Reimplementd IX with OpenSSL

ixwebsocket/include/IXDNSLookup.h

@@ -0,0 +1,67 @@
+/*
+ *  IXDNSLookup.h
+ *  Author: Benjamin Sergeant
+ *  Copyright (c) 2018 Machine Zone, Inc. All rights reserved.
+ *
+ *  Resolve a hostname+port to a struct addrinfo obtained with getaddrinfo
+ *  Does this in a background thread so that it can be cancelled, since
+ *  getaddrinfo is a blocking call, and we don't want to block the main thread on Mobile.
+ */
+
+#pragma once
+
+#include "IXCancellationRequest.h"
+#include <atomic>
+#include <memory>
+#include <mutex>
+#include <set>
+#include <string>
+
+struct addrinfo;
+
+namespace ix
+{
+    class DNSLookup : public std::enable_shared_from_this<DNSLookup>
+    {
+    public:
+        DNSLookup(const std::string& hostname, int port, int64_t wait = DNSLookup::kDefaultWait);
+        ~DNSLookup() = default;
+
+        struct addrinfo* resolve(std::string& errMsg,
+                                 const CancellationRequest& isCancellationRequested,
+                                 bool cancellable = true);
+
+        void release(struct addrinfo* addr);
+
+    private:
+        struct addrinfo* resolveCancellable(std::string& errMsg,
+                                            const CancellationRequest& isCancellationRequested);
+        struct addrinfo* resolveUnCancellable(std::string& errMsg,
+                                              const CancellationRequest& isCancellationRequested);
+
+        static struct addrinfo* getAddrInfo(const std::string& hostname,
+                                            int port,
+                                            std::string& errMsg);
+
+        void run(std::weak_ptr<DNSLookup> self, std::string hostname, int port); // thread runner
+
+        void setErrMsg(const std::string& errMsg);
+        const std::string& getErrMsg();
+
+        void setRes(struct addrinfo* addr);
+        struct addrinfo* getRes();
+
+        std::string _hostname;
+        int _port;
+        int64_t _wait;
+        const static int64_t kDefaultWait;
+
+        struct addrinfo* _res;
+        std::mutex _resMutex;
+
+        std::string _errMsg;
+        std::mutex _errMsgMutex;
+
+        std::atomic<bool> _done;
+    };
+} // namespace ix