优化UDP链接id生成性能

Author: xia-chu

src/Network/UdpServer.cpp

@@ -25,7 +25,6 @@ static UdpServer::PeerIdType makeSockId(sockaddr *addr, int) {
     UdpServer::PeerIdType ret;
     switch (addr->sa_family) {
         case AF_INET : {
-            ret.resize(18);
             ret[0] = ((struct sockaddr_in *) addr)->sin_port >> 8;
             ret[1] = ((struct sockaddr_in *) addr)->sin_port & 0xFF;
             //ipv4地址统一转换为ipv6方式处理  [AUTO-TRANSLATED:ad7cf8c3]
@@ -35,13 +34,12 @@ static UdpServer::PeerIdType makeSockId(sockaddr *addr, int) {
             return ret;
         }
         case AF_INET6 : {
-            ret.resize(18);
             ret[0] = ((struct sockaddr_in6 *) addr)->sin6_port >> 8;
             ret[1] = ((struct sockaddr_in6 *) addr)->sin6_port & 0xFF;
             memcpy(&ret[2], &(((struct sockaddr_in6 *)addr)->sin6_addr), 16);
             return ret;
         }
-        default: assert(0); return "";
+        default: throw std::invalid_argument("invalid sockaddr address");
     }
 }
 
@@ -78,7 +76,7 @@ void UdpServer::start_l(uint16_t port, const std::string &host) {
     //主server才创建session map，其他cloned server共享之  [AUTO-TRANSLATED:113cf4fd]
     //Only the main server creates a session map, other cloned servers share it
     _session_mutex = std::make_shared<std::recursive_mutex>();
-    _session_map = std::make_shared<std::unordered_map<PeerIdType, SessionHelper::Ptr> >();
+    _session_map = std::make_shared<SessionMapType>();
 
     // 新建一个定时器定时管理这些 udp 会话,这些对象只由主server做超时管理，cloned server不管理  [AUTO-TRANSLATED:d20478a2]
     //Create a timer to manage these udp sessions periodically, these objects are only managed by the main server, cloned servers do not manage them
@@ -207,7 +205,7 @@ void UdpServer::onManagerSession() {
         std::lock_guard<std::recursive_mutex> lock(*_session_mutex);
         //拷贝map，防止遍历时移除对象  [AUTO-TRANSLATED:ebbc7595]
         //Copy the map to prevent objects from being removed during traversal
-        copy_map = std::make_shared<std::unordered_map<PeerIdType, SessionHelper::Ptr> >(*_session_map);
+        copy_map = std::make_shared<SessionMapType>(*_session_map);
     }
     auto lam = [copy_map]() {
         for (auto &pr : *copy_map) {

src/Network/UdpServer.h

@@ -11,15 +11,30 @@
 #ifndef TOOLKIT_NETWORK_UDPSERVER_H
 #define TOOLKIT_NETWORK_UDPSERVER_H
 
+#include <string_view>
 #include "Server.h"
 #include "Session.h"
 
 namespace toolkit {
 
 class UdpServer : public Server {
 public:
+    class PeerIdType : public std::array<char, 18> {
+    public:
+        bool operator==(const PeerIdType &that) const {
+            return as<uint64_t>(0) == that.as<uint64_t>(0) &&
+                   as<uint64_t>(8) == that.as<uint64_t>(8) &&
+                   as<uint16_t>(16) == that.as<uint16_t>(16);
+        }
+
+    private:
+        template <class T>
+        const T& as(size_t offset) const {
+            return *(reinterpret_cast<const T *>(data() + offset));
+        }
+    };
+
     using Ptr = std::shared_ptr<UdpServer>;
-    using PeerIdType = std::string;
     using onCreateSocket = std::function<Socket::Ptr(const EventPoller::Ptr &, const Buffer::Ptr &, struct sockaddr *, int)>;
 
     explicit UdpServer(const EventPoller::Ptr &poller = nullptr);
@@ -75,6 +90,11 @@ class UdpServer : public Server {
     virtual void cloneFrom(const UdpServer &that);
 
 private:
+    struct PeerIdHash {
+        size_t operator()(const PeerIdType &v) const noexcept { return std::hash<std::string_view> {}(std::string_view(v.data(), v.size())); }
+    };
+    using SessionMapType = std::unordered_map<PeerIdType, SessionHelper::Ptr, PeerIdHash>;
+
     /**
      * @brief 开始udp server
      * @param port 本机端口，0则随机
@@ -150,7 +170,7 @@ class UdpServer : public Server {
     //cloned server共享主server的session map，防止数据在不同server间漂移  [AUTO-TRANSLATED:9a149e52]
     //Cloned server shares the session map with the main server, preventing data drift between different servers
     std::shared_ptr<std::recursive_mutex> _session_mutex;
-    std::shared_ptr<std::unordered_map<PeerIdType, SessionHelper::Ptr> > _session_map;
+    std::shared_ptr<SessionMapType> _session_map;
     //主server持有cloned server的引用  [AUTO-TRANSLATED:04a6403a]
     //Main server holds a reference to the cloned server
     std::unordered_map<EventPoller *, Ptr> _cloned_server;