001/* 002 * Copyright (C) 2012 eXo Platform SAS. 003 * 004 * This is free software; you can redistribute it and/or modify it 005 * under the terms of the GNU Lesser General Public License as 006 * published by the Free Software Foundation; either version 2.1 of 007 * the License, or (at your option) any later version. 008 * 009 * This software is distributed in the hope that it will be useful, 010 * but WITHOUT ANY WARRANTY; without even the implied warranty of 011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 012 * Lesser General Public License for more details. 013 * 014 * You should have received a copy of the GNU Lesser General Public 015 * License along with this software; if not, write to the Free 016 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 017 * 02110-1301 USA, or see the FSF site: http://www.fsf.org. 018 */ 019 020package org.crsh.shell.impl.command.pipeline; 021 022import org.crsh.command.CommandContext; 023import org.crsh.shell.impl.command.spi.CommandInvoker; 024import org.crsh.console.KeyHandler; 025import org.crsh.text.Chunk; 026 027import java.io.IOException; 028 029public class PipeLine extends CommandInvoker<Void, Chunk> { 030 031 /** . */ 032 private final CommandInvoker[] invokers; 033 034 /** . */ 035 private CommandContext<?> current; 036 037 public PipeLine(CommandInvoker[] invokers) { 038 this.invokers = invokers; 039 this.current = null; 040 } 041 042 public Class<Void> getConsumedType() { 043 return Void.class; 044 } 045 046 public Class<Chunk> getProducedType() { 047 return Chunk.class; 048 } 049 050 public void open(CommandContext<? super Chunk> consumer) { 051 open(0, consumer); 052 } 053 054 private CommandContext open(final int index, final CommandContext last) { 055 if (index < invokers.length) { 056 057 // 058 final CommandInvoker invoker = invokers[index]; 059 CommandContext next = open(index + 1, last); 060 061 // 062 final Class produced = invoker.getProducedType(); 063 final Class<?> consumed = next.getConsumedType(); 064 boolean piped = index > 0; 065 066 AbstractPipe filter; 067 if (consumed.equals(Chunk.class)) { 068 filter = new ToChunkPipe(produced, piped); 069 } else { 070 filter = new ConvertingPipe(produced, consumed, piped); 071 } 072 filter.open(next); 073 next = filter; 074 075 // 076 PipeLineElement filterContext = new PipeLineElement(invoker); 077 filterContext.open(next); 078 079 // Save current filter in field 080 // so if anything wrong happens it will be closed 081 current = filterContext; 082 083 // 084 return filterContext; 085 } else { 086 current = last; 087 return last; 088 } 089 } 090 091 @Override 092 public KeyHandler getKeyHandler() { 093 for (CommandInvoker<?, ?> invoker : invokers) { 094 KeyHandler handler = invoker.getKeyHandler(); 095 if (handler != null) { 096 return handler; 097 } 098 } 099 return null; 100 } 101 102 public void provide(Void element) throws IOException { 103 // Ignore 104 } 105 106 public void flush() throws IOException { 107 current.flush(); 108 } 109 110 public void close() throws IOException { 111 current.close(); 112 } 113}