parshap / js-opc Goto Github PK

Heyo,

Buffer class is used in test.js which is not available in Browsers:

Uncaught TypeError: Buffer.alloc is not a function
    at getBuffer (test-bundle.js:11774)
    at module.exports (test-bundle.js:11774)
    at Test.<anonymous> (test-bundle.js:11788)
    at Test.bound [as _cb] (test-bundle.js:8090)
    at Test.run (test-bundle.js:8103)
    at Test.bound [as run] (test-bundle.js:8090)
    at next (test-bundle.js:7900)
    at test-bundle.js:5322
    at Array.forEach (<anonymous>)
    at MutationObserver.<anonymous> (test-bundle.js:5321)

(Posted here so others may find it and because it exceeds 140 characters…)

Background: I am using opc in an app that controls 'sections' of pixels according to some configurable logic. I wrote a very simple/naive abstraction on top of it (1 section = 1 strand), and I am using that to get a feeling for how a higher-level OPC package could look (internally and externally).

So far, the prototype is working fine, but some questions arose from that:

• Buffers: As in your example, I am simply looping over every pixel in a strand and set its color, even when I want to set them all to the same color. Is that the recommended way to do it or does it just make for a very simple example? (This question might make more sense in the context of the next one).
• Coordination: A very general question, but maybe there is an easy answer: Do I have to care at all about coordinating all the calls I make to set pixels vs. when I write those pixels to the stream?
  To my surprise, it just worked; I would have expected issues when writing to 2 strands at the same time and writing a "half-finished" stream to the buffer. On the other hand with a local simulator everything is so fast that I might just not see any weird things going on. I have absolutely no intuition about this, so: should I coordinate inside the lib to not do any concurrent writes?
• Callbacks: Another point where I might just be confused: Upon first look, I expected stream.writePixels to take a callback(err, res), but it doesn't. Is that because it wouldn't make sense conceptually or just because it wasn't needed till now?

All 3 questions can be summarised as "should I now take the time to learn more about buffers/net/streams or will it just be fine" ;)