Simplify DownloadManager constructors

PiperOrigin-RevId: 244223870

demos/main/src/main/java/com/google/android/exoplayer2/demo/DemoApplication.java

@@ -49,7 +49,6 @@ public class DemoApplication extends Application {
   private static final String DOWNLOAD_ACTION_FILE = "actions";
   private static final String DOWNLOAD_TRACKER_ACTION_FILE = "tracked_actions";
   private static final String DOWNLOAD_CONTENT_DIRECTORY = "downloads";
-  private static final int MAX_SIMULTANEOUS_DOWNLOADS = 2;
 
   protected String userAgent;
 
@@ -122,12 +121,7 @@ public class DemoApplication extends Application {
           new DownloaderConstructorHelper(getDownloadCache(), buildHttpDataSourceFactory());
       downloadManager =
           new DownloadManager(
-              this,
-              downloadIndex,
-              new DefaultDownloaderFactory(downloaderConstructorHelper),
-              MAX_SIMULTANEOUS_DOWNLOADS,
-              DownloadManager.DEFAULT_MIN_RETRY_COUNT,
-              DownloadManager.DEFAULT_REQUIREMENTS);
+              this, downloadIndex, new DefaultDownloaderFactory(downloaderConstructorHelper));
       downloadTracker =
           new DownloadTracker(/* context= */ this, buildDataSourceFactory(), downloadManager);
     }

library/core/src/main/java/com/google/android/exoplayer2/offline/DownloadManager.java

@@ -34,7 +34,6 @@ import android.os.Message;
 import androidx.annotation.IntDef;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.database.DatabaseProvider;
 import com.google.android.exoplayer2.scheduler.Requirements;
 import com.google.android.exoplayer2.scheduler.RequirementsWatcher;
 import com.google.android.exoplayer2.upstream.cache.CacheUtil.CachingCounters;
@@ -111,8 +110,8 @@ public final class DownloadManager {
         @Requirements.RequirementFlags int notMetRequirements) {}
   }
 
-  /** The default maximum number of simultaneous downloads. */
-  public static final int DEFAULT_MAX_SIMULTANEOUS_DOWNLOADS = 1;
+  /** The default maximum number of parallel downloads. */
+  public static final int DEFAULT_MAX_PARALLEL_DOWNLOADS = 3;
   /** The default minimum number of times a download must be retried before failing. */
   public static final int DEFAULT_MIN_RETRY_COUNT = 5;
   /** The default requirement is that the device has network connectivity. */
@@ -151,8 +150,6 @@ public final class DownloadManager {
   private static final String TAG = "DownloadManager";
   private static final boolean DEBUG = false;
 
-  private final int maxSimultaneousDownloads;
-  private final int minRetryCount;
   private final Context context;
   private final WritableDownloadIndex downloadIndex;
   private final DownloaderFactory downloaderFactory;
@@ -180,51 +177,11 @@ public final class DownloadManager {
   // Mutable fields that are accessed on the internal thread.
   @Requirements.RequirementFlags private int notMetRequirements;
   private boolean downloadsResumed;
-  private int simultaneousDownloads;
+  private int parallelDownloads;
 
-  /**
-   * Constructs a {@link DownloadManager}.
-   *
-   * @param context Any context.
-   * @param databaseProvider Provides the database that holds the downloads.
-   * @param downloaderFactory A factory for creating {@link Downloader}s.
-   */
-  public DownloadManager(
-      Context context, DatabaseProvider databaseProvider, DownloaderFactory downloaderFactory) {
-    this(
-        context,
-        databaseProvider,
-        downloaderFactory,
-        DEFAULT_MAX_SIMULTANEOUS_DOWNLOADS,
-        DEFAULT_MIN_RETRY_COUNT,
-        DEFAULT_REQUIREMENTS);
-  }
-
-  /**
-   * Constructs a {@link DownloadManager}.
-   *
-   * @param context Any context.
-   * @param databaseProvider Provides the database that holds the downloads.
-   * @param downloaderFactory A factory for creating {@link Downloader}s.
-   * @param maxSimultaneousDownloads The maximum number of simultaneous downloads.
-   * @param minRetryCount The minimum number of times a download must be retried before failing.
-   * @param requirements The requirements needed to be met to start downloads.
-   */
-  public DownloadManager(
-      Context context,
-      DatabaseProvider databaseProvider,
-      DownloaderFactory downloaderFactory,
-      int maxSimultaneousDownloads,
-      int minRetryCount,
-      Requirements requirements) {
-    this(
-        context,
-        new DefaultDownloadIndex(databaseProvider),
-        downloaderFactory,
-        maxSimultaneousDownloads,
-        minRetryCount,
-        requirements);
-  }
+  // TODO: Fix these to properly support changes at runtime.
+  private volatile int maxParallelDownloads;
+  private volatile int minRetryCount;
 
   /**
    * Constructs a {@link DownloadManager}.
@@ -232,22 +189,14 @@ public final class DownloadManager {
    * @param context Any context.
    * @param downloadIndex The download index used to hold the download information.
    * @param downloaderFactory A factory for creating {@link Downloader}s.
-   * @param maxSimultaneousDownloads The maximum number of simultaneous downloads.
-   * @param minRetryCount The minimum number of times a download must be retried before failing.
-   * @param requirements The requirements needed to be met to start downloads.
    */
   public DownloadManager(
-      Context context,
-      WritableDownloadIndex downloadIndex,
-      DownloaderFactory downloaderFactory,
-      int maxSimultaneousDownloads,
-      int minRetryCount,
-      Requirements requirements) {
+      Context context, WritableDownloadIndex downloadIndex, DownloaderFactory downloaderFactory) {
     this.context = context.getApplicationContext();
     this.downloadIndex = downloadIndex;
     this.downloaderFactory = downloaderFactory;
-    this.maxSimultaneousDownloads = maxSimultaneousDownloads;
-    this.minRetryCount = minRetryCount;
+    maxParallelDownloads = DEFAULT_MAX_PARALLEL_DOWNLOADS;
+    minRetryCount = DEFAULT_MIN_RETRY_COUNT;
 
     downloadInternals = new ArrayList<>();
     downloads = new ArrayList<>();
@@ -262,7 +211,8 @@ public final class DownloadManager {
     internalThread.start();
     internalHandler = new Handler(internalThread.getLooper(), this::handleInternalMessage);
 
-    requirementsWatcher = new RequirementsWatcher(context, requirementsListener, requirements);
+    requirementsWatcher =
+        new RequirementsWatcher(context, requirementsListener, DEFAULT_REQUIREMENTS);
     int notMetRequirements = requirementsWatcher.start();
 
     pendingMessages = 1;
@@ -332,6 +282,27 @@ public final class DownloadManager {
     onRequirementsStateChanged(requirementsWatcher, notMetRequirements);
   }
 
+  /**
+   * Sets the maximum number of parallel downloads.
+   *
+   * @param maxParallelDownloads The maximum number of parallel downloads.
+   */
+  // TODO: Fix to properly support changes at runtime.
+  public void setMaxParallelDownloads(int maxParallelDownloads) {
+    this.maxParallelDownloads = maxParallelDownloads;
+  }
+
+  /**
+   * Sets the minimum number of times that a download will be retried. A download will fail if the
+   * specified number of retries is exceeded without any progress being made.
+   *
+   * @param minRetryCount The minimum number of times that a download will be retried.
+   */
+  // TODO: Fix to properly support changes at runtime.
+  public void setMinRetryCount(int minRetryCount) {
+    this.minRetryCount = minRetryCount;
+  }
+
   /** Returns the used {@link DownloadIndex}. */
   public DownloadIndex getDownloadIndex() {
     return downloadIndex;
@@ -696,15 +667,15 @@ public final class DownloadManager {
     downloadThreads.remove(downloadId);
     boolean tryToStartDownloads = false;
     if (!downloadThread.isRemove) {
-      // If maxSimultaneousDownloads was hit, there might be a download waiting for a slot.
-      tryToStartDownloads = simultaneousDownloads == maxSimultaneousDownloads;
-      simultaneousDownloads--;
+      // If maxParallelDownloads was hit, there might be a download waiting for a slot.
+      tryToStartDownloads = parallelDownloads == maxParallelDownloads;
+      parallelDownloads--;
     }
     getDownload(downloadId)
         .onDownloadThreadStopped(downloadThread.isCanceled, downloadThread.finalError);
     if (tryToStartDownloads) {
       for (int i = 0;
-          simultaneousDownloads < maxSimultaneousDownloads && i < downloadInternals.size();
+          parallelDownloads < maxParallelDownloads && i < downloadInternals.size();
           i++) {
         downloadInternals.get(i).start();
       }
@@ -760,10 +731,10 @@ public final class DownloadManager {
     }
     boolean isRemove = downloadInternal.isInRemoveState();
     if (!isRemove) {
-      if (simultaneousDownloads == maxSimultaneousDownloads) {
+      if (parallelDownloads == maxParallelDownloads) {
         return START_THREAD_TOO_MANY_DOWNLOADS;
       }
-      simultaneousDownloads++;
+      parallelDownloads++;
     }
     Downloader downloader = downloaderFactory.createDownloader(request);
     DownloadThread downloadThread =

library/core/src/test/java/com/google/android/exoplayer2/offline/DownloadManagerTest.java

@@ -517,7 +517,7 @@ public class DownloadManagerTest {
     assertEqualIgnoringTimeFields(mergedDownload, expectedDownload);
   }
 
-  private void setUpDownloadManager(final int maxActiveDownloadTasks) throws Exception {
+  private void setUpDownloadManager(final int maxParallelDownloads) throws Exception {
     if (downloadManager != null) {
       releaseDownloadManager();
     }
@@ -526,12 +526,10 @@ public class DownloadManagerTest {
           () -> {
             downloadManager =
                 new DownloadManager(
-                    ApplicationProvider.getApplicationContext(),
-                    downloadIndex,
-                    downloaderFactory,
-                    maxActiveDownloadTasks,
-                    MIN_RETRY_COUNT,
-                    new Requirements(0));
+                    ApplicationProvider.getApplicationContext(), downloadIndex, downloaderFactory);
+            downloadManager.setMaxParallelDownloads(maxParallelDownloads);
+            downloadManager.setMinRetryCount(MIN_RETRY_COUNT);
+            downloadManager.setRequirements(new Requirements(0));
             downloadManager.resumeDownloads();
             downloadManagerListener =
                 new TestDownloadManagerListener(downloadManager, dummyMainThread);

library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadManagerDashTest.java

@@ -32,7 +32,6 @@ import com.google.android.exoplayer2.offline.DownloadManager;
 import com.google.android.exoplayer2.offline.DownloadRequest;
 import com.google.android.exoplayer2.offline.DownloaderConstructorHelper;
 import com.google.android.exoplayer2.offline.StreamKey;
-import com.google.android.exoplayer2.scheduler.Requirements;
 import com.google.android.exoplayer2.testutil.DummyMainThread;
 import com.google.android.exoplayer2.testutil.DummyMainThread.TestRunnable;
 import com.google.android.exoplayer2.testutil.FakeDataSet;
@@ -259,10 +258,7 @@ public class DownloadManagerDashTest {
                   ApplicationProvider.getApplicationContext(),
                   downloadIndex,
                   new DefaultDownloaderFactory(
-                      new DownloaderConstructorHelper(cache, fakeDataSourceFactory)),
-                  /* maxSimultaneousDownloads= */ 1,
-                  /* minRetryCount= */ 3,
-                  new Requirements(0));
+                      new DownloaderConstructorHelper(cache, fakeDataSourceFactory)));
 
           downloadManagerListener =
               new TestDownloadManagerListener(

library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadServiceDashTest.java

@@ -35,7 +35,6 @@ import com.google.android.exoplayer2.offline.DownloadRequest;
 import com.google.android.exoplayer2.offline.DownloadService;
 import com.google.android.exoplayer2.offline.DownloaderConstructorHelper;
 import com.google.android.exoplayer2.offline.StreamKey;
-import com.google.android.exoplayer2.scheduler.Requirements;
 import com.google.android.exoplayer2.scheduler.Scheduler;
 import com.google.android.exoplayer2.testutil.DummyMainThread;
 import com.google.android.exoplayer2.testutil.FakeDataSet;
@@ -119,10 +118,7 @@ public class DownloadServiceDashTest {
                   ApplicationProvider.getApplicationContext(),
                   downloadIndex,
                   new DefaultDownloaderFactory(
-                      new DownloaderConstructorHelper(cache, fakeDataSourceFactory)),
-                  /* maxSimultaneousDownloads= */ 1,
-                  /* minRetryCount= */ 3,
-                  new Requirements(0));
+                      new DownloaderConstructorHelper(cache, fakeDataSourceFactory)));
           downloadManagerListener =
               new TestDownloadManagerListener(dashDownloadManager, dummyMainThread);
           dashDownloadManager.resumeDownloads();