1. Introduction to JXPL
UNCW Grid Group
Jeff Brown
11/13/2018

2. Outline Language Basics Origin Extensibility Application: OGSA-DAI
Remote Processors
Future Work
Jeff Brown
11/13/2018

3. XML for Scripting Parsers are already written
Many applications can create or edit scripts
XSLT and XPath now available in J2SE and allow easy manipulation
XML Schemas for validation
Jeff Brown
11/13/2018

4. JXPL Arithmetic Arbitrary precision decimal calculations
Exact integer calculations
Exact rational arithmetic
Jeff Brown
11/13/2018

5. Arithmetic Example <list xmlns="http://www.jxpl.org/script">
<primitive name="Math">
<property name="operation" value="pow"/>
</primitive>
<rational numerator="2345" denominator="1234"/>
<integer value="21"/>
</list>
<rational
numerator=" "
denominator=" "/>
Jeff Brown
11/13/2018

6. User-defined Functions
Local variables
Support recursion
Extend language
User-defined functions are treated exactly like built-in primitives
Functions can overwrite built-in primitives
Jeff Brown
11/13/2018

7. Before JXPL MathBoard Java Applet WYSIWYG mathematical environment
User-defined functions
Graphing
Symbolic manipulation
Jeff Brown
11/13/2018

8. MathBoard Screen Shot Jeff Brown 11/13/2018
Basic formula editing on Getting Started page
Bottom of page, sum n=1 to n=20 of n^3 / n! Change size. Change color.
F(a,b)=a^b+a/b, F(2,3) and F(2,x).
Now define x=6, and reevaluate f(2.x)
g(x)=x^x D ctl-j x g ctl-z symbolic diff
H(x)=8*sin(x)/x ctl-q drag to graph
Jeff Brown
11/13/2018

9. MathBoard Data Structures
Based on LISP
Flexible function evaluation
Easy symbolic manipulation
Simple to string encode and parse
Jeff Brown
11/13/2018

10. Saving State
MathBoard can write an applet tag that causes it to appear in its present state
Example
<APPLET ALIGN="MIDDLE" ARCHIVE="jme.jar" CODE="jme.MathBoard.class" WIDTH=346 HEIGHT=127>
<PARAM NAME="inline" VALUE="true">
<PARAM NAME="1" VALUE="c:73:76:Serif:0:20:
3 [ 5 ] sup [ 4 ] [ 7 ] / - ">
</APPLET>
Look at Taylor Polynomial example
Applet writes state for presentation purposes
Jeff Brown
11/13/2018

11. MathBoard Programming
Functions
LISP Cond statement
Create simple programs in MathBoard
Jeff Brown
11/13/2018

12. BKKC Calendar 1996 Burger King Kid Club activity calendar
Game for September
All players put marker on day 1
All players flip coin
If heads, move forward
If tails, move back, unless on day 1
First player to day 30 wins
-- applet to simulate game
Jeff Brown
11/13/2018

13. BKKC in MathBoard
people.uncw.edu/brownj/mathboard/help/game.html
Underlying data structure makes it easy to extend MathBoard
Going from mathematics language to general purpose processor is natural
Jeff Brown
11/13/2018

14. Origin lf JXPL MathBoard encoded postfix strings
XML structure perfect for LISP
XML + MathBoard Engine = JXPL
Jeff Brown
11/13/2018

15. JXPL Internal Data XML converted to Java objects
Java objects easier to manipulate than XML DOM elements (may change in future)
JxplElement: common super class
JxplList
JxplSymbol
etc
Jeff Brown
11/13/2018

16. DOM Level 3 JAX in Java 1.5 supports DOM level 3
Use XPath to query DOM
XMLQuery ??
Advances in XML support might make it feasible for JXPL to use DOM internally instead of Java objects.
Jeff Brown
11/13/2018

17. Extensibility: Defun
JXPL does not provide a way to get the length of a list
Use Defun to define function “length”
Now you can use “length” just as if it were a built-in primitive
Jeff Brown
11/13/2018

18. Extensibility: Primitive Interface
public JxplElement evaluate(JxplElement input)
Extend JXPL by implementing simple interface
Create class mypackage.MyPrimitive
Use name “mypackage.MyPrimitive” just as you would use the name of a built-in primitive
JXPL processor searches CLASSPATH for your primitive
Jeff Brown
11/13/2018

19. Application: OGSA-DAI
DAI: Data Access and Integration
Special type of Grid service called Grid Data Service (GDS)
Access to databases, relational and XML
Transformation of data (example: XSL)
Deliver data to a variety of sinks, such as GridFTP, file system, , other GDS
Jeff Brown
11/13/2018

20. GDS Scripts GDS is controlled by an OGSA-DAI XML script
OGSA-DAI scripting is not sophisticated enough to manage interaction between services
Some GDS scripts need to be created at runtime
Jeff Brown
11/13/2018

21. GDS Example GDS named source will query a database
GDS named sink will transform data
Source delivers its output to sink
OGSA-DAI uses common data format (WebRowSet) for service interaction.
Jeff Brown
11/13/2018

22. Managing GDS Interaction
Use factory to create sink instance and store the handle of the instance
Run sink service in separate thread so that it can wait for data delivery
Create GDS script to control source service, incorporating handle of sink
Use factory to create source and submit script
Jeff Brown
11/13/2018

23. Managing GDS with JXPL
A JXPL script can spawn a new thread for execution
JXPL programs can wait for JXPL code in another thread to finish
JXPL programs can create new scripts at runtime
Many languages could be used to manage GDS interaction, but JXPL can be created in the graphical GridNexus environment
Jeff Brown
11/13/2018

24. Remote JXPL Processors
Each JXPL processor has a URI
Processors can communicate with each other
A processor might send a script to a remote site for evaluation
Processors can get/set variables on remote processors
Jeff Brown
11/13/2018

25. JXPL URIs ogsa://152.21.222.213/…/instanceName
This uri is used by a JXPL processor whose evaluate method is exposed as a Grid service
rmi:// /Jxpl
This is the uri of a processor available through Remote Method Invocation (RMI)
socket:// :1090/Jxpl
Uri of processor accessed via http
Jeff Brown
11/13/2018

26. JxplSymbol A symbol is the name of a JXPL variable
Symbols use XML namespaces to indicate the uri of processor where the data is stored
When a processor evaluates a symbol it checks the symbol’s namespace. If that namespace is different from it’s uri, it contacts the remote processor for the data.
Jeff Brown
11/13/2018

27. Symbol Example <symbol xmlns:fire=“rmi://15.0.0.1/Jxpl”
name=“fire:foo bar”/>
When a processor evaluates the symbol “foo bar” it contacts the remote processor.
If a processor is directed to store data as that symbol, then it stores it on the remote processor.
Sections of a JXPL script can be named in a similar fashion, indicating that they should be executed remotely.
Jeff Brown
11/13/2018

28. Future Work: Primality Proving
Given a large integer n, determine whether or not n is prime (cannot be factored in a nontrivial way)
Agrawal, Kayal and Saxena have recently proved that there is a polynomial-time algorithm for primality proving.
The AKS algorithm is readily parallelizable.
Jeff Brown
11/13/2018

29. MIRACL Multiprecision Integer and Rational C/C++ Library
Designed specifically for the type of work needed in AKS, and other cryptography applications.
Very efficient.
Jeff Brown
11/13/2018

30. AKS Algorithm
The algorithm involves modular arithmetic on polynomials over a finite ring.
One polynomial must be raised to a very high power (n) and divided by another polynomial.
Repeated squaring and dividing.
Jeff Brown
11/13/2018

31. JXPL and MIRACL
JXPL uses the Java Native Interface (JNI) to access MIRACL functions.
It is necessary to create shared libraries for the different platforms that the JXPL processor might run on (libmiracl.so, miracl.dll)
Jeff Brown
11/13/2018

32. Parallel AKS
Start remote JXPL processors on machines in labs and classrooms on campus.
Run a JXPL script on one machine that divvies the work, sends it to remote processors and waits for the results.
Jeff Brown
11/13/2018

33. Summary JXPL is flexible enough for a variety of different tasks.
XML format makes it easy for programs to write JXPL scripts.
Designed for extensibility
Network aware
GridNexus makes it possible for non-programmers to use JXPL.
Jeff Brown
11/13/2018