#384: Add | teragrep exec foreachbatch command that sets processing to batch mode

pom.xml

@@ -52,7 +52,7 @@
     <teragrep.dpf_03.version>11.0.1</teragrep.dpf_03.version>
     <teragrep.jpr_01.version>3.1.1</teragrep.jpr_01.version>
     <teragrep.jue_01.version>0.4.3</teragrep.jue_01.version>
-    <teragrep.pth_03.version>9.0.0</teragrep.pth_03.version>
+    <teragrep.pth_03.version>9.1.0</teragrep.pth_03.version>
     <teragrep.pth_06.version>3.2.2</teragrep.pth_06.version>
     <teragrep.rlp_01.version>4.0.1</teragrep.rlp_01.version>
     <teragrep.rlp_03.version>1.7.6</teragrep.rlp_03.version>

src/main/java/com/teragrep/pth10/ast/commands/transformstatement/TeragrepTransformation.java

@@ -607,4 +607,9 @@ public Node visitT_pathParameter(DPLParser.T_pathParameterContext ctx) {
         String path = new UnquotedText(new TextString(ctx.stringType().getText())).read();
         return new StringNode(new Token(Token.Type.STRING, path));
     }
+
+    @Override
+    public Node visitT_forEachBatchParameter(DPLParser.T_forEachBatchParameterContext ctx) {
+        return new StepNode(new TeragrepForEachBatchStep());
+    }
 }

src/main/java/com/teragrep/pth10/steps/teragrep/TeragrepForEachBatchStep.java

@@ -0,0 +1,64 @@
+/*
+ * Teragrep Data Processing Language (DPL) translator for Apache Spark (pth_10)
+ * Copyright (C) 2019-2024 Suomen Kanuuna Oy
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ *
+ * Additional permission under GNU Affero General Public License version 3
+ * section 7
+ *
+ * If you modify this Program, or any covered work, by linking or combining it
+ * with other code, such other code is not for that reason alone subject to any
+ * of the requirements of the GNU Affero GPL version 3 as long as this Program
+ * is the same Program as licensed from Suomen Kanuuna Oy without any additional
+ * modifications.
+ *
+ * Supplemented terms under GNU Affero General Public License version 3
+ * section 7
+ *
+ * Origin of the software must be attributed to Suomen Kanuuna Oy. Any modified
+ * versions must be marked as "Modified version of" The Program.
+ *
+ * Names of the licensors and authors may not be used for publicity purposes.
+ *
+ * No rights are granted for use of trade names, trademarks, or service marks
+ * which are in The Program if any.
+ *
+ * Licensee must indemnify licensors and authors for any liability that these
+ * contractual assumptions impose on licensors and authors.
+ *
+ * To the extent this program is licensed as part of the Commercial versions of
+ * Teragrep, the applicable Commercial License may apply to this file if you as
+ * a licensee so wish it.
+ */
+package com.teragrep.pth10.steps.teragrep;
+
+import com.teragrep.pth10.steps.AbstractStep;
+import org.apache.spark.sql.Dataset;
+import org.apache.spark.sql.Row;
+import org.apache.spark.sql.streaming.StreamingQueryException;
+
+public final class TeragrepForEachBatchStep extends AbstractStep {
+
+    public TeragrepForEachBatchStep() {
+        this.properties.add(CommandProperty.SEQUENTIAL_ONLY); // Switch to sequential mode
+        this.properties.add(CommandProperty.USES_INTERNAL_BATCHCOLLECT); // Skip using batch collect
+    }
+
+    @Override
+    public Dataset<Row> get(Dataset<Row> dataset) throws StreamingQueryException {
+        return dataset;
+    }
+}

src/test/java/com/teragrep/pth10/TeragrepTransformationTest.java

@@ -791,4 +791,32 @@ public void tgHdfsSaveAfterBloomEstimateTestUsingRegexExtract() {
                     Assertions.assertEquals(Collections.singletonList("5"), listOfResult);
                 });
     }
+
+    @Test
+    @DisabledIfSystemProperty(
+            named = "skipSparkTest",
+            matches = "true"
+    )
+    public void tgForEachBatchWithStatsTest() {
+        streamingTestUtil.performDPLTest("index=index_A | teragrep exec foreachbatch | stats count", testFile, ds -> {
+            List<String> listOfResult = ds
+                    .select("count")
+                    .collectAsList()
+                    .stream()
+                    .map(r -> r.getAs(0).toString())
+                    .collect(Collectors.toList());
+            Assertions.assertEquals(Collections.singletonList("5"), listOfResult);
+        });
+    }
+
+    @Test
+    @DisabledIfSystemProperty(
+            named = "skipSparkTest",
+            matches = "true"
+    )
+    public void tgForEachBatchTest() {
+        streamingTestUtil.performDPLTest("index=index_A | teragrep exec foreachbatch", testFile, ds -> {
+            Assertions.assertEquals(5, ds.count());
+        });
+    }
 }