view quick-test.js @ 36:34480328bf5c

Instead of using separate values and b64values entries in JSON serialisations, allow numeric arrays to be replaced by b64 variants wherever they appear (discriminating by type). Also rename values to featureValues in feature throughout, as values turns out to be a hazardous name in a JS context. Finally use Array instead of Text for array encoding (seems clearer).

"use strict";

var exampleModule = VampExamplePluginsModule();

// It is possible to declare both parameters and return values as
// "string", in which case Emscripten will take care of
// conversions. But it's not clear how one would manage memory for
// newly-constructed returned C strings -- the returned pointer from
// vampipeRequestJson would appear (?) to be thrown away by the
// Emscripten string converter if we declare it as returning a string,
// so we have no opportunity to pass it to vampipeFreeJson, which
// suggests this would leak memory if the string isn't static. Not
// wholly sure though. Anyway, passing and returning pointers (as
// numbers) means we can manage the Emscripten heap memory however we
// want in our request wrapper function below.

var vampipeRequestJson = exampleModule.cwrap(
    'vampipeRequestJson', 'number', ['number']
);

var vampipeFreeJson = exampleModule.cwrap(
    'vampipeFreeJson', 'void', ['number']
);

function note(blah) {
    document.getElementById("test-result").innerHTML += blah + "<br>";
}

function comment(blah) {
    note("<br><i>" + blah + "</i>");
}

function request(jsonStr) {
    note("Request JSON = " + jsonStr);
    var m = exampleModule;
    // Inspection reveals that intArrayFromString converts the string
    // from utf16 to utf8, which is what we want (though the docs
    // don't mention this). Note the *Cstr values are Emscripten heap
    // pointers
    var inCstr = m.allocate(m.intArrayFromString(jsonStr), 'i8', m.ALLOC_NORMAL);
    var outCstr = vampipeRequestJson(inCstr);
    m._free(inCstr);
    var result = m.Pointer_stringify(outCstr);
    vampipeFreeJson(outCstr);
    note("Returned JSON = " + result);
    return result;
}

function test() {

    comment("Querying plugin list...");
    var result = request('{"type": "list"}');

    comment("Loading zero crossings plugin...");
    result = request('{"type":"load","content": {"pluginKey":"vamp-example-plugins:powerspectrum","inputSampleRate":16,"adapterFlags":["AdaptAllSafe"]}}');

    comment("I'm now assuming that the load succeeded and the returned pluginHandle was 1. I haven't bothered to parse the JSON. If those assumptions are wrong, this obviously isn't going to work. Configuring the plugin...");
    result = request('{"type":"configure","content":{"pluginHandle":1,"configuration":{"blockSize": 8, "channelCount": 1, "stepSize": 8}}}');

    comment("If I try to configure it again, it should fail because it's already configured... but this doesn't change anything, and subsequent processing should work fine. Just an example of a failure call. NB this only works if Emscripten has exception catching enabled -- it's off by default in opt builds, which would just end the script here. Wonder what the performance penalty is like.");
    result = request('{"type":"configure","content":{"pluginHandle":1,"configuration":{"blockSize": 8, "channelCount": 1, "stepSize": 8}}}');

    comment("Now processing a couple of blocks of data, on the same assumptions...");
    result = request('{"type":"process","content":{"pluginHandle":1,"processInput":{"timestamp":{"s":0,"n":0},"inputBuffers":[{"values":[0,1,-1,0,1,-1,0,1]}]}}}');
    result = request('{"type":"process","content":{"pluginHandle":1,"processInput":{"timestamp":{"s":0,"n":500000000},"inputBuffers":[{"values":[0,1,-1,0,1,-1,0,1]}]}}}');

    comment("Cleaning up the plugin and getting any remaining features...");
    result = request('{"type":"finish","content":{"pluginHandle":1}}');

    comment("A process call should now fail, as the plugin has been cleaned up.");
    result = request('{"type":"process","content":{"pluginHandle":1,"processInput":{"timestamp":{"s":0,"n":1000000000},"inputBuffers":[{"values":[0,1,-1,0,1,-1,0,1]}]}}}');
}

window.onload = function() {
    test();
}