Revert "rlpx review comments"

This reverts commit a6b14dcd0b.
This commit is contained in:
Jacek Sieka 2018-05-02 20:51:29 +08:00
parent a6b14dcd0b
commit 849b7c1303
2 changed files with 0 additions and 48 deletions

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@ -56,21 +56,12 @@ type
# The dispatcher stores the mapping of negotiated message IDs between
# two connected peers. The dispatcher objects are shared between
# connections running with the same set of supported protocols.
# REVIEW: why bother? there aren't millions of peers anyway, so why not
# keep it simple and keep this per peer? this just looks like
# it introduces lots of book-keeping and opportunities for logic
# errors. This also seems like the smallest piece of information
# to share - we still have to keep per-peer, per protocol state
#
# `protocolOffsets` will hold one slot of each locally supported
# protocol. If the other peer also supports the protocol, the stored
# offset indicates the numeric value of the first message of the protocol
# (for this particular connection). If the other peer doesn't support the
# particular protocol, the stored offset is -1.
# REVIEW: The alternative is to store a messagehandler that does nothing -
# or logs the call or returns a "ignored" status - this tends
# to simplify code and remove unnecessary error handling and bounds
# checking etc..
#
# `thunks` holds a mapping from valid message IDs to their handler procs.
#
@ -87,10 +78,6 @@ const
baseProtocolVersion = 4
clienId = "Nimbus 0.1.0"
# REVIEW these globals will prevent us from using rlpx as a library, for example
# when setting up a simulation or test - a major use case for research
# I think a hard no-thanks stance on mutable globals is valuable if we
# want to pursue a library-first approach
var
gProtocols = newSeq[ProtocolInfo](0)
gCapabilities = newSeq[Capability](0)
@ -188,8 +175,6 @@ proc registerMsg(protocol: var ProtocolInfo,
proc registerProtocol(protocol: ProtocolInfo) =
# XXX: This can be done at compile-time in the future
# REVIEW: as long as there's an option to disable certain protocols at run time,
# per globals-comment above
if protocol.version > 0:
let pos = lowerBound(gProtocols, protocol)
gProtocols.insert(protocol, pos)
@ -214,17 +199,11 @@ proc read*(rlp: var Rlp, T: typedesc[KeccakHash]): T =
proc writeMsgId(p: ProtocolInfo, msgId: int, peer: Peer, rlpOut: var RlpWriter) =
let baseMsgId = peer.dispatcher.protocolOffsets[p.index]
if baseMsgId == -1:
# REVIEW: what's the use case for this exception? when is it expected that
# someone will catch it and use the type to meaningfully handle the
# error? else might just assert - seems like a logic error if this happens
# and sending the message anyway seems harmless
raise newException(UnsupportedProtocol,
p.nameStr & " is not supported by peer " & $peer.id)
rlpOut.append(baseMsgId + msgId)
proc dispatchMsg(peer: Peer, msgId: int, msgData: var Rlp) =
# REVIEW: who will call dispatchMsg? right now, only nextMsg, which more looks
# like a way to short-circuit message dispatching..
template invalidIdError: untyped =
raise newException(ValueError,
"RLPx message with an invalid id " & $msgId &
@ -266,10 +245,6 @@ proc recvMsg*(peer: Peer): Future[tuple[msgId: int, msgData: Rlp]] {.async.} =
let remainingBytes = encryptedLength(msgSize) - 32
# XXX: Migrate this to a thread-local seq
# REVIEW: or pass it in, allowing the caller to choose - they'll likely be in a
# better position to decide if buffer should be reused or not. this will
# also be useuful for chunked messages where part of the buffer may have
# been processed and needs filling in
var encryptedBytes = newSeq[byte](remainingBytes)
await peer.socket.fullRecvInto(encryptedBytes.baseAddr, remainingBytes)
@ -294,27 +269,6 @@ proc nextMsg*(peer: Peer, MsgType: typedesc,
## to their responsive handlers unless `discardOthers` is set to
## true. This may be useful when the protocol requires a very
## specific response to a given request. Use with caution.
# REVIEW: it's unclear to me how prioritization between regular
# dispatching and nextMsg style dispatching should happen,
# also between multiple nextMsg calls - who gets the
# message first?
# discardOthers looks like an easy way to introduce
# "deadlocks" if there are two discardOthers calls in
# flight
# an alternative here would be a super-state-machine:
# you register message handlers not only for a peer but
# also for a particualar peer state - this would allow
# us to create states for the peer (pre-auth, hello,
# regular-comms, tear-down), keeping it clear which
# messages are handled in which states, for example when
# auditing the implementation - this could probably be
# the same state enum as ConnectionState - it doesn't really
# matter if we're disconnected or connected-but-authenticating,
# we still won't handle most messages..
# another thing to consider once you get into request-
# response is that you also have to handle the usual
# suspects of async messaging: timeouts, arrivals of
# response after the timeout, etc
const wantedId = MsgType.msgId
while true:

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@ -195,8 +195,6 @@ proc decryptHeader*(c: var SecretState, data: openarray[byte],
proc decryptHeaderAndGetMsgSize*(c: var SecretState,
encryptedHeader: openarray[byte],
outSize: var int): RlpxStatus =
# REVIEW: so this is the poster-boy example for a result type which
# would make both this and the calling code much more digestible
var decryptedHeader: RlpxHeader
result = decryptHeader(c, encryptedHeader, decryptedHeader)
if result == Success: