# # # Nim's Runtime Library # (c) Copyright 2014 Dominik Picheta # # See the file "copying.txt", included in this # distribution, for details about the copyright. # ## This module implements a high performance asynchronous HTTP server. ## ## Examples ## -------- ## ## This example will create an HTTP server on port 8080. The server will ## respond to all requests with a ``200 OK`` response code and "Hello World" ## as the response body. ## ## .. code-block::nim ## var server = newAsyncHttpServer() ## proc cb(req: TRequest) {.async.} = ## await req.respond(Http200, "Hello World") ## ## asyncCheck server.serve(Port(8080), cb) ## runForever() import strtabs, asyncnet, asyncdispatch, parseutils, uri, strutils type Request* = object client*: PAsyncSocket # TODO: Separate this into a Response object? reqMethod*: string headers*: PStringTable protocol*: tuple[orig: string, major, minor: int] url*: TUri hostname*: string ## The hostname of the client that made the request. body*: string AsyncHttpServer* = ref object socket: PAsyncSocket HttpCode* = enum Http200 = "200 OK", Http303 = "303 Moved", Http400 = "400 Bad Request", Http404 = "404 Not Found", Http500 = "500 Internal Server Error", Http502 = "502 Bad Gateway" HttpVersion* = enum HttpVer11, HttpVer10 {.deprecated: [TRequest: Request, PAsyncHttpServer: AsyncHttpServer, THttpCode: HttpCode, THttpVersion: HttpVersion].} proc `==`*(protocol: tuple[orig: string, major, minor: int], ver: THttpVersion): bool = let major = case ver of HttpVer11, HttpVer10: 1 let minor = case ver of HttpVer11: 1 of HttpVer10: 0 result = protocol.major == major and protocol.minor == minor proc newAsyncHttpServer*(): PAsyncHttpServer = ## Creates a new ``AsyncHttpServer`` instance. new result proc addHeaders(msg: var string, headers: PStringTable) = for k, v in headers: msg.add(k & ": " & v & "\c\L") proc sendHeaders*(req: TRequest, headers: PStringTable): Future[void] = ## Sends the specified headers to the requesting client. var msg = "" addHeaders(msg, headers) return req.client.send(msg) proc respond*(req: TRequest, code: THttpCode, content: string, headers: PStringTable = newStringTable()) {.async.} = ## Responds to the request with the specified ``HttpCode``, headers and ## content. ## ## This procedure will **not** close the client socket. var customHeaders = headers customHeaders["Content-Length"] = $content.len var msg = "HTTP/1.1 " & $code & "\c\L" msg.addHeaders(customHeaders) await req.client.send(msg & "\c\L" & content) proc newRequest(): TRequest = result.headers = newStringTable(modeCaseInsensitive) proc parseHeader(line: string): tuple[key, value: string] = var i = 0 i = line.parseUntil(result.key, ':') inc(i) # skip : i += line.skipWhiteSpace(i) i += line.parseUntil(result.value, {'\c', '\L'}, i) proc parseProtocol(protocol: string): tuple[orig: string, major, minor: int] = var i = protocol.skipIgnoreCase("HTTP/") if i != 5: raise newException(EInvalidValue, "Invalid request protocol. Got: " & protocol) result.orig = protocol i.inc protocol.parseInt(result.major, i) i.inc # Skip . i.inc protocol.parseInt(result.minor, i) proc sendStatus(client: PAsyncSocket, status: string): Future[void] = client.send("HTTP/1.1 " & status & "\c\L") proc processClient(client: PAsyncSocket, address: string, callback: proc (request: TRequest): Future[void] {.closure, gcsafe.}) {.async.} = while not client.closed: # GET /path HTTP/1.1 # Header: val # \n var request = newRequest() request.hostname = address assert client != nil request.client = client # First line - GET /path HTTP/1.1 let line = await client.recvLine() # TODO: Timeouts. if line == "": client.close() return let lineParts = line.split(' ') if lineParts.len != 3: await request.respond(Http400, "Invalid request. Got: " & line) continue let reqMethod = lineParts[0] let path = lineParts[1] let protocol = lineParts[2] # Headers var i = 0 while true: i = 0 let headerLine = await client.recvLine() if headerLine == "": client.close(); return if headerLine == "\c\L": break # TODO: Compiler crash #let (key, value) = parseHeader(headerLine) let kv = parseHeader(headerLine) request.headers[kv.key] = kv.value request.reqMethod = reqMethod request.url = parseUri(path) try: request.protocol = protocol.parseProtocol() except EInvalidValue: asyncCheck request.respond(Http400, "Invalid request protocol. Got: " & protocol) continue if reqMethod.normalize == "post": # Check for Expect header if request.headers.hasKey("Expect"): if request.headers["Expect"].toLower == "100-continue": await client.sendStatus("100 Continue") else: await client.sendStatus("417 Expectation Failed") # Read the body # - Check for Content-length header if request.headers.hasKey("Content-Length"): var contentLength = 0 if parseInt(request.headers["Content-Length"], contentLength) == 0: await request.respond(Http400, "Bad Request. Invalid Content-Length.") else: request.body = await client.recv(contentLength) assert request.body.len == contentLength else: await request.respond(Http400, "Bad Request. No Content-Length.") continue case reqMethod.normalize of "get", "post", "head", "put", "delete", "trace", "options", "connect", "patch": await callback(request) else: await request.respond(Http400, "Invalid request method. Got: " & reqMethod) # Persistent connections if (request.protocol == HttpVer11 and request.headers["connection"].normalize != "close") or (request.protocol == HttpVer10 and request.headers["connection"].normalize == "keep-alive"): # In HTTP 1.1 we assume that connection is persistent. Unless connection # header states otherwise. # In HTTP 1.0 we assume that the connection should not be persistent. # Unless the connection header states otherwise. discard else: request.client.close() break proc serve*(server: PAsyncHttpServer, port: Port, callback: proc (request: TRequest): Future[void] {.closure,gcsafe.}, address = "") {.async.} = ## Starts the process of listening for incoming HTTP connections on the ## specified address and port. ## ## When a request is made by a client the specified callback will be called. server.socket = newAsyncSocket() server.socket.bindAddr(port, address) server.socket.listen() while true: # TODO: Causes compiler crash. #var (address, client) = await server.socket.acceptAddr() var fut = await server.socket.acceptAddr() asyncCheck processClient(fut.client, fut.address, callback) #echo(f.isNil) #echo(f.repr) proc close*(server: PAsyncHttpServer) = ## Terminates the async http server instance. server.socket.close() when isMainModule: proc main = var server = newAsyncHttpServer() proc cb(req: TRequest) {.async.} = #echo(req.reqMethod, " ", req.url) #echo(req.headers) let headers = {"Date": "Tue, 29 Apr 2014 23:40:08 GMT", "Content-type": "text/plain; charset=utf-8"} await req.respond(Http200, "Hello World", headers.newStringTable()) asyncCheck server.serve(Port(5555), cb) runForever() main()