Pure OCaml B-tree implementation for persistent storage
feat(btree,sqlite): add in-memory pager for ~60x faster fuzz tests
Add Pager.mem for purely in-memory B-tree storage (no file backing)
and Sqlite.in_memory constructor. Fuzz tests now run in 0.5s vs ~30s
by eliminating per-iteration Eio_main.run and file I/O overhead.
Also syncs ocaml-claude-skills upstream changes (plugin restructure)
and adds fuzz skill with updated Crowbar API patterns.
+40
-17
+5
-1
lib/btree.mli
+5
-1
lib/btree.mli
···
182
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type t
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val v : page_size:int -> Eio.File.rw_ty Eio.Resource.t -> t
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-
(** [v ~page_size file] creates a pager with the given page size. *)
185
+
(** [v ~page_size file] creates a pager backed by [file]. *)
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+
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+
val mem : page_size:int -> unit -> t
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+
(** [mem ~page_size ()] creates a purely in-memory pager with no file backing.
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+
All pages are stored in memory only. [sync] is a no-op. *)
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val page_size : t -> int
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(** [page_size t] returns the page size. *)
+30
-15
lib/pager.ml
+30
-15
lib/pager.ml
···
6
6
(** Page cache and file I/O for B-tree storage. *)
7
7
8
8
type t = {
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-
file : Eio.File.rw_ty Eio.Resource.t;
9
+
file : Eio.File.rw_ty Eio.Resource.t option;
10
10
page_size : int;
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11
mutable page_count : int;
12
12
cache : (int, string) Hashtbl.t;
···
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let file_size = Optint.Int63.to_int stat.size in
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let page_count = if file_size = 0 then 0 else file_size / page_size in
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{
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-
file;
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+
file = Some file;
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page_size;
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page_count;
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cache = Hashtbl.create 64;
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dirty = Hashtbl.create 16;
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}
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+
let mem ~page_size () =
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+
{
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+
file = None;
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+
page_size;
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+
page_count = 0;
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+
cache = Hashtbl.create 64;
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+
dirty = Hashtbl.create 16;
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+
}
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+
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let page_size t = t.page_size
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let page_count t = t.page_count
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39
···
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45
| None -> (
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match Hashtbl.find_opt t.cache page_num with
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47
| Some data -> data
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-
| None ->
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-
let offset = Optint.Int63.of_int ((page_num - 1) * t.page_size) in
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-
let buf = Cstruct.create t.page_size in
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-
Eio.File.pread_exact t.file ~file_offset:offset [ buf ];
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-
let data = Cstruct.to_string buf in
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-
Hashtbl.replace t.cache page_num data;
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-
data)
48
+
| None -> (
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+
match t.file with
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+
| None -> Fmt.failwith "Page %d not in memory" page_num
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+
| Some file ->
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+
let offset = Optint.Int63.of_int ((page_num - 1) * t.page_size) in
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+
let buf = Cstruct.create t.page_size in
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+
Eio.File.pread_exact file ~file_offset:offset [ buf ];
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+
let data = Cstruct.to_string buf in
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+
Hashtbl.replace t.cache page_num data;
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+
data))
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let write t page_num data =
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if String.length data <> t.page_size then failwith "Invalid page size";
···
57
69
t.page_count
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let sync t =
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-
Hashtbl.iter
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-
(fun page_num data ->
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-
let offset = Optint.Int63.of_int ((page_num - 1) * t.page_size) in
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-
let buf = Cstruct.of_string data in
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-
Eio.File.pwrite_all t.file ~file_offset:offset [ buf ])
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-
t.dirty;
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+
(match t.file with
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+
| None -> ()
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+
| Some file ->
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+
Hashtbl.iter
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+
(fun page_num data ->
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+
let offset = Optint.Int63.of_int ((page_num - 1) * t.page_size) in
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+
let buf = Cstruct.of_string data in
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+
Eio.File.pwrite_all file ~file_offset:offset [ buf ])
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+
t.dirty);
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81
Hashtbl.clear t.dirty
+5
-1
lib/pager.mli
+5
-1
lib/pager.mli
···
9
9
(** A pager manages page-level I/O with caching. *)
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val v : page_size:int -> Eio.File.rw_ty Eio.Resource.t -> t
12
-
(** [v ~page_size file] creates a pager with the given page size. *)
12
+
(** [v ~page_size file] creates a pager backed by [file]. *)
13
+
14
+
val mem : page_size:int -> unit -> t
15
+
(** [mem ~page_size ()] creates a purely in-memory pager with no file backing.
16
+
All pages are stored in memory only. [sync] is a no-op. *)
13
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val page_size : t -> int
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(** [page_size t] returns the page size. *)