nimbus-eth1/nimbus/db/aristo/aristo_init/aristo_memory.nim

142 lines
4.0 KiB
Nim

# nimbus-eth1
# Copyright (c) 2021 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.
## In-memory backend for Aristo DB
## ===============================
{.push raises: [].}
import
std/[sequtils, tables],
stew/results,
../aristo_desc,
../aristo_desc/aristo_types_backend
type
MemBackendRef = ref object
sTab: Table[VertexID,VertexRef] ## Structural vertex table making up a trie
kMap: Table[VertexID,HashKey] ## Merkle hash key mapping
vGen: seq[VertexID]
txGen: uint ## Transaction ID generator (for debugging)
txId: uint ## Active transaction ID (for debugging)
MemPutHdlRef = ref object of PutHdlRef
txId: uint ## Transaction ID (for debugging)
const
VerifyIxId = true # for debugging
# ------------------------------------------------------------------------------
# Private functions
# ------------------------------------------------------------------------------
proc getVtxFn(db: MemBackendRef): GetVtxFn =
result =
proc(vid: VertexID): Result[VertexRef,AristoError] =
let vtx = db.sTab.getOrDefault(vid, VertexRef(nil))
if vtx != VertexRef(nil):
return ok vtx
err(MemBeVtxNotFound)
proc getKeyFn(db: MemBackendRef): GetKeyFn =
result =
proc(vid: VertexID): Result[HashKey,AristoError] =
let key = db.kMap.getOrDefault(vid, VOID_HASH_KEY)
if key != VOID_HASH_KEY:
return ok key
err(MemBeKeyNotFound)
proc getIdgFn(db: MemBackendRef): GetIdgFn =
result =
proc(): Result[seq[VertexID],AristoError]=
ok db.vGen
# -------------
proc putBegFn(db: MemBackendRef): PutBegFn =
result =
proc(): PutHdlRef =
when VerifyIxId:
doAssert db.txId == 0
db.txGen.inc
MemPutHdlRef(txId: db.txGen)
proc putVtxFn(db: MemBackendRef): PutVtxFn =
result =
proc(hdl: PutHdlRef; vrps: openArray[(VertexID,VertexRef)]) =
when VerifyIxId:
doAssert db.txId == hdl.MemPutHdlRef.txId
for (vid,vtx) in vrps:
db.sTab[vid] = vtx
proc putKeyFn(db: MemBackendRef): PutKeyFn =
result =
proc(hdl: PutHdlRef; vkps: openArray[(VertexID,HashKey)]) =
when VerifyIxId:
doAssert db.txId == hdl.MemPutHdlRef.txId
for (vid,key) in vkps:
db.kMap[vid] = key
proc putIdgFn(db: MemBackendRef): PutIdgFn =
result =
proc(hdl: PutHdlRef; vs: openArray[VertexID]) =
when VerifyIxId:
doAssert db.txId == hdl.MemPutHdlRef.txId
db.vGen = vs.toSeq
proc putEndFn(db: MemBackendRef): PutEndFn =
result =
proc(hdl: PutHdlRef): AristoError =
when VerifyIxId:
doAssert db.txId == hdl.MemPutHdlRef.txId
db.txId = 0
AristoError(0)
# -------------
proc delVtxFn(db: MemBackendRef): DelVtxFn =
result =
proc(vids: openArray[VertexID]) =
for vid in vids:
db.sTab.del vid
proc delKeyFn(db: MemBackendRef): DelKeyFn =
result =
proc(vids: openArray[VertexID]) =
for vid in vids:
db.kMap.del vid
# ------------------------------------------------------------------------------
# Public functions
# ------------------------------------------------------------------------------
proc memoryBackend*(): AristoBackendRef =
let db = MemBackendRef()
AristoBackendRef(
getVtxFn: getVtxFn db,
getKeyFn: getKeyFn db,
getIdgFn: getIdgFn db,
putBegFn: putBegFn db,
putVtxFn: putVtxFn db,
putKeyFn: putKeyFn db,
putIdgFn: putIdgFn db,
putEndFn: putEndFn db,
delVtxFn: delVtxFn db,
delKeyFn: delKeyFn db)
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------