Introduce FakeExtractorInput (based loosely on RecordableExtractorInput).

- Use it to simplify a bunch of tests.
- Will also replace RecordableExtractorInput in a subsequent CL.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117220030

library/src/androidTest/java/com/google/android/exoplayer/extractor/webm/DefaultEbmlReaderTest.java

@@ -15,14 +15,9 @@
  */
 package com.google.android.exoplayer.extractor.webm;
 
-import com.google.android.exoplayer.C;
-import com.google.android.exoplayer.extractor.DefaultExtractorInput;
 import com.google.android.exoplayer.extractor.ExtractorInput;
-import com.google.android.exoplayer.testutil.FakeDataSource;
-import com.google.android.exoplayer.upstream.DataSource;
-import com.google.android.exoplayer.upstream.DataSpec;
-
-import android.net.Uri;
+import com.google.android.exoplayer.testutil.FakeExtractorInput;
+import com.google.android.exoplayer.testutil.TestUtil;
 
 import junit.framework.TestCase;
 
@@ -140,22 +135,15 @@ public class DefaultEbmlReaderTest extends TestCase {
 
   /**
    * Helper to build an {@link ExtractorInput} from byte data.
-   * <p>
-   * Each argument must be able to cast to a byte value.
    *
    * @param data Zero or more integers with values between {@code 0x00} and {@code 0xFF}.
    * @return An {@link ExtractorInput} from which the data can be read.
-   * @throws IOException If an error occurs creating the input.
    */
-  private static ExtractorInput createTestInput(int... data) throws IOException {
-    byte[] bytes = new byte[data.length];
-    for (int i = 0; i < data.length; i++) {
-      bytes[i] = (byte) data[i];
-    }
-    DataSource dataSource = new FakeDataSource.Builder().appendReadData(bytes).build();
-    dataSource.open(new DataSpec(Uri.parse("http://www.google.com")));
-    ExtractorInput input = new DefaultExtractorInput(dataSource, 0, C.LENGTH_UNBOUNDED);
-    return input;
+  private static ExtractorInput createTestInput(int... data) {
+    return new FakeExtractorInput.Builder()
+        .setData(TestUtil.createByteArray(data))
+        .setSimulateUnknownLength(true)
+        .build();
   }
 
   /**

library/src/androidTest/java/com/google/android/exoplayer/extractor/webm/VarintReaderTest.java

@@ -16,26 +16,20 @@
 package com.google.android.exoplayer.extractor.webm;
 
 import com.google.android.exoplayer.C;
-import com.google.android.exoplayer.extractor.DefaultExtractorInput;
 import com.google.android.exoplayer.extractor.ExtractorInput;
-import com.google.android.exoplayer.testutil.FakeDataSource;
-import com.google.android.exoplayer.upstream.DataSource;
-import com.google.android.exoplayer.upstream.DataSpec;
-
-import android.net.Uri;
+import com.google.android.exoplayer.testutil.FakeExtractorInput;
+import com.google.android.exoplayer.testutil.FakeExtractorInput.SimulatedIOException;
 
 import junit.framework.TestCase;
 
 import java.io.EOFException;
 import java.io.IOException;
-import java.util.Arrays;
 
 /**
  * Tests for {@link VarintReader}.
  */
-public class VarintReaderTest extends TestCase {
+public final class VarintReaderTest extends TestCase {
 
-  private static final String TEST_URI = "http://www.google.com";
   private static final byte MAX_BYTE = (byte) 0xFF;
 
   private static final byte[] DATA_1_BYTE_0 = new byte[] {(byte) 0x80};
@@ -88,12 +82,10 @@ public class VarintReaderTest extends TestCase {
 
   public void testReadVarintEndOfInputAtStart() throws IOException, InterruptedException {
     VarintReader reader = new VarintReader();
-    // Build an input, and read to the end.
-    DataSource dataSource = buildDataSource(new byte[1]);
-    dataSource.open(new DataSpec(Uri.parse(TEST_URI)));
-    ExtractorInput input = new DefaultExtractorInput(dataSource, 0, C.LENGTH_UNBOUNDED);
-    int bytesRead = input.read(new byte[1], 0, 1);
-    assertEquals(1, bytesRead);
+    // Build an input with no data.
+    ExtractorInput input = new FakeExtractorInput.Builder()
+        .setSimulateUnknownLength(true)
+        .build();
     // End of input allowed.
     long result = reader.readUnsignedVarint(input, true, false, 8);
     assertEquals(C.RESULT_END_OF_INPUT, result);
@@ -108,9 +100,10 @@ public class VarintReaderTest extends TestCase {
 
   public void testReadVarintExceedsMaximumAllowedLength() throws IOException, InterruptedException {
     VarintReader reader = new VarintReader();
-    DataSource dataSource = buildDataSource(DATA_8_BYTE_0);
-    dataSource.open(new DataSpec(Uri.parse(TEST_URI)));
-    ExtractorInput input = new DefaultExtractorInput(dataSource, 0, C.LENGTH_UNBOUNDED);
+    ExtractorInput input = new FakeExtractorInput.Builder()
+        .setData(DATA_8_BYTE_0)
+        .setSimulateUnknownLength(true)
+        .build();
     long result = reader.readUnsignedVarint(input, false, true, 4);
     assertEquals(C.RESULT_MAX_LENGTH_EXCEEDED, result);
   }
@@ -189,9 +182,10 @@ public class VarintReaderTest extends TestCase {
 
   private static void testReadVarint(VarintReader reader, boolean removeMask, byte[] data,
       int expectedLength, long expectedValue) throws IOException, InterruptedException {
-    DataSource dataSource = buildDataSource(data);
-    dataSource.open(new DataSpec(Uri.parse(TEST_URI)));
-    ExtractorInput input = new DefaultExtractorInput(dataSource, 0, C.LENGTH_UNBOUNDED);
+    ExtractorInput input = new FakeExtractorInput.Builder()
+        .setData(data)
+        .setSimulateUnknownLength(true)
+        .build();
     long result = reader.readUnsignedVarint(input, false, removeMask, 8);
     assertEquals(expectedLength, input.getPosition());
     assertEquals(expectedValue, result);
@@ -199,45 +193,22 @@ public class VarintReaderTest extends TestCase {
 
   private static void testReadVarintFlaky(VarintReader reader, boolean removeMask, byte[] data,
       int expectedLength, long expectedValue) throws IOException, InterruptedException {
-    DataSource dataSource = buildFlakyDataSource(data);
-    ExtractorInput input = null;
-    long position = 0;
+    ExtractorInput input = new FakeExtractorInput.Builder()
+        .setData(data)
+        .setSimulateUnknownLength(true)
+        .setSimulateIOErrors(true)
+        .setSimulatePartialReads(true)
+        .build();
     long result = -1;
     while (result == -1) {
-      dataSource.open(new DataSpec(Uri.parse(TEST_URI), position, C.LENGTH_UNBOUNDED, null));
-      input = new DefaultExtractorInput(dataSource, position, C.LENGTH_UNBOUNDED);
       try {
         result = reader.readUnsignedVarint(input, false, removeMask, 8);
-        position = input.getPosition();
-      } catch (IOException e) {
-        // Expected. We'll try again from the position that the input was advanced to.
-        position = input.getPosition();
-        dataSource.close();
+      } catch (SimulatedIOException e) {
+        // Expected.
       }
     }
     assertEquals(expectedLength, input.getPosition());
     assertEquals(expectedValue, result);
   }
 
-  private static DataSource buildDataSource(byte[] data) {
-    FakeDataSource.Builder builder = new FakeDataSource.Builder();
-    builder.appendReadData(data);
-    return builder.build();
-  }
-
-  private static DataSource buildFlakyDataSource(byte[] data) {
-    FakeDataSource.Builder builder = new FakeDataSource.Builder();
-    builder.appendReadError(new IOException("A"));
-    builder.appendReadData(new byte[] {data[0]});
-    if (data.length > 1) {
-      builder.appendReadError(new IOException("B"));
-      builder.appendReadData(new byte[] {data[1]});
-    }
-    if (data.length > 2) {
-      builder.appendReadError(new IOException("C"));
-      builder.appendReadData(Arrays.copyOfRange(data, 2, data.length));
-    }
-    return builder.build();
-  }
-
 }

library/src/androidTest/java/com/google/android/exoplayer/testutil/FakeDataSource.java

@@ -48,7 +48,7 @@ public final class FakeDataSource implements DataSource {
   private int currentSegmentIndex;
   private long bytesRemaining;
 
-  public FakeDataSource(boolean simulateUnknownLength, ArrayList<Segment> segments) {
+  private FakeDataSource(boolean simulateUnknownLength, ArrayList<Segment> segments) {
     this.simulateUnknownLength = simulateUnknownLength;
     this.segments = segments;
     long totalLength = 0;
@@ -163,7 +163,7 @@ public final class FakeDataSource implements DataSource {
   /**
    * Builder of {@link FakeDataSource} instances.
    */
-  public static class Builder {
+  public static final class Builder {
 
     private final ArrayList<Segment> segments;
     private boolean simulateUnknownLength;

library/src/androidTest/java/com/google/android/exoplayer/testutil/FakeExtractorInput.java

+/*
+ * Copyright (C) 2015 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.exoplayer.testutil;
+
+import com.google.android.exoplayer.C;
+import com.google.android.exoplayer.extractor.ExtractorInput;
+
+import android.util.SparseBooleanArray;
+
+import junit.framework.Assert;
+
+import java.io.EOFException;
+import java.io.IOException;
+
+/**
+ * A fake {@link ExtractorInput} capable of simulating various scenarios.
+ * <p>
+ * Read, skip and peek errors can be simulated using {@link Builder#setSimulateIOErrors)}. When
+ * enabled each read and skip will throw a {@link SimulatedIOException} unless one has already been
+ * thrown from the current position. Each peek will throw {@link SimulatedIOException} unless one
+ * has already been thrown from the current peek position. When a {@link SimulatedIOException} is
+ * thrown the read position is left unchanged and the peek position is reset back to the read
+ * position.
+ * <p>
+ * Partial reads and skips can be simulated using {@link Builder#setSimulatePartialReads}. When
+ * enabled, {@link #read(byte[], int, int)} and {@link #skip(int)} calls will only read or skip a
+ * single byte unless a partial read or skip has already been performed that had the same target
+ * position. For example, a first read request for 10 bytes will be partially satisfied by reading
+ * a single byte and advancing the position to 1. If the following read request attempts to read 9
+ * bytes then it will be fully satisfied, since it has the same target position of 10.
+ * <p>
+ * Unknown data length can be simulated using {@link Builder#setSimulateUnknownLength}. When enabled
+ * {@link getLength()} will return {@link C#LENGTH_UNBOUNDED} rather than the length of the data.
+ */
+public final class FakeExtractorInput implements ExtractorInput {
+
+  /**
+   * Thrown when simulating an {@link IOException}.
+   */
+  public static final class SimulatedIOException extends IOException {
+
+    public SimulatedIOException(String message) {
+      super(message);
+    }
+
+  }
+
+  private final byte[] data;
+  private final boolean simulateUnknownLength;
+  private final boolean simulatePartialReads;
+  private final boolean simulateIOErrors;
+
+  private int readPosition;
+  private int peekPosition;
+
+  private final SparseBooleanArray partiallySatisfiedTargetPositions;
+  private final SparseBooleanArray failedReadPositions;
+  private final SparseBooleanArray failedPeekPositions;
+
+  private FakeExtractorInput(byte[] data, boolean simulateUnknownLength,
+      boolean simulatePartialReads, boolean simulateIOErrors) {
+    this.data = data;
+    this.simulateUnknownLength = simulateUnknownLength;
+    this.simulatePartialReads = simulatePartialReads;
+    this.simulateIOErrors = simulateIOErrors;
+    partiallySatisfiedTargetPositions = new SparseBooleanArray();
+    failedReadPositions = new SparseBooleanArray();
+    failedPeekPositions = new SparseBooleanArray();
+  }
+
+  /**
+   * Sets the read and peek positions.
+   *
+   * @param position The position to set.
+   */
+  public void setPosition(int position) {
+    Assert.assertTrue(0 <= position && position < data.length);
+    readPosition = position;
+    peekPosition = position;
+  }
+
+  @Override
+  public int read(byte[] target, int offset, int length) throws IOException {
+    length = getReadLength(length);
+    if (readFully(target, offset, length, true)) {
+      return length;
+    }
+    return C.RESULT_END_OF_INPUT;
+  }
+
+  @Override
+  public boolean readFully(byte[] target, int offset, int length, boolean allowEndOfInput)
+      throws IOException {
+    if (!checkXFully(allowEndOfInput, readPosition, length, failedReadPositions)) {
+      return false;
+    }
+    System.arraycopy(data, readPosition, target, offset, length);
+    readPosition += length;
+    peekPosition = readPosition;
+    return true;
+  }
+
+  @Override
+  public void readFully(byte[] target, int offset, int length) throws IOException {
+    readFully(target, offset, length, false);
+  }
+
+  @Override
+  public int skip(int length) throws IOException {
+    length = getReadLength(length);
+    if (skipFully(length, true)) {
+      return length;
+    }
+    return C.RESULT_END_OF_INPUT;
+  }
+
+  @Override
+  public boolean skipFully(int length, boolean allowEndOfInput) throws IOException {
+    if (!checkXFully(allowEndOfInput, readPosition, length, failedReadPositions)) {
+      return false;
+    }
+    readPosition += length;
+    peekPosition = readPosition;
+    return true;
+  }
+
+  @Override
+  public void skipFully(int length) throws IOException {
+    skipFully(length, false);
+  }
+
+  @Override
+  public boolean peekFully(byte[] target, int offset, int length, boolean allowEndOfInput)
+      throws IOException {
+    if (!checkXFully(allowEndOfInput, peekPosition, length, failedPeekPositions)) {
+      return false;
+    }
+    System.arraycopy(data, peekPosition, target, offset, length);
+    peekPosition += length;
+    return true;
+  }
+
+  @Override
+  public void peekFully(byte[] target, int offset, int length) throws IOException {
+    peekFully(target, offset, length, false);
+  }
+
+  @Override
+  public boolean advancePeekPosition(int length, boolean allowEndOfInput) throws IOException {
+    if (!checkXFully(allowEndOfInput, peekPosition, length, failedPeekPositions)) {
+      return false;
+    }
+    peekPosition += length;
+    return true;
+  }
+
+  @Override
+  public void advancePeekPosition(int length) throws IOException {
+    advancePeekPosition(length, false);
+  }
+
+  @Override
+  public void resetPeekPosition() {
+    peekPosition = readPosition;
+  }
+
+  @Override
+  public long getPeekPosition() {
+    return peekPosition;
+  }
+
+  @Override
+  public long getPosition() {
+    return readPosition;
+  }
+
+  @Override
+  public long getLength() {
+    return simulateUnknownLength ? C.LENGTH_UNBOUNDED : data.length;
+  }
+
+  private boolean checkXFully(boolean allowEndOfInput, int position, int length,
+      SparseBooleanArray failedPositions) throws IOException {
+    if (simulateIOErrors && !failedPositions.get(position)) {
+      failedPositions.put(position, true);
+      peekPosition = readPosition;
+      throw new SimulatedIOException("Simulated IO error at position: " + position);
+    }
+    if (isEof()) {
+      if (allowEndOfInput) {
+        return false;
+      }
+      throw new EOFException();
+    }
+    if (position + length > data.length) {
+      throw new IOException("Attempted to move past end of data: (" + position + " + "
+          + length + ") > " + data.length);
+    }
+    return true;
+  }
+
+  private int getReadLength(int requestedLength) {
+    int targetPosition = readPosition + requestedLength;
+    if (simulatePartialReads && requestedLength > 1
+        && !partiallySatisfiedTargetPositions.get(targetPosition)) {
+      partiallySatisfiedTargetPositions.put(targetPosition, true);
+      return 1;
+    }
+    return Math.min(requestedLength, data.length - readPosition);
+  }
+
+  private boolean isEof() {
+    return readPosition == data.length;
+  }
+
+  /**
+   * Builder of {@link FakeExtractorInput} instances.
+   */
+  public static final class Builder {
+
+    private byte[] data;
+    private boolean simulateUnknownLength;
+    private boolean simulatePartialReads;
+    private boolean simulateIOErrors;
+
+    public Builder() {
+      data = new byte[0];
+    }
+
+    public Builder setData(byte[] data) {
+      this.data = data;
+      return this;
+    }
+
+    public Builder setSimulateUnknownLength(boolean simulateUnknownLength) {
+      this.simulateUnknownLength = simulateUnknownLength;
+      return this;
+    }
+
+    public Builder setSimulatePartialReads(boolean simulatePartialReads) {
+      this.simulatePartialReads = simulatePartialReads;
+      return this;
+    }
+
+    public Builder setSimulateIOErrors(boolean simulateIOErrors) {
+      this.simulateIOErrors = simulateIOErrors;
+      return this;
+    }
+
+    public FakeExtractorInput build() {
+      return new FakeExtractorInput(data, simulateUnknownLength, simulatePartialReads,
+          simulateIOErrors);
+    }
+
+  }
+
+}

library/src/androidTest/java/com/google/android/exoplayer/testutil/TestUtil.java

@@ -15,24 +15,18 @@
  */
 package com.google.android.exoplayer.testutil;
 
-import com.google.android.exoplayer.C;
-import com.google.android.exoplayer.extractor.DefaultExtractorInput;
 import com.google.android.exoplayer.extractor.Extractor;
-import com.google.android.exoplayer.extractor.ExtractorInput;
 import com.google.android.exoplayer.extractor.PositionHolder;
-import com.google.android.exoplayer.upstream.DataSpec;
 import com.google.android.exoplayer.util.Assertions;
 import com.google.android.exoplayer.util.Util;
 
 import android.app.Instrumentation;
-import android.net.Uri;
 import android.test.InstrumentationTestCase;
 
 import org.mockito.MockitoAnnotations;
 
 import java.io.IOException;
 import java.io.InputStream;
-import java.util.Arrays;
 import java.util.Random;
 
 /**
@@ -44,32 +38,19 @@ public class TestUtil {
 
   public static void consumeTestData(Extractor extractor, byte[] data)
       throws IOException, InterruptedException {
-    ExtractorInput input = createTestExtractorInput(data);
+    FakeExtractorInput input = new FakeExtractorInput.Builder().setData(data).build();
     PositionHolder seekPositionHolder = new PositionHolder();
     int readResult = Extractor.RESULT_CONTINUE;
     while (readResult != Extractor.RESULT_END_OF_INPUT) {
       readResult = extractor.read(input, seekPositionHolder);
       if (readResult == Extractor.RESULT_SEEK) {
-        input = createTestExtractorInput(data, (int) seekPositionHolder.position);
+        long seekPosition = seekPositionHolder.position;
+        Assertions.checkState(0 < seekPosition && seekPosition <= Integer.MAX_VALUE);
+        input.setPosition((int) seekPosition);
       }
     }
   }
 
-  public static ExtractorInput createTestExtractorInput(byte[] data) throws IOException {
-    return createTestExtractorInput(data, 0);
-  }
-
-  public static ExtractorInput createTestExtractorInput(byte[] data, int offset)
-      throws IOException {
-    if (offset != 0) {
-      data = Arrays.copyOfRange(data, offset, data.length);
-    }
-    FakeDataSource dataSource = new FakeDataSource.Builder().appendReadData(data).build();
-    dataSource.open(new DataSpec(Uri.parse("http://www.google.com")));
-    ExtractorInput input = new DefaultExtractorInput(dataSource, offset, C.LENGTH_UNBOUNDED);
-    return input;
-  }
-
   public static byte[] buildTestData(int length) {
     return buildTestData(length, length);
   }