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

161 lines
5.0 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.
## Read vertex record on the layered Aristo DB delta architecture
## ==============================================================
{.push raises: [].}
import
std/tables,
results,
"."/[aristo_desc, aristo_layers]
# ------------------------------------------------------------------------------
# Public functions
# ------------------------------------------------------------------------------
proc getTuvUbe*(
db: AristoDbRef;
): Result[VertexID,AristoError] =
## Get the ID generator state from the unfiltered backened if available.
let be = db.backend
if not be.isNil:
return be.getTuvFn()
err(GetTuvNotFound)
proc getLstUbe*(
db: AristoDbRef;
): Result[SavedState,AristoError] =
## Get the last saved state
let be = db.backend
if not be.isNil:
return be.getLstFn()
err(GetLstNotFound)
proc getVtxUbe*(
db: AristoDbRef;
rvid: RootedVertexID;
): Result[VertexRef,AristoError] =
## Get the vertex from the unfiltered backened if available.
let be = db.backend
if not be.isNil:
return be.getVtxFn rvid
err GetVtxNotFound
proc getKeyUbe*(
db: AristoDbRef;
rvid: RootedVertexID;
): Result[HashKey,AristoError] =
## Get the Merkle hash/key from the unfiltered backend if available.
let be = db.backend
if not be.isNil:
return be.getKeyFn rvid
err GetKeyNotFound
# ------------------
proc getTuvBE*(
db: AristoDbRef;
): Result[VertexID,AristoError] =
## Get the ID generator state the `backened` layer if available.
if not db.balancer.isNil:
return ok(db.balancer.vTop)
db.getTuvUbe()
proc getVtxBE*(
db: AristoDbRef;
rvid: RootedVertexID;
): Result[(VertexRef, int),AristoError] =
## Get the vertex from the (filtered) backened if available.
if not db.balancer.isNil:
db.balancer.sTab.withValue(rvid, w):
if w[].isValid:
return ok (w[], -1)
return err(GetVtxNotFound)
ok (? db.getVtxUbe rvid, -2)
proc getKeyBE*(
db: AristoDbRef;
rvid: RootedVertexID;
): Result[(HashKey, int),AristoError] =
## Get the merkle hash/key from the (filtered) backend if available.
if not db.balancer.isNil:
db.balancer.kMap.withValue(rvid, w):
if w[].isValid:
return ok((w[], -1))
return err(GetKeyNotFound)
ok ((?db.getKeyUbe rvid), -2)
# ------------------
proc getVtxRc*(
db: AristoDbRef;
rvid: RootedVertexID
): Result[(VertexRef, int),AristoError] =
## Cascaded attempt to fetch a vertex from the cache layers or the backend.
##
block body:
# If the vertex marked is to be deleted on the backend, a `VertexRef(nil)`
# entry is kept in the local table in which case it is returned as the
# error symbol `GetVtxNotFound`.
let vtx = db.layersGetVtx(rvid).valueOr:
break body
if vtx[0].isValid:
return ok vtx
else:
return err(GetVtxNotFound)
db.getVtxBE rvid
proc getVtx*(db: AristoDbRef; rvid: RootedVertexID): VertexRef =
## Cascaded attempt to fetch a vertex from the cache layers or the backend.
## The function returns `nil` on error or failure.
##
db.getVtxRc(rvid).valueOr((VertexRef(nil), 0))[0]
proc getKeyRc*(db: AristoDbRef; rvid: RootedVertexID): Result[(HashKey, int),AristoError] =
## Cascaded attempt to fetch a Merkle hash from the cache layers or the
## backend. This function will never return a `VOID_HASH_KEY` but rather
## some `GetKeyNotFound` or `GetKeyUpdateNeeded` error.
##
block body:
let key = db.layersGetKey(rvid).valueOr:
break body
# If there is a zero key value, the entry is either marked for being
# updated or for deletion on the database. So check below.
if key[0].isValid:
return ok key
# The zero key value does not refer to an update mark if there is no
# valid vertex (either on the cache or the backend whatever comes first.)
let vtx = db.layersGetVtx(rvid).valueOr:
# There was no vertex on the cache. So there must be one the backend (the
# reason for the key lable to exists, at all.)
return err(GetKeyUpdateNeeded)
if vtx[0].isValid:
return err(GetKeyUpdateNeeded)
else:
# The vertex is to be deleted. So is the value key.
return err(GetKeyNotFound)
db.getKeyBE rvid
proc getKey*(db: AristoDbRef; rvid: RootedVertexID): HashKey =
## Cascaded attempt to fetch a vertex from the cache layers or the backend.
## The function returns `nil` on error or failure.
##
(db.getKeyRc(rvid).valueOr((VOID_HASH_KEY, 0)))[0]
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------