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
020 package org.crsh.lang.script;
021
022 import org.crsh.shell.impl.command.spi.CommandCreationException;
023 import org.crsh.shell.impl.command.spi.CommandInvoker;
024 import org.crsh.shell.impl.command.spi.ShellCommand;
025 import org.crsh.command.SyntaxException;
026 import org.crsh.repl.ReplSession;
027 import org.crsh.shell.impl.command.pipeline.PipeLine;
028 import org.crsh.shell.ErrorType;
029 import org.crsh.text.Chunk;
030
031 import java.util.LinkedList;
032 import java.util.regex.Pattern;
033
034 /**
035 * A factory for a pipeline.
036 */
037 public class PipeLineFactory {
038
039 /** . */
040 private static final Pattern p = Pattern.compile("^\\s*(\\S+)");
041
042 /** . */
043 final String line;
044
045 /** . */
046 final String name;
047
048 /** . */
049 final String rest;
050
051 /** . */
052 final PipeLineFactory next;
053
054 /**
055 * Create a pipeline factory for the specified line and next factory
056 *
057 * @param line the line
058 * @param next the next factory
059 * @throws SyntaxException when the line is not correct
060 */
061 public PipeLineFactory(String line, PipeLineFactory next) throws SyntaxException {
062 java.util.regex.Matcher m = p.matcher(line);
063 if (m.find()) {
064 this.name = m.group(1);
065 this.rest = line.substring(m.end());
066 this.line = line;
067 this.next = next;
068 } else {
069 StringBuilder sb = new StringBuilder("syntax error near unexpected token");
070 if (next != null) {
071 sb.append(' ');
072 for (PipeLineFactory factory = next;factory != null;factory = factory.next) {
073 sb.append('|').append(factory.line);
074 }
075 }
076 throw new SyntaxException(sb.toString());
077 }
078 }
079
080 public String getLine() {
081 return line;
082 }
083
084 public PipeLineFactory getNext() {
085 return next;
086 }
087
088 public CommandInvoker<Void, Chunk> create(ReplSession session) throws CommandCreationException {
089 LinkedList<CommandInvoker> pipes = new LinkedList<CommandInvoker>();
090 for (PipeLineFactory current = this;current != null;current = current.next) {
091 ShellCommand<?> command = session.getCommand(current.name);
092 if (command == null) {
093 throw new CommandCreationException(current.name, ErrorType.EVALUATION, "Unknown command");
094 }
095 CommandInvoker commandInvoker = command.resolveInvoker(current.rest);
096 if (commandInvoker == null) {
097 throw new CommandCreationException(current.name, ErrorType.EVALUATION, "Command " + current.rest + " cannot not be invoked");
098 }
099 pipes.add(commandInvoker);
100 }
101 return new PipeLine(pipes.toArray(new CommandInvoker[pipes.size()]));
102 }
103
104 public PipeLineFactory getLast() {
105 if (next != null) {
106 return next.getLast();
107 }
108 return this;
109 }
110 }