org.crsh.processor.term.Processor Maven / Gradle / Ivy
/*
* Copyright (C) 2012 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.processor.term;
import org.crsh.cli.impl.completion.CompletionMatch;
import org.crsh.cli.spi.Completion;
import org.crsh.io.Consumer;
import org.crsh.cli.impl.Delimiter;
import org.crsh.shell.Shell;
import org.crsh.shell.ShellProcess;
import org.crsh.text.Chunk;
import org.crsh.term.Term;
import org.crsh.term.TermEvent;
import org.crsh.text.Text;
import org.crsh.util.CloseableList;
import org.crsh.util.Strings;
import java.io.Closeable;
import java.io.IOException;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
public final class Processor implements Runnable, Consumer {
/** . */
static final Runnable NOOP = new Runnable() {
public void run() {
}
};
/** . */
final Runnable WRITE_PROMPT = new Runnable() {
public void run() {
writePromptFlush();
}
};
/** . */
final Runnable CLOSE = new Runnable() {
public void run() {
close();
}
};
/** . */
private final Runnable READ_TERM = new Runnable() {
public void run() {
readTerm();
}
};
/** . */
final Logger log = Logger.getLogger(Processor.class.getName());
/** . */
final Term term;
/** . */
final Shell shell;
/** . */
final LinkedList queue;
/** . */
final Object lock;
/** . */
ProcessContext current;
/** . */
Status status;
/** A flag useful for unit testing to know when the thread is reading. */
volatile boolean waitingEvent;
/** . */
private final CloseableList listeners;
public Processor(Term term, Shell shell) {
this.term = term;
this.shell = shell;
this.queue = new LinkedList();
this.lock = new Object();
this.status = Status.AVAILABLE;
this.listeners = new CloseableList();
this.waitingEvent = false;
}
public boolean isWaitingEvent() {
return waitingEvent;
}
public void run() {
// Display initial stuff
try {
String welcome = shell.getWelcome();
log.log(Level.FINE, "Writing welcome message to term");
term.write(Text.create(welcome));
log.log(Level.FINE, "Wrote welcome message to term");
writePromptFlush();
}
catch (IOException e) {
e.printStackTrace();
}
//
while (true) {
try {
if (!iterate()) {
break;
}
}
catch (IOException e) {
e.printStackTrace();
}
catch (InterruptedException e) {
Thread.currentThread().interrupt();
break;
}
}
}
boolean iterate() throws InterruptedException, IOException {
//
Runnable runnable;
synchronized (lock) {
switch (status) {
case AVAILABLE:
runnable = peekProcess();
if (runnable != null) {
break;
}
case PROCESSING:
case CANCELLING:
runnable = READ_TERM;
break;
case CLOSED:
return false;
default:
throw new AssertionError();
}
}
//
runnable.run();
//
return true;
}
// We assume this is called under lock synchronization
ProcessContext peekProcess() {
while (true) {
synchronized (lock) {
if (status == Status.AVAILABLE) {
if (queue.size() > 0) {
TermEvent event = queue.removeFirst();
if (event instanceof TermEvent.Complete) {
complete(((TermEvent.Complete)event).getLine());
} else {
String line = ((TermEvent.ReadLine)event).getLine().toString();
if (line.length() > 0) {
term.addToHistory(line);
}
ShellProcess process = shell.createProcess(line);
current = new ProcessContext(this, process);
status = Status.PROCESSING;
return current;
}
} else {
break;
}
} else {
break;
}
}
}
return null;
}
/** . */
private final Object termLock = new Object();
private boolean reading = false;
void readTerm() {
//
synchronized (termLock) {
if (reading) {
try {
termLock.wait();
return;
}
catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw new AssertionError(e);
}
} else {
reading = true;
}
}
//
try {
TermEvent event = term.read();
//
Runnable runnable;
if (event instanceof TermEvent.Break) {
synchronized (lock) {
queue.clear();
if (status == Status.PROCESSING) {
status = Status.CANCELLING;
runnable = new Runnable() {
ProcessContext context = current;
public void run() {
context.process.cancel();
}
};
}
else if (status == Status.AVAILABLE) {
runnable = WRITE_PROMPT;
} else {
runnable = NOOP;
}
}
} else if (event instanceof TermEvent.Close) {
synchronized (lock) {
queue.clear();
if (status == Status.PROCESSING) {
runnable = new Runnable() {
ProcessContext context = current;
public void run() {
context.process.cancel();
close();
}
};
} else if (status != Status.CLOSED) {
runnable = CLOSE;
} else {
runnable = NOOP;
}
status = Status.CLOSED;
}
} else {
synchronized (queue) {
queue.addLast(event);
runnable = NOOP;
}
}
//
runnable.run();
}
catch (IOException e) {
log.log(Level.SEVERE, "Error when reading term", e);
}
finally {
synchronized (termLock) {
reading = false;
termLock.notifyAll();
}
}
}
void close() {
listeners.close();
}
public void addListener(Closeable listener) {
listeners.add(listener);
}
public Class getConsumedType() {
return Chunk.class;
}
public void provide(Chunk element) throws IOException {
term.write(element);
}
public void flush() throws IOException {
throw new UnsupportedOperationException("what does it mean?");
}
void writePromptFlush() {
String prompt = shell.getPrompt();
try {
StringBuilder sb = new StringBuilder("\r\n");
String p = prompt == null ? "% " : prompt;
sb.append(p);
CharSequence buffer = term.getBuffer();
if (buffer != null) {
sb.append(buffer);
}
term.write(Text.create(sb));
term.flush();
} catch (IOException e) {
// Todo : improve that
e.printStackTrace();
}
}
private void complete(CharSequence prefix) {
log.log(Level.FINE, "About to get completions for " + prefix);
CompletionMatch completion = shell.complete(prefix.toString());
Completion completions = completion.getValue();
log.log(Level.FINE, "Completions for " + prefix + " are " + completions);
//
Delimiter delimiter = completion.getDelimiter();
try {
// Try to find the greatest prefix among all the results
if (completions.getSize() == 0) {
// Do nothing
} else if (completions.getSize() == 1) {
Map.Entry entry = completions.iterator().next();
Appendable buffer = term.getDirectBuffer();
String insert = entry.getKey();
term.getDirectBuffer().append(delimiter.escape(insert));
if (entry.getValue()) {
buffer.append(completion.getDelimiter().getValue());
}
} else {
String commonCompletion = Strings.findLongestCommonPrefix(completions.getValues());
// Format stuff
int width = term.getWidth();
//
String completionPrefix = completions.getPrefix();
// Get the max length
int max = 0;
for (String suffix : completions.getValues()) {
max = Math.max(max, completionPrefix.length() + suffix.length());
}
// Separator : use two whitespace like in BASH
max += 2;
//
StringBuilder sb = new StringBuilder().append('\n');
if (max < width) {
int columns = width / max;
int index = 0;
for (String suffix : completions.getValues()) {
sb.append(completionPrefix).append(suffix);
for (int l = completionPrefix.length() + suffix.length();l < max;l++) {
sb.append(' ');
}
if (++index >= columns) {
index = 0;
sb.append('\n');
}
}
if (index > 0) {
sb.append('\n');
}
} else {
for (Iterator i = completions.getValues().iterator();i.hasNext();) {
String suffix = i.next();
sb.append(commonCompletion).append(suffix);
if (i.hasNext()) {
sb.append('\n');
}
}
sb.append('\n');
}
// We propose
term.write(Text.create(sb.toString()));
// Rewrite prompt
writePromptFlush();
// If we have common completion we append it now
if (commonCompletion.length() > 0) {
term.getDirectBuffer().append(delimiter.escape(commonCompletion));
}
}
}
catch (IOException e) {
log.log(Level.SEVERE, "Could not write completion", e);
}
}
}
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