From 6ea54253acc1853099795e3ce6d3b30bbef5b924 Mon Sep 17 00:00:00 2001
From: bachinger <bachinger@google.com>
Date: Fri, 7 Jan 2022 15:35:01 +0000
Subject: [PATCH] Make EventSampleStream honour FLAG_PEEK and
 FLAG_OMIT_SAMPLE_DATA

#minor-release

PiperOrigin-RevId: 420289147
---
 .../exoplayer/dash/EventSampleStream.java     | 13 ++--
 .../exoplayer/dash/EventSampleStreamTest.java | 59 ++++++++++++++++++-
 2 files changed, 67 insertions(+), 5 deletions(-)

diff --git a/libraries/exoplayer_dash/src/main/java/androidx/media3/exoplayer/dash/EventSampleStream.java b/libraries/exoplayer_dash/src/main/java/androidx/media3/exoplayer/dash/EventSampleStream.java
index 895724672f..0c655b4e2c 100644
--- a/libraries/exoplayer_dash/src/main/java/androidx/media3/exoplayer/dash/EventSampleStream.java
+++ b/libraries/exoplayer_dash/src/main/java/androidx/media3/exoplayer/dash/EventSampleStream.java
@@ -114,10 +114,15 @@ import java.io.IOException;
       // More events may be appended later.
       return C.RESULT_NOTHING_READ;
     }
-    int sampleIndex = currentIndex++;
-    byte[] serializedEvent = eventMessageEncoder.encode(eventStream.events[sampleIndex]);
-    buffer.ensureSpaceForWrite(serializedEvent.length);
-    buffer.data.put(serializedEvent);
+    int sampleIndex = currentIndex;
+    if ((readFlags & SampleStream.FLAG_PEEK) == 0) {
+      currentIndex++;
+    }
+    if ((readFlags & SampleStream.FLAG_OMIT_SAMPLE_DATA) == 0) {
+      byte[] serializedEvent = eventMessageEncoder.encode(eventStream.events[sampleIndex]);
+      buffer.ensureSpaceForWrite(serializedEvent.length);
+      buffer.data.put(serializedEvent);
+    }
     buffer.timeUs = eventTimesUs[sampleIndex];
     buffer.setFlags(C.BUFFER_FLAG_KEY_FRAME);
     return C.RESULT_BUFFER_READ;
diff --git a/libraries/exoplayer_dash/src/test/java/androidx/media3/exoplayer/dash/EventSampleStreamTest.java b/libraries/exoplayer_dash/src/test/java/androidx/media3/exoplayer/dash/EventSampleStreamTest.java
index d994ad85b1..f6addfcee4 100644
--- a/libraries/exoplayer_dash/src/test/java/androidx/media3/exoplayer/dash/EventSampleStreamTest.java
+++ b/libraries/exoplayer_dash/src/test/java/androidx/media3/exoplayer/dash/EventSampleStreamTest.java
@@ -23,6 +23,7 @@ import androidx.media3.common.MimeTypes;
 import androidx.media3.decoder.DecoderInputBuffer;
 import androidx.media3.exoplayer.FormatHolder;
 import androidx.media3.exoplayer.dash.manifest.EventStream;
+import androidx.media3.exoplayer.source.SampleStream;
 import androidx.media3.extractor.metadata.MetadataInputBuffer;
 import androidx.media3.extractor.metadata.emsg.EventMessage;
 import androidx.media3.extractor.metadata.emsg.EventMessageEncoder;
@@ -132,6 +133,58 @@ public final class EventSampleStreamTest {
     assertThat(inputBuffer.data.array()).isEqualTo(getEncodedMessage(eventMessage));
   }
 
+  @Test
+  public void readData_peek_doesNotAdvanceSampleIndex() {
+    long presentationTimeUs = 1000000;
+    EventMessage eventMessage = newEventMessageWithId(1);
+    EventStream eventStream =
+        new EventStream(
+            SCHEME_ID,
+            VALUE,
+            TIME_SCALE,
+            new long[] {presentationTimeUs},
+            new EventMessage[] {eventMessage});
+    EventSampleStream sampleStream = new EventSampleStream(eventStream, FORMAT, false);
+    // first read - read format
+    readData(sampleStream);
+
+    // read the event with FLAG_PEEK
+    int result = readData(sampleStream, SampleStream.FLAG_PEEK);
+    assertThat(result).isEqualTo(C.RESULT_BUFFER_READ);
+    assertThat(inputBuffer.isKeyFrame()).isTrue();
+    assertThat(inputBuffer.data.array()).isEqualTo(getEncodedMessage(eventMessage));
+    // read again gives the same message again (there is only one msg)
+    result = readData(sampleStream);
+    assertThat(result).isEqualTo(C.RESULT_BUFFER_READ);
+    assertThat(inputBuffer.isKeyFrame()).isTrue();
+    assertThat(inputBuffer.data.array()).isEqualTo(getEncodedMessage(eventMessage));
+    // read again gives end of stream
+    result = readData(sampleStream);
+    assertThat(result).isEqualTo(C.RESULT_BUFFER_READ);
+    assertThat(inputBuffer.isEndOfStream()).isTrue();
+  }
+
+  @Test
+  public void readData_omitSampleData_doesOmitSampleData() {
+    long presentationTimeUs = 1000000;
+    EventMessage eventMessage = newEventMessageWithId(1);
+    EventStream eventStream =
+        new EventStream(
+            SCHEME_ID,
+            VALUE,
+            TIME_SCALE,
+            new long[] {presentationTimeUs},
+            new EventMessage[] {eventMessage});
+    EventSampleStream sampleStream = new EventSampleStream(eventStream, FORMAT, false);
+    // first read - read format
+    readData(sampleStream);
+
+    // read the event with FLAG_OMIT_SAMPLE_DATA
+    int result = readData(sampleStream, SampleStream.FLAG_OMIT_SAMPLE_DATA);
+    assertThat(result).isEqualTo(C.RESULT_BUFFER_READ);
+    assertThat(inputBuffer.data).isNull();
+  }
+
   /**
    * Tests that {@link EventSampleStream#skipData(long)} will skip until the given position, and the
    * next {@link EventSampleStream#readData(FormatHolder, DecoderInputBuffer, int)} call will return
@@ -390,8 +443,12 @@ public final class EventSampleStreamTest {
   }
 
   private int readData(EventSampleStream sampleStream) {
+    return readData(sampleStream, /* readFlags= */ 0);
+  }
+
+  private int readData(EventSampleStream sampleStream, @SampleStream.ReadFlags int readFlags) {
     inputBuffer.clear();
-    return sampleStream.readData(formatHolder, inputBuffer, /* readFlags= */ 0);
+    return sampleStream.readData(formatHolder, inputBuffer, readFlags);
   }
 
   private EventMessage newEventMessageWithId(int id) {