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|
module type Action = sig
(* Names of the attributes & The tuples *)
type tuples = string list * bytes list list
val execute : tuples -> int
end
module Scan = struct
open Disk
let execute (commit: Executor.commit) locations (entity : string) =
(*Executor.read commit locations ~filename:("schema~" ^ entity) |> function
| Some binary -> (
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 ->
let _attrs =
List.map
(fun (a : Schema.Protocol.attribute) ->
relation.name ^ "/" ^ a.name)
relation.attributes
in
Executor.read commit locations ~filename:("schema~" ^ entity)
| Error err -> failwith err)
| None -> failwith ""
*)
let entities : (string * Executor.relational_type * string) list Executor.IntMap.t =
Executor.StringMap.find_opt entity commit.references
|> function
| Some entities -> entities
| None -> Executor.IntMap.empty
in
let content: (int64 * (string*Executor.relational_literal) list) list =
Executor.IntMap.fold
(fun key elems acc ->
(key,
List.map
(fun (location, type', attribute_name) ->
(attribute_name, Executor.read_location ~hash:location locations type'))
elems)
:: acc)
entities []
in content
end
module Join = struct
open Disk
module NestedLoop = struct
let execute
(left: (int64 * (string*Executor.relational_literal) list) list)
(right: (int64 * (string*Executor.relational_literal) list) list)
(join_clause: ((int64 * (string*Executor.relational_literal) list) *
(int64 * (string*Executor.relational_literal) list)) -> bool) =
let result = ref [] in
List.iter (fun left_tuple -> List.iter (fun right_tuple -> if join_clause(left_tuple, right_tuple)
then result := (left_tuple,right_tuple)::(!result)) right) left;
!result
end
(* 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 *)
open Disk
let natural commit locations left_relation right_relation =
let left_scan = Scan.execute commit locations left_relation in
let right_scan = Scan.execute commit locations right_relation in
let common_attributes =
let left_attributes = commit.schema
|> Executor.StringMap.find left_relation in
let right_attributes = commit.schema
|> Executor.StringMap.find right_relation in
List.filter_map (fun left_attr -> if List.mem left_attr right_attributes
then Some (fst left_attr)
else None) left_attributes
in
let join_clause = fun ((_entity_id_1, left_tuple), (_entity_id_2,right_tuple)): bool ->
(* Check only the key name for now, not subtype, so literals must be equal for it to work *)
let left_tuple = Executor.StringMap.filter (fun key _ -> List.mem key common_attributes)
@@ Executor.StringMap.of_list left_tuple in
let right_tuple = Executor.StringMap.filter (fun key _ -> List.mem key common_attributes)
@@ Executor.StringMap.of_list right_tuple in
left_tuple = right_tuple
in NestedLoop.execute left_scan right_scan join_clause
end
module Filter = struct end
|
