Source file proof.ml
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open! Import
include Proof_intf
module Make
(C : Type.S)
(H : Type.S) (S : sig
type step [@@deriving irmin]
end)
(M : Type.S) =
struct
type contents = C.t [@@deriving irmin]
type hash = H.t [@@deriving irmin]
type step = S.step [@@deriving irmin]
type metadata = M.t [@@deriving irmin]
type kinded_hash = [ `Contents of hash * metadata | `Node of hash ]
[@@deriving irmin]
type 'a inode = { length : int; proofs : (int * 'a) list } [@@deriving irmin]
type 'a inode_extender = { length : int; segments : int list; proof : 'a }
[@@deriving irmin]
type tree =
| Contents of contents * metadata
| Blinded_contents of hash * metadata
| Node of (step * tree) list
| Blinded_node of hash
| Inode of inode_tree inode
| Extender of inode_tree inode_extender
[@@deriving irmin]
and inode_tree =
| Blinded_inode of hash
| Inode_values of (step * tree) list
| Inode_tree of inode_tree inode
| Inode_extender of inode_tree inode_extender
[@@deriving irmin]
type elt =
| Contents of contents
| Node of (step * kinded_hash) list
| Inode of hash inode
| Inode_extender of hash inode_extender
[@@deriving irmin]
type stream = elt Seq.t [@@deriving irmin]
type 'a t = { before : kinded_hash; after : kinded_hash; state : 'a }
[@@deriving irmin]
let before t = t.before
let after t = t.after
let state t = t.state
let v ~before ~after state = { after; before; state }
end
type bad_stream_exn =
| Stream_too_long of { context : string; reason : string }
| Stream_too_short of { context : string; reason : string }
| Proof_mismatch of { context : string; reason : string }
exception Bad_proof of { context : string }
exception Bad_stream of bad_stream_exn
let bad_proof_exn context = raise (Bad_proof { context })
let bad_stream_too_long context reason =
raise (Bad_stream (Stream_too_long { context; reason }))
let bad_stream_too_short context reason =
raise (Bad_stream (Stream_too_short { context; reason }))
let bad_stream_exn context reason =
raise (Bad_stream (Proof_mismatch { context; reason }))
let bad_stream_exn_fmt s fmt = Fmt.kstr (bad_stream_exn ("Proof.Env." ^ s)) fmt
let bad_stream_too_short_fmt s fmt =
Fmt.kstr (bad_stream_too_short ("Proof.Env." ^ s)) fmt
module Env
(B : Backend.S)
(P : S
with type contents := B.Contents.Val.t
and type hash := B.Hash.t
and type step := B.Node.Val.step
and type metadata := B.Node.Val.metadata) =
struct
module H = B.Hash
module Hashes = struct
include Hashtbl.Make (struct
type t = H.t
let hash = H.short_hash
let equal = Type.(unstage (equal H.t))
end)
let of_list l = of_seq (List.to_seq l)
let to_list t = List.of_seq (to_seq t)
let t elt_t = Type.map [%typ: (H.t * elt) list] of_list to_list
end
type mode = Produce | Serialise | Deserialise | Consume [@@deriving irmin]
type kind = Set | Stream [@@deriving irmin]
module Set = struct
type produce = {
nodes : B.Node.Val.t Hashes.t;
contents : B.Contents.Val.t Hashes.t;
}
[@@deriving irmin]
type deserialise = {
nodes : B.Node_portable.t Hashes.t;
contents : B.Contents.Val.t Hashes.t;
}
[@@deriving irmin]
type t =
| Produce of produce
| Serialise of produce
| Deserialise of deserialise
| Consume of deserialise
[@@deriving irmin]
let producer () =
Produce { contents = Hashes.create 13; nodes = Hashes.create 13 }
let deserialiser () =
Deserialise { contents = Hashes.create 13; nodes = Hashes.create 13 }
end
module Stream = struct
let ref_t v = Type.map v ref ( ! )
type produce = {
set : unit Hashes.t;
singleton_inodes : (int * H.t) Hashes.t;
rev_elts : (H.t * P.elt) list ref;
rev_elts_size : int ref;
}
[@@deriving irmin]
type consume = {
nodes : B.Node_portable.t Hashes.t;
contents : B.Contents.Val.t Hashes.t;
stream : P.elt Seq.t ref;
}
[@@deriving irmin]
type t = Produce of produce | Consume of consume [@@deriving irmin]
let producer () =
let set = Hashes.create 13 in
let singleton_inodes = Hashes.create 13 in
let rev_elts = ref [] in
let rev_elts_size = ref 0 in
Produce { set; singleton_inodes; rev_elts; rev_elts_size }
let consumer stream =
let nodes = Hashes.create 13 in
let contents = Hashes.create 13 in
let stream = ref stream in
Consume { nodes; contents; stream }
let push { rev_elts; rev_elts_size; _ } h_elt index =
incr rev_elts_size;
rev_elts := List.insert_exn !rev_elts index h_elt
end
type v = Empty | Set of Set.t | Stream of Stream.t [@@deriving irmin]
type t = v ref
let t = Type.map v_t ref ( ! )
let empty () : t = ref Empty
let is_empty t = !t = Empty
let copy ~into t = into := !t
type hash = H.t [@@deriving irmin ~equal ~pp]
let rec forward_lookup h singleton_inodes : (int * hash) list option =
match Hashes.find_opt singleton_inodes h with
| None -> None
| Some (i', h') -> (
match forward_lookup h' singleton_inodes with
| None -> Some [ (i', h') ]
| Some l -> Some ((i', h') :: l))
let apply_extenders ~length singleton_inodes skips proofs =
let rec accumulate_segments ~(acc : int Reversed_list.t) h = function
| [] -> (Reversed_list.rev acc, h)
| (i', h') :: rest -> accumulate_segments ~acc:(i' :: acc) h' rest
in
let inode = P.Inode { length; proofs } in
match proofs with
| [ (i, h) ] -> (
match forward_lookup h singleton_inodes with
| None -> inode
| Some ls -> (
let () =
match List.rev ((i, h) :: ls) with
| [] | [ _ ] -> failwith "idk"
| _ :: tl -> List.iter (fun (_, h) -> Hashes.add skips h ()) tl
in
let i, h = accumulate_segments ~acc:[ i ] h ls in
match i with
| [] | [ _ ] -> assert false
| segments -> P.Inode_extender { length; segments; proof = h }))
| _ -> inode
let post_processing singleton_inodes (stream : (hash * P.elt) list) :
P.elt list =
let skips = Hashes.create 13 in
let rec aux rev_elts = function
| [] -> List.rev rev_elts
| (h, elt) :: rest ->
if Hashes.mem skips h then aux rev_elts rest
else
let elt' : P.elt =
match (elt : P.elt) with
| P.Inode { length; proofs } ->
apply_extenders ~length singleton_inodes skips proofs
| Node ls -> Node ls
| Contents c -> Contents c
| Inode_extender _ -> assert false
in
aux (elt' :: rev_elts) rest
in
aux [] stream
let to_stream t =
match !t with
| Stream (Produce { rev_elts; singleton_inodes; _ }) ->
List.rev !rev_elts |> post_processing singleton_inodes |> List.to_seq
| _ -> assert false
let is_empty_stream t =
match !t with
| Stream (Consume { stream; _ }) -> (
match !stream () with Seq.Nil -> true | _ -> false)
| _ -> false
let set_mode t (kind : kind) mode =
match kind with
| Set -> (
match (!t, mode) with
| Empty, Produce -> t := Set Set.(producer ())
| Empty, Deserialise -> t := Set Set.(deserialiser ())
| Set (Produce set), Serialise -> t := Set Set.(Serialise set)
| Set (Deserialise set), Consume -> t := Set Set.(Consume set)
| _ -> assert false)
| Stream -> (
match (!t, mode) with
| Empty, Produce -> t := Stream (Stream.producer ())
| _ -> assert false)
let with_set_consume f =
let t = ref Empty in
set_mode t Set Deserialise;
let stop_deserialise () = set_mode t Set Consume in
let+ res = f t ~stop_deserialise in
t := Empty;
res
let with_set_produce f =
let t = ref Empty in
set_mode t Set Produce;
let start_serialise () = set_mode t Set Serialise in
let+ res = f t ~start_serialise in
t := Empty;
res
let with_stream_produce f =
let t = ref Empty in
set_mode t Stream Produce;
let to_stream () = to_stream t in
let+ res = f t ~to_stream in
t := Empty;
res
let with_stream_consume stream f =
let t = Stream (Stream.consumer stream) |> ref in
let is_empty () = is_empty_stream t in
let+ res = f t ~is_empty in
t := Empty;
res
module Contents_hash = Hash.Typed (H) (B.Contents.Val)
let check_contents_integrity v h =
let h' = Contents_hash.hash v in
if not (equal_hash h' h) then
bad_stream_exn_fmt "check_contents_integrity" "got %a expected %a" pp_hash
h' pp_hash h
let check_node_integrity v h =
let h' =
try B.Node_portable.hash_exn ~force:false v
with Not_found ->
assert false
in
if not (equal_hash h' h) then
bad_stream_exn_fmt "check_node_integrity" "got %a expected %a" pp_hash h'
pp_hash h
let dehydrate_stream_node v =
match B.Node.Val.head v with
| `Node l ->
let l =
List.map
(function
| step, `Contents (k, m) ->
(step, `Contents (B.Contents.Key.to_hash k, m))
| step, `Node k -> (step, `Node (B.Node.Key.to_hash k)))
l
in
P.Node l
| `Inode (length, proofs) -> P.Inode { length; proofs }
let rehydrate_stream_node ~depth (elt : P.elt) h =
let bad_stream_exn_fmt = bad_stream_exn_fmt "rehydrate_stream_node" in
match elt with
| Contents _ ->
bad_stream_exn_fmt
"found contents at depth %d when looking for node with hash %a" depth
pp_hash h
| Node l -> (
match B.Node_portable.of_proof ~depth (`Values l) with
| Some v -> v
| None ->
bad_stream_exn_fmt
"could not deserialise Node at depth %d when looking for hash %a"
depth pp_hash h)
| Inode { length; proofs } ->
let proofs = List.map (fun (i, h) -> (i, `Blinded h)) proofs in
let inode = `Inode (length, proofs) in
let v =
match B.Node_portable.of_proof ~depth inode with
| Some v -> v
| None ->
bad_stream_exn_fmt
"could not deserialise Inode at depth %d when looking for hash \
%a"
depth pp_hash h
in
v
| Inode_extender { length; segments; proof } ->
let elt =
List.fold_left
(fun acc i -> `Inode (length, [ (i, acc) ]))
(`Blinded proof) (List.rev segments)
in
let v =
match B.Node_portable.of_proof ~depth elt with
| Some v -> v
| None ->
bad_stream_exn_fmt
"could not deserialise Inode at depth %d when looking for hash \
%a"
depth pp_hash h
in
v
let rehydrate_stream_contents (elt : P.elt) h =
let err k =
bad_stream_exn_fmt "find_contents"
"found %s when looking Contents with hash %a" k pp_hash h
in
match elt with
| Node _ -> err "Node"
| Inode _ -> err "Inode"
| Inode_extender _ -> err "Inode"
| Contents v -> v
let find_contents t h =
match !t with
| Empty -> None
| Set (Produce set) ->
Hashes.find_opt set.contents h
| Set (Serialise set) ->
Hashes.find_opt set.contents h
| Set (Deserialise _) ->
assert false
| Set (Consume set) ->
Hashes.find_opt set.contents h
| Stream (Produce _) ->
None
| Stream (Consume { contents; stream; _ }) -> (
match Hashes.find_opt contents h with
| Some v -> Some v
| None -> (
match !stream () with
| Seq.Nil ->
bad_stream_too_short_fmt "find_contents"
"empty stream when looking for hash %a" pp_hash h
| Cons (elt, rest) ->
let v = rehydrate_stream_contents elt h in
check_contents_integrity v h;
stream := rest;
Hashes.add contents h v;
Some v))
let add_contents_from_store t h v =
match !t with
| Empty -> ()
| Set (Produce set) ->
assert (not (Hashes.mem set.contents h));
Hashes.add set.contents h v
| Set (Serialise _) ->
assert false
| Set (Deserialise _) ->
assert false
| Set (Consume _) ->
assert false
| Stream (Produce ({ set; _ } as cache)) ->
if not @@ Hashes.mem set h then (
Hashes.add set h ();
let h_elt : hash * P.elt = (h, Contents v) in
Stream.push cache h_elt 0)
| Stream (Consume _) ->
assert false
let add_contents_from_proof t h v =
match !t with
| Set (Deserialise set) ->
Hashes.replace set.contents h v
| Empty ->
()
| _ -> assert false
let find_node t h =
match !t with
| Empty -> None
| Set (Produce set) ->
Hashes.find_opt set.nodes h
| Set (Serialise set) ->
Hashes.find_opt set.nodes h
| Set (Deserialise _) ->
assert false
| Set (Consume _) ->
None
| Stream (Produce _) ->
None
| Stream (Consume _) ->
None
let find_recpnode t _find ~expected_depth h =
assert (expected_depth > 0);
match !t with
| Stream (Consume { nodes; stream; _ }) -> (
match Hashes.find_opt nodes h with
| Some v -> Some v
| None -> (
match !stream () with
| Seq.Nil ->
bad_stream_too_short_fmt "find_recnode"
"empty stream when looking for hash %a" pp_hash h
| Cons (v, rest) ->
let v = rehydrate_stream_node ~depth:expected_depth v h in
check_node_integrity v h;
stream := rest;
Hashes.add nodes h v;
Some v))
| _ -> assert false
let find_pnode t h =
match !t with
| Set (Consume set) ->
Hashes.find_opt set.nodes h
| Stream (Consume { nodes; stream; _ }) -> (
match Hashes.find_opt nodes h with
| Some v -> Some v
| None -> (
match !stream () with
| Seq.Nil ->
bad_stream_too_short_fmt "find_node"
"empty stream when looking for hash %a" pp_hash h
| Cons (v, rest) ->
stream := rest;
let v =
rehydrate_stream_node ~depth:0 v h
in
let v =
B.Node_portable.with_handler (find_recpnode t) v
in
let (_ : [ `Node of _ | `Inode of _ ]) =
B.Node_portable.head v
in
check_node_integrity v h;
Hashes.add nodes h v;
Some v))
| _ -> None
let add_recnode_from_store t find ~expected_depth k =
assert (expected_depth > 0);
match !t with
| Stream (Produce ({ set; singleton_inodes; _ } as cache)) -> (
match find ~expected_depth k with
| None -> None
| Some v ->
let h = B.Node.Key.to_hash k in
if not @@ Hashes.mem set h then (
Hashes.add set h ();
let elt = dehydrate_stream_node v in
let () =
match elt with
| P.Inode { proofs = [ bucket ]; _ } ->
Hashes.add singleton_inodes h bucket
| _ -> ()
in
Stream.push cache (h, elt) 0);
Some v)
| _ -> assert false
let add_node_from_store t h v =
match !t with
| Empty -> v
| Set (Produce set) ->
assert (not (Hashes.mem set.nodes h));
Hashes.add set.nodes h v;
v
| Set (Serialise _) ->
assert false
| Set (Deserialise _) ->
assert false
| Set (Consume _) ->
assert false
| Stream (Produce ({ set; rev_elts_size; singleton_inodes; _ } as cache)) ->
let new_hash = not @@ Hashes.mem set h in
let v =
B.Node.Val.with_handler (add_recnode_from_store t) v
in
if new_hash then (
Hashes.add set h ();
let len0 = !rev_elts_size in
let elt = dehydrate_stream_node v in
let len1 = !rev_elts_size in
let delta =
len1 - len0
in
let () =
match elt with
| P.Inode { proofs = [ bucket ]; _ } ->
Hashes.add singleton_inodes h bucket
| _ -> ()
in
Stream.push cache (h, elt) delta);
v
| Stream (Consume _) ->
assert false
let add_pnode_from_proof t h v =
match !t with
| Set (Deserialise set) ->
Hashes.replace set.nodes h v
| Empty ->
()
| _ -> assert false
end