1 files changed, 308 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/DefaultExtractorInput.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/DefaultExtractorInput.java
new file mode 100644
index 0000000000..93009f2d5c
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/DefaultExtractorInput.java
@@ -0,0 +1,308 @@
+/*
+ * Copyright (C) 2016 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 org.mozilla.thirdparty.com.google.android.exoplayer2.extractor;
+
+import org.mozilla.thirdparty.com.google.android.exoplayer2.C;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.DataSource;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Assertions;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Util;
+import java.io.EOFException;
+import java.io.IOException;
+import java.util.Arrays;
+
+/**
+ * An {@link ExtractorInput} that wraps a {@link DataSource}.
+ */
+public final class DefaultExtractorInput implements ExtractorInput {
+
+  private static final int PEEK_MIN_FREE_SPACE_AFTER_RESIZE = 64 * 1024;
+  private static final int PEEK_MAX_FREE_SPACE = 512 * 1024;
+  private static final int SCRATCH_SPACE_SIZE = 4096;
+
+  private final byte[] scratchSpace;
+  private final DataSource dataSource;
+  private final long streamLength;
+
+  private long position;
+  private byte[] peekBuffer;
+  private int peekBufferPosition;
+  private int peekBufferLength;
+
+  /**
+   * @param dataSource The wrapped {@link DataSource}.
+   * @param position The initial position in the stream.
+   * @param length The length of the stream, or {@link C#LENGTH_UNSET} if it is unknown.
+   */
+  public DefaultExtractorInput(DataSource dataSource, long position, long length) {
+    this.dataSource = dataSource;
+    this.position = position;
+    this.streamLength = length;
+    peekBuffer = new byte[PEEK_MIN_FREE_SPACE_AFTER_RESIZE];
+    scratchSpace = new byte[SCRATCH_SPACE_SIZE];
+  }
+
+  @Override
+  public int read(byte[] target, int offset, int length) throws IOException, InterruptedException {
+    int bytesRead = readFromPeekBuffer(target, offset, length);
+    if (bytesRead == 0) {
+      bytesRead =
+          readFromDataSource(
+              target, offset, length, /* bytesAlreadyRead= */ 0, /* allowEndOfInput= */ true);
+    }
+    commitBytesRead(bytesRead);
+    return bytesRead;
+  }
+
+  @Override
+  public boolean readFully(byte[] target, int offset, int length, boolean allowEndOfInput)
+      throws IOException, InterruptedException {
+    int bytesRead = readFromPeekBuffer(target, offset, length);
+    while (bytesRead < length && bytesRead != C.RESULT_END_OF_INPUT) {
+      bytesRead = readFromDataSource(target, offset, length, bytesRead, allowEndOfInput);
+    }
+    commitBytesRead(bytesRead);
+    return bytesRead != C.RESULT_END_OF_INPUT;
+  }
+
+  @Override
+  public void readFully(byte[] target, int offset, int length)
+      throws IOException, InterruptedException {
+    readFully(target, offset, length, false);
+  }
+
+  @Override
+  public int skip(int length) throws IOException, InterruptedException {
+    int bytesSkipped = skipFromPeekBuffer(length);
+    if (bytesSkipped == 0) {
+      bytesSkipped =
+          readFromDataSource(scratchSpace, 0, Math.min(length, scratchSpace.length), 0, true);
+    }
+    commitBytesRead(bytesSkipped);
+    return bytesSkipped;
+  }
+
+  @Override
+  public boolean skipFully(int length, boolean allowEndOfInput)
+      throws IOException, InterruptedException {
+    int bytesSkipped = skipFromPeekBuffer(length);
+    while (bytesSkipped < length && bytesSkipped != C.RESULT_END_OF_INPUT) {
+      int minLength = Math.min(length, bytesSkipped + scratchSpace.length);
+      bytesSkipped =
+          readFromDataSource(scratchSpace, -bytesSkipped, minLength, bytesSkipped, allowEndOfInput);
+    }
+    commitBytesRead(bytesSkipped);
+    return bytesSkipped != C.RESULT_END_OF_INPUT;
+  }
+
+  @Override
+  public void skipFully(int length) throws IOException, InterruptedException {
+    skipFully(length, false);
+  }
+
+  @Override
+  public int peek(byte[] target, int offset, int length) throws IOException, InterruptedException {
+    ensureSpaceForPeek(length);
+    int peekBufferRemainingBytes = peekBufferLength - peekBufferPosition;
+    int bytesPeeked;
+    if (peekBufferRemainingBytes == 0) {
+      bytesPeeked =
+          readFromDataSource(
+              peekBuffer,
+              peekBufferPosition,
+              length,
+              /* bytesAlreadyRead= */ 0,
+              /* allowEndOfInput= */ true);
+      if (bytesPeeked == C.RESULT_END_OF_INPUT) {
+        return C.RESULT_END_OF_INPUT;
+      }
+      peekBufferLength += bytesPeeked;
+    } else {
+      bytesPeeked = Math.min(length, peekBufferRemainingBytes);
+    }
+    System.arraycopy(peekBuffer, peekBufferPosition, target, offset, bytesPeeked);
+    peekBufferPosition += bytesPeeked;
+    return bytesPeeked;
+  }
+
+  @Override
+  public boolean peekFully(byte[] target, int offset, int length, boolean allowEndOfInput)
+      throws IOException, InterruptedException {
+    if (!advancePeekPosition(length, allowEndOfInput)) {
+      return false;
+    }
+    System.arraycopy(peekBuffer, peekBufferPosition - length, target, offset, length);
+    return true;
+  }
+
+  @Override
+  public void peekFully(byte[] target, int offset, int length)
+      throws IOException, InterruptedException {
+    peekFully(target, offset, length, false);
+  }
+
+  @Override
+  public boolean advancePeekPosition(int length, boolean allowEndOfInput)
+      throws IOException, InterruptedException {
+    ensureSpaceForPeek(length);
+    int bytesPeeked = peekBufferLength - peekBufferPosition;
+    while (bytesPeeked < length) {
+      bytesPeeked = readFromDataSource(peekBuffer, peekBufferPosition, length, bytesPeeked,
+          allowEndOfInput);
+      if (bytesPeeked == C.RESULT_END_OF_INPUT) {
+        return false;
+      }
+      peekBufferLength = peekBufferPosition + bytesPeeked;
+    }
+    peekBufferPosition += length;
+    return true;
+  }
+
+  @Override
+  public void advancePeekPosition(int length) throws IOException, InterruptedException {
+    advancePeekPosition(length, false);
+  }
+
+  @Override
+  public void resetPeekPosition() {
+    peekBufferPosition = 0;
+  }
+
+  @Override
+  public long getPeekPosition() {
+    return position + peekBufferPosition;
+  }
+
+  @Override
+  public long getPosition() {
+    return position;
+  }
+
+  @Override
+  public long getLength() {
+    return streamLength;
+  }
+
+  @Override
+  public <E extends Throwable> void setRetryPosition(long position, E e) throws E {
+    Assertions.checkArgument(position >= 0);
+    this.position = position;
+    throw e;
+  }
+
+  /**
+   * Ensures {@code peekBuffer} is large enough to store at least {@code length} bytes from the
+   * current peek position.
+   */
+  private void ensureSpaceForPeek(int length) {
+    int requiredLength = peekBufferPosition + length;
+    if (requiredLength > peekBuffer.length) {
+      int newPeekCapacity = Util.constrainValue(peekBuffer.length * 2,
+          requiredLength + PEEK_MIN_FREE_SPACE_AFTER_RESIZE, requiredLength + PEEK_MAX_FREE_SPACE);
+      peekBuffer = Arrays.copyOf(peekBuffer, newPeekCapacity);
+    }
+  }
+
+  /**
+   * Skips from the peek buffer.
+   *
+   * @param length The maximum number of bytes to skip from the peek buffer.
+   * @return The number of bytes skipped.
+   */
+  private int skipFromPeekBuffer(int length) {
+    int bytesSkipped = Math.min(peekBufferLength, length);
+    updatePeekBuffer(bytesSkipped);
+    return bytesSkipped;
+  }
+
+  /**
+   * Reads from the peek buffer.
+   *
+   * @param target A target array into which data should be written.
+   * @param offset The offset into the target array at which to write.
+   * @param length The maximum number of bytes to read from the peek buffer.
+   * @return The number of bytes read.
+   */
+  private int readFromPeekBuffer(byte[] target, int offset, int length) {
+    if (peekBufferLength == 0) {
+      return 0;
+    }
+    int peekBytes = Math.min(peekBufferLength, length);
+    System.arraycopy(peekBuffer, 0, target, offset, peekBytes);
+    updatePeekBuffer(peekBytes);
+    return peekBytes;
+  }
+
+  /**
+   * Updates the peek buffer's length, position and contents after consuming data.
+   *
+   * @param bytesConsumed The number of bytes consumed from the peek buffer.
+   */
+  private void updatePeekBuffer(int bytesConsumed) {
+    peekBufferLength -= bytesConsumed;
+    peekBufferPosition = 0;
+    byte[] newPeekBuffer = peekBuffer;
+    if (peekBufferLength < peekBuffer.length - PEEK_MAX_FREE_SPACE) {
+      newPeekBuffer = new byte[peekBufferLength + PEEK_MIN_FREE_SPACE_AFTER_RESIZE];
+    }
+    System.arraycopy(peekBuffer, bytesConsumed, newPeekBuffer, 0, peekBufferLength);
+    peekBuffer = newPeekBuffer;
+  }
+
+  /**
+   * Starts or continues a read from the data source.
+   *
+   * @param target A target array into which data should be written.
+   * @param offset The offset into the target array at which to write.
+   * @param length The maximum number of bytes to read from the input.
+   * @param bytesAlreadyRead The number of bytes already read from the input.
+   * @param allowEndOfInput True if encountering the end of the input having read no data is
+   *     allowed, and should result in {@link C#RESULT_END_OF_INPUT} being returned. False if it
+   *     should be considered an error, causing an {@link EOFException} to be thrown.
+   * @return The total number of bytes read so far, or {@link C#RESULT_END_OF_INPUT} if
+   *     {@code allowEndOfInput} is true and the input has ended having read no bytes.
+   * @throws EOFException If the end of input was encountered having partially satisfied the read
+   *     (i.e. having read at least one byte, but fewer than {@code length}), or if no bytes were
+   *     read and {@code allowEndOfInput} is false.
+   * @throws IOException If an error occurs reading from the input.
+   * @throws InterruptedException If the thread is interrupted.
+   */
+  private int readFromDataSource(byte[] target, int offset, int length, int bytesAlreadyRead,
+      boolean allowEndOfInput) throws InterruptedException, IOException {
+    if (Thread.interrupted()) {
+      throw new InterruptedException();
+    }
+    int bytesRead = dataSource.read(target, offset + bytesAlreadyRead, length - bytesAlreadyRead);
+    if (bytesRead == C.RESULT_END_OF_INPUT) {
+      if (bytesAlreadyRead == 0 && allowEndOfInput) {
+        return C.RESULT_END_OF_INPUT;
+      }
+      throw new EOFException();
+    }
+    return bytesAlreadyRead + bytesRead;
+  }
+
+  /**
+   * Advances the position by the specified number of bytes read.
+   *
+   * @param bytesRead The number of bytes read.
+   */
+  private void commitBytesRead(int bytesRead) {
+    if (bytesRead != C.RESULT_END_OF_INPUT) {
+      position += bytesRead;
+    }
+  }
+
+}