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.command.pipeline;
021    
022    import org.crsh.command.CommandContext;
023    import org.crsh.command.ScriptException;
024    import org.crsh.io.Filter;
025    import org.crsh.text.Chunk;
026    
027    import java.io.IOException;
028    import java.util.Map;
029    
030    /** @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a> */
031    class PipeLineElement<C, P> implements Filter<C, P, CommandContext<P>>, CommandContext<C> {
032    
033      /** . */
034      protected CommandContext<P> context;
035    
036      /** . */
037      final Filter<C, P, CommandContext<P>> command;
038    
039      /** . */
040      final Class<C> consumedType;
041    
042    
043      PipeLineElement(Filter<C, P, CommandContext<P>> command) {
044        this.command = command;
045        this.consumedType = command.getConsumedType();
046      }
047    
048      public final boolean takeAlternateBuffer() throws IOException {
049        return context.takeAlternateBuffer();
050      }
051    
052      public final boolean releaseAlternateBuffer() throws IOException {
053        return context.releaseAlternateBuffer();
054      }
055    
056      public final String getProperty(String propertyName) {
057        return context.getProperty(propertyName);
058      }
059    
060      public final String readLine(String msg, boolean echo) {
061        return context.readLine(msg, echo);
062      }
063    
064      public final int getWidth() {
065        return context.getWidth();
066      }
067    
068      public final int getHeight() {
069        return context.getHeight();
070      }
071    
072      public Map<String, Object> getSession() {
073        return context.getSession();
074      }
075    
076      public Map<String, Object> getAttributes() {
077        return context.getAttributes();
078      }
079    
080      public boolean isPiped() {
081        return context.isPiped();
082      }
083    
084      public Class<P> getProducedType() {
085        return command.getProducedType();
086      }
087    
088      public Class<C> getConsumedType() {
089        return command.getConsumedType();
090      }
091    
092      public void open(CommandContext<P> consumer) {
093        this.context = consumer;
094        this.command.open(consumer);
095      }
096    
097      public void write(Chunk chunk) throws IOException {
098        if (consumedType.isInstance(chunk)) {
099          provide(consumedType.cast(chunk));
100        } else {
101          context.write(chunk);
102        }
103      }
104    
105      public void provide(C element) throws IOException {
106        command.provide(element);
107      }
108    
109      public void flush() throws IOException {
110        command.flush();
111      }
112    
113      public void close() throws ScriptException, IOException {
114        command.close();
115      }
116    }