84 lines
2.6 KiB
Nim
84 lines
2.6 KiB
Nim
# nimbus-eth1
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# Copyright (c) 2021 Status Research & Development GmbH
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# Licensed under either of
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# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
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# http://www.apache.org/licenses/LICENSE-2.0)
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# * MIT license ([LICENSE-MIT](LICENSE-MIT) or
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# http://opensource.org/licenses/MIT)
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# at your option. This file may not be copied, modified, or distributed
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# except according to those terms.
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## Non persistent constructors for Kvt DB
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## ======================================
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##
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{.push raises: [].}
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import
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../kvt_desc,
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../kvt_desc/desc_backend,
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"."/[init_common, memory_db]
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type
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VoidBackendRef* = ref object of TypedBackendRef
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## Dummy descriptor type, used as `nil` reference
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MemOnlyBackend* = VoidBackendRef|MemBackendRef
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export
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BackendType,
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MemBackendRef
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# ------------------------------------------------------------------------------
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# Public helpers
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# -----------------------------------------------------------------------------
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proc kind*(
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be: BackendRef;
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): BackendType =
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## Retrieves the backend type symbol for a `be` backend database argument
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## where `BackendVoid` is returned for the`nil` backend.
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if be.isNil:
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BackendVoid
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else:
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be.TypedBackendRef.beKind
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# ------------------------------------------------------------------------------
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# Public database constuctors, destructor
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# ------------------------------------------------------------------------------
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proc init*(
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T: type KvtDbRef; # Target type
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B: type MemOnlyBackend; # Backend type
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): T =
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## Memory backend constructor.
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##
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when B is VoidBackendRef:
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KvtDbRef(top: LayerRef())
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elif B is MemBackendRef:
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KvtDbRef(top: LayerRef(), backend: memoryBackend(qidLayout))
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proc init*(
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T: type KvtDbRef; # Target type
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): T =
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## Shortcut for `KvtDbRef.init(VoidBackendRef)`
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KvtDbRef.init VoidBackendRef
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proc finish*(db: KvtDbRef; flush = false) =
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## Backend destructor. The argument `flush` indicates that a full database
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## deletion is requested. If set `false` the outcome might differ depending
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## on the type of backend (e.g. the `BackendMemory` backend will always
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## flush on close.)
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##
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## This distructor may be used on already *destructed* descriptors.
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##
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if not db.isNil:
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if not db.backend.isNil:
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db.backend.closeFn flush
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db[] = KvtDbObj(top: LayerRef())
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# ------------------------------------------------------------------------------
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# End
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# ------------------------------------------------------------------------------
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