Implement Bundleable for Timeline

PiperOrigin-RevId: 362474276

constants.gradle

@@ -32,6 +32,7 @@ project.ext {
     androidxAnnotationVersion = '1.1.0'
     androidxAnnotationVersion = '1.1.0'
     androidxAppCompatVersion = '1.1.0'
     androidxAppCompatVersion = '1.1.0'
     androidxCollectionVersion = '1.1.0'
     androidxCollectionVersion = '1.1.0'
+    androidxCoreVersion = '1.3.2'
     androidxFuturesVersion = '1.1.0'
     androidxFuturesVersion = '1.1.0'
     androidxMediaVersion = '1.2.1'
     androidxMediaVersion = '1.2.1'
     androidxMedia2Version = '1.1.2'
     androidxMedia2Version = '1.1.2'
@@ -42,6 +43,7 @@ project.ext {
     androidxTestRunnerVersion = '1.3.0'
     androidxTestRunnerVersion = '1.3.0'
     androidxTestRulesVersion = '1.3.0'
     androidxTestRulesVersion = '1.3.0'
     androidxTestServicesStorageVersion = '1.3.0'
     androidxTestServicesStorageVersion = '1.3.0'
+    androidxTestTruthVersion = '1.3.0'
     truthVersion = '1.0'
     truthVersion = '1.0'
     modulePrefix = ':'
     modulePrefix = ':'
     if (gradle.ext.has('exoplayerModulePrefix')) {
     if (gradle.ext.has('exoplayerModulePrefix')) {

library/common/build.gradle

@@ -26,6 +26,7 @@ dependencies {
         exclude group: 'org.codehaus.mojo', module: 'animal-sniffer-annotations'
         exclude group: 'org.codehaus.mojo', module: 'animal-sniffer-annotations'
     }
     }
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
+    implementation 'androidx.core:core:' + androidxCoreVersion
     compileOnly 'com.google.code.findbugs:jsr305:' + jsr305Version
     compileOnly 'com.google.code.findbugs:jsr305:' + jsr305Version
     compileOnly 'org.checkerframework:checker-compat-qual:' + checkerframeworkCompatVersion
     compileOnly 'org.checkerframework:checker-compat-qual:' + checkerframeworkCompatVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion

library/common/src/main/java/com/google/android/exoplayer2/BundleListRetriever.java

+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2;
+
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+
+import android.os.Binder;
+import android.os.Bundle;
+import android.os.IBinder;
+import android.os.Parcel;
+import android.os.RemoteException;
+import androidx.annotation.Nullable;
+import com.google.android.exoplayer2.util.Util;
+import com.google.common.collect.ImmutableList;
+import java.util.List;
+
+/**
+ * A {@link Binder} to transfer a list of {@link Bundle Bundles} across processes by splitting the
+ * list into multiple transactions.
+ *
+ * <p>Note: Using this class causes synchronous binder calls in the opposite direction regardless of
+ * the "oneway" property.
+ *
+ * <p>Example usage:
+ *
+ * <pre>{@code
+ * // Sender
+ * List<Bundle> list = ...;
+ * IBinder binder = new BundleListRetriever(list);
+ * Bundle bundle = new Bundle();
+ * bundle.putBinder("list", binder);
+ *
+ * // Receiver
+ * Bundle bundle = ...; // Received from the sender
+ * IBinder binder = bundle.getBinder("list");
+ * List<Bundle> list = BundleListRetriever.getList(binder);
+ * }</pre>
+ */
+public final class BundleListRetriever extends Binder {
+
+  // Soft limit of an IPC buffer size
+  private static final int SUGGESTED_MAX_IPC_SIZE =
+      Util.SDK_INT >= 30 ? IBinder.getSuggestedMaxIpcSizeBytes() : 64 * 1024;
+
+  private static final int REPLY_END_OF_LIST = 0;
+  private static final int REPLY_CONTINUE = 1;
+  private static final int REPLY_BREAK = 2;
+
+  private final ImmutableList<Bundle> list;
+
+  /** Creates a {@link Binder} to send a list of {@link Bundle Bundles} to another process. */
+  public BundleListRetriever(List<Bundle> list) {
+    this.list = ImmutableList.copyOf(list);
+  }
+
+  @Override
+  protected boolean onTransact(int code, Parcel data, @Nullable Parcel reply, int flags)
+      throws RemoteException {
+    if (code != FIRST_CALL_TRANSACTION) {
+      return super.onTransact(code, data, reply, flags);
+    }
+
+    if (reply == null) {
+      return false;
+    }
+
+    int count = list.size();
+    int index = data.readInt();
+    while (index < count && reply.dataSize() < SUGGESTED_MAX_IPC_SIZE) {
+      reply.writeInt(REPLY_CONTINUE);
+      reply.writeBundle(list.get(index));
+      index++;
+    }
+    reply.writeInt(index < count ? REPLY_BREAK : REPLY_END_OF_LIST);
+    return true;
+  }
+
+  /**
+   * Gets a list of {@link Bundle Bundles} from a {@link BundleListRetriever}.
+   *
+   * @param binder A binder interface backed by {@link BundleListRetriever}.
+   * @return The list of {@link Bundle Bundles}.
+   */
+  public static ImmutableList<Bundle> getList(IBinder binder) {
+    ImmutableList.Builder<Bundle> builder = ImmutableList.builder();
+
+    int index = 0;
+    int replyCode = REPLY_CONTINUE;
+
+    while (replyCode != REPLY_END_OF_LIST) {
+      Parcel data = Parcel.obtain();
+      Parcel reply = Parcel.obtain();
+      try {
+        data.writeInt(index);
+        try {
+          binder.transact(FIRST_CALL_TRANSACTION, data, reply, /* flags= */ 0);
+        } catch (RemoteException e) {
+          throw new RuntimeException(e);
+        }
+        while ((replyCode = reply.readInt()) == REPLY_CONTINUE) {
+          builder.add(checkNotNull(reply.readBundle()));
+          index++;
+        }
+      } finally {
+        reply.recycle();
+        data.recycle();
+      }
+    }
+
+    return builder.build();
+  }
+}

library/common/src/main/java/com/google/android/exoplayer2/Timeline.java

@@ -19,16 +19,21 @@ import static com.google.android.exoplayer2.util.Assertions.checkState;
 
 
 import android.net.Uri;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.Bundle;
+import android.os.IBinder;
 import android.os.SystemClock;
 import android.os.SystemClock;
 import android.util.Pair;
 import android.util.Pair;
 import androidx.annotation.IntDef;
 import androidx.annotation.IntDef;
 import androidx.annotation.Nullable;
 import androidx.annotation.Nullable;
+import androidx.core.app.BundleCompat;
 import com.google.android.exoplayer2.source.ads.AdPlaybackState;
 import com.google.android.exoplayer2.source.ads.AdPlaybackState;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.util.Util;
+import com.google.common.collect.ImmutableList;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.RetentionPolicy;
+import java.util.ArrayList;
+import java.util.List;
 
 
 /**
 /**
  * A flexible representation of the structure of media. A timeline is able to represent the
  * A flexible representation of the structure of media. A timeline is able to represent the
@@ -124,7 +129,7 @@ import java.lang.annotation.RetentionPolicy;
  * <p>This case includes mid-roll ad groups, which are defined as part of the timeline's single
  * <p>This case includes mid-roll ad groups, which are defined as part of the timeline's single
  * period. The period can be queried for information about the ad groups and the ads they contain.
  * period. The period can be queried for information about the ad groups and the ads they contain.
  */
  */
-public abstract class Timeline {
+public abstract class Timeline implements Bundleable {
 
 
   /**
   /**
    * Holds information about a window in a {@link Timeline}. A window usually corresponds to one
    * Holds information about a window in a {@link Timeline}. A window usually corresponds to one
@@ -1245,4 +1250,148 @@ public abstract class Timeline {
     }
     }
     return result;
     return result;
   }
   }
+
+  // Bundleable implementation.
+
+  @Documented
+  @Retention(RetentionPolicy.SOURCE)
+  @IntDef({FIELD_WINDOWS, FIELD_PERIODS})
+  private @interface FieldNumber {}
+
+  private static final int FIELD_WINDOWS = 0;
+  private static final int FIELD_PERIODS = 1;
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>The {@link #getWindow(int, Window)} windows} and {@link #getPeriod(int, Period) periods} of
+   * an instance restored by {@link #CREATOR} may have missing fields as described in {@link
+   * Window#toBundle()} and {@link Period#toBundle()}.
+   */
+  @Override
+  public final Bundle toBundle() {
+    List<Bundle> windowBundles = new ArrayList<>();
+    int windowCount = getWindowCount();
+    for (int i = 0; i < windowCount; i++) {
+      Window window = new Window();
+      getWindow(i, window, /* defaultPositionProjectionUs= */ 0);
+      windowBundles.add(window.toBundle());
+    }
+
+    List<Bundle> periodBundles = new ArrayList<>();
+    int periodCount = getPeriodCount();
+    for (int i = 0; i < periodCount; i++) {
+      Period period = new Period();
+      getPeriod(i, period, /* setIds= */ false);
+      periodBundles.add(period.toBundle());
+    }
+
+    Bundle bundle = new Bundle();
+    BundleCompat.putBinder(
+        bundle, keyForField(FIELD_WINDOWS), new BundleListRetriever(windowBundles));
+    BundleCompat.putBinder(
+        bundle, keyForField(FIELD_PERIODS), new BundleListRetriever(periodBundles));
+    return bundle;
+  }
+
+  /**
+   * Object that can restore a {@link Timeline} from a {@link Bundle}.
+   *
+   * <p>The {@link #getWindow(int, Window)} windows} and {@link #getPeriod(int, Period) periods} of
+   * a restored instance may have missing fields as described in {@link Window#CREATOR} and {@link
+   * Period#CREATOR}.
+   */
+  public static final Creator<Timeline> CREATOR = Timeline::fromBundle;
+
+  private static Timeline fromBundle(Bundle bundle) {
+    ImmutableList<Window> windows =
+        fromBundleListRetriever(
+            Window.CREATOR, BundleCompat.getBinder(bundle, keyForField(FIELD_WINDOWS)));
+    ImmutableList<Period> periods =
+        fromBundleListRetriever(
+            Period.CREATOR, BundleCompat.getBinder(bundle, keyForField(FIELD_PERIODS)));
+    return new RemotableTimeline(windows, periods);
+  }
+
+  private static <T extends Bundleable> ImmutableList<T> fromBundleListRetriever(
+      Creator<T> creator, @Nullable IBinder binder) {
+    if (binder == null) {
+      return ImmutableList.of();
+    }
+    ImmutableList.Builder<T> builder = new ImmutableList.Builder<>();
+    List<Bundle> bundleList = BundleListRetriever.getList(binder);
+    for (int i = 0; i < bundleList.size(); i++) {
+      builder.add(creator.fromBundle(bundleList.get(i)));
+    }
+    return builder.build();
+  }
+
+  private static String keyForField(@FieldNumber int field) {
+    return Integer.toString(field, Character.MAX_RADIX);
+  }
+
+  /**
+   * A concrete class of {@link Timeline} to restore a {@link Timeline} instance from a {@link
+   * Bundle} sent by another process via {@link IBinder}.
+   */
+  private static final class RemotableTimeline extends Timeline {
+
+    private final ImmutableList<Window> windows;
+    private final ImmutableList<Period> periods;
+
+    public RemotableTimeline(ImmutableList<Window> windows, ImmutableList<Period> periods) {
+      this.windows = windows;
+      this.periods = periods;
+    }
+
+    @Override
+    public int getWindowCount() {
+      return windows.size();
+    }
+
+    @Override
+    public Window getWindow(
+        int windowIndex, Window window, long ignoredDefaultPositionProjectionUs) {
+      Window w = windows.get(windowIndex);
+      window.set(
+          w.uid,
+          w.mediaItem,
+          w.manifest,
+          w.presentationStartTimeMs,
+          w.windowStartTimeMs,
+          w.elapsedRealtimeEpochOffsetMs,
+          w.isSeekable,
+          w.isDynamic,
+          w.liveConfiguration,
+          w.defaultPositionUs,
+          w.durationUs,
+          w.firstPeriodIndex,
+          w.lastPeriodIndex,
+          w.positionInFirstPeriodUs);
+      window.isPlaceholder = w.isPlaceholder;
+      return window;
+    }
+
+    @Override
+    public int getPeriodCount() {
+      return periods.size();
+    }
+
+    @Override
+    public Period getPeriod(int periodIndex, Period period, boolean ignoredSetIds) {
+      Period p = periods.get(periodIndex);
+      return period.set(
+          p.id, p.uid, p.windowIndex, p.durationUs, p.positionInWindowUs, p.adPlaybackState);
+    }
+
+    @Override
+    public int getIndexOfPeriod(Object uid) {
+      throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public Object getUidOfPeriod(int periodIndex) {
+      throw new UnsupportedOperationException();
+    }
+  }
 }
 }

library/common/src/test/java/com/google/android/exoplayer2/BundleListRetrieverTest.java

+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2;
+
+import android.os.Bundle;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.ext.truth.os.BundleSubject;
+import java.util.ArrayList;
+import java.util.List;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Tests for {@link BundleListRetriever}. */
+@RunWith(AndroidJUnit4.class)
+public class BundleListRetrieverTest {
+
+  @Test
+  public void getList_preservedLargeList() {
+    int count = 100_000;
+    List<Bundle> listBefore = new ArrayList<>();
+    for (int i = 0; i < count; i++) {
+      Bundle bundle = new Bundle();
+      bundle.putInt("i", i);
+      listBefore.add(bundle);
+    }
+
+    List<Bundle> listAfter = BundleListRetriever.getList(new BundleListRetriever(listBefore));
+
+    for (int i = 0; i < count; i++) {
+      Bundle bundle = listAfter.get(i);
+      BundleSubject.assertThat(bundle).integer("i").isEqualTo(i);
+    }
+  }
+}

library/common/src/test/java/com/google/android/exoplayer2/TimelineTest.java

@@ -20,6 +20,7 @@ import static com.google.common.truth.Truth.assertThat;
 import androidx.annotation.Nullable;
 import androidx.annotation.Nullable;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.android.exoplayer2.MediaItem.LiveConfiguration;
 import com.google.android.exoplayer2.MediaItem.LiveConfiguration;
+import com.google.android.exoplayer2.source.ads.AdPlaybackState;
 import com.google.android.exoplayer2.testutil.FakeTimeline;
 import com.google.android.exoplayer2.testutil.FakeTimeline;
 import com.google.android.exoplayer2.testutil.FakeTimeline.TimelineWindowDefinition;
 import com.google.android.exoplayer2.testutil.FakeTimeline.TimelineWindowDefinition;
 import com.google.android.exoplayer2.testutil.TimelineAsserts;
 import com.google.android.exoplayer2.testutil.TimelineAsserts;
@@ -202,6 +203,41 @@ public class TimelineTest {
   }
   }
 
 
   @Test
   @Test
+  public void roundtripViaBundle_ofTimeline_yieldsEqualInstanceExceptIdsAndManifest() {
+    Timeline timeline =
+        new FakeTimeline(
+            new TimelineWindowDefinition(
+                /* periodCount= */ 2,
+                /* id= */ new Object(),
+                /* isSeekable= */ true,
+                /* isDynamic= */ true,
+                /* isLive= */ true,
+                /* isPlaceholder= */ false,
+                /* durationUs= */ 2,
+                /* defaultPositionUs= */ 22,
+                /* windowOffsetInFirstPeriodUs= */ 222,
+                AdPlaybackState.NONE,
+                new MediaItem.Builder().setMediaId("mediaId2").build()),
+            new TimelineWindowDefinition(
+                /* periodCount= */ 3,
+                /* id= */ new Object(),
+                /* isSeekable= */ true,
+                /* isDynamic= */ true,
+                /* isLive= */ true,
+                /* isPlaceholder= */ false,
+                /* durationUs= */ 3,
+                /* defaultPositionUs= */ 33,
+                /* windowOffsetInFirstPeriodUs= */ 333,
+                AdPlaybackState.NONE,
+                new MediaItem.Builder().setMediaId("mediaId3").build()));
+
+    Timeline restoredTimeline = Timeline.CREATOR.fromBundle(timeline.toBundle());
+
+    TimelineAsserts.assertEqualsExceptIdsAndManifest(
+        /* expectedTimeline= */ timeline, /* actualTimeline= */ restoredTimeline);
+  }
+
+  @Test
   public void roundtripViaBundle_ofWindow_yieldsEqualInstanceExceptUidAndManifest() {
   public void roundtripViaBundle_ofWindow_yieldsEqualInstanceExceptUidAndManifest() {
     Timeline.Window window = new Timeline.Window();
     Timeline.Window window = new Timeline.Window();
     window.uid = new Object();
     window.uid = new Object();
@@ -229,9 +265,8 @@ public class TimelineTest {
     Timeline.Window restoredWindow = Timeline.Window.CREATOR.fromBundle(window.toBundle());
     Timeline.Window restoredWindow = Timeline.Window.CREATOR.fromBundle(window.toBundle());
 
 
     assertThat(restoredWindow.manifest).isNull();
     assertThat(restoredWindow.manifest).isNull();
-    window.uid = restoredWindow.uid;
-    window.manifest = null;
-    assertThat(restoredWindow).isEqualTo(window);
+    TimelineAsserts.assertWindowEqualsExceptUidAndManifest(
+        /* expectedWindow= */ window, /* actualWindow= */ restoredWindow);
   }
   }
 
 
   @Test
   @Test
@@ -245,9 +280,10 @@ public class TimelineTest {
 
 
     Timeline.Period restoredPeriod = Timeline.Period.CREATOR.fromBundle(period.toBundle());
     Timeline.Period restoredPeriod = Timeline.Period.CREATOR.fromBundle(period.toBundle());
 
 
-    period.id = null;
-    period.uid = null;
-    assertThat(restoredPeriod).isEqualTo(period);
+    assertThat(restoredPeriod.id).isNull();
+    assertThat(restoredPeriod.uid).isNull();
+    TimelineAsserts.assertPeriodEqualsExceptIds(
+        /* expectedPeriod= */ period, /* actualPeriod= */ restoredPeriod);
   }
   }
 
 
   @SuppressWarnings("deprecation") // Populates the deprecated window.tag property.
   @SuppressWarnings("deprecation") // Populates the deprecated window.tag property.

testutils/build.gradle

@@ -17,6 +17,7 @@ dependencies {
     api 'org.mockito:mockito-core:' + mockitoVersion
     api 'org.mockito:mockito-core:' + mockitoVersion
     api 'androidx.test:core:' + androidxTestCoreVersion
     api 'androidx.test:core:' + androidxTestCoreVersion
     api 'androidx.test.ext:junit:' + androidxTestJUnitVersion
     api 'androidx.test.ext:junit:' + androidxTestJUnitVersion
+    api 'androidx.test.ext:truth:' + androidxTestTruthVersion
     api 'junit:junit:' + junitVersion
     api 'junit:junit:' + junitVersion
     api 'com.google.truth:truth:' + truthVersion
     api 'com.google.truth:truth:' + truthVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion

testutils/src/main/java/com/google/android/exoplayer2/testutil/TimelineAsserts.java

@@ -17,6 +17,7 @@ package com.google.android.exoplayer2.testutil;
 
 
 import static com.google.common.truth.Truth.assertThat;
 import static com.google.common.truth.Truth.assertThat;
 
 
+import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.MediaItem;
 import com.google.android.exoplayer2.MediaItem;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.Player;
@@ -27,15 +28,13 @@ import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.util.Util;
 import org.checkerframework.checker.nullness.compatqual.NullableType;
 import org.checkerframework.checker.nullness.compatqual.NullableType;
 
 
-/** Unit test for {@link Timeline}. */
+/** Assertion methods for {@link Timeline}. */
 public final class TimelineAsserts {
 public final class TimelineAsserts {
 
 
   private static final int[] REPEAT_MODES = {
   private static final int[] REPEAT_MODES = {
     Player.REPEAT_MODE_OFF, Player.REPEAT_MODE_ONE, Player.REPEAT_MODE_ALL
     Player.REPEAT_MODE_OFF, Player.REPEAT_MODE_ONE, Player.REPEAT_MODE_ALL
   };
   };
 
 
-  private TimelineAsserts() {}
-
   /** Assert that timeline is empty (i.e. has no windows or periods). */
   /** Assert that timeline is empty (i.e. has no windows or periods). */
   public static void assertEmpty(Timeline timeline) {
   public static void assertEmpty(Timeline timeline) {
     assertWindowTags(timeline);
     assertWindowTags(timeline);
@@ -173,4 +172,64 @@ public final class TimelineAsserts {
       assertThat(period.getAdGroupCount()).isEqualTo(expectedAdGroupCounts[i]);
       assertThat(period.getAdGroupCount()).isEqualTo(expectedAdGroupCounts[i]);
     }
     }
   }
   }
+
+  /**
+   * Asserts that {@link Timeline timelines} are equal except {@link Window#uid}, {@link
+   * Window#manifest}, {@link Period#id}, and {@link Period#uid}.
+   */
+  public static void assertEqualsExceptIdsAndManifest(
+      Timeline expectedTimeline, Timeline actualTimeline) {
+    assertThat(actualTimeline.getWindowCount()).isEqualTo(expectedTimeline.getWindowCount());
+    for (int i = 0; i < actualTimeline.getWindowCount(); i++) {
+      Window expectedWindow = new Window();
+      Window actualWindow = new Window();
+      assertWindowEqualsExceptUidAndManifest(
+          expectedTimeline.getWindow(i, expectedWindow, /* defaultPositionProjectionUs= */ 0),
+          actualTimeline.getWindow(i, actualWindow, /* defaultPositionProjectionUs= */ 0));
+    }
+    assertThat(actualTimeline.getPeriodCount()).isEqualTo(expectedTimeline.getPeriodCount());
+    for (int i = 0; i < actualTimeline.getPeriodCount(); i++) {
+      Period expectedPeriod = new Period();
+      Period actualPeriod = new Period();
+      assertPeriodEqualsExceptIds(
+          expectedTimeline.getPeriod(i, expectedPeriod, /* setIds= */ false),
+          actualTimeline.getPeriod(i, actualPeriod, /* setIds= */ false));
+    }
+  }
+
+  /**
+   * Asserts that {@link Window windows} are equal except {@link Window#uid} and {@link
+   * Window#manifest}.
+   */
+  public static void assertWindowEqualsExceptUidAndManifest(
+      Window expectedWindow, Window actualWindow) {
+    Object uid = expectedWindow.uid;
+    @Nullable Object manifest = expectedWindow.manifest;
+    try {
+      expectedWindow.uid = actualWindow.uid;
+      expectedWindow.manifest = actualWindow.manifest;
+      assertThat(actualWindow).isEqualTo(expectedWindow);
+    } finally {
+      expectedWindow.uid = uid;
+      expectedWindow.manifest = manifest;
+    }
+  }
+
+  /**
+   * Asserts that {@link Period periods} are equal except {@link Period#id} and {@link Period#uid}.
+   */
+  public static void assertPeriodEqualsExceptIds(Period expectedPeriod, Period actualPeriod) {
+    @Nullable Object id = expectedPeriod.id;
+    @Nullable Object uid = expectedPeriod.uid;
+    try {
+      expectedPeriod.id = actualPeriod.id;
+      expectedPeriod.uid = actualPeriod.uid;
+      assertThat(actualPeriod).isEqualTo(expectedPeriod);
+    } finally {
+      expectedPeriod.id = id;
+      expectedPeriod.uid = uid;
+    }
+  }
+
+  private TimelineAsserts() {}
 }
 }