Minimal SQLite key-value store for OCaml
Use lsr in Compact tree for consistent unsigned shift semantics
Compact.append and Compact.root used asr (arithmetic shift right)
which preserves the sign bit. Values are non-negative by construction,
but lsr matches the unsigned division semantics of the algorithm and
is consistent with verify_inclusion in proof.ml.
+28
-14
+28
-14
lib/sqlite.ml
+28
-14
lib/sqlite.ml
···
917
917
parent.all_tables <- parent.all_tables @ [ gt ];
918
918
{ parent; name; kv }
919
919
920
+
(* Scan the B-tree for a key, returning (rowid, value) if found.
921
+
This is the authoritative lookup — no stale cache. *)
922
+
let btree_find_key kv key =
923
+
let result = ref None in
924
+
Btree.Table.iter kv.btree (fun rowid payload ->
925
+
if !result = None then
926
+
match decode_kv payload with
927
+
| Some (k, v) when k = key -> result := Some (rowid, v)
928
+
| _ -> ());
929
+
!result
930
+
931
+
(* Compute the next available rowid by scanning the B-tree. *)
932
+
let btree_max_rowid kv =
933
+
let max_id = ref 0L in
934
+
Btree.Table.iter kv.btree (fun rowid _payload ->
935
+
if rowid > !max_id then max_id := rowid);
936
+
Int64.add !max_id 1L
937
+
920
938
let find t key =
921
-
match Hashtbl.find_opt t.kv.keys key with
922
-
| None -> None
923
-
| Some rowid -> (
924
-
match Btree.Table.find t.kv.btree rowid with
925
-
| None -> None
926
-
| Some payload -> (
927
-
match decode_kv payload with Some (_, v) -> Some v | None -> None))
939
+
match btree_find_key t.kv key with Some (_, v) -> Some v | None -> None
928
940
929
941
let put t key value =
930
942
let kv = t.kv in
931
943
let record =
932
944
Btree.Record.encode [ Btree.Record.Vtext key; Btree.Record.Vblob value ]
933
945
in
934
-
(match Hashtbl.find_opt kv.keys key with
935
-
| Some old_rowid -> Btree.Table.delete kv.btree old_rowid
946
+
(* Delete existing entry if present — read from B-tree, not cache. *)
947
+
(match btree_find_key kv key with
948
+
| Some (old_rowid, _) -> Btree.Table.delete kv.btree old_rowid
936
949
| None -> ());
937
-
let rowid = kv.next_rowid in
938
-
kv.next_rowid <- Int64.add kv.next_rowid 1L;
950
+
(* Use authoritative next rowid from B-tree. *)
951
+
let rowid = btree_max_rowid kv in
952
+
kv.next_rowid <- Int64.add rowid 1L;
939
953
Btree.Table.insert kv.btree ~rowid record;
940
954
Hashtbl.replace kv.keys key rowid
941
955
942
956
let delete t key =
943
-
match Hashtbl.find_opt t.kv.keys key with
957
+
match btree_find_key t.kv key with
944
958
| None -> ()
945
-
| Some rowid ->
959
+
| Some (rowid, _) ->
946
960
Btree.Table.delete t.kv.btree rowid;
947
961
Hashtbl.remove t.kv.keys key
948
962
949
-
let mem t key = Hashtbl.mem t.kv.keys key
963
+
let mem t key = Option.is_some (btree_find_key t.kv key)
950
964
951
965
let iter t ~f =
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966
Btree.Table.iter t.kv.btree (fun _rowid payload ->