63 lines
2.1 KiB
Nim
63 lines
2.1 KiB
Nim
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# 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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## Kvt DB -- key-value table
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## =========================
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##
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{.push raises: [].}
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import
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std/tables,
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eth/common,
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./kvt_constants,
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./kvt_desc/[desc_error, desc_structural]
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from ./kvt_desc/desc_backend
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import BackendRef
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# Not auto-exporting backend
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export
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kvt_constants, desc_error, desc_structural
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type
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KvtTxRef* = ref object
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## Transaction descriptor
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db*: KvtDbRef ## Database descriptor
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parent*: KvtTxRef ## Previous transaction
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txUid*: uint ## Unique ID among transactions
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level*: int ## Stack index for this transaction
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KvtDbRef* = ref KvtDbObj
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KvtDbObj* = object
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## Three tier database object supporting distributed instances.
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top*: LayerRef ## Database working layer, mutable
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stack*: seq[LayerRef] ## Stashed immutable parent layers
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backend*: BackendRef ## Backend database (may well be `nil`)
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txRef*: KvtTxRef ## Latest active transaction
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txUidGen*: uint ## Tx-relative unique number generator
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KvtDbAction* = proc(db: KvtDbRef) {.gcsafe, raises: [CatchableError].}
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## Generic call back function/closure.
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# ------------------------------------------------------------------------------
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# Public helpers
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# ------------------------------------------------------------------------------
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func getOrVoid*(tab: Table[Blob,Blob]; w: Blob): Blob =
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tab.getOrDefault(w, EmptyBlob)
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func isValid*(key: Blob): bool =
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key != EmptyBlob
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# ------------------------------------------------------------------------------
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# End
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# ------------------------------------------------------------------------------
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