Add callback handler for HTTP server

src/ws.nim

@@ -7,32 +7,6 @@ const
   HttpBodyTimeout = 12.seconds     # timeout for receiving body (12 sec)
   HeadersMark = @[byte(0x0D), byte(0x0A), byte(0x0D), byte(0x0A)]
 
-type HeaderVerificationError* {.pure.} = enum
-  None
-    ## No error.
-  UnsupportedVersion
-    ## The Sec-Websocket-Version header gave an unsupported version.
-    ## The only currently supported version is 13.
-  NoKey
-    ## No Sec-Websocket-Key was provided.
-  ProtocolAdvertised
-    ## A protocol was advertised but the server gave no protocol.
-  NoProtocolsSupported
-    ## None of the advertised protocols match the server protocol.
-  NoProtocolAdvertised
-    ## Server asked for a protocol but no protocol was advertised.
-
-proc `$`*(error: HeaderVerificationError): string =
-  const errorTable: array[HeaderVerificationError, string] = [
-    "no error",
-    "the only supported sec-websocket-version is 13",
-    "no sec-websocket-key provided",
-    "server does not support protocol negotation",
-    "no advertised protocol supported",
-    "no protocol advertised"
-  ]
-  result = errorTable[error]
-
 type
   ReadyState* = enum
     Connecting = 0 # The connection is not yet open.
@@ -41,23 +15,23 @@ type
     Closed = 3     # The connection is closed or couldn't be opened.
 
   WebSocket* = ref object
+    tcpSocket*: StreamTransport
     version*: int
     key*: string
     protocol*: string
     readyState*: ReadyState
     masked*: bool # send masked packets
 
-  HttpServer* = ref object
+  AsyncCallback = proc (transp: StreamTransport, header: HttpRequestHeader): Future[void] {.closure, gcsafe.}
-    server*: StreamServer
+  HttpServer* = ref object of StreamServer
     callback: AsyncCallback
-    maxBody: int
 
   ReqStatus = enum
     Success, Error, ErrorFailure
 
   WebSocketError* = object of IOError
 
-proc sendAnswer(transp: StreamTransport, version: HttpVersion, code: HttpCode,
+proc sendHTTPResponse*(transp: StreamTransport, version: HttpVersion, code: HttpCode,
                 data: string = ""): Future[bool] {.async.} =
   var answer = $version
   answer.add(" ")
@@ -83,7 +57,7 @@ proc validateRequest(transp: StreamTransport,
   if header.meth notin {MethodGet}:
     # Request method is either PUT or DELETE.
     debug "GET method is only allowed", address = transp.remoteAddress()
-    if await transp.sendAnswer(header.version, Http405):
+    if await transp.sendHTTPResponse(header.version, Http405):
       result = Error
     else:
       result = ErrorFailure
@@ -93,7 +67,7 @@ proc validateRequest(transp: StreamTransport,
   if length <= 0:
     # request length could not be calculated.
     debug "Content-Length is missing or 0", address = transp.remoteAddress()
-    if await transp.sendAnswer(header.version, Http411):
+    if await transp.sendHTTPResponse(header.version, Http411):
       result = Error
     else:
       result = ErrorFailure
@@ -103,7 +77,7 @@ proc validateRequest(transp: StreamTransport,
     # request length is more then `MaxHttpRequestSize`.
     debug "Maximum size of request body reached",
           address = transp.remoteAddress()
-    if await transp.sendAnswer(header.version, Http413):
+    if await transp.sendHTTPResponse(header.version, Http413):
       result = Error
     else:
       result = ErrorFailure
@@ -111,8 +85,9 @@ proc validateRequest(transp: StreamTransport,
 
   result = Success
 
-proc serveClient(server: StreamServer, transp: StreamTransport) {.async, gcsafe.} =
+proc serveClient(server: StreamServer, transp: StreamTransport) {.async.} =
   ## Process transport data to the RPC server
+  var httpServer = cast[HttpServer](server)
   var buffer = newSeq[byte](MaxHttpHeadersSize)
   var header: HttpRequestHeader
   var connection: string
@@ -125,7 +100,7 @@ proc serveClient(server: StreamServer, transp: StreamTransport) {.async, gcsafe.
       # Timeout
       debug "Timeout expired while receiving headers",
             address = transp.remoteAddress()
-      let res = await transp.sendAnswer(HttpVersion11, Http408)
+      let res = await transp.sendHTTPResponse(HttpVersion11, Http408)
       await transp.closeWait()
       return
     else:
@@ -136,14 +111,14 @@ proc serveClient(server: StreamServer, transp: StreamTransport) {.async, gcsafe.
         # Header could not be parsed
         debug "Malformed header received",
               address = transp.remoteAddress()
-        let res = await transp.sendAnswer(HttpVersion11, Http400)
+        let res = await transp.sendHTTPResponse(HttpVersion11, Http400)
         await transp.closeWait()
         return
   except TransportLimitError:
     # size of headers exceeds `MaxHttpHeadersSize`
     debug "Maximum size of headers limit reached",
           address = transp.remoteAddress()
-    let res = await transp.sendAnswer(HttpVersion11, Http413)
+    let res = await transp.sendHTTPResponse(HttpVersion11, Http413)
     await transp.closeWait()
     return
   except TransportIncompleteError:
@@ -166,15 +141,18 @@ proc serveClient(server: StreamServer, transp: StreamTransport) {.async, gcsafe.
 
   if vres == Success:
     trace "Received valid RPC request", address = $transp.remoteAddress()
-    info "Header: ", header
+
-    debug "Disconnecting client", address = transp.remoteAddress()
+    # Call the user's callback.
-    await transp.closeWait()
+    if httpServer.callback != nil:
+      await httpServer.callback(transp, header)
+
   elif vres == ErrorFailure:
     debug "Remote peer disconnected", address = transp.remoteAddress()
     await transp.closeWait()
 
-proc newHttpServer*(address: string,
+proc newHttpServer*(address: string, handler:AsyncCallback,
               flags: set[ServerFlags] = {ReuseAddr}): HttpServer =
-  let address = initTAddress(address)
   new result
-  result.server = createStreamServer(address, serveClient, {ReuseAddr})
+  let address = initTAddress(address)
+  result.callback = handler
+  result = cast[HttpServer](createStreamServer(address, serveClient, flags, child = cast[StreamServer](result)))

test/server.nim

@@ -1,7 +1,13 @@
-import ws, chronos
+import ws, chronos, chronicles, httputils
+
+proc cb(transp: StreamTransport, header: HttpRequestHeader) {.async.} =
+  info "Header: ", header
+  let res = await transp.sendHTTPResponse(HttpVersion11, Http200, "Hello World")
+  debug "Disconnecting client", address = transp.remoteAddress()
+  await transp.closeWait()
 
 when isMainModule:
   let address = "127.0.0.1:8888"
-  var httpServer = newHttpServer(address)
+  var httpServer = newHttpServer(address, cb)
-  httpServer.server.start()
+  httpServer.start()
-  waitFor httpServer.server.join()
+  waitFor httpServer.join()