[INLONG-10866][SDK] Transform SQL support sign function (#10924)

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

@@ -0,0 +1,53 @@
+/*
+ * 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;
+
+/**
+ * SignFunction
+ * description: sign(x): Return the sign of x, where x is a negative number, 0, and positive numbers return -1, 0, and 1, respectively
+ */
+public class SignFunction implements ValueParser {
+
+    private ValueParser numberParser;
+
+    public SignFunction(Function expr) {
+        numberParser = OperatorTools.buildParser(expr.getParameters().getExpressions().get(0));
+    }
+
+    @Override
+    public Object parse(SourceData sourceData, int rowIndex, Context context) {
+        Object numberObj = numberParser.parse(sourceData, rowIndex, context);
+        BigDecimal numberValue = OperatorTools.parseBigDecimal(numberObj);
+        double value = numberValue.doubleValue();
+        if (value > 0) {
+            return 1;
+        } else if (value < 0) {
+            return -1;
+        }
+        return 0;
+    }
+}

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

@@ -47,6 +47,7 @@
 import org.apache.inlong.sdk.transform.process.function.ReverseFunction;
 import org.apache.inlong.sdk.transform.process.function.RightFunction;
 import org.apache.inlong.sdk.transform.process.function.RoundFunction;
+import org.apache.inlong.sdk.transform.process.function.SignFunction;
 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;
@@ -134,6 +135,7 @@ public class OperatorTools {
         functionMap.put("reverse", ReverseFunction::new);
         functionMap.put("substring", SubstringFunction::new);
         functionMap.put("trim", TrimFunction::new);
+        functionMap.put("sign", SignFunction::new);
         functionMap.put("replicate", ReplicateFunction::new);
         functionMap.put("locate", LocateFunction::new);
         functionMap.put("to_date", ToDateFunction::new);

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

@@ -56,6 +56,27 @@ public class TestTransformArithmeticFunctionsProcessor {
         kvSink = new KvSinkInfo("UTF-8", dstFields);
     }
 
+    @Test
+    public void testSignFunction() throws Exception {
+        String transformSql = "select sign(numeric1) from source";
+        TransformConfig config = new TransformConfig(transformSql);
+        // case1: sign(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=1");
+        // case2: sign(-3.5)
+        List<String> output2 = processor.transform("-3.5|4|6|8");
+        Assert.assertEquals(1, output2.size());
+        Assert.assertEquals(output2.get(0), "result=-1");
+        // case3: sign(0)
+        List<String> output3 = processor.transform("0|4|6|8");
+        Assert.assertEquals(1, output3.size());
+        Assert.assertEquals(output3.get(0), "result=0");
+    }
+
     @Test
     public void testModuloFunction() throws Exception {
         String transformFunctionSql = "select mod(numeric1,100) from source";