nimbus-eth1/nimbus/db/kvt/kvt_init/memory_only.nim

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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.
## Non persistent constructors for Kvt DB
## ======================================
##
{.push raises: [].}
import
../kvt_desc,
../kvt_desc/desc_backend,
"."/[init_common, memory_db]
type
VoidBackendRef* = ref object of TypedBackendRef
## Dummy descriptor type, used as `nil` reference
MemOnlyBackend* = VoidBackendRef|MemBackendRef
export
BackendType,
MemBackendRef
# ------------------------------------------------------------------------------
# Public helpers
# -----------------------------------------------------------------------------
proc kind*(
be: BackendRef;
): BackendType =
## Retrieves the backend type symbol for a `be` backend database argument
## where `BackendVoid` is returned for the`nil` backend.
if be.isNil:
BackendVoid
else:
be.TypedBackendRef.beKind
# ------------------------------------------------------------------------------
# Public database constuctors, destructor
# ------------------------------------------------------------------------------
proc init*(
T: type KvtDbRef; # Target type
B: type MemOnlyBackend; # Backend type
): T =
## Memory backend constructor.
##
when B is VoidBackendRef:
KvtDbRef(top: LayerRef.init())
elif B is MemBackendRef:
KvtDbRef(top: LayerRef.init(), backend: memoryBackend())
proc init*(
T: type KvtDbRef; # Target type
): T =
## Shortcut for `KvtDbRef.init(VoidBackendRef)`
KvtDbRef.init VoidBackendRef
proc finish*(db: KvtDbRef; flush = false) =
## Backend destructor. The argument `flush` indicates that a full database
## deletion is requested. If set `false` the outcome might differ depending
## on the type of backend (e.g. the `BackendMemory` backend will always
## flush on close.)
##
## This distructor may be used on already *destructed* descriptors.
##
if not db.backend.isNil:
db.backend.closeFn flush
discard db.getCentre.forgetOthers()
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------