[libcamera-devel] [PATCH] android: camera_metadata: Add functions for instrumenting resizing

[Paul Elder]

Add utility functions to CameraMetadata to check if it has been resized,
and for outputting the actual entry and data count. This is meant to be
used to output information on resizing, to assist developers in
choosing proper initial sizes to avoid resizing. Also make CameraDevice
use these functions for static and result metadata.

Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
---
 src/android/camera_device.cpp   | 16 ++++++++++++++++
 src/android/camera_metadata.cpp | 14 +++++++++++++-
 src/android/camera_metadata.h   |  4 ++++
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
index b32e8be5..15f81b04 100644
--- a/src/android/camera_device.cpp
+++ b/src/android/camera_device.cpp
@@ -1391,6 +1391,14 @@ const camera_metadata_t *CameraDevice::getStaticMetadata()
 		return nullptr;
 	}
 
+	if (staticMetadata_->resized()) {
+		size_t entryCount, dataCount;
+		std::tie(entryCount, dataCount) = staticMetadata_->usage();
+		LOG(HAL, Info)
+			<< "Static metadata resized: " << entryCount
+			<< " entries and " << dataCount << " bytes used";
+	}
+
 	return staticMetadata_->get();
 }
 
@@ -2269,5 +2277,13 @@ CameraDevice::getResultMetadata(const Camera3RequestDescriptor &descriptor) cons
 		LOG(HAL, Error) << "Failed to construct result metadata";
 	}
 
+	if (resultMetadata->resized()) {
+		size_t entryCount, dataCount;
+		std::tie(entryCount, dataCount) = resultMetadata->usage();
+		LOG(HAL, Info)
+			<< "Result metadata resized: " << entryCount
+			<< " entries and " << dataCount << " bytes used";
+	}
+
 	return resultMetadata;
 }
diff --git a/src/android/camera_metadata.cpp b/src/android/camera_metadata.cpp
index bf8d2781..0588ea4e 100644
--- a/src/android/camera_metadata.cpp
+++ b/src/android/camera_metadata.cpp
@@ -14,17 +14,19 @@ using namespace libcamera;
 LOG_DEFINE_CATEGORY(CameraMetadata)
 
 CameraMetadata::CameraMetadata()
-	: metadata_(nullptr), valid_(false)
+	: metadata_(nullptr), valid_(false), resized_(false)
 {
 }
 
 CameraMetadata::CameraMetadata(size_t entryCapacity, size_t dataCapacity)
+	: resized_(false)
 {
 	metadata_ = allocate_camera_metadata(entryCapacity, dataCapacity);
 	valid_ = metadata_ != nullptr;
 }
 
 CameraMetadata::CameraMetadata(const camera_metadata_t *metadata)
+	: resized_(false)
 {
 	metadata_ = clone_camera_metadata(metadata);
 	valid_ = metadata_ != nullptr;
@@ -55,6 +57,14 @@ CameraMetadata &CameraMetadata::operator=(const CameraMetadata &other)
 	return *this;
 }
 
+std::tuple<size_t, size_t> CameraMetadata::usage() const
+{
+	size_t currentEntryCount = get_camera_metadata_entry_count(metadata_);
+	size_t currentDataCount = get_camera_metadata_data_count(metadata_);
+
+	return { currentEntryCount, currentDataCount };
+}
+
 bool CameraMetadata::getEntry(uint32_t tag, camera_metadata_ro_entry_t *entry) const
 {
 	if (find_camera_metadata_ro_entry(metadata_, tag, entry))
@@ -104,6 +114,8 @@ bool CameraMetadata::resize(size_t count, size_t size)
 
 		append_camera_metadata(metadata_, oldMetadata);
 		free_camera_metadata(oldMetadata);
+
+		resized_ = true;
 	}
 
 	return true;
diff --git a/src/android/camera_metadata.h b/src/android/camera_metadata.h
index 07afd4b2..b291fbf9 100644
--- a/src/android/camera_metadata.h
+++ b/src/android/camera_metadata.h
@@ -23,6 +23,9 @@ public:
 
 	CameraMetadata &operator=(const CameraMetadata &other);
 
+	std::tuple<size_t, size_t> usage() const;
+	bool resized() const { return resized_; }
+
 	bool isValid() const { return valid_; }
 	bool resize(size_t count, size_t size);
 	bool getEntry(uint32_t tag, camera_metadata_ro_entry_t *entry) const;
@@ -81,6 +84,7 @@ public:
 private:
 	camera_metadata_t *metadata_;
 	bool valid_;
+	bool resized_;
 };
 
 #endif /* __ANDROID_CAMERA_METADATA_H__ */
-- 
2.27.0