# nimbus-eth1
# Copyright (c) 2023-2024 Status Research & Development GmbH
# Licensed under either of
#  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
#    http://www.apache.org/licenses/LICENSE-2.0)
#  * MIT license ([LICENSE-MIT](LICENSE-MIT) or
#    http://opensource.org/licenses/MIT)
# at your option. This file may not be copied, modified, or distributed
# except according to those terms.

{.push raises: [].}

import
  std/sets,
  eth/[common, trie/nibbles],
  ./aristo_desc/desc_identifiers

const
  EmptyBlob* = seq[byte].default
    ## Useful shortcut (borrowed from `sync/snap/constants.nim`)

  EmptyNibbleSeq* = EmptyBlob.initNibbleRange
    ## Useful shortcut (borrowed from `sync/snap/constants.nim`)

  EmptyVidSeq* = seq[VertexID].default
    ## Useful shortcut

  EmptyVidSet* = EmptyVidSeq.toHashSet
    ## Useful shortcut

  VOID_CODE_HASH* = EMPTY_CODE_HASH
    ## Equivalent of `nil` for `Account` object code hash field

  VOID_HASH_KEY* = HashKey()
    ## Void equivalent for Merkle hash value

  VOID_PATH_ID* = PathID()
    ## Void equivalent for Merkle hash value

  EmptyQidPairSeq* = seq[(QueueID,QueueID)].default
    ## Useful shortcut

  DEFAULT_QID_QUEUES* = [
    (128,   0), ## Consecutive list of 128 filter slots
    ( 64,  63), ## Overflow list, 64 filters, skipping 63 filters in-between
    ( 64, 127), ## ..
    ( 64, 255)]

  SUB_TREE_DISPOSAL_MAX* = 200_000
    ## Some limit for disposing sub-trees in one go using `delete()`.

  LEAST_FREE_VID* = 100
    ## Vids smaller are used as known state roots and cannot be recycled. Only
    ## the `VertexID(1)` state root is used by the `Aristo` methods. The other
    ## numbers smaller than `LEAST_FREE_VID` may be used by application
    ## functions with fixed assignments of the type of a state root (e.g. for
    ## a receipt or a transaction root.)

  LOOSE_STORAGE_TRIE_COUPLING* = true
    ## Enabling the `LOOSE_STORAGE_TRIE_COUPLING` flag a sub-trie is considered
    ## empty if the root vertex ID is zero or at least `LEAST_FREE_VID` and
    ## there is no vertex available. If the vertex ID is not zero and should
    ## be considered as such will affect calculating the Merkel hash node key
    ## for an accou.t leaf of payload type `AccountData`.
    ##
    ## Setting this flag `true` might be helpful for running an API supporting
    ## both, a legacy and# the `Aristo` database backend.
    ##

static:
  doAssert 1 < LEAST_FREE_VID # must stay away from `VertexID(1)`

# End