Since we never actually read more than one mouse_movement at a time and we only

ever wait for reports on demand, there's no need for buffering at all.
This removes some unnecessary copying and ring buffer overhead, the ring buffer
will now in fact not be created at all.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@41864 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/add-ons/kernel/drivers/input/usb_hid/MouseProtocolHandler.cpp

@@ -25,7 +25,7 @@
 MouseProtocolHandler::MouseProtocolHandler(HIDReport &report,
 	HIDReportItem &xAxis, HIDReportItem &yAxis)
 	:
-	ProtocolHandler(report.Device(), "input/mouse/usb/", 512),
+	ProtocolHandler(report.Device(), "input/mouse/usb/", 0),
 	fReport(report),
 	fXAxis(xAxis),
 	fYAxis(yAxis),
@@ -106,24 +106,29 @@ MouseProtocolHandler::AddHandlers(HIDDevice &device, HIDCollection &collection,
 
 
 status_t
-MouseProtocolHandler::Control(uint32 *cookie, uint32 op, void *buffer, size_t length)
+MouseProtocolHandler::Control(uint32 *cookie, uint32 op, void *buffer,
+	size_t length)
 {
 	switch (op) {
 		case MS_READ:
-			while (RingBufferReadable() == 0) {
+		{
-				status_t result = _ReadReport();
+			if (length < sizeof(mouse_movement))
-				if (result != B_OK)
+				return B_BUFFER_OVERFLOW;
+
+			while (true) {
+				status_t result = _ReadReport(buffer);
+				if (result != B_INTERRUPTED)
 					return result;
 			}
-
+		}
-			return RingBufferRead(buffer, sizeof(mouse_movement));
 
 		case MS_NUM_EVENTS:
 		{
-			int32 count = RingBufferReadable() / sizeof(mouse_movement);
+			if (fReport.Device()->IsRemoved())
-			if (count == 0 && fReport.Device()->IsRemoved())
 				return B_DEV_NOT_READY;
-			return count;
+
+			// we are always on demand, so 0 queued events
+			return 0;
 		}
 
 		case MS_SET_CLICKSPEED:
@@ -140,7 +145,7 @@ MouseProtocolHandler::Control(uint32 *cookie, uint32 op, void *buffer, size_t le
 
 
 status_t
-MouseProtocolHandler::_ReadReport()
+MouseProtocolHandler::_ReadReport(void *buffer)
 {
 	status_t result = fReport.WaitForReport(B_INFINITE_TIMEOUT);
 	if (result != B_OK) {
@@ -156,19 +161,19 @@ MouseProtocolHandler::_ReadReport()
 		}
 
 		// signal that we simply want to try again
-		return B_OK;
+		return B_INTERRUPTED;
 	}
 
-	mouse_movement info;
+	mouse_movement *info = (mouse_movement *)buffer;
-	memset(&info, 0, sizeof(info));
+	memset(info, 0, sizeof(mouse_movement));
 
 	if (fXAxis.Extract() == B_OK && fXAxis.Valid())
-		info.xdelta = fXAxis.Data();
+		info->xdelta = fXAxis.Data();
 	if (fYAxis.Extract() == B_OK && fYAxis.Valid())
-		info.ydelta = -fYAxis.Data();
+		info->ydelta = -fYAxis.Data();
 
 	if (fWheel != NULL && fWheel->Extract() == B_OK && fWheel->Valid())
-		info.wheel_ydelta = -fWheel->Data();
+		info->wheel_ydelta = -fWheel->Data();
 
 	for (uint32 i = 0; i < B_MAX_MOUSE_BUTTONS; i++) {
 		HIDReportItem *button = fButtons[i];
@@ -176,14 +181,14 @@ MouseProtocolHandler::_ReadReport()
 			break;
 
 		if (button->Extract() == B_OK && button->Valid())
-			info.buttons |= (button->Data() & 1) << (button->UsageID() - 1);
+			info->buttons |= (button->Data() & 1) << (button->UsageID() - 1);
 	}
 
 	fReport.DoneProcessing();
 	TRACE("got mouse report\n");
 
 	bigtime_t timestamp = system_time();
-	if (info.buttons != 0) {
+	if (info->buttons != 0) {
 		if (fLastButtons == 0) {
 			if (fLastClickTime + fClickSpeed > timestamp)
 				fClickCount++;
@@ -192,10 +197,10 @@ MouseProtocolHandler::_ReadReport()
 		}
 
 		fLastClickTime = timestamp;
-		info.clicks = fClickCount;
+		info->clicks = fClickCount;
 	}
 
-	fLastButtons = info.buttons;
+	fLastButtons = info->buttons;
-	info.timestamp = timestamp;
+	info->timestamp = timestamp;
-	return RingBufferWrite(&info, sizeof(mouse_movement));
+	return B_OK;
 }

src/add-ons/kernel/drivers/input/usb_hid/MouseProtocolHandler.h

@@ -33,9 +33,8 @@ public:
 									size_t length);
 
 private:
-			status_t			_ReadReport();
+			status_t			_ReadReport(void *buffer);
 
-private:
 			HIDReport &			fReport;
 
 			HIDReportItem &		fXAxis;