Don't use InputStream.available in ContentDataSource

Issue: #3426

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=174700804

library/core/src/androidTest/java/com/google/android/exoplayer2/upstream/AssetDataSourceTest.java

@@ -30,14 +30,14 @@ public final class AssetDataSourceTest extends InstrumentationTestCase {
     AssetDataSource dataSource = new AssetDataSource(getInstrumentation().getContext());
     DataSpec dataSpec = new DataSpec(Uri.parse("file:///android_asset/" + DATA_PATH));
     TestUtil.assertDataSourceContent(dataSource, dataSpec,
-        TestUtil.getByteArray(getInstrumentation(), DATA_PATH));
+        TestUtil.getByteArray(getInstrumentation(), DATA_PATH), true);
   }
 
   public void testReadAssetUri() throws Exception {
     AssetDataSource dataSource = new AssetDataSource(getInstrumentation().getContext());
     DataSpec dataSpec = new DataSpec(Uri.parse("asset:///" + DATA_PATH));
     TestUtil.assertDataSourceContent(dataSource, dataSpec,
-        TestUtil.getByteArray(getInstrumentation(), DATA_PATH));
+        TestUtil.getByteArray(getInstrumentation(), DATA_PATH), true);
   }
 
 }

library/core/src/androidTest/java/com/google/android/exoplayer2/upstream/ContentDataSourceTest.java

@@ -15,17 +15,22 @@
  */
 package com.google.android.exoplayer2.upstream;
 
+import android.app.Instrumentation;
 import android.content.ContentProvider;
 import android.content.ContentResolver;
 import android.content.ContentValues;
 import android.content.res.AssetFileDescriptor;
 import android.database.Cursor;
 import android.net.Uri;
+import android.os.Bundle;
+import android.os.ParcelFileDescriptor;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.test.InstrumentationTestCase;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.testutil.TestUtil;
 import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
 import java.io.IOException;
 import java.util.Arrays;
 
@@ -37,23 +42,33 @@ public final class ContentDataSourceTest extends InstrumentationTestCase {
   private static final String AUTHORITY = "com.google.android.exoplayer2.core.test";
   private static final String DATA_PATH = "binary/1024_incrementing_bytes.mp3";
 
-  public void testReadValidUri() throws Exception {
+  public void testRead() throws Exception {
-    ContentDataSource dataSource = new ContentDataSource(getInstrumentation().getContext());
+    assertData(getInstrumentation(), 0, C.LENGTH_UNSET, false);
-    Uri contentUri = new Uri.Builder()
+  }
-        .scheme(ContentResolver.SCHEME_CONTENT)
+
-        .authority(AUTHORITY)
+  public void testReadPipeMode() throws Exception {
-        .path(DATA_PATH).build();
+    assertData(getInstrumentation(), 0, C.LENGTH_UNSET, true);
-    DataSpec dataSpec = new DataSpec(contentUri);
+  }
-    TestUtil.assertDataSourceContent(dataSource, dataSpec,
+
-        TestUtil.getByteArray(getInstrumentation(), DATA_PATH));
+  public void testReadFixedLength() throws Exception {
+    assertData(getInstrumentation(), 0, 100, false);
+  }
+
+  public void testReadFromOffsetToEndOfInput() throws Exception {
+    assertData(getInstrumentation(), 1, C.LENGTH_UNSET, false);
+  }
+
+  public void testReadFromOffsetToEndOfInputPipeMode() throws Exception {
+    assertData(getInstrumentation(), 1, C.LENGTH_UNSET, true);
+  }
+
+  public void testReadFromOffsetFixedLength() throws Exception {
+    assertData(getInstrumentation(), 1, 100, false);
   }
 
   public void testReadInvalidUri() throws Exception {
     ContentDataSource dataSource = new ContentDataSource(getInstrumentation().getContext());
-    Uri contentUri = new Uri.Builder()
+    Uri contentUri = TestContentProvider.buildUri("does/not.exist", false);
-        .scheme(ContentResolver.SCHEME_CONTENT)
-        .authority(AUTHORITY)
-        .build();
     DataSpec dataSpec = new DataSpec(contentUri);
     try {
       dataSource.open(dataSpec);
@@ -66,18 +81,16 @@ public final class ContentDataSourceTest extends InstrumentationTestCase {
     }
   }
 
-  public void testReadFromOffsetToEndOfInput() throws Exception {
+  private static void assertData(Instrumentation instrumentation, int offset, int length,
-    ContentDataSource dataSource = new ContentDataSource(getInstrumentation().getContext());
+      boolean pipeMode) throws IOException {
-    Uri contentUri = new Uri.Builder()
+    Uri contentUri = TestContentProvider.buildUri(DATA_PATH, pipeMode);
-        .scheme(ContentResolver.SCHEME_CONTENT)
+    ContentDataSource dataSource = new ContentDataSource(instrumentation.getContext());
-        .authority(AUTHORITY)
-        .path(DATA_PATH).build();
     try {
-      int testOffset = 1;
+      DataSpec dataSpec = new DataSpec(contentUri, offset, length, null);
-      DataSpec dataSpec = new DataSpec(contentUri, testOffset, C.LENGTH_UNSET, null);
+      byte[] completeData = TestUtil.getByteArray(instrumentation, DATA_PATH);
-      byte[] completeData = TestUtil.getByteArray(getInstrumentation(), DATA_PATH);
+      byte[] expectedData = Arrays.copyOfRange(completeData, offset,
-      byte[] expectedData = Arrays.copyOfRange(completeData, testOffset, completeData.length);
+          length == C.LENGTH_UNSET ? completeData.length : offset + length);
-      TestUtil.assertDataSourceContent(dataSource, dataSpec, expectedData);
+      TestUtil.assertDataSourceContent(dataSource, dataSpec, expectedData, !pipeMode);
     } finally {
       dataSource.close();
     }
@@ -86,7 +99,21 @@ public final class ContentDataSourceTest extends InstrumentationTestCase {
   /**
    * A {@link ContentProvider} for the test.
    */
-  public static final class TestContentProvider extends ContentProvider {
+  public static final class TestContentProvider extends ContentProvider
+      implements ContentProvider.PipeDataWriter<Object> {
+
+    private static final String PARAM_PIPE_MODE = "pipe-mode";
+
+    public static Uri buildUri(String filePath, boolean pipeMode) {
+      Uri.Builder builder = new Uri.Builder()
+          .scheme(ContentResolver.SCHEME_CONTENT)
+          .authority(AUTHORITY)
+          .path(filePath);
+      if (pipeMode) {
+        builder.appendQueryParameter(TestContentProvider.PARAM_PIPE_MODE, "1");
+      }
+      return builder.build();
+    }
 
     @Override
     public boolean onCreate() {
@@ -106,7 +133,14 @@ public final class ContentDataSourceTest extends InstrumentationTestCase {
         return null;
       }
       try {
-        return getContext().getAssets().openFd(uri.getPath().replaceFirst("/", ""));
+        String fileName = getFileName(uri);
+        boolean pipeMode = uri.getQueryParameter(PARAM_PIPE_MODE) != null;
+        if (pipeMode) {
+          ParcelFileDescriptor fileDescriptor = openPipeHelper(uri, null, null, null, this);
+          return new AssetFileDescriptor(fileDescriptor, 0, C.LENGTH_UNSET);
+        } else {
+          return getContext().getAssets().openFd(fileName);
+        }
       } catch (IOException e) {
         FileNotFoundException exception = new FileNotFoundException(e.getMessage());
         exception.initCause(e);
@@ -125,15 +159,31 @@ public final class ContentDataSourceTest extends InstrumentationTestCase {
     }
 
     @Override
-    public int delete(@NonNull Uri uri, String selection,
+    public int delete(@NonNull Uri uri, String selection, String[] selectionArgs) {
+      throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public int update(@NonNull Uri uri, ContentValues values, String selection,
         String[] selectionArgs) {
       throw new UnsupportedOperationException();
     }
 
     @Override
-    public int update(@NonNull Uri uri, ContentValues values,
+    public void writeDataToPipe(@NonNull ParcelFileDescriptor output, @NonNull Uri uri,
-        String selection, String[] selectionArgs) {
+        @NonNull String mimeType, @Nullable Bundle opts, @Nullable Object args) {
-      throw new UnsupportedOperationException();
+      try {
+        byte[] data = TestUtil.getByteArray(getContext(), getFileName(uri));
+        FileOutputStream outputStream = new FileOutputStream(output.getFileDescriptor());
+        outputStream.write(data);
+        outputStream.close();
+      } catch (IOException e) {
+        throw new RuntimeException("Error writing to pipe", e);
+      }
+    }
+
+    private static String getFileName(Uri uri) {
+      return uri.getPath().replaceFirst("/", "");
     }
 
   }

library/core/src/main/java/com/google/android/exoplayer2/upstream/ContentDataSource.java

@@ -24,7 +24,7 @@ import java.io.EOFException;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
-import java.io.InputStream;
+import java.nio.channels.FileChannel;
 
 /**
  * A {@link DataSource} for reading from a content URI.
@@ -47,7 +47,7 @@ public final class ContentDataSource implements DataSource {
 
   private Uri uri;
   private AssetFileDescriptor assetFileDescriptor;
-  private InputStream inputStream;
+  private FileInputStream inputStream;
   private long bytesRemaining;
   private boolean opened;
 
@@ -88,14 +88,11 @@ public final class ContentDataSource implements DataSource {
       } else {
         long assetFileDescriptorLength = assetFileDescriptor.getLength();
         if (assetFileDescriptorLength == AssetFileDescriptor.UNKNOWN_LENGTH) {
-          // The asset must extend to the end of the file.
+          // The asset must extend to the end of the file. If FileInputStream.getChannel().size()
-          bytesRemaining = inputStream.available();
+          // returns 0 then the remaining length cannot be determined.
-          if (bytesRemaining == 0) {
+          FileChannel channel = inputStream.getChannel();
-            // FileInputStream.available() returns 0 if the remaining length cannot be determined,
+          long channelSize = channel.size();
-            // or if it's greater than Integer.MAX_VALUE. We don't know the true length in either
+          bytesRemaining = channelSize == 0 ? C.LENGTH_UNSET : channelSize - channel.position();
-            // case, so treat as unbounded.
-            bytesRemaining = C.LENGTH_UNSET;
-          }
         } else {
           bytesRemaining = assetFileDescriptorLength - skipped;
         }

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

@@ -16,6 +16,7 @@
 package com.google.android.exoplayer2.testutil;
 
 import android.app.Instrumentation;
+import android.content.Context;
 import android.test.MoreAsserts;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Timeline;
@@ -121,12 +122,20 @@ public class TestUtil {
 
   public static byte[] getByteArray(Instrumentation instrumentation, String fileName)
       throws IOException {
-    return Util.toByteArray(getInputStream(instrumentation, fileName));
+    return getByteArray(instrumentation.getContext(), fileName);
+  }
+
+  public static byte[] getByteArray(Context context, String fileName) throws IOException {
+    return Util.toByteArray(getInputStream(context, fileName));
   }
 
   public static InputStream getInputStream(Instrumentation instrumentation, String fileName)
       throws IOException {
-    return instrumentation.getContext().getResources().getAssets().open(fileName);
+    return getInputStream(instrumentation.getContext(), fileName);
+  }
+
+  public static InputStream getInputStream(Context context, String fileName) throws IOException {
+    return context.getResources().getAssets().open(fileName);
   }
 
   public static String getString(Instrumentation instrumentation, String fileName)
@@ -167,13 +176,15 @@ public class TestUtil {
    * @param dataSource The {@link DataSource} through which to read.
    * @param dataSpec The {@link DataSpec} to use when opening the {@link DataSource}.
    * @param expectedData The expected data.
+   * @param expectKnownLength Whether to assert that {@link DataSource#open} returns the expected
+   *     data length. If false then it's asserted that {@link C#LENGTH_UNSET} is returned.
    * @throws IOException If an error occurs reading fom the {@link DataSource}.
    */
   public static void assertDataSourceContent(DataSource dataSource, DataSpec dataSpec,
-      byte[] expectedData) throws IOException {
+      byte[] expectedData, boolean expectKnownLength) throws IOException {
     try {
       long length = dataSource.open(dataSpec);
-      Assert.assertEquals(expectedData.length, length);
+      Assert.assertEquals(expectKnownLength ? expectedData.length : C.LENGTH_UNSET, length);
       byte[] readData = TestUtil.readToEnd(dataSource);
       MoreAsserts.assertEquals(expectedData, readData);
     } finally {