Fetch many identities, returning a mapping from identities to results.
Fetch many identities, returning a mapping from identities to results. If an identity wasn't found won't appear in the keys.
Fetch one identity, returning a None if it wasn't found.
The name of the data source.
Use fetchOne
for implementing of fetchMany
.
Use fetchOne
for implementing of fetchMany
. Use only when the data
source doesn't support batching.
Derive a DataSourceIdentity
from an identity, suitable for storing the result
of such identity in a DataSourceCache
.
A
DataSource
is the recipe for fetching a certain identityI
, which yields results of typeA
.