From a67c73650efba61ffb9a9063bda2c31e940dd7a3 Mon Sep 17 00:00:00 2001
From: tonihei <tonihei@google.com>
Date: Mon, 23 Jul 2018 03:34:53 -0700
Subject: [PATCH] Add helper method to get uid of timeline period.

This removes the need to populate the entire period for the common usage of
getting the uid from the period.

Also add default implementation to get period by uid.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=205638265
---
 .../exoplayer2/ext/cast/CastTimeline.java     |  5 ++++
 .../exoplayer2/ExoPlayerImplInternal.java     | 17 ++++++--------
 .../android/exoplayer2/MediaPeriodQueue.java  |  2 +-
 .../google/android/exoplayer2/Timeline.java   | 23 +++++++++++++++++++
 .../analytics/AnalyticsCollector.java         |  3 +--
 .../source/AbstractConcatenatedTimeline.java  | 22 ++++++++++++++++++
 .../source/ConcatenatingMediaSource.java      | 19 +++++++++++----
 .../exoplayer2/source/ForwardingTimeline.java |  4 ++++
 .../source/SinglePeriodTimeline.java          |  5 ++++
 .../source/ConcatenatingMediaSourceTest.java  | 14 +++++------
 .../source/dash/DashMediaSource.java          |  5 ++++
 .../exoplayer2/testutil/FakeTimeline.java     | 15 ++++++++++--
 .../exoplayer2/testutil/TimelineAsserts.java  |  1 +
 13 files changed, 107 insertions(+), 28 deletions(-)

diff --git a/extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/CastTimeline.java b/extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/CastTimeline.java
index b3d6fe4ee6..4939e62a2b 100644
--- a/extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/CastTimeline.java
+++ b/extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/CastTimeline.java
@@ -107,6 +107,11 @@ import java.util.Map;
     return uid instanceof Integer ? idsToIndex.get((int) uid, C.INDEX_UNSET) : C.INDEX_UNSET;
   }
 
+  @Override
+  public Object getUidOfPeriod(int periodIndex) {
+    return ids[periodIndex];
+  }
+
   // equals and hashCode implementations.
 
   @Override
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java b/library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java
index cc338385cd..ba80407860 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java
@@ -904,7 +904,7 @@ import java.util.Collections;
       pendingMessageInfo.setResolvedPosition(
           periodPosition.first,
           periodPosition.second,
-          playbackInfo.timeline.getPeriod(periodPosition.first, period, true).uid);
+          playbackInfo.timeline.getUidOfPeriod(periodPosition.first));
     } else {
       // Position has been resolved for a previous timeline. Try to find the updated period index.
       int index = playbackInfo.timeline.getIndexOfPeriod(pendingMessageInfo.resolvedPeriodUid);
@@ -1203,8 +1203,8 @@ import java.util.Collections;
       return;
     }
     MediaPeriodHolder periodHolder = queue.getFrontPeriod();
-    Object playingPeriodUid = periodHolder == null
-        ? oldTimeline.getPeriod(playingPeriodIndex, period, true).uid : periodHolder.uid;
+    Object playingPeriodUid =
+        periodHolder == null ? oldTimeline.getUidOfPeriod(playingPeriodIndex) : periodHolder.uid;
     int periodIndex = timeline.getIndexOfPeriod(playingPeriodUid);
     if (periodIndex == C.INDEX_UNSET) {
       // We didn't find the current period in the new timeline. Attempt to resolve a subsequent
@@ -1221,11 +1221,10 @@ import java.util.Collections;
       newPeriodIndex = defaultPosition.first;
       contentPositionUs = defaultPosition.second;
       MediaPeriodId periodId = queue.resolveMediaPeriodIdForAds(newPeriodIndex, contentPositionUs);
-      timeline.getPeriod(newPeriodIndex, period, true);
       if (periodHolder != null) {
         // Clear the index of each holder that doesn't contain the default position. If a holder
         // contains the default position then update its index so it can be re-used when seeking.
-        Object newPeriodUid = period.uid;
+        Object newPeriodUid = timeline.getUidOfPeriod(newPeriodIndex);
         periodHolder.info = periodHolder.info.copyWithPeriodIndex(C.INDEX_UNSET);
         while (periodHolder.next != null) {
           periodHolder = periodHolder.next;
@@ -1293,8 +1292,7 @@ import java.util.Collections;
         // We've reached the end of the old timeline.
         break;
       }
-      newPeriodIndex = newTimeline.getIndexOfPeriod(
-          oldTimeline.getPeriod(oldPeriodIndex, period, true).uid);
+      newPeriodIndex = newTimeline.getIndexOfPeriod(oldTimeline.getUidOfPeriod(oldPeriodIndex));
     }
     return newPeriodIndex;
   }
@@ -1338,8 +1336,7 @@ import java.util.Collections;
       return periodPosition;
     }
     // Attempt to find the mapped period in the internal timeline.
-    int periodIndex = timeline.getIndexOfPeriod(
-        seekTimeline.getPeriod(periodPosition.first, period, true).uid);
+    int periodIndex = timeline.getIndexOfPeriod(seekTimeline.getUidOfPeriod(periodPosition.first));
     if (periodIndex != C.INDEX_UNSET) {
       // We successfully located the period in the internal timeline.
       return Pair.create(periodIndex, periodPosition.second);
@@ -1497,7 +1494,7 @@ import java.util.Collections;
       if (info == null) {
         mediaSource.maybeThrowSourceInfoRefreshError();
       } else {
-        Object uid = playbackInfo.timeline.getPeriod(info.id.periodIndex, period, true).uid;
+        Object uid = playbackInfo.timeline.getUidOfPeriod(info.id.periodIndex);
         MediaPeriod mediaPeriod =
             queue.enqueueNextMediaPeriod(
                 rendererCapabilities,
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/MediaPeriodQueue.java b/library/core/src/main/java/com/google/android/exoplayer2/MediaPeriodQueue.java
index 010de547a2..be618275c4 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/MediaPeriodQueue.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/MediaPeriodQueue.java
@@ -314,7 +314,7 @@ import com.google.android.exoplayer2.util.Assertions;
       } else {
         // Check this period holder still follows the previous one, based on the new timeline.
         if (periodIndex == C.INDEX_UNSET
-            || !periodHolder.uid.equals(timeline.getPeriod(periodIndex, period, true).uid)) {
+            || !periodHolder.uid.equals(timeline.getUidOfPeriod(periodIndex))) {
           // The holder uid is inconsistent with the new timeline.
           return !removeAfter(previousPeriodHolder);
         }
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/Timeline.java b/library/core/src/main/java/com/google/android/exoplayer2/Timeline.java
index 600fbc3014..a1a0e9b152 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/Timeline.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/Timeline.java
@@ -520,6 +520,11 @@ public abstract class Timeline {
         public int getIndexOfPeriod(Object uid) {
           return C.INDEX_UNSET;
         }
+
+        @Override
+        public Object getUidOfPeriod(int periodIndex) {
+          throw new IndexOutOfBoundsException();
+        }
       };
 
   /**
@@ -737,6 +742,17 @@ public abstract class Timeline {
     return Pair.create(periodIndex, periodPositionUs);
   }
 
+  /**
+   * Populates a {@link Period} with data for the period with the specified unique identifier.
+   *
+   * @param periodUid The unique identifier of the period.
+   * @param period The {@link Period} to populate. Must not be null.
+   * @return The populated {@link Period}, for convenience.
+   */
+  public Period getPeriodByUid(Object periodUid, Period period) {
+    return getPeriod(getIndexOfPeriod(periodUid), period, /* setIds= */ true);
+  }
+
   /**
    * Populates a {@link Period} with data for the period at the specified index. Does not populate
    * {@link Period#id} and {@link Period#uid}.
@@ -770,4 +786,11 @@ public abstract class Timeline {
    */
   public abstract int getIndexOfPeriod(Object uid);
 
+  /**
+   * Returns the unique id of the period identified by its index in the timeline.
+   *
+   * @param periodIndex The index of the period.
+   * @return The unique id of the period.
+   */
+  public abstract Object getUidOfPeriod(int periodIndex);
 }
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/analytics/AnalyticsCollector.java b/library/core/src/main/java/com/google/android/exoplayer2/analytics/AnalyticsCollector.java
index 1d51e68d4a..3efe0a00cc 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/analytics/AnalyticsCollector.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/analytics/AnalyticsCollector.java
@@ -784,8 +784,7 @@ public class AnalyticsCollector
       if (newTimeline.isEmpty() || timeline.isEmpty()) {
         return mediaPeriod;
       }
-      Object uid =
-          timeline.getPeriod(mediaPeriod.mediaPeriodId.periodIndex, period, /* setIds= */ true).uid;
+      Object uid = timeline.getUidOfPeriod(mediaPeriod.mediaPeriodId.periodIndex);
       int newPeriodIndex = newTimeline.getIndexOfPeriod(uid);
       if (newPeriodIndex == C.INDEX_UNSET) {
         return mediaPeriod;
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/AbstractConcatenatedTimeline.java b/library/core/src/main/java/com/google/android/exoplayer2/source/AbstractConcatenatedTimeline.java
index 8663b4c05c..305a249e4a 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/AbstractConcatenatedTimeline.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/AbstractConcatenatedTimeline.java
@@ -168,6 +168,19 @@ import com.google.android.exoplayer2.Timeline;
     return window;
   }
 
+  @Override
+  public final Period getPeriodByUid(Object uid, Period period) {
+    Pair<?, ?> childUidAndPeriodUid = (Pair<?, ?>) uid;
+    Object childUid = childUidAndPeriodUid.first;
+    Object periodUid = childUidAndPeriodUid.second;
+    int childIndex = getChildIndexByChildUid(childUid);
+    int firstWindowIndexInChild = getFirstWindowIndexByChildIndex(childIndex);
+    getTimelineByChildIndex(childIndex).getPeriodByUid(periodUid, period);
+    period.windowIndex += firstWindowIndexInChild;
+    period.uid = uid;
+    return period;
+  }
+
   @Override
   public final Period getPeriod(int periodIndex, Period period, boolean setIds) {
     int childIndex = getChildIndexByPeriodIndex(periodIndex);
@@ -199,6 +212,15 @@ import com.google.android.exoplayer2.Timeline;
         : getFirstPeriodIndexByChildIndex(childIndex) + periodIndexInChild;
   }
 
+  @Override
+  public final Object getUidOfPeriod(int periodIndex) {
+    int childIndex = getChildIndexByPeriodIndex(periodIndex);
+    int firstPeriodIndexInChild = getFirstPeriodIndexByChildIndex(childIndex);
+    Object periodUidInChild =
+        getTimelineByChildIndex(childIndex).getUidOfPeriod(periodIndex - firstPeriodIndexInChild);
+    return Pair.create(getChildUidByChildIndex(childIndex), periodUidInChild);
+  }
+
   /**
    * Returns the index of the child timeline containing the given period index.
    *
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/ConcatenatingMediaSource.java b/library/core/src/main/java/com/google/android/exoplayer2/source/ConcatenatingMediaSource.java
index 01a8cd3425..985c43fa55 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/ConcatenatingMediaSource.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/ConcatenatingMediaSource.java
@@ -66,7 +66,6 @@ public class ConcatenatingMediaSource extends CompositeMediaSource<MediaSourceHo
   private final boolean isAtomic;
   private final boolean useLazyPreparation;
   private final Timeline.Window window;
-  private final Timeline.Period period;
 
   private @Nullable ExoPlayer player;
   private @Nullable Handler playerApplicationHandler;
@@ -133,7 +132,6 @@ public class ConcatenatingMediaSource extends CompositeMediaSource<MediaSourceHo
     this.isAtomic = isAtomic;
     this.useLazyPreparation = useLazyPreparation;
     window = new Timeline.Window();
-    period = new Timeline.Period();
     addMediaSources(Arrays.asList(mediaSources));
   }
 
@@ -594,7 +592,7 @@ public class ConcatenatingMediaSource extends CompositeMediaSource<MediaSourceHo
           windowOffsetUpdate,
           periodOffsetUpdate);
     }
-    mediaSourceHolder.timeline = deferredTimeline.cloneWithNewTimeline(timeline, period);
+    mediaSourceHolder.timeline = deferredTimeline.cloneWithNewTimeline(timeline);
     if (!mediaSourceHolder.isPrepared && !timeline.isEmpty()) {
       timeline.getWindow(/* windowIndex= */ 0, window);
       long defaultPeriodPositionUs =
@@ -823,11 +821,11 @@ public class ConcatenatingMediaSource extends CompositeMediaSource<MediaSourceHo
       this.replacedId = replacedId;
     }
 
-    public DeferredTimeline cloneWithNewTimeline(Timeline timeline, Period period) {
+    public DeferredTimeline cloneWithNewTimeline(Timeline timeline) {
       return new DeferredTimeline(
           timeline,
           replacedId == DUMMY_ID && timeline.getPeriodCount() > 0
-              ? timeline.getPeriod(0, period, true).uid
+              ? timeline.getUidOfPeriod(0)
               : replacedId);
     }
 
@@ -848,6 +846,12 @@ public class ConcatenatingMediaSource extends CompositeMediaSource<MediaSourceHo
     public int getIndexOfPeriod(Object uid) {
       return timeline.getIndexOfPeriod(DUMMY_ID.equals(uid) ? replacedId : uid);
     }
+
+    @Override
+    public Object getUidOfPeriod(int periodIndex) {
+      Object uid = timeline.getUidOfPeriod(periodIndex);
+      return Util.areEqual(uid, replacedId) ? DUMMY_ID : uid;
+    }
   }
 
   /** Dummy placeholder timeline with one dynamic window with a period of indeterminate duration. */
@@ -894,6 +898,11 @@ public class ConcatenatingMediaSource extends CompositeMediaSource<MediaSourceHo
     public int getIndexOfPeriod(Object uid) {
       return uid == DeferredTimeline.DUMMY_ID ? 0 : C.INDEX_UNSET;
     }
+
+    @Override
+    public Object getUidOfPeriod(int periodIndex) {
+      return DeferredTimeline.DUMMY_ID;
+    }
   }
 }
 
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/ForwardingTimeline.java b/library/core/src/main/java/com/google/android/exoplayer2/source/ForwardingTimeline.java
index c7ab7615d8..45997aced4 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/ForwardingTimeline.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/ForwardingTimeline.java
@@ -77,4 +77,8 @@ public abstract class ForwardingTimeline extends Timeline {
     return timeline.getIndexOfPeriod(uid);
   }
 
+  @Override
+  public Object getUidOfPeriod(int periodIndex) {
+    return timeline.getUidOfPeriod(periodIndex);
+  }
 }
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/source/SinglePeriodTimeline.java b/library/core/src/main/java/com/google/android/exoplayer2/source/SinglePeriodTimeline.java
index 0bddd482ac..9e33a2d898 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/source/SinglePeriodTimeline.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/source/SinglePeriodTimeline.java
@@ -193,4 +193,9 @@ public final class SinglePeriodTimeline extends Timeline {
     return UID.equals(uid) ? 0 : C.INDEX_UNSET;
   }
 
+  @Override
+  public Object getUidOfPeriod(int periodIndex) {
+    Assertions.checkIndex(periodIndex, 0, 1);
+    return UID;
+  }
 }
diff --git a/library/core/src/test/java/com/google/android/exoplayer2/source/ConcatenatingMediaSourceTest.java b/library/core/src/test/java/com/google/android/exoplayer2/source/ConcatenatingMediaSourceTest.java
index f6df4721e1..f9c327ed2b 100644
--- a/library/core/src/test/java/com/google/android/exoplayer2/source/ConcatenatingMediaSourceTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/source/ConcatenatingMediaSourceTest.java
@@ -23,7 +23,6 @@ import android.os.ConditionVariable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.Timeline;
-import com.google.android.exoplayer2.Timeline.Period;
 import com.google.android.exoplayer2.source.MediaSource.MediaPeriodId;
 import com.google.android.exoplayer2.source.ShuffleOrder.DefaultShuffleOrder;
 import com.google.android.exoplayer2.testutil.DummyMainThread;
@@ -876,21 +875,20 @@ public final class ConcatenatingMediaSourceTest {
 
   @Test
   public void testReleaseAndReprepareSource() throws IOException {
-    Period period = new Period();
     FakeMediaSource[] fakeMediaSources = createMediaSources(/* count= */ 2);
     mediaSource.addMediaSource(fakeMediaSources[0]); // Child source with 1 period.
     mediaSource.addMediaSource(fakeMediaSources[1]); // Child source with 2 periods.
     Timeline timeline = testRunner.prepareSource();
-    Object periodId0 = timeline.getPeriod(/* periodIndex= */ 0, period, /* setIds= */ true).uid;
-    Object periodId1 = timeline.getPeriod(/* periodIndex= */ 1, period, /* setIds= */ true).uid;
-    Object periodId2 = timeline.getPeriod(/* periodIndex= */ 2, period, /* setIds= */ true).uid;
+    Object periodId0 = timeline.getUidOfPeriod(/* periodIndex= */ 0);
+    Object periodId1 = timeline.getUidOfPeriod(/* periodIndex= */ 1);
+    Object periodId2 = timeline.getUidOfPeriod(/* periodIndex= */ 2);
     testRunner.releaseSource();
 
     mediaSource.moveMediaSource(/* currentIndex= */ 1, /* newIndex= */ 0);
     timeline = testRunner.prepareSource();
-    Object newPeriodId0 = timeline.getPeriod(/* periodIndex= */ 0, period, /* setIds= */ true).uid;
-    Object newPeriodId1 = timeline.getPeriod(/* periodIndex= */ 1, period, /* setIds= */ true).uid;
-    Object newPeriodId2 = timeline.getPeriod(/* periodIndex= */ 2, period, /* setIds= */ true).uid;
+    Object newPeriodId0 = timeline.getUidOfPeriod(/* periodIndex= */ 0);
+    Object newPeriodId1 = timeline.getUidOfPeriod(/* periodIndex= */ 1);
+    Object newPeriodId2 = timeline.getUidOfPeriod(/* periodIndex= */ 2);
     assertThat(newPeriodId0).isEqualTo(periodId1);
     assertThat(newPeriodId1).isEqualTo(periodId2);
     assertThat(newPeriodId2).isEqualTo(periodId0);
diff --git a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java
index 42b180200a..e61400b5cc 100644
--- a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java
+++ b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java
@@ -1204,6 +1204,11 @@ public final class DashMediaSource extends BaseMediaSource {
           - defaultStartPositionInPeriodUs;
     }
 
+    @Override
+    public Object getUidOfPeriod(int periodIndex) {
+      Assertions.checkIndex(periodIndex, 0, getPeriodCount());
+      return firstPeriodId + periodIndex;
+    }
   }
 
   private final class DefaultPlayerEmsgCallback implements PlayerEmsgCallback {
diff --git a/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeTimeline.java b/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeTimeline.java
index 4e118366d7..56438a51ef 100644
--- a/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeTimeline.java
+++ b/testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeTimeline.java
@@ -19,6 +19,7 @@ import android.util.Pair;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.source.ads.AdPlaybackState;
+import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import java.util.Arrays;
 
@@ -206,15 +207,25 @@ public final class FakeTimeline extends Timeline {
 
   @Override
   public int getIndexOfPeriod(Object uid) {
-    Period period = new Period();
     for (int i = 0; i < getPeriodCount(); i++) {
-      if (getPeriod(i, period, true).uid.equals(uid)) {
+      if (getUidOfPeriod(i).equals(uid)) {
         return i;
       }
     }
     return C.INDEX_UNSET;
   }
 
+  @Override
+  public Object getUidOfPeriod(int periodIndex) {
+    Assertions.checkIndex(periodIndex, 0, getPeriodCount());
+    int windowIndex =
+        Util.binarySearchFloor(
+            periodOffsets, periodIndex, /* inclusive= */ true, /* stayInBounds= */ false);
+    int windowPeriodIndex = periodIndex - periodOffsets[windowIndex];
+    TimelineWindowDefinition windowDefinition = windowDefinitions[windowIndex];
+    return Pair.create(windowDefinition.id, windowPeriodIndex);
+  }
+
   private static TimelineWindowDefinition[] createDefaultWindowDefinitions(int windowCount) {
     TimelineWindowDefinition[] windowDefinitions = new TimelineWindowDefinition[windowCount];
     for (int i = 0; i < windowCount; i++) {
diff --git a/testutils_robolectric/src/main/java/com/google/android/exoplayer2/testutil/TimelineAsserts.java b/testutils_robolectric/src/main/java/com/google/android/exoplayer2/testutil/TimelineAsserts.java
index a0ca6af8a9..1e3c9c61d9 100644
--- a/testutils_robolectric/src/main/java/com/google/android/exoplayer2/testutil/TimelineAsserts.java
+++ b/testutils_robolectric/src/main/java/com/google/android/exoplayer2/testutil/TimelineAsserts.java
@@ -141,6 +141,7 @@ public final class TimelineAsserts {
       }
       assertThat(period.windowIndex).isEqualTo(expectedWindowIndex);
       assertThat(timeline.getIndexOfPeriod(period.uid)).isEqualTo(i);
+      assertThat(timeline.getUidOfPeriod(i)).isEqualTo(period.uid);
       for (int repeatMode : REPEAT_MODES) {
         if (i < accumulatedPeriodCounts[expectedWindowIndex + 1] - 1) {
           assertThat(timeline.getNextPeriodIndex(i, period, window, repeatMode, false))