001/*
002 * Copyright (C) 2009 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
005 * in compliance with the License. You may obtain a copy of the License at
006 *
007 * http://www.apache.org/licenses/LICENSE-2.0
008 *
009 * Unless required by applicable law or agreed to in writing, software distributed under the License
010 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
011 * or implied. See the License for the specific language governing permissions and limitations under
012 * the License.
013 */
014
015package com.google.common.io;
016
017import com.google.common.annotations.Beta;
018import com.google.common.annotations.GwtIncompatible;
019import com.google.errorprone.annotations.CanIgnoreReturnValue;
020import java.io.IOException;
021
022/**
023 * A callback interface to process bytes from a stream.
024 *
025 * <p>{@link #processBytes} will be called for each chunk of data that is read, and should return
026 * {@code false} when you want to stop processing.
027 *
028 * @author Chris Nokleberg
029 * @since 1.0
030 */
031@Beta
032@GwtIncompatible
033public interface ByteProcessor<T> {
034  /**
035   * This method will be called for each chunk of bytes in an input stream. The implementation
036   * should process the bytes from {@code buf[off]} through {@code buf[off + len - 1]} (inclusive).
037   *
038   * @param buf the byte array containing the data to process
039   * @param off the initial offset into the array
040   * @param len the length of data to be processed
041   * @return true to continue processing, false to stop
042   */
043  @CanIgnoreReturnValue // some uses know that their processor never returns false
044  boolean processBytes(byte[] buf, int off, int len) throws IOException;
045
046  /** Return the result of processing all the bytes. */
047  T getResult();
048}