Module type JoinMapRed.Problem

module type Problem = sig .. end

Input signature of the functor JoinMapRed.Make.

val identifier : string

The identifier for the problem, used to enable multiple map/reduce problems on a single server.

type init

The type of data sent by server to clients at startup.

type client_data

The type of client data (that is value computed at startup).

type input

The type of input values passed to client agents.

type key

The type of keys returned by client agents.

type value

The type of values returned by client agents.

type output

The type of overall result.

val init_client : init -> client_data

Called at client startup with the data registered at server startup. The returned value will be passed at each map call.

val compare_keys : key -> key -> int

Ordering over keys. Should follow the contract of .

val map : client_data ->
       input ->
       (key * value) list

The computation actually done by client agents.

val combine : value ->
       value -> value

Used by the server to combine values associated with the same key, compare_keys being used for key equality.

val reduce : key ->
       value ->
       output -> output

Used by the server to fold all client results at the end of the computation.