Add ACameraMetadata_fromCameraMetadata.

Test: atest android.hardware.camera2.cts.CameraManagerTest#testCameraCharacteristicsNdkFromSdk android.hardware.camera2.cts.CaptureResultTest#testCameraCaptureResultAllKeys
Bug: 80513080

Change-Id: If3ec6e9531829f2eaec788df237ff69083a6c580
diff --git a/camera/ndk/Android.bp b/camera/ndk/Android.bp
index d8220eb..56f209c 100644
--- a/camera/ndk/Android.bp
+++ b/camera/ndk/Android.bp
@@ -57,6 +57,9 @@
         "libmediandk",
         "libnativewindow",
     ],
+    header_libs: [
+        "jni_headers",
+    ],
     cflags: [
         "-fvisibility=hidden",
         "-DEXPORT=__attribute__ ((visibility (\"default\")))",
@@ -121,7 +124,6 @@
         "android.frameworks.cameraservice.common@2.0",
         "android.frameworks.cameraservice.service@2.0",
     ],
-
     static_libs: [
         "android.hardware.camera.common@1.0-helper",
         "libarect",
diff --git a/camera/ndk/NdkCameraMetadata.cpp b/camera/ndk/NdkCameraMetadata.cpp
index 9a39ed8..99691ed 100644
--- a/camera/ndk/NdkCameraMetadata.cpp
+++ b/camera/ndk/NdkCameraMetadata.cpp
@@ -26,6 +26,68 @@
 
 using namespace android;
 
+#ifndef __ANDROID_VNDK__
+namespace {
+
+constexpr const char* android_hardware_camera2_CameraMetadata_jniClassName =
+    "android/hardware/camera2/CameraMetadata";
+constexpr const char* android_hardware_camera2_CameraCharacteristics_jniClassName =
+    "android/hardware/camera2/CameraCharacteristics";
+constexpr const char* android_hardware_camera2_CaptureResult_jniClassName =
+    "android/hardware/camera2/CaptureResult";
+
+jclass android_hardware_camera2_CameraCharacteristics_clazz = nullptr;
+jclass android_hardware_camera2_CaptureResult_clazz = nullptr;
+jmethodID android_hardware_camera2_CameraMetadata_getNativeMetadataPtr = nullptr;
+
+// Called at most once to initializes global variables used by JNI.
+bool InitJni(JNIEnv* env) {
+    // From C++11 onward, static initializers are guaranteed to be executed at most once,
+    // even if called from multiple threads.
+    static bool ok = [env]() -> bool {
+        const jclass cameraMetadataClazz = env->FindClass(
+            android_hardware_camera2_CameraMetadata_jniClassName);
+        if (cameraMetadataClazz == nullptr) {
+            return false;
+        }
+        android_hardware_camera2_CameraMetadata_getNativeMetadataPtr =
+            env->GetMethodID(cameraMetadataClazz, "getNativeMetadataPtr", "()J");
+        if (android_hardware_camera2_CameraMetadata_getNativeMetadataPtr == nullptr) {
+            return false;
+        }
+
+        android_hardware_camera2_CameraCharacteristics_clazz = env->FindClass(
+            android_hardware_camera2_CameraCharacteristics_jniClassName);
+        if (android_hardware_camera2_CameraCharacteristics_clazz == nullptr) {
+            return false;
+        }
+
+        android_hardware_camera2_CaptureResult_clazz = env->FindClass(
+            android_hardware_camera2_CaptureResult_jniClassName);
+        if (android_hardware_camera2_CaptureResult_clazz == nullptr) {
+            return false;
+        }
+
+        return true;
+    }();
+    return ok;
+}
+
+// Given cameraMetadata, an instance of android.hardware.camera2.CameraMetadata, invokes
+// cameraMetadata.getNativeMetadataPtr() and returns it as a CameraMetadata*.
+CameraMetadata* CameraMetadata_getNativeMetadataPtr(JNIEnv* env, jobject cameraMetadata) {
+    if (cameraMetadata == nullptr) {
+        ALOGE("%s: Invalid Java CameraMetadata object.", __FUNCTION__);
+        return nullptr;
+    }
+    jlong ret = env->CallLongMethod(cameraMetadata,
+                                    android_hardware_camera2_CameraMetadata_getNativeMetadataPtr);
+    return reinterpret_cast<CameraMetadata *>(ret);
+}
+
+}  // namespace
+#endif  /* __ANDROID_VNDK__ */
+
 EXPORT
 camera_status_t ACameraMetadata_getConstEntry(
         const ACameraMetadata* acm, uint32_t tag, ACameraMetadata_const_entry* entry) {
@@ -58,7 +120,7 @@
         return nullptr;
     }
     ACameraMetadata* copy = new ACameraMetadata(*src);
-    copy->incStrong((void*) ACameraMetadata_copy);
+    copy->incStrong(/*id=*/(void*) ACameraMetadata_copy);
     return copy;
 }
 
@@ -86,3 +148,34 @@
 
     return staticMetadata->isLogicalMultiCamera(numPhysicalCameras, physicalCameraIds);
 }
+
+#ifndef __ANDROID_VNDK__
+EXPORT
+ACameraMetadata* ACameraMetadata_fromCameraMetadata(JNIEnv* env, jobject cameraMetadata) {
+    ATRACE_CALL();
+
+    const bool ok = InitJni(env);
+    LOG_ALWAYS_FATAL_IF(!ok, "Failed to find CameraMetadata Java classes.");
+
+    if (cameraMetadata == nullptr) {
+        return nullptr;
+    }
+
+    ACameraMetadata::ACAMERA_METADATA_TYPE type;
+    if (env->IsInstanceOf(cameraMetadata,
+        android_hardware_camera2_CameraCharacteristics_clazz)) {
+        type = ACameraMetadata::ACM_CHARACTERISTICS;
+    } else if (env->IsInstanceOf(cameraMetadata,
+        android_hardware_camera2_CaptureResult_clazz)) {
+        type = ACameraMetadata::ACM_RESULT;
+    } else {
+        return nullptr;
+    }
+
+    CameraMetadata* src = CameraMetadata_getNativeMetadataPtr(env,
+                                                              cameraMetadata);
+    ACameraMetadata* output = new ACameraMetadata(src, type);
+    output->incStrong(/*id=*/(void*) ACameraMetadata_fromCameraMetadata);
+    return output;
+}
+#endif  /* __ANDROID_VNDK__ */
\ No newline at end of file
diff --git a/camera/ndk/impl/ACameraMetadata.cpp b/camera/ndk/impl/ACameraMetadata.cpp
index e15e1a0..0ff78ab 100644
--- a/camera/ndk/impl/ACameraMetadata.cpp
+++ b/camera/ndk/impl/ACameraMetadata.cpp
@@ -28,7 +28,37 @@
  * ACameraMetadata Implementation
  */
 ACameraMetadata::ACameraMetadata(camera_metadata_t* buffer, ACAMERA_METADATA_TYPE type) :
-        mData(buffer), mType(type) {
+        mData(new CameraMetadata(buffer)),
+        mOwnsData(true),
+        mType(type) {
+    init();
+}
+
+ACameraMetadata::ACameraMetadata(CameraMetadata* cameraMetadata, ACAMERA_METADATA_TYPE type) :
+        mData(cameraMetadata),
+        mOwnsData(false),
+        mType(type) {
+    init();
+}
+
+ACameraMetadata::ACameraMetadata(const ACameraMetadata& other) :
+        mOwnsData(other.mOwnsData),
+        mType(other.mType) {
+    if (other.mOwnsData) {
+        mData = new CameraMetadata(*(other.mData));
+    } else {
+        mData = other.mData;
+    }
+}
+
+ACameraMetadata::~ACameraMetadata() {
+    if (mOwnsData) {
+        delete mData;
+    }
+}
+
+void
+ACameraMetadata::init() {
     if (mType == ACM_CHARACTERISTICS) {
         filterUnsupportedFeatures();
         filterStreamConfigurations();
@@ -61,7 +91,7 @@
 void
 ACameraMetadata::filterUnsupportedFeatures() {
     // Hide unsupported capabilities (reprocessing)
-    camera_metadata_entry entry = mData.find(ANDROID_REQUEST_AVAILABLE_CAPABILITIES);
+    camera_metadata_entry entry = mData->find(ANDROID_REQUEST_AVAILABLE_CAPABILITIES);
     if (entry.count == 0 || entry.type != TYPE_BYTE) {
         ALOGE("%s: malformed available capability key! count %zu, type %d",
                 __FUNCTION__, entry.count, entry.type);
@@ -80,7 +110,7 @@
             }
         }
     }
-    mData.update(ANDROID_REQUEST_AVAILABLE_CAPABILITIES, capabilities);
+    mData->update(ANDROID_REQUEST_AVAILABLE_CAPABILITIES, capabilities);
 }
 
 void
@@ -118,7 +148,7 @@
     const int STREAM_WIDTH_OFFSET = 1;
     const int STREAM_HEIGHT_OFFSET = 2;
     const int STREAM_DURATION_OFFSET = 3;
-    camera_metadata_entry entry = mData.find(tag);
+    camera_metadata_entry entry = mData->find(tag);
     if (entry.count == 0 || entry.count % 4 || entry.type != TYPE_INT64) {
         ALOGE("%s: malformed duration key %d! count %zu, type %d",
                 __FUNCTION__, tag, entry.count, entry.type);
@@ -194,7 +224,7 @@
         }
     }
 
-    mData.update(tag, filteredDurations);
+    mData->update(tag, filteredDurations);
 }
 
 void
@@ -204,7 +234,7 @@
     const int STREAM_WIDTH_OFFSET = 1;
     const int STREAM_HEIGHT_OFFSET = 2;
     const int STREAM_IS_INPUT_OFFSET = 3;
-    camera_metadata_entry entry = mData.find(ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS);
+    camera_metadata_entry entry = mData->find(ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS);
     if (entry.count > 0 && (entry.count % 4 || entry.type != TYPE_INT32)) {
         ALOGE("%s: malformed available stream configuration key! count %zu, type %d",
                 __FUNCTION__, entry.count, entry.type);
@@ -234,10 +264,10 @@
     }
 
     if (filteredStreamConfigs.size() > 0) {
-        mData.update(ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS, filteredStreamConfigs);
+        mData->update(ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS, filteredStreamConfigs);
     }
 
-    entry = mData.find(ANDROID_DEPTH_AVAILABLE_DEPTH_STREAM_CONFIGURATIONS);
+    entry = mData->find(ANDROID_DEPTH_AVAILABLE_DEPTH_STREAM_CONFIGURATIONS);
     if (entry.count > 0 && (entry.count % 4 || entry.type != TYPE_INT32)) {
         ALOGE("%s: malformed available depth stream configuration key! count %zu, type %d",
                 __FUNCTION__, entry.count, entry.type);
@@ -270,11 +300,11 @@
     }
 
     if (filteredDepthStreamConfigs.size() > 0) {
-        mData.update(ANDROID_DEPTH_AVAILABLE_DEPTH_STREAM_CONFIGURATIONS,
+        mData->update(ANDROID_DEPTH_AVAILABLE_DEPTH_STREAM_CONFIGURATIONS,
                 filteredDepthStreamConfigs);
     }
 
-    entry = mData.find(ANDROID_HEIC_AVAILABLE_HEIC_STREAM_CONFIGURATIONS);
+    entry = mData->find(ANDROID_HEIC_AVAILABLE_HEIC_STREAM_CONFIGURATIONS);
     Vector<int32_t> filteredHeicStreamConfigs;
     filteredHeicStreamConfigs.setCapacity(entry.count);
 
@@ -297,9 +327,9 @@
         filteredHeicStreamConfigs.push_back(height);
         filteredHeicStreamConfigs.push_back(isInput);
     }
-    mData.update(ANDROID_HEIC_AVAILABLE_HEIC_STREAM_CONFIGURATIONS, filteredHeicStreamConfigs);
+    mData->update(ANDROID_HEIC_AVAILABLE_HEIC_STREAM_CONFIGURATIONS, filteredHeicStreamConfigs);
 
-    entry = mData.find(ANDROID_DEPTH_AVAILABLE_DYNAMIC_DEPTH_STREAM_CONFIGURATIONS);
+    entry = mData->find(ANDROID_DEPTH_AVAILABLE_DYNAMIC_DEPTH_STREAM_CONFIGURATIONS);
     Vector<int32_t> filteredDynamicDepthStreamConfigs;
     filteredDynamicDepthStreamConfigs.setCapacity(entry.count);
 
@@ -322,7 +352,7 @@
         filteredDynamicDepthStreamConfigs.push_back(height);
         filteredDynamicDepthStreamConfigs.push_back(isInput);
     }
-    mData.update(ACAMERA_DEPTH_AVAILABLE_DYNAMIC_DEPTH_STREAM_CONFIGURATIONS,
+    mData->update(ACAMERA_DEPTH_AVAILABLE_DYNAMIC_DEPTH_STREAM_CONFIGURATIONS,
             filteredDynamicDepthStreamConfigs);
 }
 
@@ -343,7 +373,7 @@
 
     Mutex::Autolock _l(mLock);
 
-    camera_metadata_ro_entry rawEntry = mData.find(tag);
+    camera_metadata_ro_entry rawEntry = static_cast<const CameraMetadata*>(mData)->find(tag);
     if (rawEntry.count == 0) {
         ALOGE("%s: cannot find metadata tag %d", __FUNCTION__, tag);
         return ACAMERA_ERROR_METADATA_NOT_FOUND;
@@ -390,9 +420,9 @@
                          /*out*/const uint32_t** tags) const {
     Mutex::Autolock _l(mLock);
     if (mTags.size() == 0) {
-        size_t entry_count = mData.entryCount();
+        size_t entry_count = mData->entryCount();
         mTags.setCapacity(entry_count);
-        const camera_metadata_t* rawMetadata = mData.getAndLock();
+        const camera_metadata_t* rawMetadata = mData->getAndLock();
         for (size_t i = 0; i < entry_count; i++) {
             camera_metadata_ro_entry_t entry;
             int ret = get_camera_metadata_ro_entry(rawMetadata, i, &entry);
@@ -405,7 +435,7 @@
                 mTags.push_back(entry.tag);
             }
         }
-        mData.unlock(rawMetadata);
+        mData->unlock(rawMetadata);
     }
 
     *numTags = mTags.size();
@@ -415,7 +445,7 @@
 
 const CameraMetadata&
 ACameraMetadata::getInternalData() const {
-    return mData;
+    return (*mData);
 }
 
 bool
diff --git a/camera/ndk/impl/ACameraMetadata.h b/camera/ndk/impl/ACameraMetadata.h
index 97f7f48..a57b2ff 100644
--- a/camera/ndk/impl/ACameraMetadata.h
+++ b/camera/ndk/impl/ACameraMetadata.h
@@ -36,8 +36,8 @@
 using namespace android;
 
 /**
- * ACameraMetadata opaque struct definition
- * Leave outside of android namespace because it's NDK struct
+ * ACameraMetadata is an opaque struct definition.
+ * It is intentionally left outside of the android namespace because it's NDK struct.
  */
 struct ACameraMetadata : public RefBase {
   public:
@@ -47,11 +47,20 @@
         ACM_RESULT,          // Read only
     } ACAMERA_METADATA_TYPE;
 
-    // Takes ownership of pass-in buffer
-    ACameraMetadata(camera_metadata_t *buffer, ACAMERA_METADATA_TYPE type);
-    // Clone
-    ACameraMetadata(const ACameraMetadata& other) :
-            mData(other.mData), mType(other.mType) {};
+    // Constructs a ACameraMetadata that takes ownership of `buffer`.
+    ACameraMetadata(camera_metadata_t* buffer, ACAMERA_METADATA_TYPE type);
+
+    // Constructs a ACameraMetadata that is a view of `cameraMetadata`.
+    // `cameraMetadata` will not be deleted by ~ACameraMetadata().
+    ACameraMetadata(CameraMetadata* cameraMetadata, ACAMERA_METADATA_TYPE type);
+
+    // Copy constructor.
+    //
+    // If `other` owns its CameraMetadata, then makes a deep copy.
+    // Otherwise, the new instance is also a view of the same data.
+    ACameraMetadata(const ACameraMetadata& other);
+
+    ~ACameraMetadata();
 
     camera_status_t getConstEntry(uint32_t tag, ACameraMetadata_const_entry* entry) const;
 
@@ -70,6 +79,9 @@
 
   private:
 
+    // Common code called by constructors.
+    void init();
+
     // This function does not check whether the capability passed to it is valid.
     // The caller must make sure that it is.
     bool isNdkSupportedCapability(const int32_t capability);
@@ -95,11 +107,11 @@
 
         status_t ret = OK;
         if (count == 0 && data == nullptr) {
-            ret = mData.erase(tag);
+            ret = mData->erase(tag);
         } else {
             // Here we have to use reinterpret_cast because the NDK data type is
             // exact copy of internal data type but they do not inherit from each other
-            ret = mData.update(tag, reinterpret_cast<const INTERNAL_T*>(data), count);
+            ret = mData->update(tag, reinterpret_cast<const INTERNAL_T*>(data), count);
         }
 
         if (ret == OK) {
@@ -110,10 +122,14 @@
         }
     }
 
-    // guard access of public APIs: get/update/getTags
-    mutable Mutex    mLock;
-    CameraMetadata   mData;
-    mutable Vector<uint32_t> mTags; // updated in getTags, cleared by update
+    // Guard access of public APIs: get/update/getTags.
+    mutable Mutex mLock;
+
+    CameraMetadata* mData;
+    // If true, has ownership of mData. Otherwise, mData is a view of an external instance.
+    bool mOwnsData;
+
+    mutable Vector<uint32_t> mTags; // Updated by `getTags()`, cleared by `update()`.
     const ACAMERA_METADATA_TYPE mType;
 
     static std::unordered_set<uint32_t> sSystemTags;
diff --git a/camera/ndk/include/camera/NdkCameraMetadata.h b/camera/ndk/include/camera/NdkCameraMetadata.h
index 9bbfb83..ee75610 100644
--- a/camera/ndk/include/camera/NdkCameraMetadata.h
+++ b/camera/ndk/include/camera/NdkCameraMetadata.h
@@ -39,6 +39,12 @@
 #include <stdint.h>
 #include <sys/cdefs.h>
 
+#ifndef __ANDROID_VNDK__
+#if __ANDROID_API__ >= 30
+#include "jni.h"
+#endif  /* __ANDROID_API__ >= 30 */
+#endif  /* __ANDROID_VNDK__ */
+
 #include "NdkCameraError.h"
 #include "NdkCameraMetadataTags.h"
 
@@ -255,8 +261,40 @@
 
 #endif /* __ANDROID_API__ >= 29 */
 
+#ifndef __ANDROID_VNDK__
+#if __ANDROID_API__ >= 30
+
+/**
+ * Return a {@link ACameraMetadata} that references the same data as
+ * {@link cameraMetadata}, which is an instance of
+ * {@link android.hardware.camera2.CameraMetadata} (e.g., a
+ * {@link android.hardware.camera2.CameraCharacteristics} or
+ * {@link android.hardware.camera2.CaptureResult}).
+ *
+ * <p>The returned ACameraMetadata must be freed by the application by {@link ACameraMetadata_free}
+ * after application is done using it.</p>
+ *
+ * <p>This function does not affect the lifetime of {@link cameraMetadata}. Attempting to use the
+ * returned ACameraMetadata object after {@link cameraMetadata} has been garbage collected is
+ * unsafe. To manage the lifetime beyond the current JNI function call, use
+ * {@code env->NewGlobalRef()} and {@code env->DeleteGlobalRef()}.
+ *
+ * @param env the JNI environment.
+ * @param cameraMetadata the source {@link android.hardware.camera2.CameraMetadata} from which the
+ *                       returned {@link ACameraMetadata} is a view.
+ *
+ * @return a valid ACameraMetadata pointer or NULL if {@link cameraMetadata} is null or not a valid
+ *         instance of {@link android.hardware.camera2.CameraMetadata}.
+ *
+ */
+ACameraMetadata* ACameraMetadata_fromCameraMetadata(JNIEnv* env, jobject cameraMetadata)
+        __INTRODUCED_IN(30);
+
+#endif /* __ANDROID_API__ >= 30 */
+#endif  /* __ANDROID_VNDK__ */
+
 __END_DECLS
 
 #endif /* _NDK_CAMERA_METADATA_H */
 
-/** @} */
+/** @} */
\ No newline at end of file
diff --git a/camera/ndk/libcamera2ndk.map.txt b/camera/ndk/libcamera2ndk.map.txt
index b6f1553..2b630db 100644
--- a/camera/ndk/libcamera2ndk.map.txt
+++ b/camera/ndk/libcamera2ndk.map.txt
@@ -31,6 +31,7 @@
     ACameraMetadata_getAllTags;
     ACameraMetadata_getConstEntry;
     ACameraMetadata_isLogicalMultiCamera; # introduced=29
+    ACameraMetadata_fromCameraMetadata; # introduced=30
     ACameraOutputTarget_create;
     ACameraOutputTarget_free;
     ACaptureRequest_addTarget;