[server] Started work on the internal file server

1 files changed, 121 insertions, 0 deletions

diff --git a/dozentenmodulserver/src/main/java/fileserv/ActiveUpload.java b/dozentenmodulserver/src/main/java/fileserv/ActiveUpload.java
new file mode 100644
index 00000000..cf73a413
--- /dev/null
+++ b/dozentenmodulserver/src/main/java/fileserv/ActiveUpload.java
@@ -0,0 +1,121 @@
+package fileserv;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.util.List;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ThreadPoolExecutor;
+
+import org.apache.log4j.Logger;
+import org.openslx.filetransfer.DataReceivedCallback;
+import org.openslx.filetransfer.Downloader;
+import org.openslx.filetransfer.FileRange;
+import org.openslx.filetransfer.WantRangeCallback;
+
+public class ActiveUpload {
+	private static final Logger LOGGER = Logger.getLogger(ActiveUpload.class);
+
+	/**
+	 * This is an active upload, so on our end, we have a Downloader.
+	 */
+	private Downloader download = null;
+
+	private final String destinationFile;
+
+	private final RandomAccessFile outFile;
+
+	private ConcurrentLinkedQueue<FileChunk> chunks = new ConcurrentLinkedQueue<>();
+
+	// TODO: Hashlist for verification
+
+	public ActiveUpload(String destinationFile, long fileSize, List<byte[]> sha1Sums)
+			throws FileNotFoundException {
+		this.destinationFile = destinationFile;
+		outFile = new RandomAccessFile(destinationFile, "rw");
+		FileChunk.createChunkList(chunks, fileSize, sha1Sums);
+	}
+
+	/**
+	 * Add another connection for this file transfer. Currently only one
+	 * connection is allowed, but this might change in the future.
+	 * 
+	 * @param connection
+	 * @return true if the connection is accepted, false if it should be
+	 *         discarded
+	 */
+	public synchronized boolean addConnection(Downloader connection, ThreadPoolExecutor pool) {
+		if (download != null)
+			return false;
+		download = connection;
+		pool.execute(new Runnable() {
+			@Override
+			public void run() {
+				CbHandler cbh = new CbHandler();
+				if (!download.download(cbh, cbh) && cbh.currentChunk != null) {
+					// If the download failed and we have a current chunk, put it back into
+					// the queue, so it will be handled again later...
+					chunks.add(cbh.currentChunk);
+				}
+			}
+		});
+		return true;
+	}
+
+	/**
+	 * Write some data to the local file. Thread safe so we could
+	 * have multiple concurrent connections later.
+	 * 
+	 * @param fileOffset
+	 * @param dataLength
+	 * @param data
+	 * @return
+	 */
+	private boolean writeFileData(long fileOffset, int dataLength, byte[] data) {
+		synchronized (outFile) {
+			try {
+				outFile.seek(fileOffset);
+				outFile.write(data, 0, dataLength);
+			} catch (IOException e) {
+				LOGGER.error("Cannot write to '" + destinationFile
+						+ "'. Disk full, network storage error, bad permissions, ...?", e);
+				return false;
+			}
+		}
+		return true;
+	}
+
+	/**
+	 * Callback class for an instance of the Downloader, which supplies
+	 * the Downloader with wanted file ranges, and handles incoming data.
+	 */
+	private class CbHandler implements WantRangeCallback, DataReceivedCallback {
+		/**
+		 * The current chunk being transfered.
+		 */
+		public FileChunk currentChunk = null;
+
+		@Override
+		public boolean dataReceived(long fileOffset, int dataLength, byte[] data) {
+			// TODO: Maybe cache in RAM and write full CHUNK_SIZE blocks at a time?
+			// Would probably help with slower storage, especially if it's using
+			// rotating disks and we're running multiple uploads.
+			// Also we wouldn't have to re-read a block form disk for sha1 checking.
+			return writeFileData(fileOffset, dataLength, data);
+		}
+
+		@Override
+		public FileRange get() {
+			if (currentChunk != null) {
+				// TODO: A chunk was requested before, check hash and requeue if not matching
+				// This needs to be async (own thread) so will be a little complicated
+			}
+			// Get next missing chunk
+			currentChunk = chunks.poll();
+			if (currentChunk == null)
+				return null; // No more chunks, returning null tells the Downloader we're done.
+			return currentChunk.range;
+		}
+	}
+
+}