Try to make it work

pom.xml

@@ -8,7 +8,7 @@
     <groupId>com.microsoft.azure</groupId>
     <artifactId>kafka-sink-azure-kusto</artifactId>
     <packaging>jar</packaging>
-    <version>0.3.3</version>
+    <version>0.3.4</version>
     <build>
         <plugins>
             <plugin>

src/main/java/com/microsoft/azure/kusto/kafka/connect/sink/FileDescriptor.java → src/main/java/com/microsoft/azure/kusto/kafka/connect/sink/FileProperties.java

@@ -2,7 +2,7 @@
 
 import java.io.File;
 
-public class FileDescriptor {
+public class FileProperties {
     long rawBytes = 0;
     long zippedBytes = 0;
     long numRecords = 0;

src/main/java/com/microsoft/azure/kusto/kafka/connect/sink/FileWriter.java

@@ -10,7 +10,6 @@
 import java.util.function.Supplier;
 import java.util.zip.GZIPOutputStream;
 
-
 /**
  * This class is used to write gzipped rolling files.
  * Currently supports size based rolling, where size is for *uncompressed* size,
@@ -19,16 +18,17 @@
 public class FileWriter implements Closeable {
 
     private static final Logger log = LoggerFactory.getLogger(KustoSinkTask.class);
-    FileDescriptor currentFile;
+    FileProperties currentFile;
     private Timer timer;
-    private Consumer<FileDescriptor> onRollCallback;
+    private Consumer<FileProperties> onRollCallback;
     private final long flushInterval;
     private final boolean shouldCompressData;
     private Supplier<String> getFilePath;
     private OutputStream outputStream;
     private String basePath;
     private CountingOutputStream countingStream;
     private long fileThreshold;
+    private FileDescriptor currentFd;
 
     /**
      * @param basePath       - This is path to which to write the files to.
@@ -39,7 +39,7 @@ public class FileWriter implements Closeable {
      */
     public FileWriter(String basePath,
                       long fileThreshold,
-                      Consumer<FileDescriptor> onRollCallback,
+                      Consumer<FileProperties> onRollCallback,
                       Supplier<String> getFilePath,
                       long flushInterval,
                       boolean shouldCompressData) {
@@ -76,27 +76,28 @@ public synchronized void write(byte[] data) throws IOException {
     }
 
     public void openFile() throws IOException {
-        FileDescriptor fileDescriptor = new FileDescriptor();
+        FileProperties fileProps = new FileProperties();
 
         File folder = new File(basePath);
         if (!folder.exists() && !folder.mkdirs()) {
             throw new IOException(String.format("Failed to create new directory %s", folder.getPath()));
         }
 
         String filePath = getFilePath.get();
-        fileDescriptor.path = filePath;
+        fileProps.path = filePath;
 
         File file = new File(filePath);
 
         file.createNewFile();
 
         FileOutputStream fos = new FileOutputStream(file);
+        currentFd = fos.getFD();
         fos.getChannel().truncate(0);
 
         countingStream = new CountingOutputStream(fos);
         outputStream = shouldCompressData ? new GZIPOutputStream(countingStream) : countingStream;
-        fileDescriptor.file = file;
-        currentFile = fileDescriptor;
+        fileProps.file = file;
+        currentFile = fileProps;
     }
 
     void rotate() throws IOException {
@@ -105,6 +106,10 @@ void rotate() throws IOException {
     }
 
     void finishFile() throws IOException {
+        finishFile(true);
+    }
+
+    void finishFile(Boolean delete) throws IOException {
         if(isDirty()){
             if(shouldCompressData){
                 GZIPOutputStream gzip = (GZIPOutputStream) outputStream;
@@ -114,17 +119,28 @@ void finishFile() throws IOException {
             }
 
             onRollCallback.accept(currentFile);
+            if (delete){
+                dumpFile();
+            }
+        } else {
+            outputStream.close();
         }
+    }
 
-        // closing late so that the success callback will have a chance to use the file. This is a real thing on debug?!
+    private void dumpFile() throws IOException {
         outputStream.close();
+        currentFd = null;
+        boolean deleted = currentFile.file.delete();
+        if (!deleted) {
+            log.warn("couldn't delete temporary file. File exists: " + currentFile.file.exists());
+        }
     }
 
     public void rollback() throws IOException {
         if (outputStream != null) {
             outputStream.close();
             if (currentFile != null && currentFile.file != null) {
-                currentFile.file.delete();
+                dumpFile();
             }
         }
     }

src/main/java/com/microsoft/azure/kusto/kafka/connect/sink/TopicPartitionWriter.java

@@ -1,8 +1,6 @@
 package com.microsoft.azure.kusto.kafka.connect.sink;
 
-import com.microsoft.azure.kusto.data.ConnectionStringBuilder;
 import com.microsoft.azure.kusto.ingest.IngestClient;
-import com.microsoft.azure.kusto.ingest.IngestClientFactory;
 import com.microsoft.azure.kusto.ingest.IngestionProperties;
 import com.microsoft.azure.kusto.ingest.source.CompressionType;
 import com.microsoft.azure.kusto.ingest.source.FileSourceInfo;
@@ -42,7 +40,7 @@ public class TopicPartitionWriter {
         this.eventDataCompression = ingestionProps.eventDataCompression;
     }
 
-    public void handleRollFile(FileDescriptor fileDescriptor) {
+    public void handleRollFile(FileProperties fileDescriptor) {
         FileSourceInfo fileSourceInfo = new FileSourceInfo(fileDescriptor.path, fileDescriptor.rawBytes);
 
         try {

src/test/java/com/microsoft/azure/kusto/kafka/connect/sink/FileWriterTest.java

@@ -52,7 +52,7 @@ public void testOpen() throws IOException {
         final String FILE_PATH = Paths.get(path, "ABC").toString();
         final int MAX_FILE_SIZE = 128;
 
-        Consumer<FileDescriptor> trackFiles = (FileDescriptor f) -> {};
+        Consumer<FileProperties> trackFiles = (FileProperties f) -> {};
 
         Supplier<String> generateFileName = () -> FILE_PATH;
 
@@ -82,9 +82,9 @@ public void testGzipFileWriter() throws IOException {
 
         final int MAX_FILE_SIZE = 100;
 
-        Consumer<FileDescriptor> trackFiles = (FileDescriptor f) -> files.put(f.path, f.rawBytes);
+        Consumer<FileProperties> trackFiles = (FileProperties f) -> files.put(f.path, f.rawBytes);
 
-        Supplier<String> generateFileName = () -> Paths.get(path, String.valueOf(java.util.UUID.randomUUID())).toString();
+        Supplier<String> generateFileName = () -> Paths.get(path, String.valueOf(java.util.UUID.randomUUID())).toString() + "csv.gz";
 
         FileWriter fileWriter = new FileWriter(path, MAX_FILE_SIZE, trackFiles, generateFileName, 30000, false);
 
@@ -121,9 +121,9 @@ public void testGzipFileWriterFlush() throws IOException, InterruptedException {
 
         final int MAX_FILE_SIZE = 128 * 2;
 
-        Consumer<FileDescriptor> trackFiles = (FileDescriptor f) -> files.put(f.path, f.rawBytes);
+        Consumer<FileProperties> trackFiles = (FileProperties f) -> files.put(f.path, f.rawBytes);
 
-        Supplier<String> generateFileName = () -> Paths.get(path, java.util.UUID.randomUUID().toString()).toString();
+        Supplier<String> generateFileName = () -> Paths.get(path, java.util.UUID.randomUUID().toString()).toString() + "csv.gz";
 
         // Expect no files to be ingested as size is small and flushInterval is big
         FileWriter fileWriter = new FileWriter(path, MAX_FILE_SIZE, trackFiles, generateFileName, 30000, false);
@@ -177,7 +177,7 @@ public void testFileWriterCompressed() throws IOException {
         GZIPOutputStream gzipOutputStream = new GZIPOutputStream(byteArrayOutputStream);
         String msg = "Message";
 
-        Consumer<FileDescriptor> trackFiles = getAssertFileConsumer(msg);
+        Consumer<FileProperties> trackFiles = getAssertFileConsumer(msg);
 
         Supplier<String> generateFileName = () -> Paths.get(path, java.util.UUID.randomUUID().toString()).toString() + ".csv.gz";
 
@@ -189,11 +189,11 @@ public void testFileWriterCompressed() throws IOException {
         fileWriter.write(byteArrayOutputStream.toByteArray());
 
         fileWriter.close();
-        Assert.assertEquals(Objects.requireNonNull(folder.listFiles()).length, 0);
+        Assert.assertEquals(Objects.requireNonNull(folder.listFiles()).length, 1);
     }
 
-    static Consumer<FileDescriptor> getAssertFileConsumer(String msg) {
-        return (FileDescriptor f) -> {
+    static Consumer<FileProperties> getAssertFileConsumer(String msg) {
+        return (FileProperties f) -> {
             try (FileInputStream fileInputStream = new FileInputStream(f.file)) {
                 byte[] bytes = IOUtils.toByteArray(fileInputStream);
                 try (ByteArrayInputStream bin = new ByteArrayInputStream(bytes);

src/test/java/com/microsoft/azure/kusto/kafka/connect/sink/TopicPartitionWriterTest.java

@@ -2,7 +2,6 @@
 
 import com.microsoft.azure.kusto.ingest.IngestClient;
 import com.microsoft.azure.kusto.ingest.IngestionProperties;
-import com.microsoft.azure.kusto.ingest.source.CompressionType;
 import com.microsoft.azure.kusto.ingest.source.FileSourceInfo;
 import org.apache.commons.io.FileUtils;
 import org.apache.kafka.common.TopicPartition;
@@ -19,11 +18,9 @@
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.nio.file.Paths;
-import java.time.Instant;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.function.Consumer;
-import java.util.zip.GZIPOutputStream;
 
 import static org.mockito.Mockito.*;
 
@@ -64,7 +61,7 @@ public void testHandleRollFile() {
         props.ingestionProperties = ingestionProperties;
         TopicPartitionWriter writer = new TopicPartitionWriter(tp, mockedClient, props, basePath, fileThreshold, flushInterval);
 
-        FileDescriptor descriptor = new FileDescriptor();
+        FileProperties descriptor = new FileProperties();
         descriptor.rawBytes = 1024;
         descriptor.path = "somepath/somefile";
         descriptor.file = new File ("C://myfile.txt");
@@ -237,8 +234,8 @@ public void testWriteStringValuesAndOffset() throws IOException {
         Assert.assertEquals(currentFileName, Paths.get(basePath, String.format("kafka_%s_%d_%d.%s.gz", tp.topic(), tp.partition(), 16, IngestionProperties.DATA_FORMAT.csv.name())).toString());
 
         // Read
-        writer.fileWriter.finishFile();
-        Consumer<FileDescriptor> assertFileConsumer = FileWriterTest.getAssertFileConsumer(messages[2] + "\n");
+        writer.fileWriter.finishFile(false);
+        Consumer<FileProperties> assertFileConsumer = FileWriterTest.getAssertFileConsumer(messages[2] + "\n");
         assertFileConsumer.accept(writer.fileWriter.currentFile);
     }