nimbus-eth1/nimbus/db/kvt/kvt_desc.nim

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3.1 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.
## Kvt DB -- key-value table
## =========================
##
{.push raises: [].}
import
std/[hashes, tables],
./kvt_constants,
./kvt_desc/[desc_error, desc_structural]
from ./kvt_desc/desc_backend
import BackendRef
# Not auto-exporting backend
export
tables, kvt_constants, desc_error, desc_structural
type
KvtTxRef* = ref object
## Transaction descriptor
db*: KvtDbRef ## Database descriptor
parent*: KvtTxRef ## Previous transaction
txUid*: uint ## Unique ID among transactions
level*: int ## Stack index for this transaction
KvtDbRef* = ref object of RootRef
## Three tier database object supporting distributed instances.
top*: LayerRef ## Database working layer, mutable
stack*: seq[LayerRef] ## Stashed immutable parent layers
balancer*: LayerRef ## Balance out concurrent backend access
backend*: BackendRef ## Backend database (may well be `nil`)
txRef*: KvtTxRef ## Latest active transaction
txUidGen*: uint ## Tx-relative unique number generator
# Debugging data below, might go away in future
xIdGen*: uint64
xMap*: Table[seq[byte],uint64] ## For pretty printing
pAmx*: Table[uint64,seq[byte]] ## For pretty printing
KvtDbAction* = proc(db: KvtDbRef) {.gcsafe, raises: [].}
## Generic call back function/closure.
# ------------------------------------------------------------------------------
# Public helpers
# ------------------------------------------------------------------------------
func getOrVoid*(tab: Table[seq[byte],seq[byte]]; w: seq[byte]): seq[byte] =
tab.getOrDefault(w, EmptyBlob)
func isValid*(key: seq[byte]): bool =
key != EmptyBlob
func isValid*(layer: LayerRef): bool =
layer != LayerRef(nil)
# ------------------------------------------------------------------------------
# Public functions, miscellaneous
# ------------------------------------------------------------------------------
# Hash set helper
func hash*(db: KvtDbRef): Hash =
## Table/KeyedQueue/HashSet mixin
cast[pointer](db).hash
# ------------------------------------------------------------------------------
# Public functions, `dude` related
# ------------------------------------------------------------------------------
iterator rstack*(db: KvtDbRef): LayerRef =
# Stack in reverse order
for i in 0..<db.stack.len:
yield db.stack[db.stack.len - i - 1]
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------