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 com.google.errorprone.annotations.DoNotMock;
021import java.io.IOException;
022
023/**
024 * A callback interface to process bytes from a stream.
025 *
026 * <p>{@link #processBytes} will be called for each chunk of data that is read, and should return
027 * {@code false} when you want to stop processing.
028 *
029 * @author Chris Nokleberg
030 * @since 1.0
031 */
032@Beta
033@DoNotMock("Implement it normally")
034@GwtIncompatible
035public interface ByteProcessor<T> {
036  /**
037   * This method will be called for each chunk of bytes in an input stream. The implementation
038   * should process the bytes from {@code buf[off]} through {@code buf[off + len - 1]} (inclusive).
039   *
040   * @param buf the byte array containing the data to process
041   * @param off the initial offset into the array
042   * @param len the length of data to be processed
043   * @return true to continue processing, false to stop
044   */
045  @CanIgnoreReturnValue // some uses know that their processor never returns false
046  boolean processBytes(byte[] buf, int off, int len) throws IOException;
047
048  /** Return the result of processing all the bytes. */
049  T getResult();
050}