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/*
* Copyright (C) 2010 eXo Platform SAS.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.crsh.term;
import org.crsh.util.Input;
import org.crsh.util.InputDecoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.util.LinkedList;
import java.util.concurrent.atomic.AtomicInteger;
/**
* @author Julien Viet
* @version $Revision$
*/
public class BaseTerm extends InputDecoder implements Term {
/** . */
private static final int STATUS_INITIAL = 0;
/** . */
private static final int STATUS_OPEN = 1;
/** . */
private static final int STATUS_CLOSED = 2;
/** . */
private static final int STATUS_WANT_CLOSE = 3;
/** . */
private static final int STATUS_CLOSING = 4;
/** . */
private final Logger log = LoggerFactory.getLogger(BaseTerm.class);
/** . */
private final TermProcessor processor;
/** . */
private final AtomicInteger status;
/** . */
private final Object lock = new Object();
/** . */
private final LinkedList awaiters = new LinkedList();
/** . */
private final LinkedList history;
/** . */
private String historyBuffer;
/** . */
private int historyCursor;
/** . */
private String prompt;
/** . */
private final TermIO io;
private static class Awaiter {
TermAction action;
private Awaiter() {
}
public synchronized void give(TermAction action) {
this.action = action;
notify();
}
public synchronized TermAction take() {
try {
wait();
return action;
} catch (InterruptedException e) {
e.printStackTrace();
return null;
}
}
}
public BaseTerm(TermIO io) {
this(io, null);
}
public BaseTerm(TermIO io, TermProcessor processor) {
this.processor = processor;
this.status = new AtomicInteger(STATUS_INITIAL);
this.history = new LinkedList();
this.historyBuffer = null;
this.historyCursor = -1;
this.io = io;
}
public void run() {
//
if (!status.compareAndSet(STATUS_INITIAL, STATUS_OPEN)) {
throw new IllegalStateException();
}
//
TermAction action = new TermAction.Init();
//
while (status.get() == STATUS_OPEN) {
if (action == null) {
try {
action = _read();
log.debug("read term data " + action);
} catch (IOException e) {
if (status.get() == STATUS_OPEN) {
log.error("Could not read term data", e);
} else {
log.debug("Exception but term is considered as closed", e);
// We continue it will lead to getting out of the loop
continue;
}
}
}
//
Awaiter awaiter = null;
synchronized (lock) {
if (awaiters.size() > 0) {
awaiter = awaiters.removeFirst();
}
}
// Consume
final TermAction action2 = action;
action = null;
//
if (awaiter != null) {
awaiter.give(action2);
} else {
//
TermResponseContext ctx = new TermResponseContext() {
public void setEcho(boolean echo) {
BaseTerm.this.setEchoing(echo);
}
public TermAction read() throws IOException {
return BaseTerm.this.read();
}
public void write(String msg) throws IOException {
BaseTerm.this.write(msg);
}
public void setPrompt(String prompt) {
BaseTerm.this.prompt = prompt;
}
public void done(boolean close) {
try {
String p = prompt == null ? "%" : prompt;
BaseTerm.this.write("\r\n" + p);
} catch (IOException e) {
e.printStackTrace();
}
//
if (close) {
// Change status
if (status.compareAndSet(STATUS_OPEN, STATUS_WANT_CLOSE)) {
// If we succeded we close the term
// It will cause an exception to be thrown for the thread that are waiting in the
// blocking read operation
io.close();
}
}
}
};
//
boolean processed = processor.process(action2, ctx);
if (!processed) {
// Push back
log.debug("Pushing back action " + action2);
action = action2;
} else if (action2 instanceof TermAction.ReadLine) {
String line = ((TermAction.ReadLine)action2).getLine();
historyCursor = -1;
historyBuffer = null;
if (line.length() > 0) {
history.addFirst(((TermAction.ReadLine)action2).getLine());
}
}
}
}
}
public TermAction read() throws IOException {
Awaiter awaiter;
//
synchronized (lock) {
awaiter = new Awaiter();
awaiters.add(awaiter);
}
//
TermAction taken = awaiter.take();
return taken;
}
public void close() {
//
status.compareAndSet(STATUS_OPEN, STATUS_WANT_CLOSE);
//
if (status.compareAndSet(STATUS_WANT_CLOSE, STATUS_CLOSING)) {
try {
log.debug("Closing connection");
io.flush();
io.close();
} catch (IOException e) {
log.debug("Exception thrown during term close()", e);
} finally {
status.set(STATUS_CLOSED);
}
}
}
public TermAction _read() throws IOException {
while (true) {
int code = io.read();
CodeType type = io.getType(code);
switch (type) {
case DELETE:
appendDel();
break;
case UP:
case DOWN:
int nextHistoryCursor = historyCursor + (type == CodeType.UP ? + 1 : -1);
if (nextHistoryCursor >= -1 && nextHistoryCursor < history.size()) {
String s = nextHistoryCursor == -1 ? historyBuffer : history.get(nextHistoryCursor);
String t = set(s);
if (historyCursor == -1) {
historyBuffer = t;
}
if (nextHistoryCursor == -1) {
historyBuffer = null;
}
historyCursor = nextHistoryCursor;
}
break;
case RIGHT:
moveRight();
break;
case LEFT:
moveLeft();
break;
case CHAR:
if (code >= 0 && code < 128) {
if (code == 3) {
log.debug("Want to cancel evaluation");
return new TermAction.CancelEvaluation();
} else if (code == 10) {
appendData("\r\n");
} else {
appendData((char)code);
}
} else {
log.debug("Unhandled char " + code);
}
break;
}
//
if (hasNext()) {
Input input = next();
if (input instanceof Input.Chars) {
return new TermAction.ReadLine(((Input.Chars)input).getValue());
} else {
throw new UnsupportedOperationException();
}
}
}
}
public void write(String msg) throws IOException {
io.write(msg);
io.flush();
}
@Override
protected void doEchoCRLF() throws IOException {
io.writeCRLF();
io.flush();
}
@Override
protected void doEchoDel() throws IOException {
io.writeDel();
io.flush();
}
@Override
protected void doEcho(String s) throws IOException {
io.write(s);
io.flush();
}
@Override
protected boolean doMoveRight() throws IOException {
return io.moveRight();
}
@Override
protected boolean doMoveLeft() throws IOException {
return io.moveLeft();
}
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