Performance of different graphviz engines

[manikmagar]

PR #278 changed the order of available engines to fix execution failure on Apple Silicon. Current order is of engine available check is - V8, JDK, CMD line (dot). V8 engine is usually slower but JDK (Nashorn, default for silicon) is much slower. CMD line (dot engine) is much faster compared to both.

• With JDK Nashorn Engine - Takes 6.5 seconds to generate a simple diagram.

2022-10-20 07:27:52,321 INFO  [c.j.m.DiagramRenderer] - Initiating drawing Graph at .
2022-10-20 07:27:58,618 INFO  [c.j.m.DiagramRenderer] - Generated Graph at ~/test-api/./mule-diagram.png

• With CMD line (dot engine) - Takes 0.5 seconds to generate the same diagram.

2022-10-20 07:28:10,192 INFO  [c.j.m.DiagramRenderer] - Initiating drawing Graph at .
2022-10-20 07:28:10,945 INFO  [c.j.m.DiagramRenderer] - Generated Graph at /Users/mmagar/devlife/avio/codebase/test-api/./dot-mule-diagram.png

CMD line (dot engine) requires Graphviz Dot engine installed on the target machine. I guess the default fallback order of - CMD, V8, JDK is better if CMD engine to be used when available.

• Use default engine order when loading Graphviz Engines.
• Update tests to use a specific graph engine that is used for pre-generated output json samples.