Improve server list (+list interface) performance, and reduce background overhead

Author: Dutchman101

Client/core/ServerBrowser/CServerBrowser.MasterServerManager.cpp

@@ -24,6 +24,7 @@ class CMasterServerManager : public CMasterServerManagerInterface
     virtual void Refresh();
     virtual bool HasData();
     virtual bool ParseList(CServerListItemList& itemList);
+    virtual void CancelRefresh();
 
     // CMasterServerManager
 protected:
@@ -65,6 +66,7 @@ CMasterServerManager::CMasterServerManager()
 ///////////////////////////////////////////////////////////////
 CMasterServerManager::~CMasterServerManager()
 {
+    CancelRefresh();
     for (uint i = 0; i < m_MasterServerList.size(); i++)
         SAFE_RELEASE(m_MasterServerList[i]);
 
@@ -152,3 +154,15 @@ bool CMasterServerManager::ParseList(CServerListItemList& itemList)
 
     return uiParsedCount > 0;
 }
+
+void CMasterServerManager::CancelRefresh()
+{
+    for (uint i = 0; i < m_MasterServerList.size(); ++i)
+    {
+        if (m_MasterServerList[i])
+            m_MasterServerList[i]->Cancel();
+    }
+
+    m_iActiveAmount = 0;
+    m_ElapsedTime.Reset();
+}

Client/core/ServerBrowser/CServerBrowser.MasterServerManager.h

@@ -11,6 +11,7 @@ class CMasterServerManagerInterface
     virtual void Refresh() = 0;
     virtual bool HasData() = 0;
     virtual bool ParseList(CServerListItemList& itemList) = 0;
+    virtual void CancelRefresh() = 0;
 };
 
 CMasterServerManagerInterface* NewMasterServerManager();

Client/core/ServerBrowser/CServerBrowser.RemoteMasterServer.cpp

@@ -23,6 +23,7 @@ class CRemoteMasterServer : public CRemoteMasterServerInterface
     virtual void Refresh();
     virtual bool HasData();
     virtual bool ParseList(CServerListItemList& itemList);
+    virtual void Cancel();
 
     // CRemoteMasterServer
     void Init(const SString& strURL);
@@ -42,6 +43,7 @@ class CRemoteMasterServer : public CRemoteMasterServerInterface
     SString   m_strStage;
     SString   m_strURL;
     CBuffer   m_Data;
+    bool      m_bPendingDownload = false;
 };
 
 ///////////////////////////////////////////////////////////////
@@ -121,10 +123,35 @@ void CRemoteMasterServer::Refresh()
     // Send new request
     m_strStage = "waitingreply";
     m_llLastRefreshTime = GetTickCount64_();
-    AddRef();            // Keep alive
     SHttpRequestOptions options;
     options.uiConnectionAttempts = 1;
-    GetHTTP()->QueueFile(m_strURL, NULL, this, &CRemoteMasterServer::StaticDownloadFinished, options);
+    if (GetHTTP()->QueueFile(m_strURL, NULL, this, &CRemoteMasterServer::StaticDownloadFinished, options))
+    {
+        m_bPendingDownload = true;
+        AddRef();            // Keep alive
+    }
+    else
+    {
+        m_strStage = "nogood";
+    }
+}
+
+void CRemoteMasterServer::Cancel()
+{
+    if (!m_bPendingDownload)
+        return;
+
+    if (GetHTTP()->CancelDownload(this, &CRemoteMasterServer::StaticDownloadFinished))
+    {
+        m_bPendingDownload = false;
+        m_strStage.clear();
+        Release();
+    }
+    else
+    {
+        m_bPendingDownload = false;
+        m_strStage.clear();
+    }
 }
 
 ///////////////////////////////////////////////////////////////
@@ -150,6 +177,8 @@ void CRemoteMasterServer::StaticDownloadFinished(const SHttpDownloadResult& resu
 ///////////////////////////////////////////////////////////////
 void CRemoteMasterServer::DownloadFinished(const SHttpDownloadResult& result)
 {
+    m_bPendingDownload = false;
+
     if (result.bSuccess)
     {
         if (m_strStage == "waitingreply")

Client/core/ServerBrowser/CServerBrowser.RemoteMasterServer.h

@@ -16,6 +16,7 @@ class CRemoteMasterServerInterface : public CRefCountable
     virtual void Refresh() = 0;
     virtual bool HasData() = 0;
     virtual bool ParseList(CServerListItemList& itemList) = 0;
+    virtual void Cancel() = 0;
 };
 
 CRemoteMasterServerInterface* NewRemoteMasterServer(const SString& strURL);