OZG-7262 OZG-7566 Notify callObserver about error

ozgcloud-common-lib/src/main/java/de/ozgcloud/common/binaryfile/GrpcBinaryFileServerDownloader.java

@@ -23,22 +23,26 @@
  */
 package de.ozgcloud.common.binaryfile;
 
-import com.google.protobuf.ByteString;
-import de.ozgcloud.common.errorhandling.TechnicalException;
-import io.grpc.stub.CallStreamObserver;
-import lombok.Builder;
-import lombok.extern.log4j.Log4j2;
-import org.apache.commons.io.IOUtils;
-import org.springframework.core.task.TaskExecutor;
-
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.PipedInputStream;
 import java.io.PipedOutputStream;
+import java.util.Objects;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
 import java.util.function.Function;
 
+import org.apache.commons.io.IOUtils;
+import org.springframework.core.task.TaskExecutor;
+
+import com.google.protobuf.ByteString;
+
+import de.ozgcloud.common.errorhandling.TechnicalException;
+import io.grpc.stub.CallStreamObserver;
+import lombok.Builder;
+import lombok.extern.log4j.Log4j2;
+
 @Log4j2
 public class GrpcBinaryFileServerDownloader<T> {
 
@@ -49,10 +53,11 @@ public class GrpcBinaryFileServerDownloader<T> {
 	private final Consumer<OutputStream> downloadConsumer;
 	private final TaskExecutor taskExecutor;
 
-	private final byte[] buffer = new byte[GrpcBinaryFileServerDownloader.CHUNK_SIZE];
+	private final byte[] buffer = new byte[CHUNK_SIZE];
 	private final AtomicBoolean started = new AtomicBoolean(false);
 	private final AtomicBoolean downloadFinished = new AtomicBoolean(false);
 	private final AtomicBoolean requestFinished = new AtomicBoolean(false);
+	private final AtomicReference<TechnicalException> downloadError = new AtomicReference<>();
 
 	private PipedInputStream inputStream;
 	private PipedOutputStream outputStream;
@@ -78,19 +83,37 @@ public class GrpcBinaryFileServerDownloader<T> {
 
 	void doStart() {
 		LOG.debug("Starting download.");
-		handleSafety(this::setupStreams);
+		safelySetupStreams();
 		taskExecutor.execute(this::startDownload);
 		callObserver.setOnReadyHandler(this::sendChunks);
 	}
 
+	void safelySetupStreams() {
+		try {
+			setupStreams();
+		} catch (Exception e) {
+			closeOutputStream();
+			closeInputStream();
+			throw new TechnicalException("Error while setting up streams", e);
+		}
+	}
+
 	void setupStreams() throws IOException {
 		outputStream = new PipedOutputStream();
-		inputStream = new PipedInputStream(GrpcBinaryFileServerDownloader.CHUNK_SIZE);
+		inputStream = new PipedInputStream(CHUNK_SIZE);
 		outputStream.connect(inputStream);
 	}
 
 	void startDownload() {
-		handleSafety(this::doDownload);
+		try {
+			doDownload();
+			sendChunks();
+		} catch (Exception e) {
+			downloadError.set(new TechnicalException("Error while downloading file contents", e));
+			LOG.error(downloadError.get().getMessage(), downloadError.get());
+		} finally {
+			closeOutputStream();
+		}
 	}
 
 	void doDownload() {
@@ -98,12 +121,14 @@ public class GrpcBinaryFileServerDownloader<T> {
 		downloadConsumer.accept(outputStream);
 		LOG.debug("Download completed.");
 		downloadFinished.set(true);
-		closeOutputStream();
-		sendChunks();
 	}
 
 	synchronized void sendChunks() {
-		handleSafety(this::doSendChunks);
+		try {
+			doSendChunks();
+		} catch (Exception e) {
+			completeRequestWithError(new TechnicalException("Error while sending chunks", e));
+		}
 	}
 
 	void doSendChunks() throws IOException {
@@ -111,7 +136,7 @@ public class GrpcBinaryFileServerDownloader<T> {
 			return;
 		}
 		int bytesRead;
-		while (callObserver.isReady()) {
+		while (isReady()) {
 			if ((bytesRead = inputStream.read(buffer)) == -1) {
 				tryCompleteRequest();
 				break;
@@ -121,30 +146,33 @@ public class GrpcBinaryFileServerDownloader<T> {
 		}
 	}
 
+	private boolean isReady() {
+		return callObserver.isReady();
+	}
+
 	void tryCompleteRequest() {
-		if (shouldCompleteRequest()) {
-			completeRequest();
+		if (Objects.nonNull(downloadError.get())) {
+			throw downloadError.get();
+		} else if (downloadFinished.get()) {
+			completeRequestNormally();
 		}
 	}
 
-	boolean shouldCompleteRequest() {
-		return downloadFinished.get() && requestFinished.compareAndSet(false, true);
+	void completeRequestWithError(TechnicalException e) {
+		LOG.debug("Complete download request with error");
+		finishRequest();
+		throw e;
 	}
 
-	void completeRequest() {
+	void completeRequestNormally() {
 		LOG.debug("Complete download request");
-		closeInputStream();
+		finishRequest();
 		callObserver.onCompleted();
 	}
 
-	void handleSafety(ExceptionalRunnable runnable) {
-		try {
-			runnable.run();
-		} catch (Exception e) {
-			closeOutputStream();
-			closeInputStream();
-			throw new TechnicalException("Error occurred during downloading file content download.", e);
-		}
+	private void finishRequest() {
+		requestFinished.set(true);
+		closeInputStream();
 	}
 
 	void closeOutputStream() {
@@ -154,5 +182,4 @@ public class GrpcBinaryFileServerDownloader<T> {
 	void closeInputStream() {
 		IOUtils.closeQuietly(inputStream, e -> LOG.error("InputStream cannot be closed.", e));
 	}
-
 }
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