I can vouch for a stable and documented C API. The main thing that stopped me from re-implementing node on top of SpiderMonkey was the SM APIs changing constantly and the docs on the wiki being constantly out of date. They were too new for the last stable release and too old for the latest mainline code. (Also the build system for SM itself was a mess and very particular).
Contrast with my luvit project which I did largely on my own for the first few months and had a good chunk of node re-implemented. Lua's C API is simple and consistent. I didn't have to use C++ at all which made things much easier for me. C is a fairly simple language, C++ is crazy complicated. I'm a scripter. I've been writing programs in scripting languages for over 20 years. I've been know to write a node addon or two because I really like the extra power it gives (node-webgl was a fun 24 hour hack). My only advice for the new common API is to keep it simple and avoid C++ classes. I'm not encouraging the stack oriented nature of the Lua API, but being able to work in terms of objects, properties, functions, etc (the same terms you use in JS) would be great. Treat everything as the simple data it is. I can draft some APIs based on my experience with writing libuv bindings for various runtimes if you're interested. -Tim Caswell On Mon, Jul 8, 2013 at 1:35 PM, Timothy J Fontaine <tjfonta...@gmail.com>wrote: > [cross post from http://atxconsulting.com/2013/07/06/rewrite-it-anyway/] > > Node v1.0 is approaching, and v0.12 is imminent (as far as that goes for > FOSS > projects). As we work towards getting v0.12 out the door, there have been > a lot > of changes happening for node's primary dependency v8. Ben is working on > moving > us to the 3.20 branch, follow his progress > [here](https://github.com/joyent/node/pull/5804). > > As you can tell this is a signficant change to the API, which requires a > touch > of virtually every file in our `src/`, this has been a huge headache for > him, > and will ultimately cause a huge headache for developers of binary addons. > > You're going to have to `#ifdef` around significant portions of the API to > keep > your module working across different version of node, this is going to > cause > endless amounts of pain and issues for node and developers who have for the > most part been accepting of the churn in our underspecified addon API. > > This one is going to hurt. > > A lot. > > ## TL;DR -- A modest proposal > > Since you're going to have to rewrite your module anyway, it's time for > node to > specify and export the API we are going to "bless" for addons. That is, > just > what API we are going to support and make sure continues to work from > minor and > major releases, as well as a deprecation policy. > > More specifically I think we should be exporting a separate (and not equal) > wrapper around (at the very least) javascript object creation, get/set, > function > calling. > > Additionally we should package and distribute (if possible in npm) a > transitional library/headers which module authors can target today which > will > allow their module to compile and work from v0.8 through v1.0 > > ## The Platform Problem > > We currently allow platforms/distributors to build against shared (their > own) > versions of many of our dependencies, including but not limited to: > > * v8 > - Holy crap, we're about as tightly coupled to the version of v8 we > ship as > chromium itself is. > * libuv > - If we weren't strictly coupled to v8, we certainly are for libuv, > there > would be no (useful) node, without libuv. > * openssl > - This is a must for linux distributions, who like to break DSA keys > and then > make every dependency vulnerable as a result (sorry Debian, I keed I keed). > - This actually allows distributors who know specific things about their > platform to enable/disable the features that allow it to run best. > * zlib > - Meh, this isn't such a big deal, it doesn't really change all that > often. > * http_parser > - Really? People ship this as a separate library? > > This functionality was added to appease platform builders, the likes of > Debian, > Fedora, and even SmartOS. However, doing so has complicated and muddled the > scenario of building and linking binary addons. > > Currently node-gyp downloads the sourceball, extracts the headers from it, > and makes some assumptions from `process.config` about how to build your > addon. > In practice this has been working reasonably well. > > However, I'm very concerned about this as a long term strategy. It's > possible > for someone to have tweaked or twisted the node (or one of its > dependencies) > builds, which could lead to some unintended consequences. In the "best" > case, > you'll get a compiler error from a changed API or clashing symbol. In the > worst > case they have modified the ABI which will manifest itself in unexpected > and > often subtle ways. > > Not to mention that we have no good answer on how to build and link addon > modules against the proper version of a shared dependency (what if the > system > has multiple openssl's, what if they compiled against it in one place, but > now > run against it in another). > > And last but not least, how do modules consume symbols from our > dependencies > that node itself doesn't consume. Consider a specific crypto routine from > openssl that you want to provide as an addon module because node doesn't > currently have an interface for it. > > ## Enemies without, and enemies within > > As if it weren't bad enough that platforms may ship against a version of v8 > that we haven't blessed, we (and addon developers) have to fight against > the > beast that is the v8 API churn. > > I don't really fault Google and the chromium or v8 team for how they are > handling this, more often then not we just end up with ugly compile time > deprecation warnings, letting us know the world is about to break. > > However, there have been times -- like right now -- where node can't paper > over > the drastic change in the v8 API for module developers. And as a result we > begrudgingly pass the API change to module authors. > > To paraphrase, don't forget that execrement will inevitably lose its battle > with gravity. > > So what are we going to do? > > ## Meat and Potatoes > > This is where I don't particularly have everything fleshed out, and I'm > sure I > will take a considerable amount of heat from people on API decisions that > haven't been made. > > I want to export the following interfaces: > > * `node/js.h` > - Object creation and manipulation. > - Function calling and Error throwing. > * `node/platform.h` > - IO and event loop abstraction. > * `node/ssl.h` > * `node/zlib.h` > * `node/http.h` > > While I am not particularly attached to the names of these headers, each > represent an interface that I think module authors would opt to target. I > only > feel strongly that we export `js` and `platform` as soon as possible as > they are the primary interactions for every module. > > ### Basic Principles > > There are only a few principles: > > * Avoid (like the plague) any scenario where we expose an ABI to module > authors. > - Where possible use opaque handles and getter/setter functions. > * The exported API should be a reliable interface which authors can > depend on > working across releases. > * While a dependency may change its API, we have committed to our > external API > and need to provide a transitional interface in accordance with our > deprecation > policy. > * The API should never expose an implementation detail to module authors > (A > spidermonkey backed node one day?). > > ### Platform > > The `platform` interface is the easiest to discuss, but the pattern would > follow for `ssl`, `zlib`, and `http`. > > This would just rexport the existing `uv` API, however with a C-style > namespace > of `node_`. Any struct passing should be avoided, and libuv would need to > be > updated to reflect that. > > ### JS > > I expect the `js` interface to be the most contentious, and also fraught > with > peril. > > The interface for addon authors should be C, I don't want to forsake the > C++ > folk, but I think the binding for that should be based on our C interface. > > I was going to describe my ideal interface, and frame it in context of my > ruby > and python experience. However, after a brief investigation, the JSAPI for > spidermonkey exports almost exactly the API I had in mind. So read about > that > [here]( > https://developer.mozilla.org/en-US/docs/SpiderMonkey/JSAPI_User_Guide). > > Would it make sense, and would it be worth the effort, for node to export a > JSAPI compatible interface? > > Would it make more sense to export a JSAPI influenced API currently > targetted > at v8 which could be trivially extended to also support spidermonkey? > > UPDATE 2013-07-08: > > > It's interesting and worthy to have a conversation about being able to > > provide a backend neutral object model, though our current coupling to > v8 and > > its usage in existing addons may not make it possible to entirely hide > away > > the eccentricities of the v8 API. But what we can provide is an interface > > that is viable to target against from release to release regardless of > how > > the public v8 API changes. > > ## Prior Art > > A lot of these ideas came from a discussion I had with > [Joshua Clulow](http://blog.sysmgr.org/) while en route to > [NodeConf](http://nodeconf.com). > > Part of that conversation was about [v8+]( > https://github.com/wesolows/v8plus) > which was written by a particularly talented coworker, who had a rather > nasty > experience writing for the existing C++ API (such as it is). > > There's some overlap in how it works and how I envisioned the new API. > However, > I'm not sure I'm particularly fond of automatically converting objects into > nvlists, though that does solve some of the release and retain issues. > > In general I would advocate opaque handles and getter and setter functions, > with a helper API which could do that wholesale conversion for you. > > Really though this matters less in a world where addon authors are > following > some defined "Best Practices". > > * Only pass and return "primitives" to/from the javascript/C boundary > - Primitives would be things like: `String`, `Number`, `Buffer`. > * Only perform objection manipulation in javascript where the JIT can work > its magic > > ## Dessert > > Work on this needs to begin as soon as possible. We should be able to > distribute it in npm, and authors should be able to target it by including > a > few headers in their source and adding a dependency stanza in their > `binding.gyp`, and by doing so their module will work from v0.8 through > v1.0 > > I mean, you're going to have to rewrite it anyway. > > -- > -- > Job Board: http://jobs.nodejs.org/ > Posting guidelines: > https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > You received this message because you are subscribed to the Google > Groups "nodejs" group. > To post to this group, send email to nodejs@googlegroups.com > To unsubscribe from this group, send email to > nodejs+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/nodejs?hl=en?hl=en > > --- > You received this message because you are subscribed to the Google Groups > "nodejs" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to nodejs+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups "nodejs" group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en --- You received this message because you are subscribed to the Google Groups "nodejs" group. To unsubscribe from this group and stop receiving emails from it, send an email to nodejs+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
