[libcamera-devel] [PATCH] libcamera: V4L2Device: Remove the controls order assumption in updateControls()

[Hirokazu Honda]

The original updateControls() has the assumption that ctrls and
v4l2Ctrls lists are in the same order. It is dependent on the
caller implementation though. This changes updateControls()
implementation so that it works without the assumption.

Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
---
 src/libcamera/v4l2_device.cpp | 26 +++++++-------------------
 1 file changed, 7 insertions(+), 19 deletions(-)

diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
index 397029ac..64501523 100644
--- a/src/libcamera/v4l2_device.cpp
+++ b/src/libcamera/v4l2_device.cpp
@@ -178,12 +178,6 @@ ControlList V4L2Device::getControls(const std::vector<uint32_t> &ids)
 
 	ControlList ctrls{ controls_ };
 
-	/*
-	 * Start by filling the ControlList. This can't be combined with filling
-	 * v4l2Ctrls, as updateControls() relies on both containers having the
-	 * same order, and the control list is based on a map, which is not
-	 * sorted by insertion order.
-	 */
 	for (uint32_t id : ids) {
 		const auto iter = controls_.find(id);
 		if (iter == controls_.end()) {
@@ -520,19 +514,13 @@ void V4L2Device::listControls()
 void V4L2Device::updateControls(ControlList *ctrls,
 				Span<const v4l2_ext_control> v4l2Ctrls)
 {
-	unsigned int i = 0;
-	for (auto &ctrl : *ctrls) {
-		if (i == v4l2Ctrls.size())
-			break;
+	for (const v4l2_ext_control &v4l2Ctrl : v4l2Ctrls) {
+		const unsigned int id = v4l2Ctrl.id;
 
-		const struct v4l2_ext_control *v4l2Ctrl = &v4l2Ctrls[i];
-		unsigned int id = ctrl.first;
-		ControlValue &value = ctrl.second;
-
-		const auto iter = controls_.find(id);
-		switch (iter->first->type()) {
+		ControlValue value = ctrls->get(id);
+		switch (value.type()) {
 		case ControlTypeInteger64:
-			value.set<int64_t>(v4l2Ctrl->value64);
+			value.set<int64_t>(v4l2Ctrl.value64);
 			break;
 
 		case ControlTypeByte:
@@ -547,11 +535,11 @@ void V4L2Device::updateControls(ControlList *ctrls,
 			 * \todo To be changed when support for string controls
 			 * will be added.
 			 */
-			value.set<int32_t>(v4l2Ctrl->value);
+			value.set<int32_t>(v4l2Ctrl.value);
 			break;
 		}
 
-		i++;
+		ctrls->set(id, value);
 	}
 }
 
-- 
2.31.1.498.g6c1eba8ee3d-goog