][SDK] Transform support TRUNCATE(numeric1, integer2) fu…

…nction

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

@@ -0,0 +1,88 @@
+/*
+ * 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;
+/**
+ * TruncateFunction
+ * description: returns the number that intercepts integer2 decimal places.
+ *              If numeric1 or integer2 is NULL, NULL is returned.
+ *              If integer2 is 0, the result has no decimal point or fractional part.
+ *              integer2 can be negative, making the integer2 digit to the left of the decimal point of the value zero.
+ *              This function can also be used by passing only one numeric1 argument without setting Integer2.
+ *              If Integer2 is not set, Integer2 is 0
+ */
+@TransformFunction(names = {"truncate"})
+public class TruncateFunction implements ValueParser {
+
+    private ValueParser bigDecimalParser;
+
+    private ValueParser integerParser;
+
+    public TruncateFunction(Function expr) {
+        List<Expression> expressions = expr.getParameters().getExpressions();
+        if (expressions != null) {
+            bigDecimalParser = OperatorTools.buildParser(expressions.get(0));
+            if (expressions.size() == 2) {
+                integerParser = OperatorTools.buildParser(expressions.get(1));
+            }
+        }
+    }
+
+    @Override
+    public Object parse(SourceData sourceData, int rowIndex, Context context) {
+        Object bigDecimalObj = bigDecimalParser.parse(sourceData, rowIndex, context);
+        BigDecimal bigDecimal = OperatorTools.parseBigDecimal(bigDecimalObj);
+        if (integerParser != null) {
+            Object integerObj = integerParser.parse(sourceData, rowIndex, context);
+            int integer = OperatorTools.parseBigDecimal(integerObj).intValue();
+            return truncate(bigDecimal, integer);
+        }
+        return truncate(bigDecimal);
+    }
+
+    private BigDecimal truncate(BigDecimal numeric1, Integer integer2) {
+        if (numeric1 == null || integer2 == null) {
+            return null;
+        }
+        if (integer2 < 0) {
+            BigDecimal scaled = numeric1.movePointLeft(-integer2);
+            BigDecimal truncated = scaled.setScale(0, RoundingMode.DOWN);
+            return truncated.movePointRight(-integer2);
+        }
+        return numeric1.setScale(integer2, RoundingMode.DOWN);
+    }
+
+    private BigDecimal truncate(BigDecimal numeric1) {
+        if (numeric1 == null) {
+            return null;
+        }
+        return numeric1.setScale(0, RoundingMode.DOWN);
+    }
+
+}

inlong-sdk/transform-sdk/src/test/java/org/apache/inlong/sdk/transform/process/function/arithmetic/TestTruncateFunction.java

@@ -0,0 +1,66 @@
+/*
+ * 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.arithmetic;
+
+import org.apache.inlong.sdk.transform.decode.SourceDecoderFactory;
+import org.apache.inlong.sdk.transform.encode.SinkEncoderFactory;
+import org.apache.inlong.sdk.transform.pojo.TransformConfig;
+import org.apache.inlong.sdk.transform.process.TransformProcessor;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.List;
+
+public class TestTruncateFunction extends AbstractFunctionArithmeticTestBase {
+
+    @Test
+    public void testTruncateFunction() throws Exception {
+        String transformSql1 = "select truncate(numeric1,numeric2) from source";
+        TransformConfig config1 = new TransformConfig(transformSql1);
+        TransformProcessor<String, String> processor1 = TransformProcessor
+                .create(config1, SourceDecoderFactory.createCsvDecoder(csvSource),
+                        SinkEncoderFactory.createKvEncoder(kvSink));
+
+        // case1: truncate(42.324, 2)
+        List<String> output1 = processor1.transform("42.324|2|6|8");
+        Assert.assertEquals(1, output1.size());
+        Assert.assertEquals(output1.get(0), "result=42.32");
+
+        // case2: truncate(42.324, -1)
+        List<String> output2 = processor1.transform("42.324|-1|6|8");
+        Assert.assertEquals(1, output2.size());
+        Assert.assertEquals(output2.get(0), "result=40");
+
+        // case3: truncate(12345.6789, -3)
+        List<String> output3 = processor1.transform("12345.6789|-3|6|8");
+        Assert.assertEquals(1, output3.size());
+        Assert.assertEquals(output3.get(0), "result=12000");
+
+        String transformSql2 = "select truncate(numeric1) from source";
+        TransformConfig config2 = new TransformConfig(transformSql2);
+        TransformProcessor<String, String> processor2 = TransformProcessor
+                .create(config2, SourceDecoderFactory.createCsvDecoder(csvSource),
+                        SinkEncoderFactory.createKvEncoder(kvSink));
+
+        // case4: truncate(12345)
+        List<String> output4 = processor2.transform("12345.6789|-3|6|8");
+        Assert.assertEquals(1, output4.size());
+        Assert.assertEquals(output4.get(0), "result=12345");
+    }
+}