Add support for the data URI scheme

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=165699328

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

+/*
+ * Copyright (C) 2017 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.upstream;
+
+import android.net.Uri;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.testutil.TestUtil;
+import java.io.IOException;
+import junit.framework.TestCase;
+
+/**
+ * Unit tests for {@link DataSchemeDataSource}.
+ */
+public final class DataSchemeDataSourceTest extends TestCase {
+
+  private DataSource schemeDataDataSource;
+
+  @Override
+  public void setUp() {
+    schemeDataDataSource = new DataSchemeDataSource();
+  }
+
+  public void testBase64Data() throws IOException {
+    DataSpec dataSpec = buildDataSpec("data:text/plain;base64,eyJwcm92aWRlciI6IndpZGV2aW5lX3Rlc3QiL"
+        + "CJjb250ZW50X2lkIjoiTWpBeE5WOTBaV0Z5Y3c9PSIsImtleV9pZHMiOlsiMDAwMDAwMDAwMDAwMDAwMDAwMDAwM"
+        + "DAwMDAwMDAwMDAiXX0=");
+    TestUtil.assertDataSourceContent(schemeDataDataSource, dataSpec,
+        ("{\"provider\":\"widevine_test\",\"content_id\":\"MjAxNV90ZWFycw==\",\"key_ids\":"
+        + "[\"00000000000000000000000000000000\"]}").getBytes());
+  }
+
+  public void testAsciiData() throws IOException {
+    TestUtil.assertDataSourceContent(schemeDataDataSource, buildDataSpec("data:,A%20brief%20note"),
+        "A brief note".getBytes());
+  }
+
+  public void testPartialReads() throws IOException {
+    byte[] buffer = new byte[18];
+    DataSpec dataSpec = buildDataSpec("data:,012345678901234567");
+    assertEquals(18, schemeDataDataSource.open(dataSpec));
+    assertEquals(9, schemeDataDataSource.read(buffer, 0, 9));
+    assertEquals(0, schemeDataDataSource.read(buffer, 3, 0));
+    assertEquals(9, schemeDataDataSource.read(buffer, 9, 15));
+    assertEquals(0, schemeDataDataSource.read(buffer, 1, 0));
+    assertEquals(C.RESULT_END_OF_INPUT, schemeDataDataSource.read(buffer, 1, 1));
+    assertEquals("012345678901234567", new String(buffer, 0, 18));
+  }
+
+  public void testIncorrectScheme() {
+    try {
+      schemeDataDataSource.open(buildDataSpec("http://www.google.com"));
+      fail();
+    } catch (IOException e) {
+      // Expected.
+    }
+  }
+
+  public void testMalformedData() {
+    try {
+      schemeDataDataSource.open(buildDataSpec("data:text/plain;base64,,This%20is%20Content"));
+      fail();
+    } catch (IOException e) {
+      // Expected.
+    }
+    try {
+      schemeDataDataSource.open(buildDataSpec("data:text/plain;base64,IncorrectPadding=="));
+      fail();
+    } catch (IOException e) {
+      // Expected.
+    }
+  }
+
+  private static DataSpec buildDataSpec(String uriString) {
+    return new DataSpec(Uri.parse(uriString));
+  }
+
+}

library/core/src/main/java/com/google/android/exoplayer2/C.java

@@ -74,6 +74,10 @@ public final class C {
   public static final long NANOS_PER_SECOND = 1000000000L;
 
   /**
+   * The name of the ASCII charset.
+   */
+  public static final String ASCII_NAME = "US-ASCII";
+  /**
    * The name of the UTF-8 charset.
    */
   public static final String UTF8_NAME = "UTF-8";

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

+/*
+ * Copyright (C) 2017 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.upstream;
+
+import android.net.Uri;
+import android.util.Base64;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ParserException;
+import java.io.IOException;
+import java.net.URLDecoder;
+
+/**
+ * A {@link DataSource} for reading data URLs, as defined by RFC 2397.
+ */
+public final class DataSchemeDataSource implements DataSource {
+
+  public static final String SCHEME_DATA = "data";
+
+  private DataSpec dataSpec;
+  private int bytesRead;
+  private byte[] data;
+
+  @Override
+  public long open(DataSpec dataSpec) throws IOException {
+    this.dataSpec = dataSpec;
+    Uri uri = dataSpec.uri;
+    String scheme = uri.getScheme();
+    if (!SCHEME_DATA.equals(scheme)) {
+      throw new ParserException("Unsupported scheme: " + scheme);
+    }
+    String[] uriParts = uri.getSchemeSpecificPart().split(",");
+    if (uriParts.length > 2) {
+      throw new ParserException("Unexpected URI format: " + uri);
+    }
+    String dataString = uriParts[1];
+    if (uriParts[0].contains(";base64")) {
+      try {
+        data = Base64.decode(dataString, 0);
+      } catch (IllegalArgumentException e) {
+        throw new ParserException("Error while parsing Base64 encoded string: " + dataString, e);
+      }
+    } else {
+      // TODO: Add support for other charsets.
+      data = URLDecoder.decode(dataString, C.ASCII_NAME).getBytes();
+    }
+    return data.length;
+  }
+
+  @Override
+  public int read(byte[] buffer, int offset, int readLength) {
+    if (readLength == 0) {
+      return 0;
+    }
+    int remainingBytes = data.length - bytesRead;
+    if (remainingBytes == 0) {
+      return C.RESULT_END_OF_INPUT;
+    }
+    readLength = Math.min(readLength, remainingBytes);
+    System.arraycopy(data, bytesRead, buffer, offset, readLength);
+    bytesRead += readLength;
+    return readLength;
+  }
+
+  @Override
+  public Uri getUri() {
+    return dataSpec != null ? dataSpec.uri : null;
+  }
+
+  @Override
+  public void close() throws IOException {
+    dataSpec = null;
+    data = null;
+  }
+
+}

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

@@ -34,10 +34,11 @@ import java.lang.reflect.InvocationTargetException;
  * <li>content: For fetching data from a content URI (e.g. content://authority/path/123).
  * <li>rtmp: For fetching data over RTMP. Only supported if the project using ExoPlayer has an
  *     explicit dependency on ExoPlayer's RTMP extension.</li>
+ * <li>data: For parsing data inlined in the URI as defined in RFC 2397.</li>
  * <li>http(s): For fetching data over HTTP and HTTPS (e.g. https://www.something.com/media.mp4), if
  *     constructed using {@link #DefaultDataSource(Context, TransferListener, String, boolean)}, or
  *     any other schemes supported by a base data source if constructed using
- *     {@link #DefaultDataSource(Context, TransferListener, DataSource)}.
+ *     {@link #DefaultDataSource(Context, TransferListener, DataSource)}.</li>
  * </ul>
  */
 public final class DefaultDataSource implements DataSource {
@@ -58,6 +59,7 @@ public final class DefaultDataSource implements DataSource {
   private DataSource assetDataSource;
   private DataSource contentDataSource;
   private DataSource rtmpDataSource;
+  private DataSource dataSchemeDataSource;
 
   private DataSource dataSource;
 
@@ -130,6 +132,8 @@ public final class DefaultDataSource implements DataSource {
       dataSource = getContentDataSource();
     } else if (SCHEME_RTMP.equals(scheme)) {
       dataSource = getRtmpDataSource();
+    } else if (DataSchemeDataSource.SCHEME_DATA.equals(scheme)) {
+      dataSource = getDataSchemeDataSource();
     } else {
       dataSource = baseDataSource;
     }
@@ -202,4 +206,11 @@ public final class DefaultDataSource implements DataSource {
     return rtmpDataSource;
   }
 
+  private DataSource getDataSchemeDataSource() {
+    if (dataSchemeDataSource == null) {
+      dataSchemeDataSource = new DataSchemeDataSource();
+    }
+    return dataSchemeDataSource;
+  }
+
 }