nim-codex/dagger/blockexchange/pendingblocks.nim

74 lines
1.7 KiB
Nim

## Nim-Dagger
## Copyright (c) 2021 Status Research & Development GmbH
## Licensed under either of
## * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
## * MIT license ([LICENSE-MIT](LICENSE-MIT))
## at your option.
## This file may not be copied, modified, or distributed except according to
## those terms.
import std/tables
import pkg/chronicles
import pkg/chronos
import pkg/libp2p
import ../blocktype
logScope:
topics = "dagger blockexc pendingblocks"
type
PendingBlocksManager* = ref object of RootObj
blocks*: Table[Cid, Future[Block]] # pending Block requests
proc addOrAwait*(
p: PendingBlocksManager,
cid: Cid):
Future[Block] {.async.} =
## Add an event for a block
##
if cid notin p.blocks:
p.blocks[cid] = newFuture[Block]()
trace "Adding pending future for block", cid
let blk = p.blocks[cid]
try:
return await blk
except CancelledError as exc:
trace "Blocks cancelled", exc = exc.msg, cid
raise exc
except CatchableError as exc:
trace "Pending WANT failed or expired", exc = exc.msg
finally:
p.blocks.del(cid)
proc resolve*(
p: PendingBlocksManager,
blocks: seq[Block]) =
## Resolve pending blocks
##
for blk in blocks:
# resolve any pending blocks
if blk.cid in p.blocks:
let pending = p.blocks[blk.cid]
if not pending.finished:
trace "Resolving block", cid = $blk.cid
pending.complete(blk)
p.blocks.del(blk.cid)
proc pending*(
p: PendingBlocksManager,
cid: Cid): bool = cid in p.blocks
proc contains*(
p: PendingBlocksManager,
cid: Cid): bool = p.pending(cid)
func new*(T: type PendingBlocksManager): T =
T(
blocks: initTable[Cid, Future[Block]]()
)