libcamera: control_serializer: Add support for array controls

Add support for serializing and deserializing control values that store
arrays of values. The serialized format is extended to explicitly handle
arrays.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

2 files changed, 49 insertions, 37 deletions

diff --git a/src/libcamera/control_serializer.cpp b/src/libcamera/control_serializer.cpp
index b4c1ed41..004735fb 100644
--- a/src/libcamera/control_serializer.cpp
+++ b/src/libcamera/control_serializer.cpp
@@ -14,6 +14,7 @@
 #include <ipa/ipa_controls.h>
 #include <libcamera/control_ids.h>
 #include <libcamera/controls.h>
+#include <libcamera/span.h>
 
 #include "byte_stream_buffer.h"
 #include "log.h"
@@ -279,8 +280,9 @@ int ControlSerializer::serialize(const ControlList &list,
 
 		struct ipa_control_value_entry entry;
 		entry.id = id;
-		entry.count = 1;
 		entry.type = value.type();
+		entry.is_array = value.isArray();
+		entry.count = value.numElements();
 		entry.offset = values.offset();
 		entries.write(&entry);
 
@@ -293,40 +295,45 @@ int ControlSerializer::serialize(const ControlList &list,
 	return 0;
 }
 
-template<>
-ControlValue ControlSerializer::load<ControlValue>(ControlType type,
-						   ByteStreamBuffer &b)
+template<typename T>
+ControlValue ControlSerializer::loadControlValue(ByteStreamBuffer &buffer,
+						 bool isArray,
+						 unsigned int count)
+{
+	ControlValue value;
+
+	const T *data = buffer.read<T>(count);
+	if (!data)
+		return value;
+
+	if (isArray)
+		value.set(Span<const T>{ data, count });
+	else
+		value.set(*data);
+
+	return value;
+}
+
+ControlValue ControlSerializer::loadControlValue(ControlType type,
+						 ByteStreamBuffer &buffer,
+						 bool isArray,
+						 unsigned int count)
 {
 	switch (type) {
-	case ControlTypeBool: {
-		bool value;
-		b.read(&value);
-		return ControlValue(value);
-	}
+	case ControlTypeBool:
+		return loadControlValue<bool>(buffer, isArray, count);
 
-	case ControlTypeByte: {
-		uint8_t value;
-		b.read(&value);
-		return ControlValue(value);
-	}
+	case ControlTypeByte:
+		return loadControlValue<uint8_t>(buffer, isArray, count);
 
-	case ControlTypeInteger32: {
-		int32_t value;
-		b.read(&value);
-		return ControlValue(value);
-	}
+	case ControlTypeInteger32:
+		return loadControlValue<int32_t>(buffer, isArray, count);
 
-	case ControlTypeInteger64: {
-		int64_t value;
-		b.read(&value);
-		return ControlValue(value);
-	}
+	case ControlTypeInteger64:
+		return loadControlValue<int64_t>(buffer, isArray, count);
 
-	case ControlTypeFloat: {
-		float value;
-		b.read(&value);
-		return ControlValue(value);
-	}
+	case ControlTypeFloat:
+		return loadControlValue<float>(buffer, isArray, count);
 
 	case ControlTypeNone:
 		return ControlValue();
@@ -335,12 +342,11 @@ ControlValue ControlSerializer::load<ControlValue>(ControlType type,
 	return ControlValue();
 }
 
-template<>
-ControlRange ControlSerializer::load<ControlRange>(ControlType type,
-						   ByteStreamBuffer &b)
+ControlRange ControlSerializer::loadControlRange(ControlType type,
+						 ByteStreamBuffer &b)
 {
-	ControlValue min = load<ControlValue>(type, b);
-	ControlValue max = load<ControlValue>(type, b);
+	ControlValue min = loadControlValue(type, b);
+	ControlValue max = loadControlValue(type, b);
 
 	return ControlRange(min, max);
 }
@@ -414,7 +420,7 @@ ControlInfoMap ControlSerializer::deserialize<ControlInfoMap>(ByteStreamBuffer &
 
 		/* Create and store the ControlRange. */
 		ctrls.emplace(controlIds_.back().get(),
-			      load<ControlRange>(type, values));
+			      loadControlRange(type, values));
 	}
 
 	/*
@@ -502,7 +508,9 @@ ControlList ControlSerializer::deserialize<ControlList>(ByteStreamBuffer &buffer
 		}
 
 		ControlType type = static_cast<ControlType>(entry->type);
-		ctrls.set(entry->id, load<ControlValue>(type, values));
+		ctrls.set(entry->id,
+			  loadControlValue(type, values, entry->is_array,
+					   entry->count));
 	}
 
 	return ctrls;
diff --git a/src/libcamera/include/control_serializer.h b/src/libcamera/include/control_serializer.h
index 55259913..b91d1315 100644
--- a/src/libcamera/include/control_serializer.h
+++ b/src/libcamera/include/control_serializer.h
@@ -41,7 +41,11 @@ private:
 	static void store(const ControlRange &range, ByteStreamBuffer &buffer);
 
 	template<typename T>
-	T load(ControlType type, ByteStreamBuffer &b);
+	ControlValue loadControlValue(ByteStreamBuffer &buffer, bool isArray,
+				      unsigned int count);
+	ControlValue loadControlValue(ControlType type, ByteStreamBuffer &buffer,
+				      bool isArray = false, unsigned int count = 1);
+	ControlRange loadControlRange(ControlType type, ByteStreamBuffer &buffer);
 
 	unsigned int serial_;
 	std::vector<std::unique_ptr<ControlId>> controlIds_;