path: root/lib/planner.ml

module Scan = struct
  (* open Disk
  let execute commit locations (entity: string) =
    let binary = Executor.read commit locations ~filename:("schema~" ^ entity) in
    let relation =
      Result.map_error (fun _ -> "Failed to deserialize relation from binary format.")
      @@ Data_encoding.Binary.of_bytes Schema.Protocol.relation_encoding (Bytes.concat Bytes.empty binary) in
    match relation with
    | Ok relation ->
       begin
         let attrs = List.map (fun (a: Schema.Protocol.attribute) -> relation.name ^ "/" ^ a.name) relation.attributes in
         Executor.read commit locations ~filename:("schema~" ^ entity)
       end
    | Error err -> failwith err *)
end

module Join = struct
  (* open Disk
  let execute (left_attributes: bytes list) (right_attributes: bytes list) locations =
    (* Redundant operations that are already in the locations, but this is easier to implement now *)
    (* Fix this when we persist the indexes *)
    let left_computed_hashes: (int * string) list = List.mapi (fun index elem -> (index, Interop.Sha256.compute_hash elem)) left_attributes in
    let right_computed_hashes: (int * string) list = List.mapi (fun index elem -> (index, Interop.Sha256.compute_hash elem)) right_attributes in
    let references_locations_right = List.filter_map (fun (index, rhash) -> Option.map (fun (elem: Executor.Location.t) -> index, rhash, elem.references)
                                                                            @@ Executor.StringMap.find_opt rhash locations) right_computed_hashes in
    let indexes =
      List.filter_map (fun (lindex, lhash) -> Option.map (fun (rindex, rhash, _) -> lindex, rindex, lhash, rhash)
                                              @@ List.find_opt (fun (_rindex, _rhash, references) -> List.exists ((=) lhash) references) references_locations_right) left_computed_hashes
    in List.map (fun (lindex, rindex, _, _) -> List.nth left_attributes lindex, List.nth right_attributes rindex) indexes *)
end

module Filter = struct
end