Further cleanups on AresHandler

Assume that we're not using a 15+ year old c-ares and remove the checks
for versions older than 1.7.0. On autotools systems, check for the
existance of ares_getaddrinfo. Assume we have it on Windows and macOS.

MSVC/build/config.h

@@ -108,7 +108,7 @@
 #define HAVE_STD__MIN 1
 #define HAVE_STD__MAX 1
 
-#define HAVE_ARES_LIBRARY_INIT 1
+#define HAVE_ARES_GETADDRINFO 1
 
 #ifndef DEBUG_TRACE
 #define DEBUG_TRACE

Xcode/config.h

@@ -45,8 +45,8 @@
 /* libm includes acosf */
 #define HAVE_ACOSF 1
 
-/* Define if libcares includes ares_library_init. */
-#define HAVE_ARES_LIBRARY_INIT 1
+/* Define if libcares includes ares_getaddrinfo */
+#define HAVE_ARES_GETADDRINFO 1
 
 /* libm includes asinf */
 #define HAVE_ASINF 1

configure.ac

@@ -290,7 +290,7 @@ AC_LINK_IFELSE([AC_LANG_PROGRAM([[
 ]])],[AC_MSG_RESULT([yes])],[AC_MSG_FAILURE([working c-ares library was not found])])
 LIBS="$PRELIBS"
 
-AC_CHECK_LIB(cares, ares_library_init, AC_DEFINE([HAVE_ARES_LIBRARY_INIT],[1],[Define if libcares includes ares_library_init.]))
+AC_CHECK_LIB(cares, ares_getaddrinfo, AC_DEFINE([HAVE_ARES_GETADDRINFO],[1],[Define if libcares includes ares_getaddrinfo.]))
 
 
 

include/AresHandler.h

@@ -54,22 +54,15 @@ class AresHandler
         return status;
     };
 private:
-#if ARES_VERSION_MAJOR > 1 || ARES_VERSION_MINOR >= 16
-    static void staticCallback1(void *arg, int status,
+#if HAVE_ARES_GETADDRINFO
+    static void staticCallbackAddrInfo(void *arg, int status,
                                 int timeout, struct ares_addrinfo *result);
+    void      callbackAddrInfo(int status, struct ares_addrinfo *result);
 #endif
-
-#if ARES_VERSION_MAJOR >= 1 && ARES_VERSION_MINOR >= 5
     static void   staticCallback(void *arg, int statusCallback, int timeouts,
                                  struct hostent *hostent);
-#else
-    static void   staticCallback(void *arg, int statusCallback,
-                                 struct hostent *hostent);
-#endif
     void      callback(int status, struct hostent *hostent);
-#if ARES_VERSION_MAJOR > 1 || ARES_VERSION_MINOR >= 16
-    void      callback1(int status, struct ares_addrinfo *result);
-#endif
+
     int       index;
 
     std::string   hostName;

src/net/AresHandler.cxx

@@ -72,20 +72,16 @@ bool AresHandler::globalInit()
 {
     if (!globallyInited)
     {
-#ifdef HAVE_ARES_LIBRARY_INIT
         if (ares_library_init(ARES_LIB_INIT_ALL) == ARES_SUCCESS)
-#endif
             globallyInited = true;
     }
     return globallyInited;
 }
 
 void AresHandler::globalShutdown()
 {
-#ifdef HAVE_ARES_LIBRARY_INIT
     if (globallyInited)
         ares_library_cleanup();
-#endif
 }
 
 void AresHandler::queryHostname(const struct sockaddr *clientAddr)
@@ -121,37 +117,21 @@ void AresHandler::queryHost(const char *name)
     // launch the asynchronous query to look up this hostname
     status = HbNPending;
 
-#if ARES_VERSION_MAJOR > 1 || ARES_VERSION_MINOR >= 16
+#if HAVE_ARES_GETADDRINFO
     struct ares_addrinfo_hints hints;
     memset(&hints, 0, sizeof(hints));
     hints.ai_family = AF_INET;
 
-    ares_getaddrinfo(aresChannel, name, NULL, &hints, staticCallback1,
+    ares_getaddrinfo(aresChannel, name, NULL, &hints, staticCallbackAddrInfo,
                      (void *)this);
 #else
     ares_gethostbyname(aresChannel, name, AF_INET, staticCallback,
                        (void *)this);
 #endif
 }
 
-#if ARES_VERSION_MAJOR > 1 || ARES_VERSION_MINOR >= 16
-void AresHandler::staticCallback1(void *arg, int status,
-                                  int, struct ares_addrinfo *result)
-{
-    if (status == ARES_EDESTRUCTION)
-        return;
-
-    ((AresHandler *)arg)->callback1(status, result);
-}
-#endif
-
-#if ARES_VERSION_MAJOR > 1 || ARES_VERSION_MINOR >= 5
 void AresHandler::staticCallback(void *arg, int callbackStatus,
                                  int, struct hostent *hostent)
-#else
-void AresHandler::staticCallback(void *arg, int callbackStatus,
-                                 struct hostent *hostent)
-#endif
 {
     ((AresHandler *)arg)->callback(callbackStatus, hostent);
 }
@@ -182,8 +162,17 @@ void AresHandler::callback(int callbackStatus, struct hostent *hostent)
     }
 }
 
-#if ARES_VERSION_MAJOR > 1 || ARES_VERSION_MINOR >= 16
-void AresHandler::callback1(int callbackStatus, struct ares_addrinfo *result)
+#if HAVE_ARES_GETADDRINFO
+void AresHandler::staticCallbackAddrInfo(void *arg, int status,
+                                  int, struct ares_addrinfo *result)
+{
+    if (status == ARES_EDESTRUCTION)
+        return;
+
+    ((AresHandler *)arg)->callbackAddrInfo(status, result);
+}
+
+void AresHandler::callbackAddrInfo(int callbackStatus, struct ares_addrinfo *result)
 {
     const std::lock_guard<std::mutex> lock(callback_mutex);