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Diffstat (limited to '')
| -rw-r--r-- | lib/manipulation.ml | 1060 |
1 files changed, 49 insertions, 1011 deletions
diff --git a/lib/manipulation.ml b/lib/manipulation.ml index 7ae2753..dd09378 100644 --- a/lib/manipulation.ml +++ b/lib/manipulation.ml @@ -1,350 +1,85 @@ -(** Database manipulation operations. +(** Multigroup manipulation operations. This module implements the core operations for the relational engine: - - Database creation + - Multigroup creation - Relation creation and deletion - Tuple insertion and deletion - Query operations - All operations are immutable: they return new database/relation states + All operations are immutable: they return new multigroup/relation states rather than modifying existing ones. The storage layer handles persistence. This is a functor that takes a storage backend, ensuring all tuple data is properly persisted to the content-addressed store. *) -module RelationMap = Management.Database.RelationMap - -(** Build membership criteria from schema (validates type membership). Returns a - function that takes a tree-lookup function and a tuple, checking schema - conformance and tree membership at call time. *) -let build_membership_criteria ~name schema : - (string -> Merkle.t option) -> Tuple.t -> bool = - let value_conforms_to_domain domain_name (value : Conventions.AbstractValue.t) - = - match domain_name with - | "integer" -> Obj.is_int value - | "natural" -> Obj.is_int value && (Obj.obj value : int) >= 0 - | "string" -> Obj.tag value = Obj.string_tag - | _ -> - (* Unknown domain: could be a relation-typed attribute (nested tuple) - or a user-defined domain. Accept for now; full validation would - require looking up the target relation's schema. *) - true - in - let n_expected = List.length schema in - fun tree_of tuple -> - match tuple with - | Tuple.NonMaterialized nm -> ( - match tree_of name with - | None -> false - | Some t -> - Merkle.member nm.hash t - && Tuple.AttributeMap.cardinal nm.attributes = n_expected - && List.for_all - (fun (attr_name, _) -> - Tuple.AttributeMap.mem attr_name nm.attributes) - schema) - | Tuple.Materialized m -> - Tuple.AttributeMap.cardinal m.attributes = n_expected - && List.for_all - (fun (attr_name, domain_name) -> - match Tuple.AttributeMap.find_opt attr_name m.attributes with - | None -> false - | Some attr -> - value_conforms_to_domain domain_name attr.Attribute.value) - schema - -let tree_of_db (db : Management.Database.t) name = - Option.bind (Management.Database.get_relation db name) (fun r -> - r.Relation.tree) - -module Constraint = struct - include Constraint - - (** Mutation direction for cascade constraint checking *) - type mutation = Insert | Delete - - type mutation_context = { - target_relation : string; - transition : (string * Conventions.AbstractValue.t) list; - kind : mutation; - } - (** Context for a single tuple mutation, used by cascade checking *) -end - (** Functor to create manipulation operations with a storage backend *) module Make (Storage : Management.Physical.S) = struct + include Nt + type storage = Storage.t type error = Error.t - - let of_string_error s = Error.StorageError s - let ( let* ) = Result.bind - let normalize_name n = Qualified_name.(parse n |> to_key) - - let rec normalize_constraint_body c = - match c with - | Constraint.MemberOf { target; binding } -> - Constraint.MemberOf { target = normalize_name target; binding } - | Constraint.Not { body; universe } -> - Constraint.Not - { - body = normalize_constraint_body body; - universe = normalize_name universe; - } - | Constraint.And cs -> - Constraint.And (List.map normalize_constraint_body cs) - | Constraint.Or cs -> Constraint.Or (List.map normalize_constraint_body cs) - | Constraint.Exists { variable; quantifier; body } -> - Constraint.Exists - { - variable; - quantifier = normalize_name quantifier; - body = normalize_constraint_body body; - } - | Constraint.Forall { variable; quantifier; body } -> - Constraint.Forall - { - variable; - quantifier = normalize_name quantifier; - body = normalize_constraint_body body; - } - - let fold_result (f : 'a -> 'b -> ('a, error) Result.t) (init : 'a) - (xs : 'b list) : ('a, error) Result.t = - List.fold_left - (fun acc x -> - let* a = acc in - f a x) - (Ok init) xs - - (** Build an eval_context closed over a specific (storage, db) snapshot. All - relation lookups resolve against this exact database version. *) - let build_eval_context (storage : storage) (db : Management.Database.t) : - Constraint.eval_context = - let load_value attr_hash = - match Storage.load_raw storage attr_hash with - | Error _ | Ok None -> None - | Ok (Some vbytes) -> - Some (Marshal.from_bytes vbytes 0 : Conventions.AbstractValue.t) - in - let rec load_attrs acc = function - | [] -> Some (List.rev acc) - | (name, attr_hash) :: rest -> ( - match load_value attr_hash with - | None -> None - | Some value -> load_attrs ((name, value) :: acc) rest) - in - let load_tuple hash = - match Storage.load_raw storage hash with - | Error _ | Ok None -> None - | Ok (Some bytes) -> - load_attrs [] - (Storable.Tuple.of_bytes bytes).Storable.Tuple.attributes - in - let rec load_all acc = function - | [] -> Some (List.rev acc) - | h :: rest -> ( - match load_tuple h with - | None -> None - | Some pairs -> load_all (pairs :: acc) rest) - in - let check_membership rel_name bound_pairs = - match Management.Database.get_relation db rel_name with - | None -> false - | Some rel -> - let attributes = - List.fold_left - (fun acc (k, v) -> - Tuple.AttributeMap.add k { Attribute.value = v } acc) - Tuple.AttributeMap.empty bound_pairs - in - let tuple = - Tuple.Materialized { Tuple.relation = rel_name; attributes } - in - rel.membership_criteria (tree_of_db db) tuple - in - let iterate_finite rel_name = - match Management.Database.get_relation db rel_name with - | None -> None - | Some rel -> ( - match rel.cardinality with - | Conventions.Cardinality.Finite _ - | Conventions.Cardinality.ConstrainedFinite -> - let hashes = - match rel.tree with None -> [] | Some tree -> Merkle.keys tree - in - load_all [] hashes - | _ -> None) - in - { Constraint.check_membership; iterate_finite } - + (* State Persistence - Store relation and database states *) (** Store a relation state to storage *) - let store_relation (storage : storage) (relation : Relation.t) : + let store_relation (storage : storage) (relation : Relation.relation) : (unit, error) Result.t = - match relation.hash with - | None -> Error (Error.StorageError "Relation has no hash") - | Some rel_hash -> ( - let tree_keys = - match relation.tree with None -> [] | Some tree -> Merkle.keys tree - in - let stored : Storable.Relation.t = - { - name = relation.name; - schema = relation.schema; - tree_keys; - cardinality = relation.cardinality; - } - in - match - Storage.store_raw storage rel_hash (Storable.Relation.to_bytes stored) - with - | Error _ -> Error (Error.StorageError "Failed to store relation") - | Ok () -> Ok ()) + match + Storage.store_raw storage relation#hash (Storable.Relation.to_bytes @@ relation#serialize ()) + with + | Error _ -> Error (Error.StorageError "Failed to store relation") + | Ok () -> Ok () (** Store a database state to storage *) - let store_database (storage : storage) (db : Management.Database.t) : + let store_multigroup (storage : storage) (db : Management.Multigroup.multigroup) : (unit, error) Result.t = - if db.hash = "" then Ok () (* Don't store empty/initial database *) - else - (* Extract relation hashes from the actual relations *) - let relation_hashes = - Management.Database.RelationMap.fold - (fun name rel acc -> - match rel.Relation.hash with - | Some h -> (name, h) :: acc - | None -> acc) - db.relations [] - in - let stored : Storable.Database.t = - { - name = db.name; - relations = relation_hashes; - tree_keys = Merkle.keys db.tree; - history = db.history; - timestamp = db.timestamp; - } - in match - Storage.store_raw storage db.hash (Storable.Database.to_bytes stored) + Storage.store_raw storage db#hash (Storable.Multigroup.to_bytes @@ db#serialize ()) with - | Error _ -> Error (Error.StorageError "Failed to store database") + | Error _ -> Error (Error.StorageError "Failed to store multigroup") | Ok () -> Ok () (** Load a relation state from storage by hash *) - let load_relation (storage : storage) (rel_hash : Conventions.Hash.t) : - (Relation.t option, error) Result.t = + let load_relation (storage : storage) (rel_hash : Conventions.Hash.t) : (Relation.stored option, error) Result.t = match Storage.load_raw storage rel_hash with | Error _ -> Error (Error.StorageError "Failed to load relation") | Ok None -> Ok None | Ok (Some bytes) -> - let stored = Storable.Relation.of_bytes bytes in - let tree = - List.fold_left - (fun t h -> Merkle.insert h t) - Merkle.empty stored.tree_keys - in + let _stored = Storable.Relation.of_bytes bytes in + let name = failwith "NOT IMPLEMENTED" in + let schema = failwith "NOT IMPLEMENTED" in + let constraints = failwith "NOT IMPLEMENTED" in + let cardinality = failwith "NOT IMPLEMENTED" in + let membership_criteria = Constraint.build_membership_criteria ~_name:name ~schema in let relation = - Relation.make ~hash:(Some rel_hash) ~name:stored.name - ~schema:stored.schema ~tree:(Some tree) ~constraints:None - ~cardinality:stored.cardinality ~generator:None - ~membership_criteria: - (build_membership_criteria ~name:stored.name stored.schema) - ~provenance:(Relation.Provenance.Base stored.name) - ~lineage:(Relation.Lineage.Base stored.name) () + new Relation.stored + ~name + ~schema + ~constraints + ~cardinality + ~membership_criteria + ~provenance:None + ~lineage:None in Ok (Some relation) - (** Load a database state from storage by hash. Note: This loads the database - structure with relation hashes, but the relations themselves need to be - loaded separately. *) - let load_database (storage : storage) (db_hash : Conventions.Hash.t) : - (Management.Database.t option, error) Result.t = - match Storage.load_raw storage db_hash with - | Error _ -> Error (Error.StorageError "Failed to load database") + let load_multigroup (storage : storage) (mg_hash : Conventions.Hash.t) : + (Management.Multigroup.multigroup option, error) Result.t = + match Storage.load_raw storage mg_hash with + | Error _ -> Error (Error.StorageError "Failed to load multigroup") | Ok None -> Ok None | Ok (Some bytes) -> - let stored = Storable.Database.of_bytes bytes in - let tree = - List.fold_left - (fun t h -> Merkle.insert h t) - Merkle.empty stored.tree_keys - in - let rec load_relations acc = function - | [] -> Ok (List.rev acc) - | (name, rel_hash) :: rest -> ( - let* rel_opt = load_relation storage rel_hash in - match rel_opt with - | None -> - Error (Error.StorageError ("Relation not found: " ^ name)) - | Some rel -> load_relations ((name, rel) :: acc) rest) - in - let* relation_list = load_relations [] stored.relations in - let relations = - List.fold_left - (fun m (name, rel) -> - Management.Database.RelationMap.add name rel m) - Management.Database.RelationMap.empty relation_list - in - Ok - (Some - { - Management.Database.hash = db_hash; - name = stored.name; - tree; - relations; - domains = Management.Database.RelationMap.empty; - history = stored.history; - timestamp = stored.timestamp; - deferred = []; - }) - - (* Relation Operations - forward declarations needed by catalog helpers - *) - - (** Create a new empty relation with the given schema *) - let create_relation_raw (storage : storage) (db : Management.Database.t) - ~(name : string) ~(schema : Schema.t) : - (Management.Database.t * Relation.t, Error.t) Result.t = - if Management.Database.has_relation db name then - Error (Error.RelationAlreadyExists name) - else - let tree = Merkle.empty in - let relation_hash = Hashing.hash_relation ~name ~schema ~tree in - let relation = - Relation.make ~hash:(Some relation_hash) ~name ~schema ~tree:(Some tree) - ~constraints:None ~cardinality:(Conventions.Cardinality.Finite 0) - ~generator:None - ~membership_criteria:(build_membership_criteria ~name schema) - ~provenance:(Relation.Provenance.Base name) - ~lineage:(Relation.Lineage.Base name) () - in - let new_db = Management.Database.add_relation db ~relation in - let* () = store_relation storage relation in - Ok (new_db, relation) + (* TODO: Properly deserialize multigroup state *) + let _stored = Storable.Multigroup.of_bytes bytes in + let name = failwith "NOT IMPLEMENTED" in + let mg = new Management.Multigroup.multigroup ~name in + Ok (Some mg) (* Tuple Operations - Storage Integrated *) (** Store each attribute value and return map of attr_name -> attr_hash *) - let store_attributes (storage : storage) (tuple : Tuple.materialized) : - ((string * Conventions.Hash.t) list, error) Result.t = - let attrs = Tuple.AttributeMap.bindings tuple.attributes in - let rec store_all acc = function - | [] -> Ok (List.rev acc) - | (name, attr) :: rest -> ( - let value_bytes = - Marshal.to_bytes attr.Attribute.value [ Marshal.Closures ] - in - let value_hash = - Conventions.Hash.hash_text (Hashing.bytes_to_hex value_bytes) - in - match Storage.store_raw storage value_hash value_bytes with - | Error _ -> - Error (Error.StorageError ("Failed to store attribute: " ^ name)) - | Ok () -> store_all ((name, value_hash) :: acc) rest) - in - store_all [] attrs + let store_attributes (_storage : storage) (_tuple : Tuple.materialized) : + ((string * Conventions.Hash.t) list, error) Result.t = failwith "NOT IMPLEMENTED" (** Load a tuple from storage by its hash *) let load_tuple (storage : storage) (tuple_hash : Conventions.Hash.t) : @@ -353,7 +88,9 @@ module Make (Storage : Management.Physical.S) = struct | Error _ -> Error (Error.StorageError "Failed to load tuple") | Ok None -> Ok None | Ok (Some tuple_bytes) -> - let stored = Storable.Tuple.of_bytes tuple_bytes in + let _stored = Storable.Tuple.of_bytes tuple_bytes in + let attributes = failwith "NOT IMPLEMENTED" in + let relation = failwith "NOT IMPLEMENTED" in let rec load_attrs acc = function | [] -> Ok (List.rev acc) | (name, attr_hash) :: rest -> ( @@ -370,708 +107,9 @@ module Make (Storage : Management.Physical.S) = struct let attr : Attribute.materialized = { value } in load_attrs ((name, attr) :: acc) rest) in - let* attrs = load_attrs [] stored.attributes in - let attributes = - List.fold_left - (fun m (k, v) -> Tuple.AttributeMap.add k v m) - Tuple.AttributeMap.empty attrs - in - Ok (Some { Tuple.relation = stored.relation; attributes }) - - (** Load multiple tuples from storage *) - let load_tuples (storage : storage) (hashes : Conventions.Hash.t list) : - (Tuple.materialized list, error) Result.t = - let rec load_all acc = function - | [] -> Ok (List.rev acc) - | hash :: rest -> ( - let* tup_opt = load_tuple storage hash in - match tup_opt with - | None -> Error (Error.TupleNotFound hash) - | Some tuple -> load_all (tuple :: acc) rest) - in - load_all [] hashes - - let with_loaded_tuple storage tuple_hash ~on_some = - let* tup_opt = load_tuple storage tuple_hash in - match tup_opt with - | Some tup -> on_some tup - | None -> - Error - (Error.StorageError - ("Tuple missing for referenced hash: " ^ tuple_hash)) - - let transition_attrs (tuple : Tuple.materialized) = - Tuple.AttributeMap.bindings tuple.attributes - |> List.map (fun (k, attr) -> (k, attr.Attribute.value)) - - let ensure_relation_exists (db : Management.Database.t) name = - if Management.Database.has_relation db name then Ok () - else Error (Error.RelationNotFound name) - - let bump_cardinality delta = function - | Conventions.Cardinality.Finite n -> - Conventions.Cardinality.Finite (max 0 (n + delta)) - | other -> other - - let rehashed_relation_with_tree ~name ~schema (relation : Relation.t) tree - cardinality = - let hash = Hashing.hash_relation ~name ~schema ~tree in - { - relation with - hash = Some hash; - tree = Some tree; - cardinality; - membership_criteria = build_membership_criteria ~name schema; - } - - let validate_tuple_constraints (storage : storage) - (db : Management.Database.t) (relation : Relation.t) - (tuple : Tuple.materialized) = - let eval_result = - match relation.constraints with - | None | Some [] -> Ok true - | Some named_constraints -> - let ctx = build_eval_context storage db in - Constraint.evaluate_named ctx tuple named_constraints - in - match eval_result with - | Ok true -> Ok () - | Ok false -> Error (Error.ConstraintViolation "Constraint not satisfied") - | Error (Constraint.ConstraintFailures failures) -> - let msg = - String.concat "; " - (List.map (fun (n, _) -> "constraint " ^ n ^ " violated") failures) - in - Error (Error.ConstraintViolation msg) - | Error _ -> - Error (Error.ConstraintViolation "Constraint evaluation failed") - - let store_tuple_payload storage tuple_hash (tuple : Tuple.materialized) = - let* attr_hashes = store_attributes storage tuple in - let stored_tuple : Storable.Tuple.t = - { relation = tuple.relation; attributes = attr_hashes } - in - let tuple_bytes = Storable.Tuple.to_bytes stored_tuple in - match Storage.store_raw storage tuple_hash tuple_bytes with - | Error _ -> Error (Error.StorageError "Failed to store tuple") - | Ok () -> Ok () - - (* Cascade constraint helpers *) - - let polarity_triggered_by kind pol = - match (kind, pol) with - | Constraint.Insert, (Constraint.Negative | Constraint.Both) -> true - | Constraint.Delete, (Constraint.Positive | Constraint.Both) -> true - | _ -> false - - let cascade_violation_msg kind target_relation cname constrained_name = - let verb = - match kind with - | Constraint.Insert -> "inserting into" - | Constraint.Delete -> "deleting from" - in - Printf.sprintf "cascade: %s %s violates constraint %s on %s" verb - target_relation cname constrained_name - - let is_deferred (db : Management.Database.t) rel_name cname = - List.exists - (fun (d : Management.Database.deferred_entry) -> - d.constraint_name = cname && d.relation_name = rel_name) - db.deferred - - let needs_recheck filter (tup : Tuple.materialized) = - filter = [] - || List.for_all - (fun (attr, fval) -> - match Tuple.AttributeMap.find_opt attr tup.attributes with - | Some a -> Stdlib.( = ) a.Attribute.value fval - | None -> false) - filter - - let recheck_one storage ctx (mctx : Constraint.mutation_context) cname cbody - constrained_name filter (h : Conventions.Hash.t) : (unit, error) Result.t - = - with_loaded_tuple storage h ~on_some:(fun tup -> - if not (needs_recheck filter tup) then Ok () - else - let cbody' = - Constraint.substitute_transition cbody mctx.target_relation - mctx.transition - in - match - Constraint.evaluate_first_failure ctx tup [ (cname, cbody') ] - with - | Ok true -> Ok () - | Ok false | Error _ -> - Error - (Error.ConstraintViolation - (cascade_violation_msg mctx.kind mctx.target_relation cname - constrained_name))) - - let check_one_constraint storage ctx db (mctx : Constraint.mutation_context) - constrained_name constrained_rel (cname, cbody) : (unit, error) Result.t = - if is_deferred db constrained_name cname then Ok () - else - let pols = Constraint.polarity_of cbody in - match Constraint.polarity_find mctx.target_relation pols with - | None -> Ok () - | Some pol when not (polarity_triggered_by mctx.kind pol) -> Ok () - | Some _ -> - let filter = - Constraint.focused_filter cbody mctx.target_relation mctx.transition - in - let hashes = - match constrained_rel.Relation.tree with - | None -> [] - | Some t -> Merkle.keys t - in - fold_result - (fun () h -> - recheck_one storage ctx mctx cname cbody constrained_name filter h) - () hashes - - (** Scan every relation in [db] for constraints that reference - [mctx.target_relation] with a polarity matched by the mutation kind, then - re-evaluate those constraints against the affected tuples in each - constrained relation. - - Returns [Ok ()] when all cascade checks pass. *) - let check_cascade_constraints (storage : storage) (db : Management.Database.t) - (mctx : Constraint.mutation_context) = - let ctx = build_eval_context storage db in - Management.Database.RelationMap.fold - (fun constrained_name constrained_rel acc -> - let* () = acc in - match constrained_rel.Relation.constraints with - | None | Some [] -> Ok () - | Some named -> - fold_result - (fun () nc -> - check_one_constraint storage ctx db mctx constrained_name - constrained_rel nc) - () named) - db.relations (Ok ()) - - (** Insert a tuple into a relation, storing it in the backend *) - let create_tuple (storage : storage) (db : Management.Database.t) - (relation : Relation.t) (tuple : Tuple.materialized) : - (Management.Database.t * Relation.t * Conventions.Hash.t, error) Result.t - = - let name = relation.name in - let* () = ensure_relation_exists db name in - if - not - (relation.membership_criteria (tree_of_db db) (Tuple.Materialized tuple)) - then - Error - (Error.ConstraintViolation "Tuple does not satisfy membership criteria") - else - let* () = validate_tuple_constraints storage db relation tuple in - let tuple_hash = Hashing.hash_tuple tuple in - let current_tree = - match relation.tree with Some t -> t | None -> Merkle.empty - in - if Merkle.member tuple_hash current_tree then - Error (Error.DuplicateTuple tuple_hash) - else - let* () = store_tuple_payload storage tuple_hash tuple in - let new_tree = Merkle.insert tuple_hash current_tree in - let new_relation = - rehashed_relation_with_tree ~name ~schema:relation.schema relation - new_tree - (bump_cardinality 1 relation.cardinality) - in - let new_db = - Management.Database.update_relation db ~relation:new_relation - in - let* () = - check_cascade_constraints storage new_db - { - target_relation = name; - transition = transition_attrs tuple; - kind = Constraint.Insert; - } - in - let* () = store_relation storage new_relation in - let* () = store_database storage new_db in - Ok (new_db, new_relation, tuple_hash) - - (** Insert multiple tuples into a relation *) - let create_tuples (storage : storage) (db : Management.Database.t) - (relation : Relation.t) (tuples : Tuple.materialized list) : - ( Management.Database.t * Relation.t * Conventions.Hash.t list, - error ) - Result.t = - let rec insert_all db rel hashes = function - | [] -> Ok (db, rel, List.rev hashes) - | tuple :: rest -> - let* new_db, new_rel, hash = create_tuple storage db rel tuple in - insert_all new_db new_rel (hash :: hashes) rest - in - insert_all db relation [] tuples - - (** Remove a tuple from a relation by its hash *) - let retract_tuple (storage : storage) (db : Management.Database.t) - (relation : Relation.t) ~(tuple_hash : Conventions.Hash.t) : - (Management.Database.t * Relation.t, error) Result.t = - let name = relation.name in - let* () = ensure_relation_exists db name in - let* current_tree = - match relation.tree with - | None -> Error (Error.TupleNotFound tuple_hash) - | Some tree -> Ok tree - in - if not (Merkle.member tuple_hash current_tree) then - Error (Error.TupleNotFound tuple_hash) - else - (* Note: We don't delete from storage - content-addressed storage is append-only. - The tuple data remains for historical queries / garbage collection later. *) - let new_tree = Merkle.delete tuple_hash current_tree in - let new_relation = - rehashed_relation_with_tree ~name ~schema:relation.schema relation - new_tree - (bump_cardinality (-1) relation.cardinality) - in - let new_db = - Management.Database.update_relation db ~relation:new_relation - in - let* () = - with_loaded_tuple storage tuple_hash ~on_some:(fun deleted_tuple -> - check_cascade_constraints storage new_db - { - target_relation = name; - transition = transition_attrs deleted_tuple; - kind = Constraint.Delete; - }) - in - let* () = store_relation storage new_relation in - let* () = store_database storage new_db in - Ok (new_db, new_relation) - - (* - System Catalog Maintenance - *) - - (** Update catalog when a new user relation is created. Skipped if the - relation being created is itself a catalog relation. *) - let update_catalog_on_create (storage : storage) (db : Management.Database.t) - (relation : Relation.t) : (Management.Database.t, error) Result.t = - if Prelude.Catalog.is_catalog_relation relation.name then Ok db - else - (* Insert into public:relation *) - match - Management.Database.get_relation db Prelude.Catalog.relation_rel_name - with - | None -> Ok db (* catalog not yet initialized *) - | Some rel_cat -> ( - let rel_tuple = Prelude.Catalog.build_relation_tuple relation.name in - let* db, _, _ = create_tuple storage db rel_cat rel_tuple in - (* Insert into public:attribute for each schema entry *) - match - Management.Database.get_relation db - Prelude.Catalog.attribute_rel_name - with - | None -> Ok db - | Some attr_cat -> - let attr_tuples = - Prelude.Catalog.build_attribute_tuples - ~relation_name:relation.name relation.schema - in - let* db, _, _ = create_tuples storage db attr_cat attr_tuples in - Ok db) - - (** Update catalog when a user relation is retracted. Skipped if the relation - being retracted is itself a catalog relation. *) - let update_catalog_on_retract (storage : storage) (db : Management.Database.t) - (relation : Relation.t) : (Management.Database.t, error) Result.t = - if Prelude.Catalog.is_catalog_relation relation.name then Ok db - else - let* db = - match - Management.Database.get_relation db Prelude.Catalog.relation_rel_name - with - | None -> Ok db - | Some rel_cat -> - let rel_tuple_hash = - Hashing.hash_tuple - (Prelude.Catalog.build_relation_tuple relation.name) - in - let tree = - match rel_cat.tree with Some t -> t | None -> Merkle.empty - in - if Merkle.member rel_tuple_hash tree then - let* new_db, _ = - retract_tuple storage db rel_cat ~tuple_hash:rel_tuple_hash - in - Ok new_db - else Ok db - in - (* Remove attribute tuples for this relation from public:attribute *) - let attr_tuples = - Prelude.Catalog.build_attribute_tuples ~relation_name:relation.name - relation.schema - in - fold_result - (fun db tup -> - let tup_hash = Hashing.hash_tuple tup in - match - Management.Database.get_relation db - Prelude.Catalog.attribute_rel_name - with - | None -> Ok db - | Some attr_cat -> - let tree = - match attr_cat.tree with Some t -> t | None -> Merkle.empty - in - if Merkle.member tup_hash tree then - let* new_db, _ = - retract_tuple storage db attr_cat ~tuple_hash:tup_hash - in - Ok new_db - else Ok db) - db attr_tuples - - (** Bootstrap the 6 system catalog relations into a fresh database. Called - only from [create_database]; suppresses recursive catalog updates. *) - let init_catalog_relations (storage : storage) (db : Management.Database.t) : - (Management.Database.t, error) Result.t = - let* db = - fold_result - (fun db (name, schema) -> - let* new_db, _ = create_relation_raw storage db ~name ~schema in - Ok new_db) - db Prelude.Catalog.catalog_definitions - in - let get_required (db : Management.Database.t) rel_name = - match Management.Database.get_relation db rel_name with - | Some rel -> Ok rel - | None -> - Error (Error.StorageError ("Catalog relation missing: " ^ rel_name)) - in - let* relation_rel = get_required db Prelude.Catalog.relation_rel_name in - let* db, _, _ = - create_tuples storage db relation_rel - (List.map Prelude.Catalog.build_relation_tuple - Prelude.Catalog.catalog_relation_names) - in - let* attribute_rel = get_required db Prelude.Catalog.attribute_rel_name in - let* db, _, _ = - create_tuples storage db attribute_rel - (List.concat_map - (fun (name, schema) -> - Prelude.Catalog.build_attribute_tuples ~relation_name:name schema) - Prelude.Catalog.catalog_definitions) - in - let* on_rel = get_required db Prelude.Catalog.on_rel_name in - let* db, _, _ = - create_tuples storage db on_rel - (List.map Prelude.Catalog.build_on_tuple - [ "insert"; "update"; "delete" ]) - in - let* timing_rel = get_required db Prelude.Catalog.timing_rel_name in - let* db, _, _ = - create_tuples storage db timing_rel - (List.map Prelude.Catalog.build_timing_tuple - [ "immediate"; "deferred" ]) - in - let* domain_rel = get_required db Prelude.Catalog.domain_rel_name in - let* db, _, _ = - create_tuples storage db domain_rel - (List.map Prelude.Catalog.build_domain_tuple - [ "integer"; "natural"; "rational"; "string" ]) - in - let* schema_rel = get_required db Prelude.Catalog.schema_rel_name in - let* db, _, _ = - create_tuples storage db schema_rel - [ Prelude.Catalog.build_schema_tuple Qualified_name.default_schema ] - in - Ok db - - (* - Database Operations - *) - - (** Register a domain in the database. Can be called after [create_database] - to add user-defined domains (e.g. [money], [email], [uuid]). Also inserts - a tuple into [public:domain] if the catalog is live. *) - let register_domain (storage : storage) (db : Management.Database.t) - (domain : Domain.t) : (Management.Database.t, error) Result.t = - let db = Management.Database.add_domain db domain in - match - Management.Database.get_relation db Prelude.Catalog.domain_rel_name - with - | None -> Ok db (* catalog not yet initialized *) - | Some dom_cat -> - let dom_tuple = Prelude.Catalog.build_domain_tuple domain.name in - let* new_db, _, _ = create_tuple storage db dom_cat dom_tuple in - Ok new_db - - (** Create a new database pre-seeded with the standard prelude domains and the - system catalog relations. *) - let create_database (storage : storage) ~name : - (Management.Database.t, error) Result.t = - (* Register prelude domains first (catalog does not exist yet, so no catalog update) *) - let db = - List.fold_left Management.Database.add_domain - (Management.Database.empty ~name) - Prelude.Domains.[ integer; natural; rational; string ] - in - (* Bootstrap catalog relations and seed them *) - init_catalog_relations storage db - - (** Get database history *) - let database_history (db : Management.Database.t) : Conventions.Hash.t list = - db.history - - (* - Relation Operations - *) - - (** Create a new empty relation with the given schema. Also updates - [public:relation] and [public:attribute] in the system catalog. *) - let create_relation (storage : storage) (db : Management.Database.t) - ~(name : string) ~(schema : Schema.t) : - (Management.Database.t * Relation.t, error) Result.t = - let name = normalize_name name in - if Management.Database.has_relation db name then - Error (Error.RelationAlreadyExists name) - else - let tree = Merkle.empty in - let relation_hash = Hashing.hash_relation ~name ~schema ~tree in - let relation = - Relation.make ~hash:(Some relation_hash) ~name ~schema ~tree:(Some tree) - ~constraints:None ~cardinality:(Conventions.Cardinality.Finite 0) - ~generator:None - ~membership_criteria:(build_membership_criteria ~name schema) - ~provenance:(Relation.Provenance.Base name) - ~lineage:(Relation.Lineage.Base name) () - in - let new_db = Management.Database.add_relation db ~relation in - let* () = store_relation storage relation in - let* final_db = update_catalog_on_create storage new_db relation in - let* () = store_database storage final_db in - Ok (final_db, relation) - - (** Create an immutable/generator-based relation *) - let create_immutable_relation (storage : storage) (db : Management.Database.t) - ~(name : string) ~(schema : Schema.t) ~(generator : Generator.t) - ~(membership_criteria : (string -> Merkle.t option) -> Tuple.t -> bool) - ~(cardinality : Conventions.Cardinality.t) - ~(producer : Relation.producer option) : - (Management.Database.t * Relation.t, error) Result.t = - let name = normalize_name name in - if Management.Database.has_relation db name then - Error (Error.RelationAlreadyExists name) - else - let relation_hash = - Hashing.hash_relation ~name ~schema ~tree:Merkle.empty - in - let relation = - Relation.make ~hash:(Some relation_hash) ~name ~schema - ~tree:None (* No tree for generator-based relations *) - ~constraints:None ~cardinality ~generator:(Some generator) ~producer - ~membership_criteria ~provenance:(Relation.Provenance.Base name) - ~lineage:(Relation.Lineage.Base name) () - in - let new_db = Management.Database.add_relation db ~relation in - let* () = store_relation storage relation in - let* final_db = update_catalog_on_create storage new_db relation in - let* () = store_database storage final_db in - Ok (final_db, relation) - - (** Remove a relation from the database. Also removes its entries from - [public:relation] and [public:attribute]. *) - let retract_relation (storage : storage) (db : Management.Database.t) - ~(name : string) : (Management.Database.t, error) Result.t = - let name = normalize_name name in - match Management.Database.get_relation db name with - | None -> Error (Error.RelationNotFound name) - | Some relation -> - let new_db = Management.Database.remove_relation db ~name in - (* Update catalog on the db state that no longer contains the retracted relation *) - let* final_db = update_catalog_on_retract storage new_db relation in - let* () = store_database storage final_db in - Ok final_db - - (** Clear all tuples from a relation (truncate) *) - let clear_relation (storage : storage) (db : Management.Database.t) - (relation : Relation.t) : - (Management.Database.t * Relation.t, error) Result.t = - let name = relation.name in - match Management.Database.get_relation db name with - | None -> Error (Error.RelationNotFound name) - | Some _ -> - let new_tree = Merkle.empty in - let new_hash = - Hashing.hash_relation ~name ~schema:relation.schema ~tree:new_tree - in - let new_relation = - { - relation with - hash = Some new_hash; - tree = Some new_tree; - cardinality = Conventions.Cardinality.Finite 0; - membership_criteria = - build_membership_criteria ~name relation.schema; - } - in - let new_db = - Management.Database.update_relation db ~relation:new_relation - in - let* () = store_relation storage new_relation in - let* () = store_database storage new_db in - Ok (new_db, new_relation) - - (** Attach constraints to an existing relation. Rebuilds membership_criteria - to include constraint checking, re-hashes, and persists. *) - let update_relation_constraints (storage : storage) - (db : Management.Database.t) ~(relation_name : string) - ~(constraints : Relation.RelationConstraint.t) : - (Management.Database.t * Relation.t, error) Result.t = - let relation_name = normalize_name relation_name in - match Management.Database.get_relation db relation_name with - | None -> Error (Error.RelationNotFound relation_name) - | Some relation -> - let merged_constraints = - match relation.constraints with - | None -> constraints - | Some existing -> Constraint.merge existing constraints - in - (* Do not bake constraint evaluation into membership_criteria. - create_tuple evaluates constraints with the current db snapshot. - membership_criteria stays for schema/domain validation only. *) - let new_relation = - { relation with constraints = Some merged_constraints } - in - (* Re-hash *) - let new_relation = - match new_relation.tree with - | Some tree -> - let h = - Hashing.hash_relation ~name:relation_name - ~schema:relation.schema ~tree - in - { new_relation with hash = Some h } - | None -> new_relation - in - let new_db = - Management.Database.update_relation db ~relation:new_relation - in - let* () = store_relation storage new_relation in - let* () = store_database storage new_db in - Ok (new_db, new_relation) - - (** Register a named constraint on a relation. Attaches the constraint body to - the relation AND records it in [public:constraint]. *) - let register_constraint (storage : storage) (db : Management.Database.t) - ~(constraint_name : string) ~(relation_name : string) - ~(body : Constraint.t) : (Management.Database.t, error) Result.t = - let relation_name = normalize_name relation_name in - let body = normalize_constraint_body body in - let* db, _ = - update_relation_constraints storage db ~relation_name - ~constraints:[ (constraint_name, body) ] - in - match - Management.Database.get_relation db Prelude.Catalog.constraint_rel_name - with - | None -> Ok db - | Some con_cat -> - let con_tuple = - Prelude.Catalog.build_constraint_tuple constraint_name relation_name - in - let* new_db, _, _ = create_tuple storage db con_cat con_tuple in - Ok new_db - - (*Query Operations *) - - (** Get all tuple hashes from a relation *) - let tuple_hashes (relation : Relation.t) : Conventions.Hash.t list = - match relation.tree with None -> [] | Some tree -> Merkle.keys tree - - (** Get relation by name from database *) - let get_relation (db : Management.Database.t) ~(name : string) : - Relation.t option = - Management.Database.get_relation db (normalize_name name) - - (** Count tuples in a relation *) - let tuple_count (relation : Relation.t) : int = - match relation.tree with None -> 0 | Some tree -> Merkle.size tree - - (** Check if a tuple exists in a relation *) - let tuple_exists (relation : Relation.t) (tuple_hash : Conventions.Hash.t) : - bool = - match relation.tree with - | None -> false - | Some tree -> Merkle.member tuple_hash tree - - (** Attach a named constraint with timing metadata. Immediate constraints are - added to the relation's constraint list. Deferred constraints are recorded - in the database's deferred list and also attached to the relation (for - schema visibility). *) - let attach_constraint (storage : storage) (db : Management.Database.t) - ~(constraint_name : string) ~(relation_name : string) - ~(body : Constraint.t) ~(timing : Constraint.timing) : - (Management.Database.t, error) Result.t = - let relation_name = normalize_name relation_name in - let body = normalize_constraint_body body in - let* db, _ = - update_relation_constraints storage db ~relation_name - ~constraints:[ (constraint_name, body) ] - in - match timing with - | Constraint.Immediate -> Ok db - | Constraint.Deferred -> - let entry : Management.Database.deferred_entry = - { relation_name; constraint_name; body } - in - Ok { db with deferred = entry :: db.deferred } - - (** Check all deferred constraints against the current database state. Returns - [Ok ()] if all pass, or an error on the first violation. *) - let check_deferred_constraints (storage : storage) - (db : Management.Database.t) : (unit, error) Result.t = - let ctx = build_eval_context storage db in - fold_result - (fun () (entry : Management.Database.deferred_entry) -> - match Management.Database.get_relation db entry.relation_name with - | None -> Ok () - | Some rel -> - let hashes = - match rel.tree with None -> [] | Some t -> Merkle.keys t - in - fold_result - (fun () h -> - with_loaded_tuple storage h ~on_some:(fun tup -> - match - Constraint.evaluate_first_failure ctx tup - [ (entry.constraint_name, entry.body) ] - with - | Ok true -> Ok () - | Ok false | Error _ -> - Error - (Error.ConstraintViolation - (Printf.sprintf - "deferred constraint %s on %s violated" - entry.constraint_name entry.relation_name)))) - () hashes) - () db.deferred - - (** Complete a mutation sequence by evaluating all deferred constraints - against the current database state. - - On success, returns the database with the deferred list cleared. - Subsequent mutations start a fresh deferral window. On failure, returns - the constraint violation error and leaves the database unchanged so the - caller can inspect or roll back. - - Typical usage: let db = create_tuple storage db rel t1 in let db = - retract_tuple storage db rel t2 in let db = commit storage db in (* - deferred checks run here *) ... *) - let commit (storage : storage) (db : Management.Database.t) : - (Management.Database.t, error) Result.t = - let* () = check_deferred_constraints storage db in - let db' = { db with deferred = [] } in - let* () = store_database storage db' in - Ok db' + load_attrs [] attributes + |> Result.map (List.fold_left + (fun m (k, v) -> Tuple.AttributeMap.add k v m) + Tuple.AttributeMap.empty) + |> Result.map (fun attributes -> Some { Tuple.relation = relation; attributes }) end |