@Override
public JsonIterator iter(final Context context) throws Exception {
final JsonString cmd = (JsonString) exprs[1].eval(context);
if (cmd == null) {
return JsonIterator.NULL;
}
iter = exprs[0].iter(context);
if (iter.isNull()) {
return JsonIterator.NULL;
}
proc = Runtime.getRuntime().exec(cmd.toString());
// TODO: add thread pool to context
InputThread inputThread = new InputThread();
ErrorThread errorThread = new ErrorThread();
final MutableJsonString str = new MutableJsonString();
try {
InputStream is = proc.getInputStream();
final BufferedReader reader = new BufferedReader(new InputStreamReader(is));
errorThread.start();
inputThread.start();
return new JsonIterator(str) {
@Override
public boolean moveNext() throws Exception {
try {
String s = reader.readLine();
if (s == null) {
reader.close();
int rc = proc.waitFor();
if (rc != 0) {
System.err.println("non-zero exit code from process [" + cmd + "]: " + rc);
}
return false;
}
str.setCopy(s);
return true; // currentValue == str
} catch (Throwable e) {
if (error == null) {
error = e;
}
proc.destroy();
if (error instanceof Exception) {
throw (Exception) error;
}
throw new UndeclaredThrowableException(error);
}
}
};
} catch (Throwable e) {
if (error == null) {
error = e;
}
proc.destroy();
if (error instanceof Exception) {
throw (Exception) error;
}
throw new UndeclaredThrowableException(error);
}
}
private void initProcess(Context context) throws Exception {
ProcessBuilder pb = new ProcessBuilder();
if (cmd instanceof JsonString) {
String tmp = ((JsonString) cmd).toString();
String[] cmdArray = tmp.split(" ");
ArrayList<String> array = new ArrayList<String>();
for (String s : cmdArray) {
if (s.length() > 0) array.add(s.trim());
}
pb.command(array);
}
Configuration cfg = new Configuration();
File directory = new File(cfg.get("mapred.local.dir", "."));
pb.directory(directory);
// unset environment variables that jvm dump to stderr
pb.environment().remove("_JAVA_OPTIONS");
pb.environment().remove("JAVA_TOOL_OPTIONS");
process = pb.start();
ErrorThread errorThread = new ErrorThread();
errorThread.start();
stdin = process.getInputStream();
stdout = process.getOutputStream();
OutputAdapter outAdapter =
(OutputAdapter) JaqlUtil.getAdapterStore().output.getAdapter(writeOpts);
if (!(outAdapter instanceof StreamOutputAdapter))
throw new IllegalArgumentException(
"The adapter of writeOpts must be an instance of com.ibm.jaql.io.stream.StreamOutputAdapter");
((StreamOutputAdapter) outAdapter).setDefaultOutput(stdout);
outAdapter.open();
writer = outAdapter.getWriter();
InputAdapter inAdapter = (InputAdapter) JaqlUtil.getAdapterStore().input.getAdapter(readOpts);
if (!(inAdapter instanceof StreamInputAdapter))
throw new IllegalArgumentException(
"The adapter of readOpts must be an instance of com.ibm.jaql.io.stream.ExternalCallStreamInputAdapter");
((StreamInputAdapter) inAdapter).setInputStream(stdin);
inAdapter.open();
reader = inAdapter.iter();
}
private void init(InputStream in, OutputStream out, InputStream err) {
m_out = new PrintWriter(out);
m_isProgramDead = false;
m_queue = new ArrayBlockingQueue<Message>(10);
m_inputThread = new InputThread(in, m_queue);
if (err != null) {
m_errorThread = new ErrorThread(err, m_queue);
m_errorThread.start();
}
m_inputThread.start();
}
