[engine] new JS VM

[florianlenz]

Feature / Issue

Otto doesn't really work out for us since it doesn't offer the performance we need nor the sandboxing features (like limiting the allocated memory). We should switch to duktape (there are go bindings).

things to figure out:

• we need duk_create_heap for sandboxing to make sure there is no way to allocate more mem than we provide. However it doesn't seem to be implemented (https://github.com/olebedev/go-duktape/blob/v3/api.go#L1597). However, it's used here but it's not exported so we might need to fork.
• take in account this file. We need to understand it in order to build a secure VM.

Acceptance criteria

• tests
• all current feature of the DApp engine must work
• sandboxing

[borjantrajanoski]

Some sample code on how a call back can be done with duktape

Is there any reason why a map cannot be used in this way?

Callback proof of concept rc1

[florianlenz]

Good question, I didn't look too much into how function should work, but there should be a call method or something like this on a value (you might need to transform it to a function - there should be a toFunction method)

Maps are not supported afaik. But we can go without them :) For e.g. the database we can just export dbPut instead of the object .

[borjantrajanoski]

@kevowevo this will be done at the 28th

[borjantrajanoski]

Finished initial migration from Otto to Duktape PR 94

Needs careful review and potential small fixes to make sure integration is fully compatible