curl/Request: move struct Pause to class CurlResponseHandler

src/input/plugins/CurlInputPlugin.cxx

@@ -309,7 +309,7 @@ CurlInputStream::OnData(ConstBuffer<void> data)
 
 	if (data.size > GetBufferSpace()) {
 		AsyncInputStream::Pause();
-		throw CurlRequest::Pause();
+		throw CurlResponseHandler::Pause{};
 	}
 
 	AppendToBuffer(data.data, data.size);

src/lib/curl/Handler.hxx

@@ -44,6 +44,13 @@
 class CurlResponseHandler {
 public:
 	/**
+	 * OnData() shall throw this to pause the stream.  Call
+	 * CurlEasy::Unpause() or CurlRequest::Resume() to resume the
+	 * transfer.
+	 */
+	struct Pause {};
+
+	/**
 	 * Status line and headers have been received.
 	 */
 	virtual void OnHeaders(unsigned status,
@@ -51,6 +58,8 @@ public:
 
 	/**
 	 * Response body data has been received.
+	 *
+	 * May throw #Pause.
 	 */
 	virtual void OnData(ConstBuffer<void> data) = 0;
 

src/lib/curl/Request.cxx

@@ -241,7 +241,7 @@ CurlRequest::DataReceived(const void *ptr, size_t received_size) noexcept
 		FinishHeaders();
 		handler.OnData({ptr, received_size});
 		return received_size;
-	} catch (Pause) {
+	} catch (CurlResponseHandler::Pause) {
 		return CURL_WRITEFUNC_PAUSE;
 	} catch (...) {
 		state = State::CLOSED;

src/lib/curl/Request.hxx

@@ -146,12 +146,6 @@ public:
 		easy.SetRequestBody(data, size);
 	}
 
-	/**
-	 * CurlResponseHandler::OnData() shall throw this to pause the
-	 * stream.  Call Resume() to resume the transfer.
-	 */
-	struct Pause {};
-
 	void Resume() noexcept;
 
 	/**