How to use

seek

method

in

org.elasticsearch.common.io.stream.ReleasableBytesStreamOutput

/**
 * Writes all operations in the given iterable to the given output stream including the size of the array
 * use {@link #readOperations(StreamInput, String)} to read it back.
 */
public static void writeOperations(StreamOutput outStream, List<Operation> toWrite) throws IOException {
  final ReleasableBytesStreamOutput out = new ReleasableBytesStreamOutput(BigArrays.NON_RECYCLING_INSTANCE);
  try {
    outStream.writeInt(toWrite.size());
    final BufferedChecksumStreamOutput checksumStreamOutput = new BufferedChecksumStreamOutput(out);
    for (Operation op : toWrite) {
      out.reset();
      final long start = out.position();
      out.skip(Integer.BYTES);
      writeOperationNoSize(checksumStreamOutput, op);
      long end = out.position();
      int operationSize = (int) (out.position() - Integer.BYTES - start);
      out.seek(start);
      out.writeInt(operationSize);
      out.seek(end);
      ReleasablePagedBytesReference bytes = out.bytes();
      bytes.writeTo(outStream);
    }
  } finally {
    Releasables.close(out);
  }
}

final long end = out.position();
final int operationSize = (int) (end - Integer.BYTES - start);
out.seek(start);
out.writeInt(operationSize);
out.seek(end);
final ReleasablePagedBytesReference bytes = out.bytes();
try (ReleasableLock ignored = readLock.acquire()) {

/**
 * Writes all operations in the given iterable to the given output stream including the size of the array
 * use {@link #readOperations(StreamInput)} to read it back.
 */
public static void writeOperations(StreamOutput outStream, List<Operation> toWrite) throws IOException {
  final ReleasableBytesStreamOutput out = new ReleasableBytesStreamOutput(BigArrays.NON_RECYCLING_INSTANCE);
  try {
    outStream.writeInt(toWrite.size());
    final BufferedChecksumStreamOutput checksumStreamOutput = new BufferedChecksumStreamOutput(out);
    for (Operation op : toWrite) {
      out.reset();
      final long start = out.position();
      out.skip(Integer.BYTES);
      writeOperationNoSize(checksumStreamOutput, op);
      long end = out.position();
      int operationSize = (int) (out.position() - Integer.BYTES - start);
      out.seek(start);
      out.writeInt(operationSize);
      out.seek(end);
      ReleasablePagedBytesReference bytes = out.bytes();
      bytes.writeTo(outStream);
    }
  } finally {
    Releasables.close(out);
  }
}

/**
 * Writes all operations in the given iterable to the given output stream including the size of the array
 * use {@link #readOperations(StreamInput, String)} to read it back.
 */
public static void writeOperations(StreamOutput outStream, List<Operation> toWrite) throws IOException {
  final ReleasableBytesStreamOutput out = new ReleasableBytesStreamOutput(BigArrays.NON_RECYCLING_INSTANCE);
  try {
    outStream.writeInt(toWrite.size());
    final BufferedChecksumStreamOutput checksumStreamOutput = new BufferedChecksumStreamOutput(out);
    for (Operation op : toWrite) {
      out.reset();
      final long start = out.position();
      out.skip(Integer.BYTES);
      writeOperationNoSize(checksumStreamOutput, op);
      long end = out.position();
      int operationSize = (int) (out.position() - Integer.BYTES - start);
      out.seek(start);
      out.writeInt(operationSize);
      out.seek(end);
      ReleasablePagedBytesReference bytes = out.bytes();
      bytes.writeTo(outStream);
    }
  } finally {
    Releasables.close(out);
  }
}

/**
 * Writes all operations in the given iterable to the given output stream including the size of the array
 * use {@link #readOperations(StreamInput)} to read it back.
 */
public static void writeOperations(StreamOutput outStream, List<Operation> toWrite) throws IOException {
  final ReleasableBytesStreamOutput out = new ReleasableBytesStreamOutput(BigArrays.NON_RECYCLING_INSTANCE);
  try {
    outStream.writeInt(toWrite.size());
    final BufferedChecksumStreamOutput checksumStreamOutput = new BufferedChecksumStreamOutput(out);
    for (Operation op : toWrite) {
      out.reset();
      final long start = out.position();
      out.skip(RamUsageEstimator.NUM_BYTES_INT);
      writeOperationNoSize(checksumStreamOutput, op);
      long end = out.position();
      int operationSize = (int) (out.position() - RamUsageEstimator.NUM_BYTES_INT - start);
      out.seek(start);
      out.writeInt(operationSize);
      out.seek(end);
      ReleasablePagedBytesReference bytes = out.bytes();
      bytes.writeTo(outStream);
    }
  } finally {
    Releasables.close(out.bytes());
  }
}

final long end = out.position();
final int operationSize = (int) (end - Integer.BYTES - start);
out.seek(start);
out.writeInt(operationSize);
out.seek(end);
final ReleasablePagedBytesReference bytes = out.bytes();
try (ReleasableLock ignored = readLock.acquire()) {

final long end = out.position();
final int operationSize = (int) (end - Integer.BYTES - start);
out.seek(start);
out.writeInt(operationSize);
out.seek(end);
final ReleasablePagedBytesReference bytes = out.bytes();
try (ReleasableLock ignored = readLock.acquire()) {

final long end = out.position();
final int operationSize = (int) (end - RamUsageEstimator.NUM_BYTES_INT - start);
out.seek(start);
out.writeInt(operationSize);
out.seek(end);
final ReleasablePagedBytesReference bytes = out.bytes();
try (ReleasableLock lock = readLock.acquire()) {