nimbus-eth1/nimbus/sync/snap/worker/com/get_byte_codes.nim

130 lines
3.8 KiB
Nim

# Nimbus
# 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.
## Note: this module is currently unused
import
std/[options, sequtils],
chronos,
eth/[common/eth_types, p2p],
"../../.."/[protocol, protocol/trace_config],
"../.."/[range_desc, worker_desc],
./get_error
{.push raises: [Defect].}
logScope:
topics = "snap-fetch"
type
# SnapByteCodes* = object
# codes*: seq[Blob]
GetByteCodes* = object
leftOver*: seq[NodeKey]
kvPairs*: seq[(Nodekey,Blob)]
const
emptyBlob = seq[byte].default
# ------------------------------------------------------------------------------
# Private functions
# ------------------------------------------------------------------------------
proc getByteCodesReq(
buddy: SnapBuddyRef;
keys: seq[Hash256];
): Future[Result[Option[SnapByteCodes],void]]
{.async.} =
let
peer = buddy.peer
try:
let reply = await peer.getByteCodes(keys, snapRequestBytesLimit)
return ok(reply)
except CatchableError as e:
trace trSnapRecvError & "waiting for GetByteCodes reply", peer,
error=e.msg
return err()
# ------------------------------------------------------------------------------
# Public functions
# ------------------------------------------------------------------------------
proc getByteCodes*(
buddy: SnapBuddyRef;
keys: seq[NodeKey],
): Future[Result[GetByteCodes,ComError]]
{.async.} =
## Fetch data using the `snap#` protocol, returns the byte codes requested
## (if any.)
let
peer = buddy.peer
nKeys = keys.len
if nKeys == 0:
return err(ComEmptyRequestArguments)
if trSnapTracePacketsOk:
trace trSnapSendSending & "GetByteCodes", peer,
nkeys, bytesLimit=snapRequestBytesLimit
let byteCodes = block:
let rc = await buddy.getByteCodesReq(
keys.mapIt(Hash256(data: it.ByteArray32)))
if rc.isErr:
return err(ComNetworkProblem)
if rc.value.isNone:
trace trSnapRecvTimeoutWaiting & "for reply to GetByteCodes", peer, nKeys
return err(ComResponseTimeout)
let blobs = rc.value.get.codes
if nKeys < blobs.len:
# Ooops, makes no sense
return err(ComTooManyByteCodes)
blobs
let
nCodes = byteCodes.len
if nCodes == 0:
# github.com/ethereum/devp2p/blob/master/caps/snap.md#getbytecodes-0x04
#
# Notes:
# * Nodes must always respond to the query.
# * The returned codes must be in the request order.
# * The responding node is allowed to return less data than requested
# (serving QoS limits), but the node must return at least one bytecode,
# unless none requested are available, in which case it must answer with
# an empty response.
# * If a bytecode is unavailable, the node must skip that slot and proceed
# to the next one. The node must not return nil or other placeholders.
trace trSnapRecvReceived & "empty ByteCodes", peer, nKeys, nCodes
return err(ComNoByteCodesAvailable)
# Assemble return value
var dd: GetByteCodes
for n in 0 ..< nCodes:
if byteCodes[n].len == 0:
dd.leftOver.add keys[n]
else:
dd.kvPairs.add (keys[n], byteCodes[n])
dd.leftOver.add keys[byteCodes.len+1 ..< nKeys]
trace trSnapRecvReceived & "ByteCodes", peer,
nKeys, nCodes, nLeftOver=dd.leftOver.len
return ok(dd)
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------