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context.onecontext #


A library to merge existing V contexts.


Have you ever faced the situation where you have to merge multiple existing contexts? If not, then you might, eventually.

For example, we can face the situation where we are building an application using a library that gives us a global context. This context expires once the application is stopped.

Meanwhile, we are exposing a service like this:

fn (f Foo) get(ctx context.Context, bar Bar) ?Baz {
    . . .

Here, we receive another context provided by the service.

Then, in the get implementation, we want for example to query a database and we must provide a context for that.

Ideally, we would like to provide a merged context that would expire either:

  • When the application is stopped
  • Or when the received service context expires

This is exactly the purpose of this library.

In our case, we can now merge the two contexts in a single one like this:

ctx, cancel := onecontext.merge(ctx1, ctx2)

This returns a merged context that we can now propagate

Constants #

const canceled = error('canceled context')

canceled is the error returned when the cancel function is called on a merged context

fn merge #

fn merge(ctx context.Context, ctxs ...context.Context) (context.Context, context.CancelFn)

merge allows to merge multiple contexts it returns the merged context

fn (OneContext) deadline #

fn (octx OneContext) deadline() ?time.Time

fn (OneContext) done #

fn (octx OneContext) done() chan int

fn (OneContext) err #

fn (mut octx OneContext) err() IError

fn (OneContext) value #

fn (octx OneContext) value(key context.Key) ?context.Any

fn (OneContext) run #

fn (mut octx OneContext) run()

fn (OneContext) str #

fn (octx OneContext) str() string

fn (OneContext) cancel #

fn (mut octx OneContext) cancel(err IError)

fn (OneContext) run_two_contexts #

fn (mut octx OneContext) run_two_contexts(mut ctx1 context.Context, mut ctx2 context.Context)

fn (OneContext) run_multiple_contexts #

fn (mut octx OneContext) run_multiple_contexts(mut ctx context.Context)