Report failure for http requests with response code different from 200

include/openspace/util/httprequest.h

@@ -39,16 +39,27 @@
 namespace openspace {
     
 namespace curlfunctions {
-    size_t writeCallback(char *ptr,
-                         size_t size,
-                         size_t nmemb,
-                         void *userdata);
+    size_t writeCallback(
+        char *ptr,
+        size_t size,
+        size_t nmemb,
+        void *userdata
+    );
 
-    int progressCallback(void *clientp,
-                         int64_t dltotal,
-                         int64_t dlnow,
-                         int64_t ultotal,
-                         int64_t ulnow);
+    int progressCallback(
+        void *clientp,
+        int64_t dltotal,
+        int64_t dlnow,
+        int64_t ultotal,
+        int64_t ulnow
+    );
+
+    size_t headerCallback(
+        char* ptr,
+        size_t size,
+        size_t nmemb,
+        void* userData
+    );
 }
 
 // Synchronous http request
@@ -57,7 +68,7 @@ public:
     enum class ReadyState : unsigned int {
         Unsent,
         Loading,
-        ReceivedHeaders,
+        ReceivedHeader,
         Fail,
         Success
     };
@@ -73,6 +84,11 @@ public:
         size_t size;
     };
 
+    struct Header {
+        char* buffer;
+        size_t size;
+    };
+
     using ReadyStateChangeCallback = std::function<void(ReadyState)>;
     
     // ProgressCallback: Return non-zero value to cancel download.
@@ -83,6 +99,11 @@ public:
     // the request will fail.
     using DataCallback = std::function<size_t(Data)>;
 
+    // HeaderCallback: Return number of bytes successfully stored.
+    // If this does not match the data buffer sice reported in Header,
+    // the request will fail.
+    using HeaderCallback = std::function<size_t(Header)>;
+
     struct RequestOptions {
         int requestTimeoutSeconds; // 0 for no timeout
     };
@@ -90,6 +111,7 @@ public:
     HttpRequest(std::string url);
 
     void onReadyStateChange(ReadyStateChangeCallback cb);
+    void onHeader(HeaderCallback cb);
     void onProgress(ProgressCallback cb);
     void onData(DataCallback cb);
 
@@ -103,6 +125,7 @@ private:
     ReadyStateChangeCallback _onReadyStateChange;
     ProgressCallback _onProgress;
     DataCallback _onData;
+    HeaderCallback _onHeader;
 
     ReadyState _readyState;
     Progress _progress;
@@ -120,16 +143,24 @@ private:
         int64_t dlnow,
         int64_t ultotal,
         int64_t ulnow);
+
+    friend size_t curlfunctions::headerCallback(
+       char *ptr,
+       size_t size,
+       size_t nmemb,
+       void *userdata);
 };
 
 class HttpDownload {
 public:
     using ProgressCallback = std::function<bool(HttpRequest::Progress)>;
+    using HeaderCallback = std::function<bool(HttpRequest::Header)>;
 
     HttpDownload();
     HttpDownload(HttpDownload&& d) = default;
     virtual ~HttpDownload() = default;
     void onProgress(ProgressCallback progressCallback);
+    void onHeader(HeaderCallback headerCallback);
     bool hasStarted();
     bool hasFailed();
     bool hasSucceeded();