Rollback of https://github.com/google/ExoPlayer/commit/2462aeb44358b156e7838e25a3e32926a20861ab

*** Original commit ***

Add peek() method to ExtractorInput

***

PiperOrigin-RevId: 284539719

library/core/src/main/java/com/google/android/exoplayer2/extractor/DefaultExtractorInput.java

@@ -58,9 +58,7 @@ public final class DefaultExtractorInput implements ExtractorInput {
   public int read(byte[] target, int offset, int length) throws IOException, InterruptedException {
   public int read(byte[] target, int offset, int length) throws IOException, InterruptedException {
     int bytesRead = readFromPeekBuffer(target, offset, length);
     int bytesRead = readFromPeekBuffer(target, offset, length);
     if (bytesRead == 0) {
     if (bytesRead == 0) {
-      bytesRead =
-          readFromDataSource(
-              target, offset, length, /* bytesAlreadyRead= */ 0, /* allowEndOfInput= */ true);
+      bytesRead = readFromDataSource(target, offset, length, 0, true);
     }
     }
     commitBytesRead(bytesRead);
     commitBytesRead(bytesRead);
     return bytesRead;
     return bytesRead;
@@ -113,31 +111,6 @@ public final class DefaultExtractorInput implements ExtractorInput {
   }
   }
 
 
   @Override
   @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)
   public boolean peekFully(byte[] target, int offset, int length, boolean allowEndOfInput)
       throws IOException, InterruptedException {
       throws IOException, InterruptedException {
     if (!advancePeekPosition(length, allowEndOfInput)) {
     if (!advancePeekPosition(length, allowEndOfInput)) {
@@ -228,7 +201,7 @@ public final class DefaultExtractorInput implements ExtractorInput {
   }
   }
 
 
   /**
   /**
-   * Reads from the peek buffer.
+   * Reads from the peek buffer
    *
    *
    * @param target A target array into which data should be written.
    * @param target A target array into which data should be written.
    * @param offset The offset into the target array at which to write.
    * @param offset The offset into the target array at which to write.

library/core/src/main/java/com/google/android/exoplayer2/extractor/ExtractorInput.java

@@ -27,19 +27,19 @@ import java.io.InputStream;
  * for more info about each mode.
  * for more info about each mode.
  *
  *
  * <ul>
  * <ul>
- *   <li>The {@code read()/peek()} and {@code skip()} methods provide {@link InputStream}-like
- *       byte-level access operations.
+ *   <li>The {@code read()} and {@code skip()} methods provide {@link InputStream}-like byte-level
+ *       access operations.
  *   <li>The {@code read/skip/peekFully()} and {@code advancePeekPosition()} methods assume the user
  *   <li>The {@code read/skip/peekFully()} and {@code advancePeekPosition()} methods assume the user
  *       wants to read an entire block/frame/header of known length.
  *       wants to read an entire block/frame/header of known length.
  * </ul>
  * </ul>
  *
  *
  * <h3>{@link InputStream}-like methods</h3>
  * <h3>{@link InputStream}-like methods</h3>
  *
  *
- * <p>The {@code read()/peek()} and {@code skip()} methods provide {@link InputStream}-like
- * byte-level access operations. The {@code length} parameter is a maximum, and each method returns
- * the number of bytes actually processed. This may be less than {@code length} because the end of
- * the input was reached, or the method was interrupted, or the operation was aborted early for
- * another reason.
+ * <p>The {@code read()} and {@code skip()} methods provide {@link InputStream}-like byte-level
+ * access operations. The {@code length} parameter is a maximum, and each method returns the number
+ * of bytes actually processed. This may be less than {@code length} because the end of the input
+ * was reached, or the method was interrupted, or the operation was aborted early for another
+ * reason.
  *
  *
  * <h3>Block-based methods</h3>
  * <h3>Block-based methods</h3>
  *
  *
@@ -102,8 +102,7 @@ public interface ExtractorInput {
       throws IOException, InterruptedException;
       throws IOException, InterruptedException;
 
 
   /**
   /**
-   * Equivalent to {@link #readFully(byte[], int, int, boolean) readFully(target, offset, length,
-   * false)}.
+   * Equivalent to {@code readFully(target, offset, length, false)}.
    *
    *
    * @param target A target array into which data should be written.
    * @param target A target array into which data should be written.
    * @param offset The offset into the target array at which to write.
    * @param offset The offset into the target array at which to write.
@@ -156,11 +155,8 @@ public interface ExtractorInput {
   void skipFully(int length) throws IOException, InterruptedException;
   void skipFully(int length) throws IOException, InterruptedException;
 
 
   /**
   /**
-   * Peeks up to {@code length} bytes from the peek position. The current read position is left
-   * unchanged.
-   *
-   * <p>This method blocks until at least one byte of data can be peeked, the end of the input is
-   * detected, or an exception is thrown.
+   * Peeks {@code length} bytes from the peek position, writing them into {@code target} at index
+   * {@code offset}. The current read position is left unchanged.
    *
    *
    * <p>Calling {@link #resetPeekPosition()} resets the peek position to equal the current read
    * <p>Calling {@link #resetPeekPosition()} resets the peek position to equal the current read
    * position, so the caller can peek the same data again. Reading or skipping also resets the peek
    * position, so the caller can peek the same data again. Reading or skipping also resets the peek
@@ -168,18 +164,6 @@ public interface ExtractorInput {
    *
    *
    * @param target A target array into which data should be written.
    * @param target A target array into which data should be written.
    * @param offset The offset into the target array at which to write.
    * @param offset The offset into the target array at which to write.
-   * @param length The maximum number of bytes to peek from the input.
-   * @return The number of bytes peeked, or {@link C#RESULT_END_OF_INPUT} if the input has ended.
-   * @throws IOException If an error occurs peeking from the input.
-   * @throws InterruptedException If the thread has been interrupted.
-   */
-  int peek(byte[] target, int offset, int length) throws IOException, InterruptedException;
-
-  /**
-   * Like {@link #peek(byte[], int, int)}, but peeks the requested {@code length} in full.
-   *
-   * @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 number of bytes to peek from the input.
    * @param length The number of bytes to peek from the input.
    * @param allowEndOfInput True if encountering the end of the input having peeked no data is
    * @param allowEndOfInput True if encountering the end of the input having peeked no data is
    *     allowed, and should result in {@code false} being returned. False if it should be
    *     allowed, and should result in {@code false} being returned. False if it should be
@@ -197,8 +181,12 @@ public interface ExtractorInput {
       throws IOException, InterruptedException;
       throws IOException, InterruptedException;
 
 
   /**
   /**
-   * Equivalent to {@link #peekFully(byte[], int, int, boolean) peekFully(target, offset, length,
-   * false)}.
+   * Peeks {@code length} bytes from the peek position, writing them into {@code target} at index
+   * {@code offset}. The current read position is left unchanged.
+   * <p>
+   * Calling {@link #resetPeekPosition()} resets the peek position to equal the current read
+   * position, so the caller can peek the same data again. Reading and skipping also reset the peek
+   * position.
    *
    *
    * @param target A target array into which data should be written.
    * @param target A target array into which data should be written.
    * @param offset The offset into the target array at which to write.
    * @param offset The offset into the target array at which to write.

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

@@ -65,8 +65,7 @@ public final class FakeExtractorInput implements ExtractorInput {
   private int readPosition;
   private int readPosition;
   private int peekPosition;
   private int peekPosition;
 
 
-  private final SparseBooleanArray partiallySatisfiedTargetReadPositions;
-  private final SparseBooleanArray partiallySatisfiedTargetPeekPositions;
+  private final SparseBooleanArray partiallySatisfiedTargetPositions;
   private final SparseBooleanArray failedReadPositions;
   private final SparseBooleanArray failedReadPositions;
   private final SparseBooleanArray failedPeekPositions;
   private final SparseBooleanArray failedPeekPositions;
 
 
@@ -76,8 +75,7 @@ public final class FakeExtractorInput implements ExtractorInput {
     this.simulateUnknownLength = simulateUnknownLength;
     this.simulateUnknownLength = simulateUnknownLength;
     this.simulatePartialReads = simulatePartialReads;
     this.simulatePartialReads = simulatePartialReads;
     this.simulateIOErrors = simulateIOErrors;
     this.simulateIOErrors = simulateIOErrors;
-    partiallySatisfiedTargetReadPositions = new SparseBooleanArray();
-    partiallySatisfiedTargetPeekPositions = new SparseBooleanArray();
+    partiallySatisfiedTargetPositions = new SparseBooleanArray();
     failedReadPositions = new SparseBooleanArray();
     failedReadPositions = new SparseBooleanArray();
     failedPeekPositions = new SparseBooleanArray();
     failedPeekPositions = new SparseBooleanArray();
   }
   }
@@ -86,8 +84,7 @@ public final class FakeExtractorInput implements ExtractorInput {
   public void reset() {
   public void reset() {
     readPosition = 0;
     readPosition = 0;
     peekPosition = 0;
     peekPosition = 0;
-    partiallySatisfiedTargetReadPositions.clear();
-    partiallySatisfiedTargetPeekPositions.clear();
+    partiallySatisfiedTargetPositions.clear();
     failedReadPositions.clear();
     failedReadPositions.clear();
     failedPeekPositions.clear();
     failedPeekPositions.clear();
   }
   }
@@ -107,7 +104,7 @@ public final class FakeExtractorInput implements ExtractorInput {
   @Override
   @Override
   public int read(byte[] target, int offset, int length) throws IOException {
   public int read(byte[] target, int offset, int length) throws IOException {
     checkIOException(readPosition, failedReadPositions);
     checkIOException(readPosition, failedReadPositions);
-    length = getLengthToRead(readPosition, length, partiallySatisfiedTargetReadPositions);
+    length = getReadLength(length);
     return readFullyInternal(target, offset, length, true) ? length : C.RESULT_END_OF_INPUT;
     return readFullyInternal(target, offset, length, true) ? length : C.RESULT_END_OF_INPUT;
   }
   }
 
 
@@ -126,7 +123,7 @@ public final class FakeExtractorInput implements ExtractorInput {
   @Override
   @Override
   public int skip(int length) throws IOException {
   public int skip(int length) throws IOException {
     checkIOException(readPosition, failedReadPositions);
     checkIOException(readPosition, failedReadPositions);
-    length = getLengthToRead(readPosition, length, partiallySatisfiedTargetReadPositions);
+    length = getReadLength(length);
     return skipFullyInternal(length, true) ? length : C.RESULT_END_OF_INPUT;
     return skipFullyInternal(length, true) ? length : C.RESULT_END_OF_INPUT;
   }
   }
 
 
@@ -142,17 +139,15 @@ public final class FakeExtractorInput implements ExtractorInput {
   }
   }
 
 
   @Override
   @Override
-  public int peek(byte[] target, int offset, int length) throws IOException {
-    checkIOException(peekPosition, failedPeekPositions);
-    length = getLengthToRead(peekPosition, length, partiallySatisfiedTargetPeekPositions);
-    return peekFullyInternal(target, offset, length, true) ? length : C.RESULT_END_OF_INPUT;
-  }
-
-  @Override
   public boolean peekFully(byte[] target, int offset, int length, boolean allowEndOfInput)
   public boolean peekFully(byte[] target, int offset, int length, boolean allowEndOfInput)
       throws IOException {
       throws IOException {
     checkIOException(peekPosition, failedPeekPositions);
     checkIOException(peekPosition, failedPeekPositions);
-    return peekFullyInternal(target, offset, length, allowEndOfInput);
+    if (!checkXFully(allowEndOfInput, peekPosition, length)) {
+      return false;
+    }
+    System.arraycopy(data, peekPosition, target, offset, length);
+    peekPosition += length;
+    return true;
   }
   }
 
 
   @Override
   @Override
@@ -226,19 +221,18 @@ public final class FakeExtractorInput implements ExtractorInput {
     return true;
     return true;
   }
   }
 
 
-  private int getLengthToRead(
-      int position, int requestedLength, SparseBooleanArray partiallySatisfiedTargetPositions) {
-    if (position == data.length) {
+  private int getReadLength(int requestedLength) {
+    if (readPosition == data.length) {
       // If the requested length is non-zero, the end of the input will be read.
       // If the requested length is non-zero, the end of the input will be read.
       return requestedLength == 0 ? 0 : Integer.MAX_VALUE;
       return requestedLength == 0 ? 0 : Integer.MAX_VALUE;
     }
     }
-    int targetPosition = position + requestedLength;
+    int targetPosition = readPosition + requestedLength;
     if (simulatePartialReads && requestedLength > 1
     if (simulatePartialReads && requestedLength > 1
         && !partiallySatisfiedTargetPositions.get(targetPosition)) {
         && !partiallySatisfiedTargetPositions.get(targetPosition)) {
       partiallySatisfiedTargetPositions.put(targetPosition, true);
       partiallySatisfiedTargetPositions.put(targetPosition, true);
       return 1;
       return 1;
     }
     }
-    return Math.min(requestedLength, data.length - position);
+    return Math.min(requestedLength, data.length - readPosition);
   }
   }
 
 
   private boolean readFullyInternal(byte[] target, int offset, int length, boolean allowEndOfInput)
   private boolean readFullyInternal(byte[] target, int offset, int length, boolean allowEndOfInput)
@@ -261,16 +255,6 @@ public final class FakeExtractorInput implements ExtractorInput {
     return true;
     return true;
   }
   }
 
 
-  private boolean peekFullyInternal(byte[] target, int offset, int length, boolean allowEndOfInput)
-      throws EOFException {
-    if (!checkXFully(allowEndOfInput, peekPosition, length)) {
-      return false;
-    }
-    System.arraycopy(data, peekPosition, target, offset, length);
-    peekPosition += length;
-    return true;
-  }
-
   /**
   /**
    * Builder of {@link FakeExtractorInput} instances.
    * Builder of {@link FakeExtractorInput} instances.
    */
    */