in algebricks/algebricks-runtime/src/main/java/org/apache/hyracks/algebricks/runtime/operators/std/StringStreamingRuntimeFactory.java [57:193]
public AbstractOneInputOneOutputOneFramePushRuntime createOneOutputPushRuntime(final IHyracksTaskContext ctx)
throws AlgebricksException {
final IPrinter[] printers = new IPrinter[printerFactories.length];
for (int i = 0; i < printerFactories.length; i++) {
printers[i] = printerFactories[i].createPrinter();
}
return new AbstractOneInputOneOutputOneFramePushRuntime() {
final class ForwardScriptOutput implements Runnable {
private InputStream inStream;
private ITupleParser parser;
public ForwardScriptOutput(ITupleParser parser, InputStream inStream) {
this.parser = parser;
this.inStream = inStream;
}
@Override
public void run() {
try {
parser.parse(inStream, writer);
} catch (HyracksDataException e) {
throw new RuntimeException(e);
} finally {
try {
inStream.close();
} catch (Exception e) {
}
}
}
}
final class DumpInStreamToPrintStream implements Runnable {
private BufferedReader reader;
private PrintStream printStream;
public DumpInStreamToPrintStream(InputStream inStream, PrintStream printStream) {
this.reader = new BufferedReader(new InputStreamReader(inStream));
this.printStream = printStream;
}
@Override
public void run() {
String s;
try {
while ((s = reader.readLine()) != null) {
printStream.println(s);
}
} catch (IOException e) {
throw new RuntimeException(e);
} finally {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
printStream.close();
}
}
}
private Process process;
private PrintStream ps;
private boolean first = true;
private Thread outputPipe;
private Thread dumpStderr;
@Override
public void open() throws HyracksDataException {
if (first) {
first = false;
initAccessAppendRef(ctx);
}
try {
ITupleParser parser = parserFactory.createTupleParser(ctx);
process = Runtime.getRuntime().exec(command);
ps = new PrintStream(process.getOutputStream());
ForwardScriptOutput fso = new ForwardScriptOutput(parser, process.getInputStream());
outputPipe = new Thread(fso);
outputPipe.start();
DumpInStreamToPrintStream disps = new DumpInStreamToPrintStream(process.getErrorStream(),
System.err);
dumpStderr = new Thread(disps);
dumpStderr.start();
} catch (IOException e) {
throw new HyracksDataException(e);
}
}
@Override
public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
tAccess.reset(buffer);
int nTuple = tAccess.getTupleCount();
for (int t = 0; t < nTuple; t++) {
tRef.reset(tAccess, t);
for (int i = 0; i < printers.length; i++) {
printers[i].print(buffer.array(), tRef.getFieldStart(i), tRef.getFieldLength(i), ps);
ps.print(fieldDelimiter);
if (i == printers.length - 1) {
ps.print('\n');
}
}
}
}
@Override
public void close() throws HyracksDataException {
// first close the printer printing to the process
ps.close();
int ret = 0;
// then wait for the process to finish
try {
ret = process.waitFor();
outputPipe.join();
dumpStderr.join();
} catch (InterruptedException e) {
throw new HyracksDataException(e);
}
if (ret != 0) {
throw new HyracksDataException("Process exit value: " + ret);
}
// close the following operator in the chain
super.close();
}
@Override
public void flush() throws HyracksDataException {
ps.flush();
}
};
}