@GwtIncompatible
public final class CharStreams {

  // 2K chars (4K bytes)
  private static final int DEFAULT_BUF_SIZE = 0x800;

  /** Creates a new {@code CharBuffer} for buffering reads or writes. */
  static CharBuffer createBuffer() {
    return CharBuffer.allocate(DEFAULT_BUF_SIZE);
  }

  private CharStreams() {}

  /**
   * Copies all characters between the {@link Readable} and {@link Appendable} objects. Does not

 * the License.
 */

package com.google.common.io;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.io.CharStreams.createBuffer;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.io.IOException;

  }

  /** Compares the contents of the two {@link InputStream}s for equality. */
  static boolean contentsEqual(InputStream in1, InputStream in2) throws IOException {
    byte[] buf1 = createBuffer();
    byte[] buf2 = createBuffer();
    while (true) {
      int read1 = read(in1, buf1, 0, BUFFER_SIZE);
      int read2 = read(in2, buf2, 0, BUFFER_SIZE);
      if (read1 != read2 || !arraysEqual(buf1, buf2, read1)) {

@NullUnmarked
public class CharStreamsCopyBenchmark {
  enum CopyStrategy {
    OLD {
      @Override
      long copy(Readable from, Appendable to) throws IOException {
        CharBuffer buf = CharStreams.createBuffer();
        long total = 0;
        while (from.read(buf) != -1) {
          ((Buffer) buf).flip();
          to.append(buf);
          total += buf.remaining();
          ((Buffer) buf).clear();
        }