Source file delegate_slashed_deposits_storage.ml

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(* Open Source License                                                       *)
(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com>     *)
(* Copyright (c) 2021 Nomadic Labs, <contact@nomadic-labs.com>               *)
(* Copyright (c) 2022 G.B. Fefe, <gb.fefe@protonmail.com>                    *)
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let already_slashed_for_double_endorsing ctxt delegate (level : Level_repr.t) =
  Storage.Slashed_deposits.find (ctxt, level.cycle) (level.level, delegate)
  >>=? function
  | None -> return_false
  | Some slashed -> return slashed.for_double_endorsing

let already_slashed_for_double_baking ctxt delegate (level : Level_repr.t) =
  Storage.Slashed_deposits.find (ctxt, level.cycle) (level.level, delegate)
  >>=? function
  | None -> return_false
  | Some slashed -> return slashed.for_double_baking

let punish_double_endorsing ctxt delegate (level : Level_repr.t) =
  let open Lwt_result_syntax in
  let* slashed =
    Storage.Slashed_deposits.find (ctxt, level.cycle) (level.level, delegate)
  in
  let updated_slashed =
    match slashed with
    | None -> {Storage.for_double_endorsing = true; for_double_baking = false}
    | Some slashed ->
        assert (Compare.Bool.(slashed.for_double_endorsing = false)) ;
        {slashed with for_double_endorsing = true}
  in
  let delegate_contract = Contract_repr.Implicit delegate in
  let* frozen_deposits = Frozen_deposits_storage.get ctxt delegate_contract in
  let slashing_ratio : Ratio_repr.t =
    Constants_storage.ratio_of_frozen_deposits_slashed_per_double_endorsement
      ctxt
  in
  let punish_value =
    Tez_repr.(
      div_exn
        (mul_exn frozen_deposits.initial_amount slashing_ratio.numerator)
        slashing_ratio.denominator)
  in
  let amount_to_burn =
    Tez_repr.(min frozen_deposits.current_amount punish_value)
  in
  let* ctxt, balance_updates =
    Token.transfer
      ctxt
      (`Frozen_deposits delegate)
      `Double_signing_punishments
      amount_to_burn
  in
  let* ctxt = Stake_storage.remove_stake ctxt delegate amount_to_burn in
  let*! ctxt =
    Storage.Slashed_deposits.add
      (ctxt, level.cycle)
      (level.level, delegate)
      updated_slashed
  in
  return (ctxt, amount_to_burn, balance_updates)

let punish_double_baking ctxt delegate (level : Level_repr.t) =
  let open Lwt_result_syntax in
  let* slashed =
    Storage.Slashed_deposits.find (ctxt, level.cycle) (level.level, delegate)
  in
  let updated_slashed =
    match slashed with
    | None -> {Storage.for_double_baking = true; for_double_endorsing = false}
    | Some slashed ->
        assert (Compare.Bool.(slashed.for_double_baking = false)) ;
        {slashed with for_double_baking = true}
  in
  let delegate_contract = Contract_repr.Implicit delegate in
  let* frozen_deposits = Frozen_deposits_storage.get ctxt delegate_contract in
  let slashing_for_one_block =
    Constants_storage.double_baking_punishment ctxt
  in
  let amount_to_burn =
    Tez_repr.(min frozen_deposits.current_amount slashing_for_one_block)
  in
  let* ctxt, balance_updates =
    Token.transfer
      ctxt
      (`Frozen_deposits delegate)
      `Double_signing_punishments
      amount_to_burn
  in
  let* ctxt = Stake_storage.remove_stake ctxt delegate amount_to_burn in
  let*! ctxt =
    Storage.Slashed_deposits.add
      (ctxt, level.cycle)
      (level.level, delegate)
      updated_slashed
  in
  return (ctxt, amount_to_burn, balance_updates)

let clear_outdated_slashed_deposits ctxt ~new_cycle =
  let max_slashable_period = Constants_storage.max_slashing_period ctxt in
  match Cycle_repr.(sub new_cycle max_slashable_period) with
  | None -> Lwt.return ctxt
  | Some outdated_cycle -> Storage.Slashed_deposits.clear (ctxt, outdated_cycle)