Can’t use on Deno Deploy

[RoyalIcing]

I’ve tried deploying this to Deno Deploy, and get the following error:

EvalError: Code generation from strings disallowed for this context
    at new Function (<anonymous>)
    at Qb (https://raw.githubusercontent.com/DjDeveloperr/deno-canvas/v1.3.0/src/lib.js:3977:17)
    at Rb (https://raw.githubusercontent.com/DjDeveloperr/deno-canvas/v1.3.0/src/lib.js:3985:15)
    at Module.<anonymous> (https://raw.githubusercontent.com/DjDeveloperr/deno-canvas/v1.3.0/src/lib.js:5090:30)
    at init (https://raw.githubusercontent.com/DjDeveloperr/deno-canvas/v1.3.0/src/canvaskit.ts:6:22)
    at init (https://raw.githubusercontent.com/DjDeveloperr/deno-canvas/v1.3.0/src/canvas.ts:6:20)
    at https://raw.githubusercontent.com/DjDeveloperr/deno-canvas/v1.3.0/mod.ts:2:22

https://raw.githubusercontent.com/DjDeveloperr/deno-canvas/v1.3.0/src/lib.js

The culprit on line 3977 looks like:

function Qb(a, b) {
        a = Pb(a);
        return (new Function(
          "body",
          "return function " + a +
            '() {\n    "use strict";    return body.apply(this, arguments);\n};\n',
        ))(b);
      }

There‘s also another dynamic function on line 5884:

kb: function (a, b, c, f) {
          a = dd(a);
          var g = ld[b];
          if (!g) {
            g = "";
            for (var l = 0; l < b; ++l) g += (0 !== l ? ", " : "") + "arg" + l;
            var p = "return function emval_allocator_" + b +
              "(constructor, argTypes, args) {\n";
            for (l = 0; l < b; ++l) {
              p += "var argType" + l +
                " = requireRegisteredType(Module['HEAP32'][(argTypes >>> 2) + " +
                l + '], "parameter ' + l + '");\nvar arg' + l + " = argType" +
                l + ".readValueFromPointer(args);\nargs += argType" + l +
                "['argPackAdvance'];\n";
            }
            g =
              (new Function(
                "requireRegisteredType",
                "Module",
                "__emval_register",
                p +
                  ("var obj = new constructor(" + g +
                    ");\nreturn __emval_register(obj);\n}\n"),
              ))(ad, r, xc);
            ld[b] = g;
          }
          return g(a, c, f);
        },

Is there any way to change what these functions are doing without dynamic functions?

[DjDeveloperr]

It should be possible, I have removed them before but hit into timeouts / memory limits. So essentially it doesn't really help running on Deploy. It does not give enough resources for deno-canvas to be usable.

[bnoordhuis]

@DjDeveloperr I can maybe help out getting it to work on Deploy. Can you give a rough estimate of deno-canvas's CPU and memory requirements under normal conditions?

I had a real quick look and deno-canvas seems to load src/wasm.js, a 9 MB file.

(A 9 MB base64-encoded string that's first decoded, then executed as WASM. I assume that's where you're hitting Deploy's resource limits.)

Maybe you can try loading canvaskit-opt.wasm (6.8 MB) directly with WebAssembly.instantiateStreaming(). Deno's docs website loads a similarly sized blob without problem.

[DjDeveloperr]

@bnoordhuis Not sure about its CPU / memory requirements, but it's mainly because of WASM I assume. I will take a stab at making this module work in Deploy again and let you know about exact issue I'm hitting

WebAssembly.instantiateStreaming() looks interesting, I will try loading WASM using that in Deploy

[DjDeveloperr]

I have tried changing these two functions to not use dynamic code generation in this branch, but there's another issue: it seems canvaskit entirely depends on dynamically generated code in recent versions, to provide bindings for wasm exported functions. And all of which comes from WASM land... which I cannot patch manually

[jespertheend]

It's working fine for me on Deno Deploy apparently!

[DjDeveloperr]

It's working fine for me on Deno Deploy apparently!

Yes, apparently some limitations were lifted some time in between so it works now. Thanks for confirming! I'll close this issue then.