Add a progress callback for wxWebRequestCURL

This commit adds a progress callback for use with wxWebRequestCURL
objects. This has some complications because over the years curl has
changed the signature of the callback.

A combination of compile-time and run-time checks is used to make sure
the appropriate callback and preferred return value are used.

include/wx/private/webrequest_curl.h

@@ -114,6 +114,7 @@ public:
     // Methods called from libcurl callbacks
     size_t CURLOnWrite(void *buffer, size_t size);
     size_t CURLOnHeader(const char* buffer, size_t size);
+    int CURLOnProgress();
 
 private:
     wxWebRequestHeaderMap m_headers;
@@ -149,6 +150,9 @@ public:
 
     void CancelRequest(wxWebRequestCURL* request);
 
+    static bool CurlRuntimeAtLeastVersion(unsigned int, unsigned int,
+                                          unsigned int);
+
 private:
     static int TimerCallback(CURLM*, long, void*);
     static int SocketCallback(CURL*, curl_socket_t, int, void*, void*);
@@ -165,6 +169,7 @@ private:
     CURLM* m_handle;
 
     static int ms_activeSessions;
+    static unsigned int ms_runtimeVersion;
 
     wxDECLARE_NO_COPY_CLASS(wxWebSessionCURL);
 };

src/common/webrequest_curl.cpp

@@ -44,12 +44,6 @@
   (LIBCURL_VERSION_NUM >= CURL_VERSION_BITS(x, y, z))
 #endif
 
-#if CURL_AT_LEAST_VERSION(7, 28, 0)
-    #define wxCURL_HAVE_MULTI_WAIT 1
-#else
-    #define wxCURL_HAVE_MULTI_WAIT 0
-#endif
-
 // The new name was introduced in curl 7.21.6.
 #ifndef CURLOPT_ACCEPT_ENCODING
     #define CURLOPT_ACCEPT_ENCODING CURLOPT_ENCODING
@@ -73,12 +67,53 @@ static size_t wxCURLHeader(char *buffer, size_t size, size_t nitems, void *userd
     return static_cast<wxWebResponseCURL*>(userdata)->CURLOnHeader(buffer, size * nitems);
 }
 
+int wxCURLXferInfo(void* clientp, curl_off_t WXUNUSED(dltotal),
+                   curl_off_t WXUNUSED(dlnow),
+                   curl_off_t WXUNUSED(ultotal),
+                   curl_off_t WXUNUSED(ulnow))
+{
+    wxCHECK_MSG( clientp, 0, "invalid curl progress callback data" );
+
+    wxWebResponseCURL* response = reinterpret_cast<wxWebResponseCURL*>(clientp);
+    return response->CURLOnProgress();
+}
+
+int wxCURLProgress(void* clientp, double dltotal, double dlnow, double ultotal,
+                   double ulnow)
+{
+    return wxCURLXferInfo(clientp, static_cast<curl_off_t>(dltotal),
+                          static_cast<curl_off_t>(dlnow),
+                          static_cast<curl_off_t>(ultotal),
+                          static_cast<curl_off_t>(ulnow));
+}
+
 wxWebResponseCURL::wxWebResponseCURL(wxWebRequestCURL& request) :
     wxWebResponseImpl(request)
 {
     curl_easy_setopt(GetHandle(), CURLOPT_WRITEDATA, static_cast<void*>(this));
     curl_easy_setopt(GetHandle(), CURLOPT_HEADERDATA, static_cast<void*>(this));
 
+ // Set the progress callback.
+    #if CURL_AT_LEAST_VERSION(7, 32, 0)
+        if ( wxWebSessionCURL::CurlRuntimeAtLeastVersion(7, 32, 0) )
+        {
+            curl_easy_setopt(GetHandle(), CURLOPT_XFERINFOFUNCTION,
+                             wxCURLXferInfo);
+            curl_easy_setopt(GetHandle(), CURLOPT_XFERINFODATA,
+                             static_cast<void*>(this));
+        }
+        else
+    #endif
+        {
+            curl_easy_setopt(GetHandle(), CURLOPT_PROGRESSFUNCTION,
+                             wxCURLProgress);
+            curl_easy_setopt(GetHandle(), CURLOPT_PROGRESSDATA,
+                             static_cast<void*>(this));
+        }
+
+    // Have curl call the progress callback.
+    curl_easy_setopt(GetHandle(), CURLOPT_NOPROGRESS, 0L);
+
     Init();
 }
 
@@ -117,6 +152,11 @@ size_t wxWebResponseCURL::CURLOnHeader(const char * buffer, size_t size)
     return size;
 }
 
+int wxWebResponseCURL::CURLOnProgress()
+{
+    return 0;
+}
+
 wxFileOffset wxWebResponseCURL::GetContentLength() const
 {
 #if CURL_AT_LEAST_VERSION(7, 55, 0)
@@ -877,6 +917,7 @@ void SocketPoller::ThreadCheckSockets()
 //
 
 int wxWebSessionCURL::ms_activeSessions = 0;
+unsigned int wxWebSessionCURL::ms_runtimeVersion = 0;
 
 wxWebSessionCURL::wxWebSessionCURL() :
     m_handle(NULL)
@@ -885,8 +926,15 @@ wxWebSessionCURL::wxWebSessionCURL() :
     if ( ms_activeSessions == 0 )
     {
         if ( curl_global_init(CURL_GLOBAL_ALL) )
+        {
             wxLogError(_("libcurl could not be initialized"));
         }
+        else
+        {
+            curl_version_info_data* data = curl_version_info(CURLVERSION_NOW);
+            ms_runtimeVersion = data->version_num;
+        }
+    }
 
     ms_activeSessions++;
 
@@ -970,6 +1018,13 @@ wxVersionInfo  wxWebSessionCURL::GetLibraryVersionInfo()
         desc);
 }
 
+bool wxWebSessionCURL::CurlRuntimeAtLeastVersion(unsigned int major,
+                                                 unsigned int minor,
+                                                 unsigned int patch)
+{
+    return (ms_runtimeVersion >= CURL_VERSION_BITS(major, minor, patch));
+}
+
 // curl interacts with the wxWebSessionCURL class through 2 callback functions
 // 1) TimerCallback is called whenever curl wants us to start or stop a timer.
 // 2) SocketCallback is called when curl wants us to start monitoring a socket