@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);
}
}
@Override
public JsonString eval(Context context) throws Exception {
JsonString inpath = (JsonString) exprs[0].eval(context);
String outpath;
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
Path path = new Path(inpath.toString());
if (path.isAbsolute()) {
String uri = fs.getUri().toString();
outpath = uri + inpath;
} else {
String home = fs.getHomeDirectory().toString();
outpath = home + "/" + inpath;
}
if (!fs.exists(new Path(outpath))) {
throw new IllegalArgumentException("The input path doesn't exist in HDFS");
}
return new JsonString(outpath);
}
/*
* (non-Javadoc)
*
* @see com.ibm.jaql.lang.expr.core.IterExpr#iter(com.ibm.jaql.lang.core.Context)
*/
public JsonArray eval(final Context context) throws Exception {
final JsonRegex regex = (JsonRegex) exprs[0].eval(context);
if (regex == null) {
return null;
}
JsonString text = (JsonString) exprs[1].eval(context);
if (text == null) {
return null;
}
final Matcher matcher = regex.takeMatcher();
matcher.reset(text.toString());
if (!matcher.find()) {
regex.returnMatcher(matcher);
return null;
}
int n = matcher.groupCount();
BufferedJsonArray arr = new BufferedJsonArray(n); // TODO: memory
for (int i = 0; i < n; i++) {
String s = matcher.group(i + 1);
arr.set(i, s == null ? null : new JsonString(s)); // TODO: memory
}
regex.returnMatcher(matcher);
return arr;
}
