107 lines
3.3 KiB
Nim
107 lines
3.3 KiB
Nim
# nimbus-eth1
|
|
# Copyright (c) 2021 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.
|
|
|
|
## Read vertex record on the layered Aristo DB delta architecture
|
|
## ==============================================================
|
|
|
|
{.push raises: [].}
|
|
|
|
import
|
|
std/tables,
|
|
stew/results,
|
|
"."/aristo_desc
|
|
|
|
type
|
|
VidVtxPair* = object
|
|
vid*: VertexID ## Table lookup vertex ID (if any)
|
|
vtx*: VertexRef ## Reference to vertex
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Public functions
|
|
# ------------------------------------------------------------------------------
|
|
|
|
proc getVtxBackend*(
|
|
db: AristoDb;
|
|
vid: VertexID;
|
|
): Result[VertexRef,AristoError] =
|
|
## Get the vertex from the `backened` layer if available.
|
|
let be = db.backend
|
|
if not be.isNil:
|
|
return be.getVtxFn vid
|
|
err(GetVtxNotFound)
|
|
|
|
proc getKeyBackend*(
|
|
db: AristoDb;
|
|
vid: VertexID;
|
|
): Result[HashKey,AristoError] =
|
|
## Get the merkle hash/key from the backend
|
|
let be = db.backend
|
|
if not be.isNil:
|
|
return be.getKeyFn vid
|
|
err(GetKeyNotFound)
|
|
|
|
# ------------------
|
|
|
|
proc getLeaf*(
|
|
db: AristoDb;
|
|
lty: LeafTie;
|
|
): Result[VidVtxPair,AristoError] =
|
|
## Get the vertex from the top layer by the `Patricia Trie` path. This
|
|
## function does not search on the `backend` layer.
|
|
let vid = db.top.lTab.getOrVoid lty
|
|
if not vid.isValid:
|
|
return err(GetLeafNotFound)
|
|
|
|
let vtx = db.top.sTab.getOrVoid vid
|
|
if not vtx.isValid:
|
|
return err(GetVtxNotFound)
|
|
|
|
ok VidVtxPair(vid: vid, vtx: vtx)
|
|
|
|
proc getLeafVtx*(db: AristoDb; lty: LeafTie): VertexRef =
|
|
## Variant of `getLeaf()` returning `nil` on error (while ignoring the
|
|
## detailed error type information.)
|
|
##
|
|
let rc = db.getLeaf lty
|
|
if rc.isOk:
|
|
return rc.value.vtx
|
|
|
|
# ------------------
|
|
|
|
proc getVtx*(db: AristoDb; vid: VertexID): VertexRef =
|
|
## Cascaded attempt to fetch a vertex from the top layer or the backend.
|
|
## The function returns `nil` on error or failure.
|
|
##
|
|
if db.top.sTab.hasKey vid:
|
|
# If the vertex is to be deleted on the backend, a `VertexRef(nil)` entry
|
|
# is kept in the local table in which case it is OK to return this value.
|
|
return db.top.sTab.getOrVoid vid
|
|
let rc = db.getVtxBackend vid
|
|
if rc.isOk:
|
|
return rc.value
|
|
VertexRef(nil)
|
|
|
|
proc getKey*(db: AristoDb; vid: VertexID): HashKey =
|
|
## Cascaded attempt to fetch a Merkle hash from the top layer or the backend.
|
|
## The function returns `VOID_HASH_KEY` on error or failure.
|
|
##
|
|
if db.top.kMap.hasKey vid:
|
|
# If the key is to be deleted on the backend, a `VOID_HASH_LABEL` entry
|
|
# is kept on the local table in which case it is OK to return this value.
|
|
return db.top.kMap.getOrVoid(vid).key
|
|
let rc = db.getKeyBackend vid
|
|
if rc.isOk:
|
|
return rc.value
|
|
VOID_HASH_KEY
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# End
|
|
# ------------------------------------------------------------------------------
|