1. Axel Faust Senior IT-Consultant / Software Architect PRODYNA AG
From Rhino to Nashorn
Axel Faust
Senior IT-Consultant / Software Architect
PRODYNA AG

2. Proof of concept Part of Enhanced Script Environment
Replace Rhino with Nashorn
Explore potential improvements 1

3. Rhino
Rhino
Since Alfresco 1.3
ECMA-262 Ed. 3 (1999) 2

4. Rhino vs. Nashorn Rhino Nashorn / JDK 8 Since Alfresco 1.3
ECMA-262 Ed. 3 (1999)
Nashorn / JDK 8
ECMA-262 Ed. 5.1 (2011) 3

5. Nashorn benefits Performance invokedynamic Dynamic linking (cached)
Persistent script caching 4

6. Nashorn benefits How much faster? My micro-benchmarks (YMMV)
ms (10k runs)
Each benchmark consists of 10k engine warmup and 10k timed executions
Trivial JS
- JS source code: var a = 3, b = 8, result; result = Math.pow(a, b);
Interop:
JS source code: var a = 3, b = 2.5, c = 'String', idx, max = 100; for(idx = 0; idx < max; idx++) { obj.testCall(a + idx, b, c);}
Java class: 3 overloaded methods => boolean testCall(double, double, String) - boolean testCall(int, double, String) - boolean testCall(Number, Number, String)
Java method: trivial => return a == b || c.equals("String"); 5

7. Nashorn benefits How much faster? My micro-benchmarks (YMMV)
ms (10k runs)
Each benchmark consists of 10k engine warmup and 10k timed executions
Trivial JS
- JS source code: var a = 3, b = 8, result; result = Math.pow(a, b);
Interop:
JS source code: var a = 3, b = 2.5, c = 'String', idx, max = 100; for(idx = 0; idx < max; idx++) { obj.testCall(a + idx, b, c);}
Java class: 3 overloaded methods => boolean testCall(double, double, String) - boolean testCall(int, double, String) - boolean testCall(Number, Number, String)
Java method: trivial => return a == b || c.equals("String"); 6

8. Nashorn benefits SAM / lambda support
removeIf => Collection default method (JDK8)
page.url.args.keys().removeIf(function(key) {
var isEmptyArg = page.url.args[key] === null
|| page.url.args[key].length === 0;
return isEmptyArg;
}); 7

9. Nashorn benefits Improved native primitive handling
E.g. jsString === javaString
Collection handling
List + Map = native(-ish)
Conversion util 8

10. Nashorn benefits Security Integrated with Security Manager
Script-specific security policies 9

11. Primary challenge
Rhino is virtually everywhere 10

12. Primary challenge Rhino is virtually everywhere
Value objects and services 11

13. Primary challenge Rhino is virtually everywhere
Value objects and services
Execution context and scope … 12

14. Primary tools Sub-class proxies Value conversion Adapter functionality
Virtually identical API
Value conversion
E.g. NativeArray Rhino <=> Nashorn 13

15. JSObject ~= Scriptable (special interop interface)
JSObject proxy
JSObject ~= Scriptable (special interop interface)
ScriptNode
JSObject Mixin
JSObject
cglib (sub-class) 14

16. JSObject ~= Scriptable (special interop interface)
JSObject proxy
JSObject ~= Scriptable (special interop interface)
ScriptNode
JSObject Mixin
JSObject
cglib (sub-class)
Value Converter
JSObject Mixin
Method lookup
and param
conversion
Scope + Context Mixin
Result conversion JS
ScriptNode JS 15

17. Other migration tools Bytecode instrumentation: Remove „final“
Signature mapping (specialization)
Input for value conversion 16

18. Status „Migrated“ Repository-tier (4.2.f) Capable of running Share
Custom import API ( importScript() )
Enhanced logging
Capable of running Share
Dashboards / DocLib / Sites
Read / Write 17

19. In the Future Migrate existing tools (i.e. batch processor)
Evaluate debugability
„Migrate“ Share? 18

20. Open issues - Nashorn Customizability Performance guides
== / === based on equals()
Locale + time zone handling
Performance guides 19

21. Open issues - Alfresco Script API refactoring Clean up legacy scripts
Agnostic interfaces
Abstract functional aspects
Clean up legacy scripts 20

22. Resources Thanks to @sundararajan_a (Twitter support)
Nashorn (OpenJDK project)
GitHub (nashorn_PoC branch)