Package eu.simuline.octave.exec

Class OctaveExec

java.lang.Object

eu.simuline.octave.exec.OctaveExec

public final class OctaveExec
extends Object

The object connecting to the octave process.

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	destroyed
private ReaderWriterPipeThread	errorStreamThread	The error thread of the error stream of process writing the error stream to a given writer.
private ExecutorService	executor	Used in method evalRW(WriteFunctor, ReadFunctor) to submit essentially the write functor which submits the input and thereafter the read function which collects the output.
private static org.apache.commons.logging.Log	LOG
static String	MSG_EXE_NH
static String	MSG_IOE_NH
static String	MSG_RTE_NH
private Process	process	The octave process created in the constructor with given command, arguments, environment and working directory.
private BufferedReader	processReader	The input reader for process derived from Process.getInputStream().
private Writer	processWriter	The output writer for process derived from Process.getOutputStream().
private Random	random

Constructor Summary

Constructors

Constructor	Description
OctaveExec(int numThreadsReuse, Writer stdinLog, Writer stderrLog, Charset charset, String[] cmdArray, String[] environment, File workingDir)	Will start the octave process.

Method Summary

Modifier and Type	Method	Description
void	close()	Close the octave process in an orderly fashion: Send command exit and expect a single line in return, namely an empty one.
void	destroy()	Kill the octave process without remorse.
void	evalRW(WriteFunctor input, ReadFunctor output)	Passes input to octave, get back output and throws according exceptions if reading or writing went wrong.
private String	generateSpacer()
private RuntimeException	getFromFuture(Future<Void> future)	Completes computation on future and returns an exception thrown or null.
private boolean	isDestroyed()	Returns destroyed.
private OctaveException	reInstException(OctaveException exc)	Used by getFromFuture(Future) to re-instantiate an OctaveException if this occurs as the cause of an ExecutionException.
private void	setDestroyed(boolean destroyed)	Sets destroyed to the parameter value given.
void	setErrorWriter(Writer writer)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MSG_IOE_NH

public static final String MSG_IOE_NH

See Also:

Constant Field Values

MSG_EXE_NH

public static final String MSG_EXE_NH

See Also:

Constant Field Values

MSG_RTE_NH

public static final String MSG_RTE_NH

See Also:

Constant Field Values

LOG

private static final org.apache.commons.logging.Log LOG

process

private final Process process

The octave process created in the constructor with given command, arguments, environment and working directory. This is initialized in OctaveExec(int, Writer, Writer, Charset, String[], String[], File) and used in close() and destroy() only.

processWriter

private final Writer processWriter

The output writer for process derived from Process.getOutputStream().

processReader

private final BufferedReader processReader

The input reader for process derived from Process.getInputStream(). This is used by evalRW(WriteFunctor, ReadFunctor) and used to close via close().

executor

private final ExecutorService executor

Used in method evalRW(WriteFunctor, ReadFunctor) to submit essentially the write functor which submits the input and thereafter the read function which collects the output. Besides this, the executor is invoked to shutdown.

errorStreamThread

private final ReaderWriterPipeThread errorStreamThread

The error thread of the error stream of process writing the error stream to a given writer. This is used to close but also to change the error writer by setErrorWriter(Writer).

destroyed

private boolean destroyed

random

private final Random random

Constructor Detail

OctaveExec

public OctaveExec(int numThreadsReuse,
                  Writer stdinLog,
                  Writer stderrLog,
                  Charset charset,
                  String[] cmdArray,
                  String[] environment,
                  File workingDir)

Will start the octave process.

Parameters:

numThreadsReuse - the number of threads to be reused in a fixed thread pool. This is either positive or -1, which means that a cached thread pool is used instead of a fixed one.

stdinLog - This writer will capture all that is written to the octave process via stdin, if null the data will not be captured.

stderrLog - This writer will capture all that is written from the octave process on stderr, if null the data will not be captured.

charset - the charset used for communication with the octave process.

cmdArray - The array consisting of command and arguments: The 0th entry is either the path to the octave program, or the command found by looking at the built-in variable "paths" reconstructing the path. starting with the 1th entry, may follow the array of arguments to start the octave program with. CAUTION: allowed values depend on the octave version.

environment - Either the environment for the octave process, i.e. the set of values of environment variables with each entry of the form name=value or null to make process, the process created, inherit the environment of the current process.

workingDir - Either the working directory for the octave process, or null to make process, the process created, inherit the working directory of the current process.

Throws:

OctaveIOException - If execution

Method Detail

generateSpacer

private String generateSpacer()

evalRW

public void evalRW(WriteFunctor input,
                   ReadFunctor output)

Passes input to octave, get back output and throws according exceptions if reading or writing went wrong.

Parameters:

input - a write functor which represents the script to be executed in octave.

output - the read functor which reads the result of octave execution. After evaluation of this method, the output is asked for the result.

getFromFuture

private RuntimeException getFromFuture(Future<Void> future)

Completes computation on future and returns an exception thrown or null.

reInstException

private OctaveException reInstException(OctaveException exc)

Used by getFromFuture(Future) to re-instantiate an OctaveException if this occurs as the cause of an ExecutionException.

setDestroyed

private void setDestroyed(boolean destroyed)

Sets destroyed to the parameter value given.

isDestroyed

private boolean isDestroyed()

Returns destroyed.

destroy

public void destroy()

Kill the octave process without remorse.

close

public void close()

Close the octave process in an orderly fashion: Send command exit and expect a single line in return, namely an empty one.

Throws:

OctaveIOException - if

setErrorWriter

public void setErrorWriter(Writer writer)

Parameters:

writer - the new writer to write the error output to