How to handle a failing compilation

[wchao1115]

Update CompilationPreference to follow WebGL convention for context creation. Update the code sample to show how a certain compilation could fail such as when the model uses data type not supported by the hardware, and how to recover from the failure. #36

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[huningxin]

Thanks @wchao1115 for the PR. Left my comments. Please take a look.

[gramalingam]

I am fine with the proposal. My main concern was to avoid mixing potentially different concerns/options into one. It is fine to add more options later on as and when appropriate.

[huningxin]

It is fine to add more options later on as and when appropriate.

To allow adding more options later, I propose to change the argument into a dictionary, it also aligns to the WebGL WebGLContextAttributes that contains WebGLPowerPreference.

For example:

enum PowerPreference {
  "low-power",
  "high-performance"
};

dictionary CompilationOptions {
  PowerPreference powerPreference;
};

interface Model {
  Promise<Compilation> createCompilation(optional CompilationOptions options = {});
};

[huningxin]

Another question is in the latest commit, I failed to find the sample code that handles a failing compilation. Are there any reasons to drop it?

[wchao1115]

Another question is in the latest commit, I failed to find the sample code that handles a failing compilation. Are there any reasons to drop it?

As stated in the commit's comment, with this change the browser is expected to handle failing case due to unsupported data type, most likely by falling back to the default option.

[wchao1115]

dictionary CompilationOptions {
PowerPreference powerPreference;
};

I think the dictionary has merit if we believe we need something similar to WebGLContextAttributes in the future. For instance, a Boolean field similar to WebGL failIfMajorPerformanceCaveat flag could be useful in the future if we need to give the caller some control over how to handle cases where the browser's choice isn't what they are expecting.

I pushed out a new commit that addresses this feedback. Please have a look.

[huningxin]

It looks good. Thanks @wchao1115 !

[huningxin]

@wchao1115 , please help resolve the conflicts due to merging PR #49 . Thanks.

[wchao1115]

The change is reviewed and merged. I believe we can now close this issue. In summary, we decided that it's the UA responsibility to handle compilation failure for a given power preference. If an unrecoverable failure is triggered, fatal exception will then be thrown.

[huningxin]

@wchao1115 , thanks for rebasing and merging.