[mob] Sort clustering on fileCreationTime asc

mobile/lib/db/files_db.dart

@@ -1304,6 +1304,23 @@ class FilesDB {
     return result;
   }
 
+  Future<Map<int,int>> getFileIDToCreationTime() async {
+    final db = await instance.database;
+    final rows = await db.rawQuery(
+      '''
+      SELECT $columnUploadedFileID, $columnCreationTime
+      FROM $filesTable
+      WHERE 
+      ($columnUploadedFileID IS NOT NULL AND $columnUploadedFileID IS NOT -1);
+    ''',
+    );
+    final result = <int, int>{};
+    for (final row in rows) {
+      result[row[columnUploadedFileID] as int] = row[columnCreationTime] as int;
+    }
+    return result;
+  }
+
   // getCollectionFileFirstOrLast returns the first or last uploaded file in
   // the collection based on the given collectionID and the order.
   Future<EnteFile?> getCollectionFileFirstOrLast(

mobile/lib/services/machine_learning/face_ml/face_clustering/linear_clustering_service.dart

@@ -94,7 +94,12 @@ class FaceLinearClustering {
         switch (function) {
           case ClusterOperation.linearIncrementalClustering:
             final input = args['input'] as Map<String, (int?, Uint8List)>;
-            final result = FaceLinearClustering._runLinearClustering(input);
+            final fileIDToCreationTime =
+                args['fileIDToCreationTime'] as Map<int, int>?;
+            final result = FaceLinearClustering._runLinearClustering(
+              input,
+              fileIDToCreationTime: fileIDToCreationTime,
+            );
             sendPort.send(result);
             break;
         }
@@ -169,8 +174,9 @@ class FaceLinearClustering {
   ///
   /// WARNING: Make sure to always input data in the same ordering, otherwise the clustering can less less deterministic.
   Future<Map<String, int>?> predict(
-    Map<String, (int?, Uint8List)> input,
-  ) async {
+    Map<String, (int?, Uint8List)> input, {
+    Map<int, int>? fileIDToCreationTime,
+  }) async {
     if (input.isEmpty) {
       _logger.warning(
         "Clustering dataset of embeddings is empty, returning empty list.",
@@ -192,7 +198,10 @@ class FaceLinearClustering {
     // final Map<String, int> faceIdToCluster =
     //     await _runLinearClusteringInComputer(input);
     final Map<String, int> faceIdToCluster = await _runInIsolate(
-      (ClusterOperation.linearIncrementalClustering, {'input': input}),
+      (
+        ClusterOperation.linearIncrementalClustering,
+        {'input': input, 'fileIDToCreationTime': fileIDToCreationTime}
+      ),
     );
     // return _runLinearClusteringInComputer(input);
     _logger.info(
@@ -205,8 +214,9 @@ class FaceLinearClustering {
   }
 
   static Map<String, int> _runLinearClustering(
-    Map<String, (int?, Uint8List)> x,
-  ) {
+    Map<String, (int?, Uint8List)> x, {
+    Map<int, int>? fileIDToCreationTime,
+  }) {
     log(
       "[ClusterIsolate] ${DateTime.now()} Copied to isolate ${x.length} faces",
     );
@@ -217,9 +227,27 @@ class FaceLinearClustering {
           faceID: entry.key,
           embedding: EVector.fromBuffer(entry.value.$2).values,
           clusterId: entry.value.$1,
+          fileCreationTime:
+              fileIDToCreationTime?[getFileIdFromFaceId(entry.key)],
         ),
       );
     }
+
+    // Sort the faceInfos based on fileCreationTime, in ascending order, so oldest faces are first
+    if (fileIDToCreationTime != null) {
+      faceInfos.sort((a, b) {
+        if (a.fileCreationTime == null && b.fileCreationTime == null) {
+          return 0;
+        } else if (a.fileCreationTime == null) {
+          return 1;
+        } else if (b.fileCreationTime == null) {
+          return -1;
+        } else {
+          return a.fileCreationTime!.compareTo(b.fileCreationTime!);
+        }
+      });
+    }
+
     // Sort the faceInfos such that the ones with null clusterId are at the end
     faceInfos.sort((a, b) {
       if (a.clusterId == null && b.clusterId == null) {

mobile/lib/services/machine_learning/face_ml/face_ml_result.dart

@@ -37,7 +37,7 @@ class ClusterResult {
 
   String get thumbnailFaceId => _thumbnailFaceId;
 
-  int get thumbnailFileId => _getFileIdFromFaceId(_thumbnailFaceId);
+  int get thumbnailFileId => getFileIdFromFaceId(_thumbnailFaceId);
 
   /// Sets the thumbnail faceId to the given faceId.
   /// Throws an exception if the faceId is not in the list of faceIds.
@@ -89,7 +89,7 @@ class ClusterResult {
     int removedCount = 0;
     for (var i = 0; i < _fileIds.length; i++) {
       if (_fileIds[i] == fileId) {
-        assert(_getFileIdFromFaceId(_faceIds[i]) == fileId);
+        assert(getFileIdFromFaceId(_faceIds[i]) == fileId);
         _fileIds.removeAt(i);
         _faceIds.removeAt(i);
         debugPrint(
@@ -748,6 +748,6 @@ class FaceResultBuilder {
   }
 }
 
-int _getFileIdFromFaceId(String faceId) {
+int getFileIdFromFaceId(String faceId) {
   return int.parse(faceId.split("_")[0]);
 }

mobile/lib/services/machine_learning/face_ml/face_ml_service.dart

@@ -13,6 +13,7 @@ import "package:logging/logging.dart";
 import "package:onnxruntime/onnxruntime.dart";
 import "package:photos/core/configuration.dart";
 import "package:photos/core/event_bus.dart";
+import "package:photos/db/files_db.dart";
 import "package:photos/db/ml_data_db.dart";
 import "package:photos/events/diff_sync_complete_event.dart";
 import "package:photos/extensions/list.dart";
@@ -375,9 +376,15 @@ class FaceMlService {
       );
       _logger.info('read embeddings ${faceIdToEmbedding.length} ');
 
+      // Read the creation times from Files DB, in a map from fileID to creation time
+      final fileIDToCreationTime =
+          await FilesDB.instance.getFileIDToCreationTime();
+
       // Cluster the embeddings using the linear clustering algorithm, returning a map from faceID to clusterID
-      final faceIdToCluster =
-          await FaceLinearClustering.instance.predict(faceIdToEmbedding);
+      final faceIdToCluster = await FaceLinearClustering.instance.predict(
+        faceIdToEmbedding,
+        fileIDToCreationTime: fileIDToCreationTime,
+      );
       if (faceIdToCluster == null) {
         _logger.warning("faceIdToCluster is null");
         return;