[INLONG-10873][SDK] Transform support factorial function

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

@@ -0,0 +1,79 @@
+/*
+ * 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.Function;
+
+import java.math.BigDecimal;
+
+/**
+ * FactorialFunction
+ * description: factorial(numeric)--returns the factorial of a non-negative
+ * integer
+ */
+public class FactorialFunction implements ValueParser {
+
+    private ValueParser numberParser;
+
+    /**
+     * Constructor
+     * 
+     * @param expr
+     */
+    public FactorialFunction(Function expr) {
+        numberParser = OperatorTools.buildParser(expr.getParameters().getExpressions().get(0));
+    }
+
+    /**
+     * parse
+     * 
+     * @param sourceData
+     * @param rowIndex
+     * @return
+     */
+    @Override
+    public Object parse(SourceData sourceData, int rowIndex, Context context) {
+        Object numberObj = numberParser.parse(sourceData, rowIndex, context);
+        BigDecimal numberValue = OperatorTools.parseBigDecimal(numberObj);
+
+        // Ensure the number is a non-negative integer
+        if (numberValue.scale() > 0 || numberValue.compareTo(BigDecimal.ZERO) < 0) {
+            throw new IllegalArgumentException("Factorial is only defined for non-negative integers.");
+        }
+
+        return factorial(numberValue.intValue());
+    }
+
+    /**
+     * Helper method to calculate factorial
+     * 
+     * @param n
+     * @return
+     */
+    private BigDecimal factorial(int n) {
+        BigDecimal result = BigDecimal.ONE;
+        for (int i = 2; i <= n; i++) {
+            result = result.multiply(BigDecimal.valueOf(i));
+        }
+        return result;
+    }
+}

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

@@ -43,6 +43,7 @@
 import org.apache.inlong.sdk.transform.process.function.ToDateFunction;
 import org.apache.inlong.sdk.transform.process.function.ToTimestampFunction;
 import org.apache.inlong.sdk.transform.process.function.UnixTimestampFunction;
+import org.apache.inlong.sdk.transform.process.function.FactorialFunction;
 import org.apache.inlong.sdk.transform.process.parser.AdditionParser;
 import org.apache.inlong.sdk.transform.process.parser.ColumnParser;
 import org.apache.inlong.sdk.transform.process.parser.DateParser;
@@ -55,6 +56,7 @@
 import org.apache.inlong.sdk.transform.process.parser.TimestampParser;
 import org.apache.inlong.sdk.transform.process.parser.ValueParser;
 
+
 import net.sf.jsqlparser.expression.DateValue;
 import net.sf.jsqlparser.expression.Expression;
 import net.sf.jsqlparser.expression.Function;

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

@@ -174,6 +174,41 @@ public void testLog10Function() throws Exception {
         Assert.assertEquals(output2.get(0), "result=3.0");
     }
 
+    @Test
+    public void testFactorialFunction() throws Exception {
+        String transformSql = "select factorial(numeric1) from source";
+        TransformConfig config = new TransformConfig(transformSql);
+        TransformProcessor<String, String> processor = TransformProcessor
+                .create(config, SourceDecoderFactory.createCsvDecoder(csvSource),
+                        SinkEncoderFactory.createKvEncoder(kvSink));
+        // case1: 测试非负整数的阶乘
+        List<String> output1 = processor.transform("5|4|6|8");
+        Assert.assertEquals(1, output1.size());
+        Assert.assertEquals(output1.get(0), "result=120");
+
+        // case2: 测试0的阶乘
+        List<String> output2 = processor.transform("0|4|6|8");
+        Assert.assertEquals(1, output2.size());
+        Assert.assertEquals(output2.get(0), "result=1");
+
+        // case3: 测试带有小数的输入，应抛出异常
+        try {
+            List<String> output3 = processor.transform("5.5|4|6|8");
+            Assert.fail("Expected an exception for non-integer input");
+        } catch (IllegalArgumentException e) {
+            Assert.assertEquals("Factorial is only defined for non-negative integers.", e.getMessage());
+        }
+
+        // case4: 测试负数的输入，应抛出异常
+        try {
+            List<String> output4 = processor.transform("-5|4|6|8");
+            Assert.fail("Expected an exception for negative input");
+        } catch (IllegalArgumentException e) {
+            Assert.assertEquals("Factorial is only defined for non-negative integers.", e.getMessage());
+        }
+    }
+}
+
     @Test
     public void testLog2Function() throws Exception {
         String transformSql = "select log2(numeric1) from source";