nimbus-eth1/lc_proxy/block_cache.nim

63 lines
1.8 KiB
Nim

# light client proxy
# Copyright (c) 2022 Status Research & Development GmbH
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
{.push raises: [Defect].}
import
std/tables,
web3/ethtypes,
stew/[results, keyed_queue]
## payloads received through block gossip (and validated by light client).
## Payloads are stored in order of arrival. When cache is full the oldest
## payload is deleted first.
type BlockCache* = ref object
max: int
blocks: KeyedQueue[BlockHash, ExecutionPayloadV1]
proc `==`(x, y: Quantity): bool {.borrow, noSideEffect.}
proc new*(T: type BlockCache, max: uint32): T =
let maxAsInt = int(max)
return BlockCache(
max: maxAsInt,
blocks: KeyedQueue[BlockHash, ExecutionPayloadV1].init(maxAsInt)
)
func len*(self: BlockCache): int =
return len(self.blocks)
func isEmpty*(self: BlockCache): bool =
return len(self.blocks) == 0
proc add*(self: BlockCache, payload: ExecutionPayloadV1) =
if self.blocks.hasKey(payload.blockHash):
return
if len(self.blocks) >= self.max:
discard self.blocks.shift()
discard self.blocks.append(payload.blockHash, payload)
proc latest*(self: BlockCache): results.Opt[ExecutionPayloadV1] =
let latestPair = ? self.blocks.last()
return Opt.some(latestPair.data)
proc getByNumber*(
self: BlockCache,
number: Quantity): Opt[ExecutionPayloadV1] =
var payloadResult: Opt[ExecutionPayloadV1]
for payload in self.blocks.prevValues:
if payload.blockNumber == number:
payloadResult = Opt.some(payload)
break
return payloadResult