134 lines
3.7 KiB
Nim
134 lines
3.7 KiB
Nim
## Nim-LibP2P
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## Copyright (c) 2018 Status Research & Development GmbH
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## Licensed under either of
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## * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
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## * MIT license ([LICENSE-MIT](LICENSE-MIT))
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## at your option.
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## This file may not be copied, modified, or distributed except according to
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## those terms.
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import sequtils, strutils
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import chronos
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import connection, varint, vbuffer, protocol
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const MsgSize* = 64*1024
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const Codec* = "/multistream/1.0.0"
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const MultiCodec* = "\x13" & Codec & "\n"
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const Na = "\x03na\n"
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const Ls = "\x03ls\n"
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type
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MultisteamSelectException = object of CatchableError
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Matcher* = proc (proto: string): bool {.gcsafe.}
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HandlerHolder* = object
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proto: string
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protocol: LPProtocol
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match: Matcher
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MultisteamSelect* = ref object of RootObj
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handlers*: seq[HandlerHolder]
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codec*: string
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na: string
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ls: string
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proc newMultistream*(): MultisteamSelect =
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new result
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result.codec = MultiCodec
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result.ls = Ls
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result.na = Na
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proc select*(m: MultisteamSelect,
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conn: Connection,
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proto: seq[string]):
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Future[string] {.async.} =
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## select a remote protocol
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await conn.write(m.codec) # write handshake
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if proto.len() > 0:
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await conn.writeLp(proto[0]) # select proto
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var ms = cast[string](await conn.readLp()) # read ms header
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ms.removeSuffix("\n")
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if ms != Codec:
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return ""
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if proto.len() == 0: # no protocols, must be a handshake call
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return ""
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ms = cast[string](await conn.readLp()) # read the first proto
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ms.removeSuffix("\n")
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if ms == proto[0]:
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result = ms
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if not result.len > 0:
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for p in proto[1..<proto.len()]:
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await conn.writeLp(p) # select proto
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ms = cast[string](await conn.readLp()) # read the first proto
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ms.removeSuffix("\n")
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if ms == p:
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result = p
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break
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proc select*(m: MultisteamSelect,
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conn: Connection,
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proto: string): Future[string] =
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result = if proto.len > 0: m.select(conn, @[proto]) else: m.select(conn, @[])
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proc select*(m: MultisteamSelect,
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conn: Connection): Future[string] =
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result = m.select(conn, @[])
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proc list*(m: MultisteamSelect,
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conn: Connection): Future[seq[string]] {.async.} =
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## list remote protos requests on connection
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if not (await m.select(conn)).len > 0:
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return
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await conn.write(m.ls) # send ls
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var list = newSeq[string]()
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let ms = cast[string](await conn.readLp())
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for s in ms.split("\n"):
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if s.len() > 0:
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list.add(s)
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result = list
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proc handle*(m: MultisteamSelect, conn: Connection) {.async, gcsafe.} =
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## handle requests on connection
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if not (await m.select(conn)).len > 0:
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return
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while not conn.closed:
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var ms = cast[string](await conn.readLp())
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ms.removeSuffix("\n")
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if ms.len() <= 0:
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await conn.write(m.na)
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if m.handlers.len() == 0:
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await conn.write(m.na)
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continue
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case ms:
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of "ls":
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var protos = ""
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for h in m.handlers:
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protos &= (h.proto & "\n")
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await conn.writeLp(cast[seq[byte]](toSeq(protos.items)))
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else:
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for h in m.handlers:
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if (not isNil(h.match) and h.match(ms)) or ms == h.proto:
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await conn.writeLp(h.proto & "\n")
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await h.protocol.handler(conn, ms)
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return
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await conn.write(m.na)
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proc addHandler*[T: LPProtocol](m: MultisteamSelect,
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codec: string,
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protocol: T,
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matcher: Matcher = nil) =
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## register a handler for the protocol
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m.handlers.add(HandlerHolder(proto: codec,
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protocol: protocol,
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match: matcher))
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