Feature/httpd (#94)

* Stub code for http server

* can send a response, cannot process body yet

* write headers to the response

* remove commented code

* add simple test + set default http handler

* tweak CI + unittest

* add missing file

* rewrite http::trim in a simple way

* doc

ixwebsocket/IXHttpServer.cpp

@@ -0,0 +1,158 @@
+/*
+ *  IXHttpServer.cpp
+ *  Author: Benjamin Sergeant
+ *  Copyright (c) 2019 Machine Zone, Inc. All rights reserved.
+ */
+
+#include "IXHttpServer.h"
+#include "IXSocketConnect.h"
+#include "IXSocketFactory.h"
+#include "IXNetSystem.h"
+
+#include <iostream>
+#include <sstream>
+#include <fstream>
+#include <vector>
+
+namespace
+{
+    std::pair<bool, std::vector<uint8_t>> load(const std::string& path)
+    {
+        std::vector<uint8_t> memblock;
+
+        std::ifstream file(path);
+        if (!file.is_open()) return std::make_pair(false, memblock);
+
+        file.seekg(0, file.end);
+        std::streamoff size = file.tellg();
+        file.seekg(0, file.beg);
+
+        memblock.resize((size_t) size);
+        file.read((char*)&memblock.front(), static_cast<std::streamsize>(size));
+
+        return std::make_pair(true, memblock);
+    }
+
+    std::pair<bool, std::string> readAsString(const std::string& path)
+    {
+        auto res = load(path);
+        auto vec = res.second;
+        return std::make_pair(res.first, std::string(vec.begin(), vec.end()));
+    }
+}
+
+namespace ix
+{
+    HttpServer::HttpServer(int port,
+                           const std::string& host,
+                           int backlog,
+                           size_t maxConnections) : SocketServer(port, host, backlog, maxConnections),
+        _connectedClientsCount(0)
+    {
+        setDefaultConnectionCallback();
+    }
+
+    HttpServer::~HttpServer()
+    {
+        stop();
+    }
+
+    void HttpServer::stop()
+    {
+        stopAcceptingConnections();
+
+        // FIXME: cancelling / closing active clients ...
+
+        SocketServer::stop();
+    }
+
+    void HttpServer::setOnConnectionCallback(const OnConnectionCallback& callback)
+    {
+        _onConnectionCallback = callback;
+    }
+
+    void HttpServer::handleConnection(
+        int fd,
+        std::shared_ptr<ConnectionState> connectionState)
+    {
+        _connectedClientsCount++;
+
+        std::string errorMsg;
+        auto socket = createSocket(fd, errorMsg);
+
+        // Set the socket to non blocking mode + other tweaks
+        SocketConnect::configure(fd);
+
+        auto ret = Http::parseRequest(socket);
+        // FIXME: handle errors in parseRequest
+
+        if (std::get<0>(ret))
+        {
+            auto response = _onConnectionCallback(std::get<2>(ret), connectionState);
+            if (!Http::sendResponse(response, socket))
+            {
+                logError("Cannot send response");
+            }
+        }
+        connectionState->setTerminated();
+
+        _connectedClientsCount--;
+    }
+
+    size_t HttpServer::getConnectedClientsCount()
+    {
+        return _connectedClientsCount;
+    }
+
+    void HttpServer::setDefaultConnectionCallback()
+    {
+        setOnConnectionCallback(
+            [this](HttpRequestPtr request,
+                   std::shared_ptr<ConnectionState> /*connectionState*/) -> HttpResponsePtr
+            {
+                std::string uri(request->uri);
+                if (uri.empty() || uri == "/")
+                {
+                    uri = "/index.html";
+                }
+
+                std::string path("." + uri);
+                auto res = readAsString(path);
+                bool found = res.first;
+                if (!found)
+                {
+                    return std::make_shared<HttpResponse>(404, "Not Found",
+                                                          HttpErrorCode::Ok,
+                                                          WebSocketHttpHeaders(),
+                                                          std::string());
+                }
+
+                std::string content = res.second;
+
+                // Log request
+                std::stringstream ss;
+                ss << request->method 
+                   << " "
+                   << request->uri
+                   << " "
+                   << content.size();
+                logInfo(ss.str());
+
+                WebSocketHttpHeaders headers;
+                // FIXME: check extensions to set the content type
+                // headers["Content-Type"] = "application/octet-stream";
+                headers["Accept-Ranges"] = "none";
+
+                for (auto&& it : request->headers)
+                {
+                    headers[it.first] = it.second;
+                }
+
+                return std::make_shared<HttpResponse>(200, "OK",
+                                                      HttpErrorCode::Ok,
+                                                      headers,
+                                                      content);
+            }
+        );
+    }
+}