nimbus-eth1/nimbus/db/aristo/aristo_fetch.nim

92 lines
3.0 KiB
Nim

# 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.
## Aristo DB -- Obects Retrival Via Traversal Path
## ===============================================
##
{.push raises: [].}
import
eth/trie/nibbles,
results,
"."/[aristo_desc, aristo_get, aristo_hike]
# ------------------------------------------------------------------------------
# Private functions
# ------------------------------------------------------------------------------
proc fetchPayloadImpl(
rc: Result[Hike,(VertexID,AristoError,Hike)];
): Result[PayloadRef,(VertexID,AristoError)] =
if rc.isErr:
if rc.error[1] in HikeAcceptableStopsNotFound:
return err((rc.error[0], FetchPathNotFound))
return err((rc.error[0], rc.error[1]))
ok rc.value.legs[^1].wp.vtx.lData
proc fetchPayloadImpl(
db: AristoDbRef;
root: VertexID;
path: openArray[byte];
): Result[PayloadRef,(VertexID,AristoError)] =
path.initNibbleRange.hikeUp(root, db).fetchPayloadImpl
# ------------------------------------------------------------------------------
# Public functions
# ------------------------------------------------------------------------------
proc fetchPayload*(
db: AristoDbRef;
key: LeafTie;
): Result[PayloadRef,(VertexID,AristoError)] =
## Cascaded attempt to traverse the `Aristo Trie` and fetch the value of a
## leaf vertex. This function is complementary to `mergePayload()`.
##
key.hikeUp(db).fetchPayloadImpl
proc fetchPayload*(
db: AristoDbRef;
root: VertexID;
path: openArray[byte];
): Result[PayloadRef,(VertexID,AristoError)] =
## Variant of `fetchPayload()`
##
if path.len == 0:
return err((VertexID(0),LeafKeyInvalid))
db.fetchPayloadImpl(root, path)
proc hasPath*(
db: AristoDbRef; # Database
root: VertexID;
path: openArray[byte]; # Key of database record
): Result[bool,(VertexID,AristoError)] =
## Variant of `fetchPayload()`
##
if path.len == 0:
return err((VertexID(0),LeafKeyInvalid))
let rc = db.fetchPayloadImpl(root, path)
if rc.isOk:
return ok(true)
if rc.error[1] == FetchPathNotFound:
return ok(false)
err(rc.error)
proc fetchLastSavedState*(
db: AristoDbRef;
): Result[SavedState,AristoError] =
## Wrapper around `getLstUbe()`. The function returns the state of the last
## saved state. This is a Merkle hash tag for vertex with ID 1 and a bespoke
## `uint64` identifier (may be interpreted as block number.)
db.getLstUbe()
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------