1 /* 2 * Copyright (C) 2016, Christian Halstrick <christian.halstrick@sap.com> 3 * and other copyright owners as documented in the project's IP log. 4 * 5 * This program and the accompanying materials are made available 6 * under the terms of the Eclipse Distribution License v1.0 which 7 * accompanies this distribution, is reproduced below, and is 8 * available at http://www.eclipse.org/org/documents/edl-v10.php 9 * 10 * All rights reserved. 11 * 12 * Redistribution and use in source and binary forms, with or 13 * without modification, are permitted provided that the following 14 * conditions are met: 15 * 16 * - Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 19 * - Redistributions in binary form must reproduce the above 20 * copyright notice, this list of conditions and the following 21 * disclaimer in the documentation and/or other materials provided 22 * with the distribution. 23 * 24 * - Neither the name of the Eclipse Foundation, Inc. nor the 25 * names of its contributors may be used to endorse or promote 26 * products derived from this software without specific prior 27 * written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 30 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 31 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 34 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 35 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 37 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 38 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 40 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 41 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 42 */ 43 package org.eclipse.jgit.attributes; 44 45 import java.io.IOException; 46 import java.io.InputStream; 47 import java.io.OutputStream; 48 49 /** 50 * An abstraction for JGit's builtin implementations for hooks and filters. 51 * Instead of spawning an external processes to start a filter/hook and to pump 52 * data from/to stdin/stdout these builtin commmands may be used. They are 53 * constructed by {@link org.eclipse.jgit.attributes.FilterCommandFactory}. 54 * 55 * @since 4.6 56 */ 57 public abstract class FilterCommand { 58 /** 59 * The {@link InputStream} this command should read from 60 */ 61 protected InputStream in; 62 63 /** 64 * The {@link OutputStream} this command should write to 65 */ 66 protected OutputStream out; 67 68 /** 69 * Constructor for FilterCommand 70 * <p> 71 * FilterCommand implementors are required to manage the in and out streams 72 * (close on success and/or exception). 73 * 74 * @param in 75 * The {@link java.io.InputStream} this command should read from 76 * @param out 77 * The {@link java.io.OutputStream} this command should write to 78 */ 79 public FilterCommand(InputStream in, OutputStream out) { 80 this.in = in; 81 this.out = out; 82 } 83 84 /** 85 * Execute the command. The command is supposed to read data from 86 * {@link #in} and to write the result to {@link #out}. It returns the 87 * number of bytes it read from {@link #in}. It should be called in a loop 88 * until it returns -1 signaling that the {@link java.io.InputStream} is 89 * completely processed. 90 * <p> 91 * On successful completion (return -1) or on Exception, the streams 92 * {@link #in} and {@link #out} are closed by the implementation. 93 * 94 * @return the number of bytes read from the {@link java.io.InputStream} or 95 * -1. -1 means that the {@link java.io.InputStream} is completely 96 * processed. 97 * @throws java.io.IOException 98 * when {@link java.io.IOException} occurred while reading from 99 * {@link #in} or writing to {@link #out} 100 */ 101 public abstract int run() throws IOException; 102 }