Embedded GigaGet download manager. First try.

app/src/main/java/us/shandian/giga/get/DownloadRunnable.java

@@ -0,0 +1,174 @@
+package us.shandian.giga.get;
+
+import android.os.Handler;
+import android.util.Log;
+
+import java.io.BufferedInputStream;
+import java.io.RandomAccessFile;
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+import static org.schabi.newpipe.BuildConfig.DEBUG;
+
+public class DownloadRunnable implements Runnable
+{
+	private static final String TAG = DownloadRunnable.class.getSimpleName();
+	
+	private DownloadMission mMission;
+	private int mId;
+	
+	public DownloadRunnable(DownloadMission mission, int id) {
+		mMission = mission;
+		mId = id;
+	}
+	
+	@Override
+	public void run() {
+		boolean retry = mMission.recovered;
+		long position = mMission.getPosition(mId);
+		
+		if (DEBUG) {
+			Log.d(TAG, mId + ":default pos " + position);
+			Log.d(TAG, mId + ":recovered: " + mMission.recovered);
+		}
+		
+		while (mMission.errCode == -1 && mMission.running && position < mMission.blocks) {
+			
+			if (Thread.currentThread().isInterrupted()) {
+				mMission.pause();
+				return;
+			}
+			
+			if (DEBUG && retry) {
+				Log.d(TAG, mId + ":retry is true. Resuming at " + position);
+			}
+			
+			// Wait for an unblocked position
+			while (!retry && position < mMission.blocks && mMission.isBlockPreserved(position)) {
+				
+				if (DEBUG) {
+					Log.d(TAG, mId + ":position " + position + " preserved, passing");
+				}
+				
+				position++;
+			}
+			
+			retry = false;
+			
+			if (position >= mMission.blocks) {
+				break;
+			}
+			
+			if (DEBUG) {
+				Log.d(TAG, mId + ":preserving position " + position);
+			}
+			
+			mMission.preserveBlock(position);
+			mMission.setPosition(mId, position);
+			
+			long start = position * DownloadManager.BLOCK_SIZE;
+			long end = start + DownloadManager.BLOCK_SIZE - 1;
+			
+			if (end >= mMission.length) {
+				end = mMission.length - 1;
+			}
+			
+			HttpURLConnection conn = null;
+			
+			int total = 0;
+			
+			try {
+				URL url = new URL(mMission.url);
+				conn = (HttpURLConnection) url.openConnection();
+				conn.setRequestProperty("Range", "bytes=" + start + "-" + end);
+				
+				if (DEBUG) {
+					Log.d(TAG, mId + ":" + conn.getRequestProperty("Range"));
+					Log.d(TAG, mId + ":Content-Length=" + conn.getContentLength() + " Code:" + conn.getResponseCode());
+				}
+				
+				// A server may be ignoring the range requet
+				if (conn.getResponseCode() != 206) {
+					mMission.errCode = DownloadMission.ERROR_SERVER_UNSUPPORTED;
+					notifyError(DownloadMission.ERROR_SERVER_UNSUPPORTED);
+					
+					if (DEBUG) {
+						Log.e(TAG, mId + ":Unsupported " + conn.getResponseCode());
+					}
+					
+					break;
+				}
+				
+				RandomAccessFile f = new RandomAccessFile(mMission.location + "/" + mMission.name, "rw");
+				f.seek(start);
+				BufferedInputStream ipt = new BufferedInputStream(conn.getInputStream());
+				byte[] buf = new byte[512];
+				
+				while (start < end && mMission.running) {
+					int len = ipt.read(buf, 0, 512);
+					
+					if (len == -1) {
+						break;
+					} else {
+						start += len;
+						total += len;
+						f.write(buf, 0, len);
+						notifyProgress(len);
+					}
+				}
+				
+				if (DEBUG && mMission.running) {
+					Log.d(TAG, mId + ":position " + position + " finished, total length " + total);
+				}
+				
+				f.close();
+				ipt.close();
+				
+				// TODO We should save progress for each thread
+			} catch (Exception e) {
+				// TODO Retry count limit & notify error
+				retry = true;
+				
+				notifyProgress(-total);
+				
+				if (DEBUG) {
+					Log.d(TAG, mId + ":position " + position + " retrying");
+				}
+			}
+		}
+		
+		if (DEBUG) {
+			Log.d(TAG, "thread " + mId + " exited main loop");
+		}
+		
+		if (mMission.errCode == -1 && mMission.running) {
+			if (DEBUG) {
+				Log.d(TAG, "no error has happened, notifying");
+			}
+			notifyFinished();
+		}
+		
+		if (DEBUG && !mMission.running) {
+			Log.d(TAG, "The mission has been paused. Passing.");
+		}
+	}
+	
+	private void notifyProgress(final long len) {
+		synchronized (mMission) {
+			mMission.notifyProgress(len);
+		}
+	}
+	
+	private void notifyError(final int err) {
+		synchronized (mMission) {
+			mMission.notifyError(err);
+			mMission.pause();
+		}
+	}
+	
+	private void notifyFinished() {
+		synchronized (mMission) {
+			mMission.notifyFinished();
+		}
+	}
+}