Windows socket duplication implementation

dub.json

@@ -13,6 +13,7 @@
 		"money": "~>3.0.2"
 	},
 	"targetType": "sourceLibrary",
+	"libs-windows": ["ws2_32"],
 	"-ddoxTool": "scod",
 	"configurations": [
 		{

src/dpq2/connection.d

@@ -207,27 +207,55 @@ class Connection
     }
 
     /// Obtains duplicate file descriptor number of the connection socket to the server
+    version(Posix)
     socket_t posixSocketDuplicate()
     {
-        version(Windows)
-        {
-            assert(false, "FIXME: implement socket duplication");
-        }
-        else // Posix OS
-        {
-            import core.sys.posix.unistd: dup;
+        import core.sys.posix.unistd: dup;
 
-            return cast(socket_t) dup(cast(socket_t) posixSocket);
-        }
+        static assert(socket_t.sizeof == int.sizeof);
+
+        return cast(socket_t) dup(cast(socket_t) posixSocket);
+    }
+
+    /// Obtains duplicate file descriptor number of the connection socket to the server
+    version(Windows)
+    SOCKET posixSocketDuplicate()
+    {
+        import core.stdc.stdlib: malloc, free;
+        import core.sys.windows.winbase: GetCurrentProcessId;
+
+        auto protocolInfo = cast(WSAPROTOCOL_INFOW*) malloc(WSAPROTOCOL_INFOW.sizeof);
+        scope(failure) free(protocolInfo);
+
+        int dupStatus = WSADuplicateSocketW(posixSocket, GetCurrentProcessId, protocolInfo);
+
+        if(dupStatus)
+            throw new ConnectionException("WSADuplicateSocketW error, code "~WSAGetLastError().to!string);
+
+        SOCKET s = WSASocketW(
+                FROM_PROTOCOL_INFO,
+                FROM_PROTOCOL_INFO,
+                FROM_PROTOCOL_INFO,
+                protocolInfo,
+                0,
+                0
+            );
+
+        if(s == INVALID_SOCKET)
+            throw new ConnectionException("WSASocket error, code "~WSAGetLastError().to!string);
+
+        return s;
     }
 
     /// Obtains std.socket.Socket of the connection to the server
     ///
-    /// Due to a limitation of Socket actually for the Socket creation
+    /// Due to a limitation of Dlang Socket actually for the Socket creation
     /// duplicate of internal posix socket will be used.
     Socket socket()
     {
-        return new Socket(posixSocketDuplicate, AddressFamily.UNSPEC);
+        version(Windows) static assert(SOCKET.sizeof == socket_t.sizeof);
+
+        return new Socket(cast(socket_t) posixSocketDuplicate, AddressFamily.UNSPEC);
     }
 
     /// Returns the error message most recently generated by an operation on the connection
@@ -401,6 +429,58 @@ class Connection
     }
 }
 
+// Socket duplication stuff for Win32
+version(Windows)
+private
+{
+    import core.sys.windows.windef;
+    import core.sys.windows.basetyps: GUID;
+
+    alias GROUP = uint;
+
+    enum INVALID_SOCKET = 0;
+    enum FROM_PROTOCOL_INFO =-1;
+    enum MAX_PROTOCOL_CHAIN = 7;
+    enum WSAPROTOCOL_LEN = 255;
+
+    struct WSAPROTOCOLCHAIN
+    {
+        int ChainLen;
+        DWORD[MAX_PROTOCOL_CHAIN] ChainEntries;
+    }
+
+    struct WSAPROTOCOL_INFOW
+    {
+        DWORD dwServiceFlags1;
+        DWORD dwServiceFlags2;
+        DWORD dwServiceFlags3;
+        DWORD dwServiceFlags4;
+        DWORD dwProviderFlags;
+        GUID ProviderId;
+        DWORD dwCatalogEntryId;
+        WSAPROTOCOLCHAIN ProtocolChain;
+        int iVersion;
+        int iAddressFamily;
+        int iMaxSockAddr;
+        int iMinSockAddr;
+        int iSocketType;
+        int iProtocol;
+        int iProtocolMaxOffset;
+        int iNetworkByteOrder;
+        int iSecurityScheme;
+        DWORD dwMessageSize;
+        DWORD dwProviderReserved;
+        WCHAR[WSAPROTOCOL_LEN+1] szProtocol;
+    }
+
+    extern(Windows) nothrow @nogc
+    {
+        import core.sys.windows.winsock2: WSAGetLastError;
+        int WSADuplicateSocketW(SOCKET s, DWORD dwProcessId, WSAPROTOCOL_INFOW* lpProtocolInfo);
+        SOCKET WSASocketW(int af, int type, int protocol, WSAPROTOCOL_INFOW*, GROUP, DWORD dwFlags);
+    }
+}
+
 private auto keyValToPQparamsArrays(in string[string] keyValueParams)
 {
     static struct PQparamsArrays

src/dpq2/conv/native_tests.d

@@ -46,7 +46,9 @@ public void _integration_test( string connParam ) @system
     // to return times in other than UTC time zone but fixed time zone so make the test reproducible in databases with other TZ
     conn.exec("SET TIMEZONE TO +02");
 
-    conn.exec("SET lc_monetary = 'en_US.UTF-8'");
+    // It is found what Linux and Windows have different approach for monetary
+    // types formatting at same locales. This line sets equal approach.
+    conn.exec("SET lc_monetary = 'C'");
 
     QueryParams params;
     params.resultFormat = ValueFormat.BINARY;