Add MultiAddress.init(integer) for tcp,udp,dccp,sctp protocols.

Add tests for it.

libp2p/multiaddress.nim

@@ -12,7 +12,7 @@ import nativesockets
 import tables, strutils, net
 import chronos
 import multicodec, multihash, multibase, transcoder, vbuffer
-import stew/[base58, base32]
+import stew/[base58, base32, endians2]
 from peer import PeerID
 
 {.deadCodeElim:on.}
@@ -704,6 +704,24 @@ proc init*(mtype: typedesc[MultiAddress], protocol: MultiCodec): MultiAddress =
   result.data.writeVarint(cast[uint64](proto.mcodec))
   result.data.finish()
 
+proc init*(mtype: typedesc[MultiAddress], protocol: MultiCodec,
+           value: int): MultiAddress =
+  ## Initialize MultiAddress object from protocol id ``protocol`` and integer
+  ## ``value``. This procedure can be used to instantiate ``tcp``, ``udp``,
+  ## ``dccp`` and ``sctp`` MultiAddresses.
+  var allowed = [multiCodec("tcp"), multiCodec("udp"), multiCodec("dccp"),
+                 multiCodec("sctp")]
+  if protocol notin allowed:
+    raise newException(MultiAddressError,
+                       "Incorrect protocol for integer value")
+  let proto = CodeAddresses.getOrDefault(protocol)
+  result.data = initVBuffer()
+  result.data.writeVarint(cast[uint64](proto.mcodec))
+  if value < 0 or value > 65535:
+    raise newException(MultiAddressError, "Incorrect integer value")
+  result.data.writeArray(toBytesBE(cast[uint16](value)))
+  result.data.finish()
+
 proc getProtocol(name: string): MAProtocol {.inline.} =
   let mc = MultiCodec.codec(name)
   if mc != InvalidMultiCodec:

tests/testmultiaddress.nim

@@ -1,5 +1,5 @@
 import unittest
-import ../libp2p/multiaddress
+import ../libp2p/[multicodec, multiaddress]
 
 when defined(nimHasUsed): {.used.}
 
@@ -363,3 +363,31 @@ suite "MultiAddress test suite":
       for bitem in item.bad:
         var a = MultiAddress.init(bitem)
         check item.pattern.match(a) == false
+
+  test "MultiAddress init(\"tcp/udp/dccp/sctp\", int) test":
+    check:
+      $MultiAddress.init(multiCodec("tcp"), 0) == "/tcp/0"
+      $MultiAddress.init(multiCodec("tcp"), 65535) == "/tcp/65535"
+      $MultiAddress.init(multiCodec("tcp"), 34000) == "/tcp/34000"
+      $MultiAddress.init(multiCodec("udp"), 0) == "/udp/0"
+      $MultiAddress.init(multiCodec("udp"), 65535) == "/udp/65535"
+      $MultiAddress.init(multiCodec("udp"), 34000) == "/udp/34000"
+      $MultiAddress.init(multiCodec("dccp"), 0) == "/dccp/0"
+      $MultiAddress.init(multiCodec("dccp"), 65535) == "/dccp/65535"
+      $MultiAddress.init(multiCodec("dccp"), 34000) == "/dccp/34000"
+      $MultiAddress.init(multiCodec("sctp"), 0) == "/sctp/0"
+      $MultiAddress.init(multiCodec("sctp"), 65535) == "/sctp/65535"
+      $MultiAddress.init(multiCodec("sctp"), 34000) == "/sctp/34000"
+
+    expect(MultiAddressError):
+      discard MultiAddress.init(multiCodec("ip4"), 0)
+      discard MultiAddress.init(multiCodec("ip6"), 0)
+      discard MultiAddress.init(multiCodec("p2p"), 0)
+      discard MultiAddress.init(multiCodec("tcp"), 65536)
+      discard MultiAddress.init(multiCodec("udp"), 65536)
+      discard MultiAddress.init(multiCodec("dccp"), 65536)
+      discard MultiAddress.init(multiCodec("sctp"), 65536)
+      discard MultiAddress.init(multiCodec("tcp"), -1)
+      discard MultiAddress.init(multiCodec("udp"), -1)
+      discard MultiAddress.init(multiCodec("dccp"), -1)
+      discard MultiAddress.init(multiCodec("sctp"), -1)