@Documented @Retention(value=RUNTIME) @Target(value=METHOD) @Experimental(value=SPLITTABLE_DO_FN) public static @interface DoFn.GetPartition
byte getPartitition(InputT element, RestrictionT restriction);
Returns an immutable representation of the partition identifier as a byte.
By default, the partition identifier is represented as the encoded element and restriction
pair and should only be provided if the splittable
DoFn can only provide a size over a
shared resource such as a message queue that potentially multiple element and restriction pairs
are doing work on. The partition identifier is used by runners for various size calculations.
Sizes reported with the same partition identifier represent a point in time reporting of the
size for that partition. For example, a runner can compute a global size by summing all
reported sizes over all unique partition identifiers while it can compute the size of a
specific partition based upon the last reported value.
For example splittable
DoFns which consume elements from: