ok_http: Add BaseClient Implementation and make asynchronous requests.

[Anikate-De]

Items in this PR:

• Generated necessary JNI Bindings for BaseClient implementation
• Allow asynchronous requests using the enqueue() API
• Reuse the Books example from pkgs/cronet_http/example/
• Setup Integration Tests
• Add minimal documentation
• Update CHANGELOG.md: 0.1.0-wip entry
• Add testing workflow

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[brianquinlan]

Amazing job!

You might need to run dart format to fix the analysis errors.

[Anikate-De]

@brianquinlan Thank you!

I'll go ahead and do that.

There seems to be a problem with the test setup as it always force terminates while executing test multiple clients multiple clients with simultaneous requests. I tried with a larger timeout of 360s, but no luck :(

Upon further testing, I believe java.net.SocketTimeoutException is the culprit as OkHttp has a default timeout of 10s. I'll try increasing this and see if it works. Do you have any suggestions for this?

[Anikate-De]

SocketTimeoutException was all good, I managed to increase the timeout by generating the bindings of java.util.concurrent.TimeUnit. I propose that we make the timeout configurable for this package. I'll hold that off for later PRs.

As for the test, I traced the issue back to how the response is being sent by the test server. Things that fix it:

1. Add a 1 second delay anywhere inside onResponse

await Future.delayed(const Duration(seconds: 1));

2. OR, Don't send i and remove test expect for response body (defeats the purpose of the test)

  responseFutures.add(client.get(Uri.http(host, '')));
}
final responses = await Future.wait(responseFutures);
  for (var i = 0; i < 5; ++i) {
    expect(responses[i].statusCode, 200);
    // expect(responses[i].body, i.toString());
  }

(1.) shows that the enqueue API of OkHttp is unable to return outputs in the same thread when it is forced to wait for the server to add a response.
I believe that this will be fixed once we implement functionality to Stream Responses.

I'm making some assumptions here, so hopefully this analysis is not wrong.

[brianquinlan]

Nice!

[Anikate-De]

Thanks a lot! @brianquinlan