/* Copyright (c) 2007-2014 by panayotis.com
*
* JavaPlot 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, version 2.
*
* JavaPlot is free 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 CrossMobile; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Created on October 14, 2007, 1:42 PM
*/
package com.panayotis.gnuplot;
import com.panayotis.gnuplot.terminal.GNUPlotTerminal;
import com.panayotis.gnuplot.utils.Debug;
import com.panayotis.gnuplot.utils.FileUtils;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
/**
* Object representing the low level gnuplot executable. This object is used in
* the plot() method of GNUPlot.
*
* @author teras
*/
class GNUPlotExec {
private static final transient String DEFAULT_PATH = FileUtils.findPathExec();
private transient String gnuplotexec;
private boolean ispersist;
private final static String[] persistcommand = {"path", "file", "-persist"};
private final static String[] nopersist = {"path", "file"};
/**
* Create a new GNUPlotExec object with defaultĪ© gnuplot path. Under POSIX
* environment, it is able to automatically find gnuplot executable in the
* $PATH
*
* @throws java.io.IOException if something went wrong and it is impossible
* to continue without further notice
*/
GNUPlotExec() throws IOException {
this(null);
}
/**
* Create a new GNUPlotExec object with a specific gnuplot path.
*
* @param path Path of gnuplot executable
* @throws java.io.IOException if the gnuplot executable is not found
*/
GNUPlotExec(String path) throws IOException {
if (path == null)
path = DEFAULT_PATH;
setGNUPlotPath(path);
ispersist = true;
}
/**
* Set the desired path for gnuplot executable.
*
* @param path Filename of gnuplot executable
* @throws java.io.IOException gnuplot is not found, or not valid
*/
final void setGNUPlotPath(String path) throws IOException {
if (new File(path).isFile())
gnuplotexec = path;
else
throw new IOException("GnuPlot executable \"" + path + "\" not found.");
}
/**
* Retrieve the file path of gnuplot
*
* @return The gnuplot file path
*/
String getGNUPlotPath() {
return gnuplotexec;
}
/**
* Retrieves the command which will actually send to gnuplot, if we perform
* a plot with the given parameters to the selected terminal. <br> This
* method is used for debugging purposes.
*
* @return The commands to send to the gnuplot executable
*/
public String getCommands(GNUPlotParameters par, GNUPlotTerminal terminal) {
// Could cache these commands..
return par.getPlotCommands(terminal);
}
/**
* Plot using specific parameters and selected terminal.
*
* @param par The parameters to use
* @param terminal The terminal to use
* @throws com.panayotis.gnuplot.GNUPlotException throw if something goes
* wrong
*/
void plot(GNUPlotParameters par, GNUPlotTerminal terminal) throws GNUPlotException {
try {
final GNUPlotTerminal term = terminal; // Use this thread-aware variable instead of "terminal"
final String comms = getCommands(par, term); // Get the commands to send to gnuplot
final Messages msg = new Messages(); // Where to store messages from output threads
/*
* Display plot commands to send to gnuplot
*/
GNUPlot.getDebugger().msg("** Start of plot commands **", Debug.INFO);
GNUPlot.getDebugger().msg(comms, Debug.INFO);
GNUPlot.getDebugger().msg("** End of plot commands **", Debug.INFO);
/*
* It's time now to start the actual gnuplot application
*/
String[] command;
if (ispersist)
command = persistcommand;
else
command = nopersist;
command[0] = getGNUPlotPath();
command[1] = FileUtils.createTempFile(comms);
{
String cmdStr = "";
for (String cmd : command)
cmdStr += cmd + " ";
GNUPlot.getDebugger().msg("exec(" + cmdStr + ")", Debug.INFO);
}
final Process proc = Runtime.getRuntime().exec(command);
/*
* Windows buffers DEMAND asynchronus read & write
*/
/*
* Thread to process the STDERR of gnuplot
*/
Thread err_thread = new Thread() {
@Override
public void run() {
BufferedReader err = new BufferedReader(new InputStreamReader(proc.getErrorStream()));
StringBuilder buf = new StringBuilder();
String line;
try {
while ((line = err.readLine()) != null)
if (!line.trim().equals(""))
buf.append(line).append('\n');
err.close();
msg.output = buf.toString(); // Store output stream
} catch (IOException ex) {
ex.printStackTrace(new PrintStream(System.out));
}
}
};
/*
* Thread to process the STDOUT of gnuplot
*/
err_thread.start();
Thread out_thread = new Thread() {
@Override
public void run() {
msg.process = term.processOutput(proc.getInputStream()); // Execute terminal specific output parsing
}
};
out_thread.start();
try {
proc.waitFor(); // wait for process to finish
out_thread.join(); // wait for output (terminal related) thread to finish
err_thread.join(); // wait for error (messages) output to finish
} catch (InterruptedException ex) {
throw new GNUPlotException("Interrupted execution of gnuplot");
}
new File(command[1]).delete();
/*
* Find the error message, if any, with precendence to the error
* thread
*/
String message = msg.error != null ? msg.error : msg.process;
/*
* Determine if error stream should be dumbed or not
*/
int level = Debug.VERBOSE;
if (message != null)
level = Debug.ERROR;
GNUPlot.getDebugger().msg("** Start of error stream **", level);
GNUPlot.getDebugger().msg(msg.output, level);
GNUPlot.getDebugger().msg("** End of error stream **", level);
/*
* Throw an exception if an error occured
*/
if (message != null)
throw new GNUPlotException(message);
} catch (IOException ex) {
throw new GNUPlotException("IOException while executing \"" + getGNUPlotPath() + "\":" + ex.getLocalizedMessage());
}
}
void setPersist(boolean persist) {
ispersist = persist;
}
private class Messages {
String output = "";
String error = null;
String process = null;
}
}