Merge pull request #1443 from cloudsufi/patch/empty-input-format

[PLUGIN-1742] Add GCSEmptyInputFormat (Allow Empty Input)

Author: psainics

src/main/java/io/cdap/plugin/gcp/common/GCSEmptyInputFormat.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright © 2024 Cask Data, Inc.
+ *
+ * Licensed 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 io.cdap.plugin.gcp.common;
+
+import io.cdap.plugin.format.input.AbstractEmptyInputFormat;
+
+
+/**
+ * An InputFormat that returns no data.
+ * @param <K> the type of key
+ * @param <V> the type of value
+ */
+public class GCSEmptyInputFormat<K, V> extends AbstractEmptyInputFormat<K, V> {
+  // no-op
+}

src/main/java/io/cdap/plugin/gcp/gcs/source/GCSSource.java

@@ -43,6 +43,7 @@
 import io.cdap.plugin.format.plugin.FileSourceProperties;
 import io.cdap.plugin.gcp.common.GCPConnectorConfig;
 import io.cdap.plugin.gcp.common.GCPUtils;
+import io.cdap.plugin.gcp.common.GCSEmptyInputFormat;
 import io.cdap.plugin.gcp.crypto.EncryptedFileSystem;
 import io.cdap.plugin.gcp.gcs.GCSPath;
 import io.cdap.plugin.gcp.gcs.connector.GCSConnector;
@@ -77,6 +78,11 @@ public void configurePipeline(PipelineConfigurer pipelineConfigurer) {
     super.configurePipeline(pipelineConfigurer);
   }
 
+  @Override
+  protected String getEmptyInputFormatClassName() {
+    return GCSEmptyInputFormat.class.getName();
+  }
+
   @Override
   public void prepareRun(BatchSourceContext context) throws Exception {
     // Get location of the source for lineage
@@ -268,11 +274,6 @@ public Long getMinSplitSize() {
       return minSplitSize;
     }
 
-    @Override
-    public boolean shouldAllowEmptyInput() {
-      return false;
-    }
-
     public boolean isCopyHeader() {
       return shouldCopyHeader();
     }