nimbus-eth2/beacon_chain/spec/ssz_codec.nim

# beacon_chain
# Copyright (c) 2018-2021 Status Research & Development GmbH
# Licensed and distributed under either of
#   * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
#   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.

{.push raises: [Defect].}
{.pragma: raisesssz, raises: [Defect, MalformedSszError, SszSizeMismatchError].}

import
  std/[typetraits],
  ssz_serialization/codec,
  ./datatypes/base

export codec, base, typetraits

# Coding and decoding of SSZ to spec-specific types

template toSszType*(v: Slot|Epoch): auto = uint64(v)
template toSszType*(v: BlsCurveType): auto = toRaw(v)
template toSszType*(v: ForkDigest|GraffitiBytes): auto = distinctBase(v)
template toSszType*(v: Version): auto = distinctBase(v)
template toSszType*(v: JustificationBits): auto = distinctBase(v)

func fromSszBytes*(T: type GraffitiBytes, data: openArray[byte]): T {.raisesssz.} =
  if data.len != sizeof(result):
    raiseIncorrectSize T
  copyMem(result.addr, unsafeAddr data[0], sizeof(result))

template fromSszBytes*(T: type Slot, bytes: openArray[byte]): T =
  T fromSszBytes(uint64, bytes)

template fromSszBytes*(T: type Epoch, bytes: openArray[byte]): T =
  T fromSszBytes(uint64, bytes)

func fromSszBytes*(T: type ForkDigest, bytes: openArray[byte]): T {.raisesssz.} =
  if bytes.len != sizeof(result):
    raiseIncorrectSize T
  copyMem(result.addr, unsafeAddr bytes[0], sizeof(result))

func fromSszBytes*(T: type Version, bytes: openArray[byte]): T {.raisesssz.} =
  if bytes.len != sizeof(result):
    raiseIncorrectSize T
  copyMem(result.addr, unsafeAddr bytes[0], sizeof(result))

func fromSszBytes*(T: type JustificationBits, bytes: openArray[byte]): T {.raisesssz.} =
  if bytes.len != sizeof(result):
    raiseIncorrectSize T
  copyMem(result.addr, unsafeAddr bytes[0], sizeof(result))