修复pendingXfer协议；在pendingXfer-EndXfer协议中抛弃首张图片

twain/ds/huagaods.cpp

@@ -1088,13 +1088,28 @@ Result huagao_ds::pendingXfersGet(const Identity&, PendingXfers& data)
 }
 Result huagao_ds::pendingXfersEnd(const Identity& id, PendingXfers& data)
 {
+	// complete transferring of current image ...
+	pending_xfer_.clear();
+	if (scanner_.get())
+	{
+		scanner_->discard_first_image();
+	}
+
 	return pendingXfersGet(id, data);
 }
 Result huagao_ds::pendingXfersReset(const Identity& id, PendingXfers& data)
 {
 	pending_xfer_.clear();
+	if (scanner_.get())
+	{
+		scanner_->stop();
+		while (scanner_->discard_first_image());
+	}
+	data.setCount(0);
 
-	return pendingXfersGet(id, data);
+	return success();
+
+	//return pendingXfersGet(id, data);
 }
 Result huagao_ds::setupMemXferGet(const Identity& id, SetupMemXfer& data)
 {

twain/ds/s2t_api.h

@@ -165,6 +165,7 @@ public:
 	COM_API_DECLARE(int, get_scanned_images(DWORD milliseconds = 0));
 	COM_API_DECLARE(IScanImg*, take_first_image(twain_xfer xfer = TWAIN_XFER_Native));		// call 'release' on returned value, plz
 	COM_API_DECLARE(bool, get_first_image_header(SANE_Parameters* header, size_t* bytes = nullptr, int *dpi = nullptr));
+	COM_API_DECLARE(bool, discard_first_image(void));
 	COM_API_DECLARE(bool, is_online(void));
 	COM_API_DECLARE(bool, is_paper_on(void));
 	COM_API_DECLARE(int, last_error(void));

twain/ds/scanner.cpp

@@ -2309,11 +2309,12 @@ COM_API_IMPLEMENT(scanner, int, get_scanned_images(DWORD milliseconds))
 }
 COM_API_IMPLEMENT(scanner, IScanImg*, take_first_image(twain_xfer xfer))
 {
-	scanned_img* img = images_.take();
+	scanned_img* img = images_.take(false);
 
 	if (img)
 	{
 		img->prepare_data_for_transfer(xfer);
+		img->add_ref();
 
 		utils::to_log(LOG_LEVEL_DEBUG, "Begin transferring image %d of %p\r\n", fetch_imgs_ + 1, img);
 	}
@@ -2324,6 +2325,19 @@ COM_API_IMPLEMENT(scanner, bool, get_first_image_header(SANE_Parameters* header,
 {
 	return images_.get_header(header, bytes, dpi);
 }
+COM_API_IMPLEMENT(scanner, bool, discard_first_image(void))
+{
+	scanned_img* img = images_.take();
+	if (img)
+	{
+		img->release();
+		return true;
+	}
+	else
+	{
+		return false;
+	}
+}
 COM_API_IMPLEMENT(scanner, bool, is_online(void))
 {
 	std::string	sn("");

twain/ds/scanner.h

@@ -213,6 +213,7 @@ public:
 	COM_API_OVERRIDE(int, get_scanned_images(DWORD milliseconds = 0));
 	COM_API_OVERRIDE(IScanImg*, take_first_image(twain_xfer xfer = TWAIN_XFER_Native));		// call 'release' on returned value, plz
 	COM_API_OVERRIDE(bool, get_first_image_header(SANE_Parameters* header, size_t* bytes = NULL, int* dpi = NULL));
+	COM_API_OVERRIDE(bool, discard_first_image(void));
 	COM_API_OVERRIDE(bool, is_online(void));
 	COM_API_OVERRIDE(bool, is_paper_on(void));
 	COM_API_OVERRIDE(int, last_error(void));