mirror of https://github.com/status-im/nim-eth.git
807 lines
26 KiB
Nim
807 lines
26 KiB
Nim
import
|
|
macros,
|
|
std_shims/macros_shim, chronos
|
|
|
|
type
|
|
MessageKind* = enum
|
|
msgHandshake
|
|
msgNotification
|
|
msgRequest
|
|
msgResponse
|
|
|
|
Message* = ref object
|
|
id*: int
|
|
ident*: NimNode
|
|
kind*: MessageKind
|
|
procDef*: NimNode
|
|
timeoutParam*: NimNode
|
|
recIdent*: NimNode
|
|
recBody*: NimNode
|
|
protocol*: P2PProtocol
|
|
response*: Message
|
|
userHandler*: NimNode
|
|
initResponderCall*: NimNode
|
|
|
|
Request* = ref object
|
|
queries*: seq[Message]
|
|
response*: Message
|
|
|
|
SendProc* = object
|
|
## A `SendProc` is a proc used to send a single P2P message.
|
|
## If it's a Request, then the return type will be a Future
|
|
## of the respective Response type. All send procs also have
|
|
## an automatically inserted `timeout` parameter.
|
|
|
|
msg*: Message
|
|
## The message being implemented
|
|
|
|
def*: NimNode
|
|
## The definition of the proc
|
|
|
|
peerParam*: NimNode
|
|
## Cached ident for the peer param
|
|
|
|
msgParams*: seq[NimNode]
|
|
## Cached param ident for all values that must be written
|
|
## on the wire. The automatically inserted `timeout` is not
|
|
## included.
|
|
|
|
timeoutParam*: NimNode
|
|
## Cached ident for the timeout parameter
|
|
|
|
allDefs*: NimNode
|
|
## The final definitions that must be become part of the
|
|
## p2pProtocol macro output. May include helper templates.
|
|
|
|
P2PProtocol* = ref object
|
|
# Settings
|
|
name*: string
|
|
version*: int
|
|
timeouts*: int64
|
|
useRequestIds*: bool
|
|
shortName*: string
|
|
outgoingRequestDecorator*: NimNode
|
|
incomingRequestDecorator*: NimNode
|
|
incomingRequestThunkDecorator*: NimNode
|
|
incomingResponseDecorator*: NimNode
|
|
incomingResponseThunkDecorator*: NimNode
|
|
PeerStateType*: NimNode
|
|
NetworkStateType*: NimNode
|
|
backend*: Backend
|
|
|
|
# Cached properties
|
|
nameIdent*: NimNode
|
|
protocolInfoVar*: NimNode
|
|
|
|
# All messages
|
|
messages*: seq[Message]
|
|
|
|
# Messages by type:
|
|
handshake*: Message
|
|
notifications*: seq[Message]
|
|
requests*: seq[Request]
|
|
|
|
# Output procs
|
|
outSendProcs*: NimNode
|
|
outRecvProcs*: NimNode
|
|
outProcRegistrations*: NimNode
|
|
|
|
# Event handlers
|
|
onPeerConnected*: NimNode
|
|
onPeerDisconnected*: NimNode
|
|
|
|
Backend* = ref object
|
|
# Code generators
|
|
implementMsg*: proc (msg: Message)
|
|
implementProtocolInit*: proc (protocol: P2PProtocol): NimNode
|
|
|
|
afterProtocolInit*: proc (protocol: P2PProtocol)
|
|
|
|
# Bound symbols to the back-end run-time types and procs
|
|
PeerType*: NimNode
|
|
NetworkType*: NimNode
|
|
SerializationFormat*: NimNode
|
|
ResponderType*: NimNode
|
|
|
|
registerProtocol*: NimNode
|
|
setEventHandlers*: NimNode
|
|
|
|
BackendFactory* = proc (p: P2PProtocol): Backend
|
|
|
|
P2PBackendError* = object of CatchableError
|
|
InvalidMsgError* = object of P2PBackendError
|
|
|
|
const
|
|
defaultReqTimeout = 10.seconds
|
|
|
|
let
|
|
# Variable names affecting the public interface of the library:
|
|
reqIdVar* {.compileTime.} = ident "reqId"
|
|
# XXX: Binding the int type causes instantiation failure for some reason
|
|
ReqIdType* {.compileTime.} = ident "int"
|
|
peerVar* {.compileTime.} = ident "peer"
|
|
responseVar* {.compileTime.} = ident "response"
|
|
perProtocolMsgIdVar* {.compileTime.} = ident "perProtocolMsgId"
|
|
currentProtocolSym* {.compileTime.} = ident "CurrentProtocol"
|
|
resultIdent* {.compileTime.} = ident "result"
|
|
|
|
# Locally used symbols:
|
|
Option {.compileTime.} = ident "Option"
|
|
Future {.compileTime.} = ident "Future"
|
|
Void {.compileTime.} = ident "void"
|
|
|
|
template Opt(T): auto = newTree(nnkBracketExpr, Option, T)
|
|
template Fut(T): auto = newTree(nnkBracketExpr, Future, T)
|
|
|
|
proc createPeerState[Peer, ProtocolState](peer: Peer): RootRef =
|
|
var res = new ProtocolState
|
|
mixin initProtocolState
|
|
initProtocolState(res, peer)
|
|
return cast[RootRef](res)
|
|
|
|
proc createNetworkState[NetworkNode, NetworkState](network: NetworkNode): RootRef {.gcsafe.} =
|
|
var res = new NetworkState
|
|
mixin initProtocolState
|
|
initProtocolState(res, network)
|
|
return cast[RootRef](res)
|
|
|
|
proc expectBlockWithProcs*(n: NimNode): seq[NimNode] =
|
|
template helperName: auto = $n[0]
|
|
|
|
if n.len != 2 or n[1].kind != nnkStmtList:
|
|
error(helperName & " expects a block", n)
|
|
|
|
for p in n[1]:
|
|
if p.kind == nnkProcDef:
|
|
result.add p
|
|
elif p.kind == nnkCommentStmt:
|
|
continue
|
|
else:
|
|
error(helperName & " expects a proc definition.", p)
|
|
|
|
proc nameOrNil*(procDef: NimNode): NimNode =
|
|
if procDef != nil:
|
|
procDef.name
|
|
else:
|
|
newNilLit()
|
|
|
|
proc chooseFieldType(n: NimNode): NimNode =
|
|
## Examines the parameter types used in the message signature
|
|
## and selects the corresponding field type for use in the
|
|
## message object type (i.e. `p2p.hello`).
|
|
##
|
|
## For now, only openarray types are remapped to sequences.
|
|
result = n
|
|
if n.kind == nnkBracketExpr and eqIdent(n[0], "openarray"):
|
|
result = n.copyNimTree
|
|
result[0] = ident("seq")
|
|
|
|
proc verifyStateType(t: NimNode): NimNode =
|
|
result = t[1]
|
|
if result.kind == nnkSym and $result == "nil":
|
|
return nil
|
|
if result.kind != nnkBracketExpr or $result[0] != "ref":
|
|
error $result & " must be a ref type"
|
|
|
|
proc processProtocolBody*(p: P2PProtocol, protocolBody: NimNode)
|
|
|
|
proc init*(T: type P2PProtocol, backendFactory: BackendFactory,
|
|
name: string, version: int, body: NimNode,
|
|
timeouts: int64, useRequestIds: bool, shortName: string,
|
|
outgoingRequestDecorator: NimNode,
|
|
incomingRequestDecorator: NimNode,
|
|
incomingRequestThunkDecorator: NimNode,
|
|
incomingResponseDecorator: NimNode,
|
|
incomingResponseThunkDecorator: NimNode,
|
|
peerState, networkState: NimNode): P2PProtocol =
|
|
|
|
result = P2PProtocol(
|
|
name: name,
|
|
version: version,
|
|
timeouts: timeouts,
|
|
useRequestIds: useRequestIds,
|
|
shortName: shortName,
|
|
outgoingRequestDecorator: outgoingRequestDecorator,
|
|
incomingRequestDecorator: incomingRequestDecorator,
|
|
incomingRequestThunkDecorator: incomingRequestThunkDecorator,
|
|
incomingResponseDecorator: incomingResponseDecorator,
|
|
incomingResponseThunkDecorator: incomingResponseThunkDecorator,
|
|
PeerStateType: verifyStateType peerState,
|
|
NetworkStateType: verifyStateType networkState,
|
|
nameIdent: ident(name),
|
|
protocolInfoVar: ident(name & "Protocol"),
|
|
outSendProcs: newStmtList(),
|
|
outRecvProcs: newStmtList(),
|
|
outProcRegistrations: newStmtList())
|
|
|
|
result.backend = backendFactory(result)
|
|
assert(not result.backend.implementProtocolInit.isNil)
|
|
assert(not result.backend.ResponderType.isNil)
|
|
|
|
result.processProtocolBody body
|
|
|
|
if not result.backend.afterProtocolInit.isNil:
|
|
result.backend.afterProtocolInit(result)
|
|
|
|
proc augmentUserHandler(p: P2PProtocol, userHandlerProc: NimNode, msgId = -1) =
|
|
## This procs adds a set of common helpers available in all messages handlers
|
|
## (e.g. `perProtocolMsgId`, `peer.state`, etc).
|
|
|
|
userHandlerProc.addPragma ident"gcsafe"
|
|
userHandlerProc.addPragma ident"async"
|
|
|
|
var
|
|
getState = ident"getState"
|
|
getNetworkState = ident"getNetworkState"
|
|
protocolInfoVar = p.protocolInfoVar
|
|
protocolNameIdent = p.nameIdent
|
|
PeerType = p.backend.PeerType
|
|
PeerStateType = p.PeerStateType
|
|
NetworkStateType = p.NetworkStateType
|
|
prelude = newStmtList()
|
|
|
|
userHandlerProc.body.insert 0, prelude
|
|
|
|
when false:
|
|
# TODO
|
|
## Turns a regular proc definition into an async proc and adds
|
|
## the helpers for accessing the peer and network protocol states.
|
|
case msgKind
|
|
of msgRequest: userHandlerProc.applyDecorator incomingRequestDecorator
|
|
of msgResponse: userHandlerProc.applyDecorator incomingResponseDecorator
|
|
else: discard
|
|
|
|
# We allow the user handler to use `openarray` params, but we turn
|
|
# those into sequences to make the `async` pragma happy.
|
|
for i in 1 ..< userHandlerProc.params.len:
|
|
var param = userHandlerProc.params[i]
|
|
param[^2] = chooseFieldType(param[^2])
|
|
|
|
prelude.add quote do:
|
|
type `currentProtocolSym` = `protocolNameIdent`
|
|
|
|
if msgId >= 0:
|
|
prelude.add quote do:
|
|
const `perProtocolMsgIdVar` = `msgId`
|
|
|
|
# Define local accessors for the peer and the network protocol states
|
|
# inside each user message handler proc (e.g. peer.state.foo = bar)
|
|
if PeerStateType != nil:
|
|
prelude.add quote do:
|
|
template state(p: `PeerType`): `PeerStateType` =
|
|
cast[`PeerStateType`](`getState`(p, `protocolInfoVar`))
|
|
|
|
if NetworkStateType != nil:
|
|
prelude.add quote do:
|
|
template networkState(p: `PeerType`): `NetworkStateType` =
|
|
cast[`NetworkStateType`](`getNetworkState`(p.network, `protocolInfoVar`))
|
|
|
|
proc addPreludeDefs*(userHandlerProc: NimNode, definitions: NimNode) =
|
|
userHandlerProc.body[0].add definitions
|
|
|
|
proc eventHandlerToProc(p: P2PProtocol, doBlock: NimNode, handlerName: string): NimNode =
|
|
## Turns a "named" do block to a regular async proc
|
|
## (e.g. onPeerConnected do ...)
|
|
result = newTree(nnkProcDef)
|
|
doBlock.copyChildrenTo(result)
|
|
result.name = ident(p.name & handlerName) # genSym(nskProc, p.name & handlerName)
|
|
p.augmentUserHandler result
|
|
|
|
proc ensureTimeoutParam(procDef: NimNode, timeouts: int64): NimNode =
|
|
## Make sure the messages has a timeout parameter and it has the correct type.
|
|
## The parameter will be removed from the signature and returned for caching
|
|
## in the Message's timeoutParam field. It is needed only for the send procs.
|
|
var
|
|
Duration = bindSym"Duration"
|
|
milliseconds = bindSym"milliseconds"
|
|
lastParam = procDef.params[^1]
|
|
|
|
if eqIdent(lastParam[0], "timeout"):
|
|
if lastParam[2].kind == nnkEmpty:
|
|
error "You must specify a default value for the `timeout` parameter", lastParam
|
|
lastParam[2] = newCall(milliseconds, newLit(100))# newCall(Duration, lastParam[2])
|
|
if lastParam[1].kind == nnkEmpty:
|
|
lastParam[1] = Duration
|
|
elif not eqIdent(lastParam[1], "Duration"):
|
|
error "The timeout parameter should be of type 'chronos.Duration'", lastParam[1]
|
|
|
|
result = lastParam
|
|
procDef.params.del(procDef.params.len - 1)
|
|
|
|
else:
|
|
result = newTree(nnkIdentDefs,
|
|
ident"timeout",
|
|
Duration,
|
|
newCall(milliseconds, newLit(timeouts)))
|
|
|
|
proc hasReqId*(msg: Message): bool =
|
|
msg.protocol.useRequestIds and msg.kind in {msgRequest, msgResponse}
|
|
|
|
proc ResponderType(msg: Message): NimNode =
|
|
var resp = if msg.kind == msgRequest: msg.response else: msg
|
|
newTree(nnkBracketExpr,
|
|
msg.protocol.backend.ResponderType, resp.recIdent)
|
|
|
|
proc newMsg(protocol: P2PProtocol, kind: MessageKind, id: int,
|
|
procDef: NimNode, timeoutParam: NimNode = nil,
|
|
response: Message = nil): Message =
|
|
|
|
if procDef[0].kind == nnkPostfix:
|
|
error("p2pProcotol procs are public by default. " &
|
|
"Please remove the postfix `*`.", procDef)
|
|
|
|
var
|
|
msgIdent = procDef.name
|
|
msgName = $msgIdent
|
|
recFields = newTree(nnkRecList)
|
|
recBody = newTree(nnkObjectTy, newEmptyNode(), newEmptyNode(), recFields)
|
|
recName = ident(msgName & "Obj")
|
|
|
|
for param, paramType in procDef.typedParams(skip = 1):
|
|
recFields.add newTree(nnkIdentDefs,
|
|
newTree(nnkPostfix, ident("*"), param), # The fields are public
|
|
chooseFieldType(paramType), # some types such as openarray
|
|
# are automatically remapped
|
|
newEmptyNode())
|
|
|
|
result = Message(protocol: protocol, id: id, ident: msgIdent, kind: kind,
|
|
procDef: procDef, recIdent: recName, recBody: recBody,
|
|
timeoutParam: timeoutParam, response: response)
|
|
|
|
if procDef.body.kind != nnkEmpty:
|
|
var userHandler = copy procDef
|
|
|
|
protocol.augmentUserHandler userHandler
|
|
userHandler.name = genSym(nskProc, msgName)
|
|
|
|
# Request and Response handlers get an extra `reqId` parameter if the
|
|
# protocol uses them:
|
|
if result.hasReqId:
|
|
userHandler.params.insert(2, newIdentDefs(reqIdVar, ReqIdType))
|
|
|
|
# All request handlers get an automatically inserter `response` variable:
|
|
if kind == msgRequest:
|
|
assert response != nil
|
|
let
|
|
peerParam = userHandler.params[1][0]
|
|
ResponderType = result.ResponderType
|
|
initResponderCall = newCall(ident"init", ResponderType, peerParam)
|
|
|
|
if protocol.useRequestIds:
|
|
initResponderCall.add reqIdVar
|
|
|
|
userHandler.addPreludeDefs quote do:
|
|
let `responseVar` = `initResponderCall`
|
|
|
|
result.initResponderCall = initResponderCall
|
|
|
|
protocol.outRecvProcs.add userHandler
|
|
result.userHandler = userHandler
|
|
|
|
protocol.messages.add result
|
|
|
|
proc identWithExportMarker*(msg: Message): NimNode =
|
|
newTree(nnkPostfix, ident("*"), msg.ident)
|
|
|
|
proc createSendProc*(msg: Message,
|
|
procType = nnkProcDef,
|
|
isRawSender = false): SendProc =
|
|
# TODO: file an issue:
|
|
# macros.newProc and macros.params doesn't work with nnkMacroDef
|
|
|
|
let
|
|
name = if not isRawSender: msg.identWithExportMarker
|
|
else: genSym(nskProc, $msg.ident & "RawSender")
|
|
|
|
pragmas = if procType == nnkProcDef: newTree(nnkPragma, ident"gcsafe")
|
|
else: newEmptyNode()
|
|
|
|
var def = newNimNode(procType).add(
|
|
name,
|
|
newEmptyNode(),
|
|
newEmptyNode(),
|
|
copy msg.procDef.params,
|
|
pragmas,
|
|
newEmptyNode(),
|
|
newStmtList()) ## body
|
|
|
|
result.msg = msg
|
|
result.def = def
|
|
result.allDefs = newStmtList(def)
|
|
|
|
for param, paramType in def.typedParams():
|
|
if result.peerParam.isNil:
|
|
result.peerParam = param
|
|
else:
|
|
result.msgParams.add param
|
|
|
|
case msg.kind
|
|
of msgHandshake, msgRequest:
|
|
# Add a timeout parameter for all request procs
|
|
let timeout = copy msg.timeoutParam
|
|
def[3].add timeout
|
|
result.timeoutParam = timeout[0]
|
|
|
|
of msgResponse:
|
|
# A response proc must be called with a response object that originates
|
|
# from a certain request. Here we change the Peer parameter at position
|
|
# 1 to the correct strongly-typed ResponderType. The incoming procs still
|
|
# gets the normal Peer paramter.
|
|
let
|
|
ResponderType = msg.ResponderType
|
|
sendProcName = msg.ident
|
|
|
|
def[3][1][1] = ResponderType
|
|
|
|
# We create a helper that enables the `response.send()` syntax
|
|
# inside the user handler of the request proc:
|
|
result.allDefs.add quote do:
|
|
template send*(r: `ResponderType`, args: varargs[untyped]): auto =
|
|
`sendProcName`(r, args)
|
|
|
|
of msgNotification:
|
|
discard
|
|
|
|
def[3][0] = if procType == nnkMacroDef:
|
|
ident "untyped"
|
|
elif msg.kind == msgRequest and not isRawSender:
|
|
Fut(Opt(msg.response.recIdent))
|
|
elif msg.kind == msgHandshake and not isRawSender:
|
|
Fut(msg.recIdent)
|
|
else:
|
|
Fut(Void)
|
|
|
|
const tracingEnabled = defined(p2pdump)
|
|
|
|
when tracingEnabled:
|
|
proc logSentMsgFields(peer: NimNode,
|
|
protocolInfo: NimNode,
|
|
msgName: string,
|
|
fields: openarray[NimNode]): NimNode =
|
|
## This generates the tracing code inserted in the message sending procs
|
|
## `fields` contains all the params that were serialized in the message
|
|
var tracer = ident("tracer")
|
|
|
|
result = quote do:
|
|
var `tracer` = init StringJsonWriter
|
|
beginRecord(`tracer`)
|
|
|
|
for f in fields:
|
|
result.add newCall(bindSym"writeField", tracer, newLit($f), f)
|
|
|
|
result.add quote do:
|
|
endRecord(`tracer`)
|
|
logMsgEventImpl("outgoing_msg", `peer`,
|
|
`protocolInfo`, `msgName`, getOutput(`tracer`))
|
|
|
|
proc initFuture*[T](loc: var Future[T]) =
|
|
loc = newFuture[T]()
|
|
|
|
proc implementBody*(sendProc: SendProc,
|
|
preludeGenerator: proc(stream: NimNode): NimNode,
|
|
sendCallGenerator: proc (peer, bytes: NimNode): NimNode) =
|
|
let
|
|
msg = sendProc.msg
|
|
outputStream = ident "outputStream"
|
|
msgBytes = ident "msgBytes"
|
|
writer = ident "writer"
|
|
writeField = ident "writeField"
|
|
|
|
initFuture = bindSym "initFuture"
|
|
recipient = sendProc.peerParam
|
|
msgRecName = msg.recIdent
|
|
Format = msg.protocol.backend.SerializationFormat
|
|
|
|
prelude = if preludeGenerator.isNil: newStmtList()
|
|
else: preludeGenerator(outputStream)
|
|
appendParams = newStmtList()
|
|
|
|
initResultFuture = if msg.kind != msgRequest: newStmtList()
|
|
else: newCall(initFuture, resultIdent)
|
|
|
|
sendCall = sendCallGenerator(recipient, msgBytes)
|
|
|
|
tracing = when tracingEnabled: logSentMsgFields(recipient,
|
|
newLit(msg.protocol.name),
|
|
$msg.ident,
|
|
sendProc.msgParams)
|
|
else: newStmtList()
|
|
|
|
for param in sendProc.msgParams:
|
|
appendParams.add newCall(writeField, writer, newLit($param), param)
|
|
|
|
sendProc.def.body = quote do:
|
|
mixin init, WriterType, beginRecord, endRecord, getOutput
|
|
|
|
`initResultFuture`
|
|
var `outputStream` = init OutputStream
|
|
`prelude`
|
|
var `writer` = init(WriterType(`Format`), `outputStream`)
|
|
var recordStartMemo = beginRecord(`writer`, `msgRecName`)
|
|
`appendParams`
|
|
`tracing`
|
|
endRecord(`writer`, recordStartMemo)
|
|
let `msgBytes` = getOutput(`outputStream`)
|
|
`sendCall`
|
|
|
|
proc genAwaitUserHandler*(msg: Message, receivedMsg: NimNode,
|
|
leadingParams: varargs[NimNode]): NimNode =
|
|
if msg.userHandler == nil:
|
|
return newStmtList()
|
|
|
|
var userHandlerCall = newCall(msg.userHandler.name, leadingParams)
|
|
|
|
for param, paramType in msg.procDef.typedParams(skip = 1):
|
|
# If there is user message handler, we'll place a call to it by
|
|
# unpacking the fields of the received message:
|
|
userHandlerCall.add newDotExpr(receivedMsg, param)
|
|
|
|
return newCall("await", userHandlerCall)
|
|
|
|
proc appendAllParams*(node: NimNode, procDef: NimNode, skipFirst = 0): NimNode =
|
|
result = node
|
|
for p, _ in procDef.typedParams(skip = skipFirst):
|
|
result.add p
|
|
|
|
proc netInit*(p: P2PProtocol): NimNode =
|
|
if p.NetworkStateType == nil:
|
|
newNilLit()
|
|
else:
|
|
newTree(nnkBracketExpr, bindSym"createNetworkState",
|
|
p.backend.NetworkType,
|
|
p.NetworkStateType)
|
|
|
|
proc genHandshakeTemplate*(msg: Message,
|
|
rawSendProc, handshakeImpl, nextMsg: NimNode): NimNode =
|
|
let
|
|
handshakeExchanger = msg.createSendProc(procType = nnkTemplateDef)
|
|
forwardCall = newCall(rawSendProc).appendAllParams(handshakeExchanger.def)
|
|
peerValue = forwardCall[1]
|
|
timeoutValue = msg.timeoutParam[0]
|
|
peerVarSym = genSym(nskLet, "peer")
|
|
msgRecName = msg.recIdent
|
|
|
|
forwardCall[1] = peerVarSym
|
|
forwardCall.del(forwardCall.len - 1)
|
|
|
|
handshakeExchanger.def.body = quote do:
|
|
let `peerVarSym` = `peerValue`
|
|
let sendingFuture = `forwardCall`
|
|
`handshakeImpl`(`peerVarSym`,
|
|
sendingFuture,
|
|
`nextMsg`(`peerVarSym`, `msgRecName`),
|
|
`timeoutValue`)
|
|
|
|
return handshakeExchanger.def
|
|
|
|
proc peerInit*(p: P2PProtocol): NimNode =
|
|
if p.PeerStateType == nil:
|
|
newNilLit()
|
|
else:
|
|
newTree(nnkBracketExpr, bindSym"createPeerState",
|
|
p.backend.PeerType,
|
|
p.PeerStateType)
|
|
|
|
proc processProtocolBody*(p: P2PProtocol, protocolBody: NimNode) =
|
|
## This procs handles all DSL statements valid inside a p2pProtocol.
|
|
##
|
|
## It will populate the protocol's fields such as:
|
|
## * handshake
|
|
## * requests
|
|
## * notifications
|
|
## * onPeerConnected
|
|
## * onPeerDisconnected
|
|
##
|
|
## All messages will have properly computed numeric IDs
|
|
##
|
|
var nextId = 0
|
|
|
|
for n in protocolBody:
|
|
case n.kind
|
|
of {nnkCall, nnkCommand}:
|
|
if eqIdent(n[0], "nextID"):
|
|
# By default message IDs are assigned in increasing order
|
|
# `nextID` can be used to skip some of the numeric slots
|
|
if n.len == 2 and n[1].kind == nnkIntLit:
|
|
nextId = n[1].intVal.int
|
|
else:
|
|
error("nextID expects a single int value", n)
|
|
|
|
elif eqIdent(n[0], "requestResponse"):
|
|
# `requestResponse` can be given a block of 2 or more procs.
|
|
# The last one is considered to be a response message, while
|
|
# all preceeding ones are requests triggering the response.
|
|
# The system makes sure to automatically insert a hidden `reqId`
|
|
# parameter used to discriminate the individual messages.
|
|
let procs = expectBlockWithProcs(n)
|
|
if procs.len < 2:
|
|
error "requestResponse expects a block with at least two proc definitions"
|
|
|
|
var queries = newSeq[Message]()
|
|
let responseMsg = p.newMsg(msgResponse, nextId + procs.len - 1, procs[^1])
|
|
|
|
for i in 0 .. procs.len - 2:
|
|
var timeout = ensureTimeoutParam(procs[i], p.timeouts)
|
|
queries.add p.newMsg(msgRequest, nextId + i, procs[i], timeout,
|
|
response = responseMsg)
|
|
|
|
p.requests.add Request(queries: queries, response: responseMsg)
|
|
|
|
inc nextId, procs.len
|
|
|
|
elif eqIdent(n[0], "handshake"):
|
|
let procs = expectBlockWithProcs(n)
|
|
if procs.len != 1:
|
|
error "handshake expects a block with a single proc definition", n
|
|
|
|
if p.handshake != nil:
|
|
error "The handshake for the protocol is already defined", n
|
|
|
|
var timeout = ensureTimeoutParam(procs[0], p.timeouts)
|
|
p.handshake = p.newMsg(msgHandshake, nextId, procs[0], timeout)
|
|
inc nextId
|
|
|
|
elif eqIdent(n[0], "onPeerConnected"):
|
|
p.onPeerConnected = p.eventHandlerToProc(n[1], "PeerConnected")
|
|
|
|
elif eqIdent(n[0], "onPeerDisconnected"):
|
|
p.onPeerDisconnected = p.eventHandlerToProc(n[1], "PeerDisconnected")
|
|
|
|
else:
|
|
error(repr(n) & " is not a recognized call in P2P protocol definitions", n)
|
|
|
|
of nnkProcDef:
|
|
p.notifications.add p.newMsg(msgNotification, nextId, n)
|
|
inc nextId
|
|
|
|
of nnkCommentStmt:
|
|
discard
|
|
|
|
else:
|
|
error "Illegal syntax in a P2P protocol definition", n
|
|
|
|
proc genTypeSection*(p: P2PProtocol): NimNode =
|
|
var
|
|
protocolName = p.nameIdent
|
|
peerState = p.PeerStateType
|
|
networkState= p.NetworkStateType
|
|
|
|
result = newStmtList()
|
|
result.add quote do:
|
|
# Create a type acting as a pseudo-object representing the protocol
|
|
# (e.g. p2p)
|
|
type `protocolName`* = object
|
|
|
|
if peerState != nil:
|
|
result.add quote do:
|
|
template State*(P: type `protocolName`): type = `peerState`
|
|
|
|
if networkState != nil:
|
|
result.add quote do:
|
|
template NetworkState*(P: type `protocolName`): type = `networkState`
|
|
|
|
for msg in p.messages:
|
|
let
|
|
msgId = msg.id
|
|
msgName = msg.ident
|
|
msgRecName = msg.recIdent
|
|
msgRecBody = msg.recBody
|
|
|
|
result.add quote do:
|
|
# This is a type featuring a single field for each message param:
|
|
type `msgRecName`* = `msgRecBody`
|
|
|
|
# Add a helper template for accessing the message type:
|
|
# e.g. p2p.hello:
|
|
template `msgName`*(T: type `protocolName`): type = `msgRecName`
|
|
|
|
# Add a helper template for obtaining the message Id for
|
|
# a particular message type:
|
|
template msgId*(T: type `msgRecName`): int = `msgId`
|
|
template msgProtocol*(T: type `msgRecName`): type = `protocolName`
|
|
|
|
proc genCode*(p: P2PProtocol): NimNode =
|
|
# TODO: try switching to a simpler for msg in p.messages: loop
|
|
when true:
|
|
for msg in p.messages:
|
|
p.backend.implementMsg msg
|
|
else:
|
|
if p.handshake != nil:
|
|
p.backend.implementMsg p.handshake
|
|
|
|
for msg in p.notifications:
|
|
p.backend.implementMsg msg
|
|
|
|
for req in p.requests:
|
|
p.backend.implementMsg req.response
|
|
for query in req.queries: p.backend.implementMsg(query)
|
|
|
|
result = newStmtList()
|
|
result.add p.genTypeSection()
|
|
|
|
let
|
|
protocolInfoVar = p.protocolInfoVar
|
|
protocolName = p.nameIdent
|
|
protocolInit = p.backend.implementProtocolInit(p)
|
|
|
|
result.add quote do:
|
|
# One global variable per protocol holds the protocol run-time data
|
|
var p = `protocolInit`
|
|
var `protocolInfoVar` = addr p
|
|
|
|
# The protocol run-time data is available as a pseudo-field
|
|
# (e.g. `p2p.protocolInfo`)
|
|
template protocolInfo*(P: type `protocolName`): auto = `protocolInfoVar`
|
|
|
|
result.add p.outSendProcs,
|
|
p.outRecvProcs,
|
|
p.outProcRegistrations
|
|
|
|
if p.onPeerConnected != nil: result.add p.onPeerConnected
|
|
if p.onPeerDisconnected != nil: result.add p.onPeerDisconnected
|
|
|
|
result.add newCall(p.backend.setEventHandlers,
|
|
protocolInfoVar,
|
|
nameOrNil p.onPeerConnected,
|
|
nameOrNil p.onPeerDisconnected)
|
|
|
|
result.add newCall(p.backend.registerProtocol, protocolInfoVar)
|
|
|
|
macro emitForSingleBackend(
|
|
name: static[string],
|
|
version: static[int],
|
|
backend: static[BackendFactory],
|
|
body: untyped,
|
|
# TODO Nim can't handle a proper duration paramter here
|
|
timeouts: static[int64] = defaultReqTimeout.milliseconds,
|
|
useRequestIds: static[bool] = true,
|
|
shortName: static[string] = "",
|
|
outgoingRequestDecorator: untyped = nil,
|
|
incomingRequestDecorator: untyped = nil,
|
|
incomingRequestThunkDecorator: untyped = nil,
|
|
incomingResponseDecorator: untyped = nil,
|
|
incomingResponseThunkDecorator: untyped = nil,
|
|
peerState = type(nil),
|
|
networkState = type(nil)): untyped =
|
|
|
|
var p = P2PProtocol.init(
|
|
backend,
|
|
name, version, body, timeouts,
|
|
useRequestIds, shortName,
|
|
outgoingRequestDecorator,
|
|
incomingRequestDecorator,
|
|
incomingRequestThunkDecorator,
|
|
incomingResponseDecorator,
|
|
incomingResponseThunkDecorator,
|
|
peerState.getType, networkState.getType)
|
|
|
|
result = p.genCode()
|
|
|
|
when defined(debugP2pProtocol) or defined(debugMacros):
|
|
echo repr(result)
|
|
|
|
macro emitForAllBackends(backendSyms: typed, options: untyped, body: untyped): untyped =
|
|
let name = $(options[0])
|
|
|
|
var backends = newSeq[NimNode]()
|
|
if backendSyms.kind == nnkSym:
|
|
backends.add backendSyms
|
|
else:
|
|
for backend in backendSyms:
|
|
backends.add backend
|
|
|
|
result = newStmtList()
|
|
|
|
for backend in backends:
|
|
let call = copy options
|
|
call[0] = bindSym"emitForSingleBackend"
|
|
call.add newTree(nnkExprEqExpr, ident("name"), newLit(name))
|
|
call.add newTree(nnkExprEqExpr, ident("backend"), backend)
|
|
call.add newTree(nnkExprEqExpr, ident("body"), body)
|
|
result.add call
|
|
|
|
template p2pProtocol*(options: untyped, body: untyped) {.dirty.} =
|
|
bind emitForAllBackends
|
|
emitForAllBackends(p2pProtocolBackendImpl, options, body)
|
|
|