Example #1
0
 private static void endInterpreter(String contextId) throws EvalError {
   Interpreter i = interpreters.get(contextId);
   if (i == null) return;
   i.eval("clear();"); // can't hurt to tell bsh to clean up internally
   interpreters.remove(contextId); // now wait for GC
   Log.log("Destroyed context: " + contextId + " (" + i + ")");
 }
Example #2
0
  private static Interpreter getInterpreter(String contextId) throws EvalError {
    // Get the appropriate interpreter
    Interpreter i = null;
    boolean createdInterp = false;
    synchronized (interpreters) { // serialize two gets of the same name
      i = interpreters.get(contextId);
      if (i == null) {
        i = new Interpreter();
        interpreters.put(contextId, i);
        createdInterp = true;
      }
    }
    if (createdInterp) {
      Log.log("Created context: " + contextId + " (" + i + ")");

      // Now configure stdin and stdout to capture 10k of content
      // Store references to the circular buffers within the interpreter itself.
      // This provides a nice place to store them plus theoretically allows
      // advanced use from within the bsh environment.
      // On Windows print() outputs \r\n but in XQuery that's normalized to \n
      // so the 10k of Java buffer may produce less than 10k of content in XQuery!
      OutputStream circularOutput = new CircularByteArrayOutputStream(10240);
      PrintStream printOutput = new PrintStream(circularOutput);
      i.setOut(printOutput);
      i.set("mljamout", circularOutput);

      OutputStream circularError = new CircularByteArrayOutputStream(10240);
      PrintStream printError = new PrintStream(circularError);
      i.setErr(printError);
      i.set("mljamerr", circularError);

      // Capture the built-in System.out and System.err also.
      // (Commented out since System appears global, can't do per interpreter.)
      // i.set("mljamprintout", printOutput);
      // i.set("mljamprinterr", printError);
      // i.eval("System.setOut(mljamprintout);");
      // i.eval("System.setErr(mljamprinterr);");

      // Need to expose hexdecode() and base64decode() built-in functions
      i.eval("hexdecode(String s) { return com.xqdev.jam.MLJAM.hexDecode(s); }");
      i.eval("base64decode(String s) { return com.xqdev.jam.MLJAM.base64Decode(s); }");

      // Let's tell the context what its id is
      i.set("mljamid", contextId);
    }

    // Update the last accessed time, used for cleaning
    i.set("mljamlast", System.currentTimeMillis());

    // If it's been long enough, go snooping for stale contexts
    if (System.currentTimeMillis() > lastClean + CLEAN_INTERVAL) {
      Log.log("Initiated periodic scan for stale context objects");
      lastClean = System.currentTimeMillis();
      Iterator<Interpreter> itr = interpreters.values().iterator();
      while (itr.hasNext()) {
        Interpreter interp = itr.next();
        Long last = (Long) interp.get("mljamlast");
        if (System.currentTimeMillis() > last + STALE_TIMEOUT) {
          itr.remove();
          Log.log("Staled context: " + interp.get("mljamid") + " (" + interp + ")");
        } else if ((System.currentTimeMillis() > last + TEMP_STALE_TIMEOUT)
            && ("" + interp.get("mljamid")).startsWith("temp:")) {
          itr.remove();
          Log.log("Staled temp context: " + interp.get("mljamid") + " (" + interp + ")");
        }
      }
    }

    return i;
  }
Example #3
0
  protected void doPost(HttpServletRequest req, HttpServletResponse res)
      throws ServletException, IOException {
    try {
      // A good request looks like /mljam/contextid/verb?name=varname
      // The extra path info includes the context id and verb
      String extra = req.getPathInfo(); // "/contextid/verb"
      if (extra == null || extra.equals("")) {
        throw new ClientProblemException(
            "Request requires a context id and verb in its extra path info");
      }
      String[] parts = extra.split("/"); // { "", "contextid", "verb" }
      if (parts.length < 2) {
        throw new ClientProblemException(
            "Request requires a context id and verb in its extra path info");
      } else if (parts.length < 3) {
        throw new ClientProblemException("Request requires a verb in its extra path info");
      }

      String contextId = parts[1];
      String verb = parts[2];
      String method = req.getMethod();

      if (method.equalsIgnoreCase("get")) {

        // We have three GET verbs: get, get-stdout, get-stderr.
        // These are all idempotent, while the POST verbs aren't.  The get
        // verb accept a "name" query string parameter.  The get verb returns
        // either XQuery to evaluate (indicated by x-marklogic/xquery content type)
        // or a raw binary (indicated by an application/binary-encoded content type).

        if (verb.equalsIgnoreCase("get")) {
          String name = req.getParameter("name");
          if (name == null || name.equals("")) {
            throw new ClientProblemException("The get verb requires a name parameter");
          }
          Interpreter i = getInterpreter(contextId);
          Object o = i.get(name);
          if (o instanceof byte[]) {
            sendBinaryResponse(res, (byte[]) o);
          } else if (o instanceof String) {
            sendStringResponse(res, (String) o);
          } else {
            sendXQueryResponse(res, o);
          }
        } else if (verb.equalsIgnoreCase("get-stdout")) {
          Interpreter i = getInterpreter(contextId);
          i.getOut().flush();
          CircularByteArrayOutputStream circ = (CircularByteArrayOutputStream) i.get("mljamout");
          if (circ != null) {
            sendStringResponse(res, circ.toString());
            circ.reset();
          } else {
            throw new ServerProblemException("Could not fetch mljamout from interpreter context");
          }
        } else if (verb.equalsIgnoreCase("get-stderr")) {
          Interpreter i = getInterpreter(contextId);
          i.getErr().flush();
          CircularByteArrayOutputStream circ = (CircularByteArrayOutputStream) i.get("mljamerr");
          if (circ != null) {
            sendStringResponse(res, circ.toString());
            circ.reset();
          } else {
            throw new ServerProblemException("Could not fetch mljamerr from interpreter context");
          }
        } else {
          throw new ClientProblemException("Unrecognized GET verb: " + verb);
        }
      } else if (method.equalsIgnoreCase("post")) {
        // We have six POST verbs: eval, unset, end, source, set-string, and set-binary.
        // These are POST verbs because they aren't idempotent.
        // The set-string, set-binary, unset, and source verbs accept a "name"
        // query string parameter.  The set-string and set-binary verbs accept
        // a value in their post body.  The eval verb accepts code in its post body.

        if (verb.equalsIgnoreCase("set-string")) {
          String name = req.getParameter("name");
          if (name == null || name.equals("")) {
            throw new ClientProblemException("The set-string verb requires a name parameter");
          }
          String body = getBody(req); // a value of "" is legit
          Interpreter i = getInterpreter(contextId);
          i.unset(name);
          i.set(name, body);
          sendNoResponse(res);
        } else if (verb.equalsIgnoreCase("set-binary")) {
          String name = req.getParameter("name");
          if (name == null || name.equals("")) {
            throw new ClientProblemException("The set-binary verb requires a name parameter");
          }
          String body = getBody(req); // a value of "" is legit
          byte[] bodyBytes = hexDecode(body); // later could do this streaming for speed
          Interpreter i = getInterpreter(contextId);
          i.unset(name);
          i.set(name, bodyBytes);
          sendNoResponse(res);
        } else if (verb.equalsIgnoreCase("eval")) {
          String body = getBody(req);
          if (body == null || body.equals("")) {
            throw new ClientProblemException(
                "The eval verb requires a post body containing code to eval");
          }
          Interpreter i = getInterpreter(contextId);
          i.eval(body);
          sendNoResponse(res);
        } else if (verb.equalsIgnoreCase("eval-get")) {
          String body = getBody(req);
          if (body == null || body.equals("")) {
            throw new ClientProblemException(
                "The eval-get verb requires a post body containing code to eval");
          }
          Interpreter i = getInterpreter(contextId);
          Object o = i.eval(body);
          if (o instanceof byte[]) {
            sendBinaryResponse(res, (byte[]) o);
          } else if (o instanceof String) {
            sendStringResponse(res, (String) o);
          } else {
            sendXQueryResponse(res, o);
          }
        } else if (verb.equalsIgnoreCase("unset")) {
          String name = req.getParameter("name");
          if (name == null || name.equals("")) {
            throw new ClientProblemException("The unset verb requires a name parameter");
          }
          Interpreter i = getInterpreter(contextId);
          i.unset(name);
          sendNoResponse(res);
        } else if (verb.equalsIgnoreCase("end")) {
          endInterpreter(contextId);
          sendNoResponse(res);
        } else if (verb.equalsIgnoreCase("source")) {
          String name = req.getParameter("name");
          if (name == null || name.equals("")) {
            throw new ClientProblemException("The source verb requires a name parameter");
          }
          Interpreter i = getInterpreter(contextId);
          i.source(name);
          sendNoResponse(res);
        } else {
          throw new ClientProblemException("Unrecognized POST verb: " + verb);
        }
      }
    } catch (TargetError e) {
      Throwable target = e.getTarget();
      Log.log(e);
      Log.log("Target: " + target);
      sendServerProblemResponse(
          res,
          target.getClass().getName()
              + ": "
              + target.getMessage()
              + " when executing Java code: "
              + e.getErrorText()); // include full trace?
    } catch (EvalError e) {
      Log.log(e);
      sendServerProblemResponse(
          res, e.getClass().getName() + ": " + e.getMessage()); // include full trace?
    } catch (ClientProblemException e) {
      Log.log(e);
      sendClientProblemResponse(res, e.getMessage());
    } catch (ServerProblemException e) {
      Log.log(e);
      sendServerProblemResponse(res, e.getMessage());
    }
  }