Proto: use integer comparison while checking proof-of-work.

src/client/embedded/bootstrap/client_proto_rpcs.mli

@@ -29,7 +29,7 @@ module Constants : sig
   val first_free_mining_slot: block -> int32 tzresult Lwt.t
   val max_signing_slot: block -> int tzresult Lwt.t
   val instructions_per_transaction: block -> int tzresult Lwt.t
-  val stamp_threshold: block -> int tzresult Lwt.t
+  val stamp_threshold: block -> int64 tzresult Lwt.t
 end
 
 module Context : sig

src/proto/bootstrap/constants_repr.ml

@@ -39,7 +39,7 @@ type constants = {
   first_free_mining_slot: int32 ;
   max_signing_slot: int ;
   instructions_per_transaction: int ;
-  proof_of_work_threshold: int ;
+  proof_of_work_threshold: int64 ;
 }
 
 let default = {
@@ -56,7 +56,8 @@ let default = {
   first_free_mining_slot = 16l ;
   max_signing_slot = 15 ;
   instructions_per_transaction = 16 * 1024 ;
-  proof_of_work_threshold = 8 ;
+  proof_of_work_threshold =
+    Int64.(lognot (sub (shift_left 1L 56) 1L)) ;
 }
 
 let opt (=) def v = if def = v then None else Some v
@@ -95,7 +96,7 @@ let constants_encoding =
          opt Int.(=)
            default.instructions_per_transaction c.instructions_per_transaction
        and proof_of_work_threshold =
-         opt Int.(=)
+         opt Int64.(=)
            default.proof_of_work_threshold c.proof_of_work_threshold
        in
        ( cycle_length,
@@ -144,7 +145,7 @@ let constants_encoding =
         (opt "first_free_mining_slot" int32)
         (opt "max_signing_slot" int31)
         (opt "instructions_per_transaction" int31)
-        (opt "proof_of_work_threshold" int31)
+        (opt "proof_of_work_threshold" int64)
     )
 
 type error += Constant_read of exn

src/proto/bootstrap/mining.ml

@@ -132,16 +132,10 @@ let first_endorsement_slots
   endorsement_priorities ctxt level >>=? fun delegate_list ->
   select_delegate delegate delegate_list max_priority
 
-
 let check_hash hash stamp_threshold =
-  let bytes = Block_hash.to_bytes hash in
-  let len = MBytes.length bytes * 8 in
-  try
-    for i = len - 1 downto (len - stamp_threshold) do
-      if MBytes.get_bool bytes i then raise Exit
-    done;
-    true
-  with Exit -> false
+  let bytes = Block_hash.to_raw hash in
+  let word = String.get_int64 bytes 0 in
+  Compare.Uint64.(word < stamp_threshold)
 
 let check_header_hash {Block.shell;proto;signature} stamp_threshold =
   let hash =

src/proto/bootstrap/mining.mli

@@ -70,7 +70,7 @@ val first_endorsement_slots:
 val check_signature:
   context -> Block.header -> public_key_hash -> unit tzresult Lwt.t
 
-val check_hash: Block_hash.t -> int -> bool
+val check_hash: Block_hash.t -> int64 -> bool
 val check_proof_of_work_stamp:
   context -> Block.header -> unit tzresult Lwt.t
 

src/proto/bootstrap/services.ml

@@ -97,7 +97,7 @@ module Constants = struct
       ~description: "Stamp threshold"
       ~input: empty
       ~output: (wrap_tzerror @@
-                describe ~title: "proof_of_work threshold" int31)
+                describe ~title: "proof_of_work threshold" int64)
       RPC.Path.(custom_root / "constants" / "proof_of_work_threshold")
 
   let errors custom_root =

src/proto/bootstrap/services_registration.ml

@@ -79,7 +79,8 @@ let () =
 let proof_of_work_threshold ctxt =
   return @@ Constants.proof_of_work_threshold ctxt
 
-let () = register0 Services.Constants.proof_of_work_threshold proof_of_work_threshold
+let () =
+  register0 Services.Constants.proof_of_work_threshold proof_of_work_threshold
 
 let () =
   register1_noctxt Services.Constants.errors

src/proto/bootstrap/tezos_context.mli

@@ -185,7 +185,7 @@ module Constants : sig
   val first_free_mining_slot: context -> int32
   val max_signing_slot: context -> int
   val instructions_per_transaction: context -> int
-  val proof_of_work_threshold: context -> int
+  val proof_of_work_threshold: context -> int64
 
 end
 

src/proto/environment/mBytes.mli

@@ -41,9 +41,6 @@ val substring: t -> int -> int -> string
 val get_char: t -> int -> char
 (** [get_char buff i] reads 1 byte at offset i as a char *)
 
-val get_bool: t -> int -> bool
-(** [get_bool buff i] reads 1 bit at offset i as an unsigned int bit. *)
-
 val get_uint8: t -> int -> int
 (** [get_uint8 buff i] reads 1 byte at offset i as an unsigned int of 8
     bits. i.e. It returns a value between 0 and 2^8-1 *)

src/utils/mBytes.ml

@@ -73,9 +73,6 @@ let substring src srcoff len =
 
 include EndianBigstring.BigEndian
 
-let get_bool s off =
-  ((get_uint8 s (off / 8)) lsr (off mod 8)) land 1 = 1
-
 let of_float f =
   let buf = create 8 in
   set_float buf 0 f;

src/utils/mBytes.mli

@@ -49,9 +49,6 @@ val substring: t -> int -> int -> string
 val get_char: t -> int -> char
 (** [get_char buff i] reads 1 byte at offset i as a char *)
 
-val get_bool: t -> int -> bool
-(** [get_bool buff i] reads 1 bit at offset i as an unsigned int bit. *)
-
 val get_uint8: t -> int -> int
 (** [get_uint8 buff i] reads 1 byte at offset i as an unsigned int of 8
     bits. i.e. It returns a value between 0 and 2^8-1 *)