[WIP] Questions/Brainstorming

GretaCB commented 7 years ago

Per discussion with @springmeyer , outlining possible next steps for node-cpp-skel and capturing best practices to document and integrate into the skel design.

Questions to answer

What does it look like to have the variable that represents an instance of a class accessible in the threadpool?
What is the role of a singleton and how is it related to other design patterns for sync/async?
When passing data to thread pool, the data needs to be a type that is safe to pass into the thread pool. What makes a type safe to pass into the thread pool?
- Two scenarios that are safe:
- Copy data to a C++ object (pure, part of the C++ std lib...not V8)
- Copy V8 data: Extra work to keep the V8 object alive, avoids the object perhaps getting deleted (trick: use v8::Persistant)

Designing skel:

Goal 1)

Provide examples of objects that feel real-world, actionable, and sturdy
Unlocks: ability to fork and run fast and feel confidence the foundation is a best practice

Goal 2)

Provide incremental examples that build complexity gradually
Unlocks: easier for beginning developers to understand gradually why extra complexity is needed

Preliminary conclusion: object-sync is caught between these worlds

Terms to learn

[ ] @gretacb to add to cpp glossary

Standard C++

Singleton - is a general programming concept for creating a instance once in the process
- mapnik uses singletons for datasource plugin and font registration
static keyword
reference (what does the & mean?)

V8

Nan::Persistent (which is really v8::Persistent)
v8::FunctionTemplate and v8::Function
Nan::ObjectWrap

Possible next steps:

[x] @springmeyer could add/edit comments and provide them in another PR
[x] Build ^^ items into the cpp glossary (@gretacb first pass)
[x] Object async example: Demonstrate how we safely and efficiently utilize the threadpool to do work on data. Two options:
- vt-shaver example:
- Filters class, exposed in JS
- Able to create the Filters class once (as object in JS)
- Standalone shave function access Filters as an argument
- Filters is passed into the threadpool
- node-mapnik design: Classes expose method

GretaCB commented 7 years ago

Update

Per chat with @springmeyer when running through https://github.com/mapbox/node-cpp-skel/pull/51, I plan to:

[x] split the README into different docs:
- /docs/*.md: Info about C++ best practices, add-on conventions, explanation of files, and general 101
- README.md: The main README will be a great template README that developers can use for their own add-ons when using the skel as a baseline (how to install, run tests, build, publish, etc)
[x] Finalize object_async example
[x] Expand in the docs why each example is relevant/useful and when you would use each
[x] Comment sweep: Run through each example and config files to make sure relevant info is included and consistent within the comments, and that API.md is up to date
[x] Run .clang-format
[x] Performance section? Per chat with @springmeyer , we discussed that we should iterate on the bench/performance docs after having a realworld module in progress using the skel. See next check box below. But really want to make this a highlight since this is one of the main inspirations behind this skel, how to write high performance code.
[x] Put it into action by creating a new module from scratch (chat with @springmeyer about what module that could be). And use this as a way to feed missing docs/comments/examples back into the skel.
[ ] Get feedback from mapbox team

springmeyer commented 7 years ago

Build ^^ items into the cpp glossary (@GretaCB first pass)

https://github.com/mapbox/cpp/commit/92af06817b7f7df1506fdd696b6359e95e3fc476 and https://github.com/mapbox/cpp/commit/beb75bfde7ead41aab53d0520cd53ab1c27729b6

springmeyer commented 7 years ago

@GretaCB thanks for catching up on skel today voice. To help get to the finish line for this phase I've reviewed all open issues and commented on ones that I think are actionable. Of those that are actionable I think these are the priority things to finish before you move along:

[x] Finish docs re-org: https://github.com/mapbox/node-cpp-skel/pull/53
[x] Add support for code formatting and asserting on correct format: https://github.com/mapbox/node-cpp-skel/issues/37#issuecomment-319539643
[x] Land this improvement for handling strings: https://github.com/mapbox/node-cpp-skel/issues/54
[x] Quick check to make sure the sanitizers are working on travis: https://github.com/mapbox/node-cpp-skel/issues/40#issuecomment-319525532
[x] Land the first phase of benchmark scripts in node-cpp-skel master: https://github.com/mapbox/node-cpp-skel/pull/29#issuecomment-319533657

springmeyer commented 7 years ago

woot @GretaCB - everything above is checked. Shall we close?

mapbox / node-cpp-skel