Add the Resolver class (#47)

Author: an-tao

CMakeLists.txt

@@ -40,7 +40,7 @@ include_directories(
 #         ${PROJECT_BINARY_DIR}
 # )
 
-set(trantor_sources
+set(TRANTOR_SOURCES
     trantor/utils/AsyncFileLogger.cc
     trantor/utils/ConcurrentTaskQueue.cc
     trantor/utils/Date.cc
@@ -70,12 +70,24 @@ find_package(OpenSSL)
 if(OpenSSL_FOUND)
     include_directories(${OPENSSL_INCLUDE_DIR})
     link_libraries(${OPENSSL_LIBRARIES})
-    set(trantor_sources ${trantor_sources} trantor/net/ssl/SSLConnection.cc)
+    set(TRANTOR_SOURCES ${TRANTOR_SOURCES} trantor/net/ssl/SSLConnection.cc)
 else()
-    set(trantor_sources ${trantor_sources} trantor/net/ssl/SSLConnectionSkipped.cc)
+    set(TRANTOR_SOURCES ${TRANTOR_SOURCES} trantor/net/ssl/SSLConnectionSkipped.cc)
 endif()
 
-add_library(trantor ${trantor_sources})
+find_path(CARES_INCLUDE_DIR ares.h)
+find_library(CARES_LIBRARY NAMES cares)
+if(CARES_INCLUDE_DIR AND CARES_LIBRARY)
+    message(STATUS "found cares")
+    message(STATUS "inc:" ${CARES_INCLUDE_DIR})
+    message(STATUS "lib:" ${CARES_LIBRARY})
+    include_directories(${CARES_INCLUDE_DIR})
+    link_libraries(${CARES_LIBRARY})
+    set(TRANTOR_SOURCES ${TRANTOR_SOURCES} trantor/net/inner/AresResolver.cc)
+else()
+    set(TRANTOR_SOURCES ${TRANTOR_SOURCES} trantor/net/inner/NormalResolver.cc)
+endif()
+add_library(trantor ${TRANTOR_SOURCES})
 set_property(TARGET trantor PROPERTY CXX_STANDARD 14)
 set_property(TARGET trantor PROPERTY CXX_STANDARD_REQUIRED ON)
 set_property(TARGET trantor PROPERTY CXX_EXTENSIONS OFF)
@@ -92,7 +104,8 @@ set(public_net_headers
     trantor/net/TcpClient.h
     trantor/net/TcpConnection.h
     trantor/net/TcpServer.h
-    trantor/net/callbacks.h)
+    trantor/net/callbacks.h
+    trantor/net/Resolver.h)
 
 set(public_utils_headers
     trantor/utils/AsyncFileLogger.h

ChangeLog.md

@@ -3,6 +3,14 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+### API change list
+
+- Remove the resolve method from the InetAddress class.
+
+### Added
+
+- Add the Resolver class.
+  
 ## [1.0.0-rc4] - 2019-08-08
 
 ### API change list

trantor/net/InetAddress.cc

@@ -84,8 +84,8 @@ InetAddress::InetAddress(const std::string &ip, uint16_t port, bool ipv6)
         _addr6.sin6_port = htons(port);
         if (::inet_pton(AF_INET6, ip.c_str(), &_addr6.sin6_addr) <= 0)
         {
-            LOG_SYSERR << "sockets::fromIpPort";
-            abort();
+            // LOG_SYSERR << "sockets::fromIpPort";
+            // abort();
         }
     }
     else
@@ -95,8 +95,8 @@ InetAddress::InetAddress(const std::string &ip, uint16_t port, bool ipv6)
         _addr.sin_port = htons(port);
         if (::inet_pton(AF_INET, ip.c_str(), &_addr.sin_addr) <= 0)
         {
-            LOG_SYSERR << "sockets::fromIpPort";
-            abort();
+            // LOG_SYSERR << "sockets::fromIpPort";
+            // abort();
         }
     }
 }
@@ -208,77 +208,3 @@ uint16_t InetAddress::toPort() const
 {
     return ntohs(portNetEndian());
 }
-#ifdef __linux__
-static __thread char t_resolveBuffer[64 * 1024];
-#endif
-std::mutex InetAddress::_dnsMutex;
-std::unordered_map<std::string, std::pair<struct in_addr, trantor::Date>>
-    InetAddress::_dnsCache;
-bool InetAddress::resolve(const std::string &hostname,
-                          InetAddress *out,
-                          size_t timeout)
-{
-    assert(out != NULL);
-    {
-        std::lock_guard<std::mutex> guard(_dnsMutex);
-        if (_dnsCache.find(hostname) != _dnsCache.end())
-        {
-            auto &addr = _dnsCache[hostname];
-            if (timeout == 0 || (timeout > 0 && (addr.second.after(timeout) >
-                                                 trantor::Date::date())))
-            {
-                LOG_TRACE << "dns:Hit cache";
-                out->_addr.sin_addr = addr.first;
-                return true;
-            }
-        }
-    }
-#ifdef __linux__
-    struct hostent hent;
-    struct hostent *he = NULL;
-    int herrno = 0;
-    memset(&hent, 0, sizeof(hent));
-
-    int ret = gethostbyname_r(hostname.c_str(),
-                              &hent,
-                              t_resolveBuffer,
-                              sizeof t_resolveBuffer,
-                              &he,
-                              &herrno);
-    if (ret == 0 && he != NULL)
-#else
-    /// Multi-threads safety
-    static std::mutex _mutex;
-    struct hostent *he = NULL;
-    struct hostent hent;
-    {
-        std::lock_guard<std::mutex> guard(_mutex);
-        auto result = gethostbyname(hostname.c_str());
-        if (result != NULL)
-        {
-            memcpy(&hent, result, sizeof(hent));
-            he = &hent;
-        }
-    }
-
-    if (he != NULL)
-#endif
-    {
-        assert(he->h_addrtype == AF_INET && he->h_length == sizeof(uint32_t));
-        out->_addr.sin_addr = *reinterpret_cast<struct in_addr *>(he->h_addr);
-        {
-            std::lock_guard<std::mutex> guard(_dnsMutex);
-            _dnsCache[hostname].first = out->_addr.sin_addr;
-            _dnsCache[hostname].second = trantor::Date::date();
-        }
-        return true;
-    }
-    else
-    {
-        //        if (ret)
-        {
-            LOG_SYSERR << "InetAddress::resolve";
-        }
-        return false;
-    }
-}

trantor/net/InetAddress.h

@@ -87,15 +87,10 @@ class InetAddress
     {
         return _addr.sin_port;
     }
-
-    // resolve hostname to IP address, not changing port or sin_family
-    // return true on success.
-    // thread safe
-    static bool resolve(const std::string &hostname,
-                        InetAddress *result,
-                        size_t timeout = 3600);
-    // static std::vector<InetAddress> resolveAll(const char* hostname, uint16_t
-    // port = 0);
+    void setPortNetEndian(uint16_t port)
+    {
+        _addr.sin_port = port;
+    }
 
   private:
     union {

trantor/net/Resolver.h

@@ -0,0 +1,27 @@
+// Copyright 2016, Tao An.  All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the License file.
+
+// Author: Tao An
+
+#pragma once
+#include <memory>
+#include <trantor/net/EventLoop.h>
+#include <trantor/net/InetAddress.h>
+
+namespace trantor
+{
+class Resolver
+{
+  public:
+    typedef std::function<void(const trantor::InetAddress&)> Callback;
+    static std::shared_ptr<Resolver> newResolver(EventLoop* loop = nullptr,
+                                                 size_t timeout = 60);
+    virtual void resolve(const std::string& hostname,
+                         const Callback& callback) = 0;
+    virtual ~Resolver()
+    {
+    }
+};
+}  // namespace trantor