17915, "vasslitvinov", "Expose targetLocales indices to the user?", "2021-06-14T13:21:14Z"
Background: Currently distributions like
Block store the locales that the indices are to be distributed over in an array
targetLocales. "Local descriptor" classes (in DSI slang) are stored in arrays of the same shape as
targetLocales. When some computation needs to access a local descriptor, it needs to perform a translation from
here to the index into
targetLocales. This happens, for example, for queries like
localSubdomains(). This may be complicated because there may be multiple indices into
targetLocales in the case of oversubscription.
This issue proposes to expose the indices into
targetLocales to the user, for example via an iterator. This will enable:
- easy handling of certain operations in the case of oversubscriptions,
- determining the locale that is the left/right/... neighbor for the current computation.