add conversion check

Signed-off-by: kta-intel <[email protected]>

openfl/federated/task/runner_xgb.py

@@ -15,6 +15,27 @@
 from openfl.utilities.split import split_tensor_dict_for_holdouts
 
 
+def check_precision_loss(logger, converted_data, original_data):
+    """
+    Checks for precision loss during conversion to float32 and back.
+
+    Parameters:
+    logger (Logger): The logger object to log warnings.
+    converted_data (np.ndarray): The data that has been converted to float32.
+    original_data (list): The original data to be checked for precision loss.
+    """
+    # Convert the float32 array back to bytes and decode to JSON
+    reconstructed_bytes = converted_data.astype(np.uint8).tobytes()
+    reconstructed_json = reconstructed_bytes.decode("utf-8")
+    reconstructed_data = json.loads(reconstructed_json)
+
+    assert type(original_data) == type(reconstructed_data), "Reconstructed datatype does not match original."
+
+    # Compare the original and reconstructed data
+    if original_data != reconstructed_data:
+        logger.warn("Precision loss detected during conversion.")
+
+
 class XGBoostTaskRunner(TaskRunner):
     def __init__(self, **kwargs):
         """
@@ -209,6 +230,8 @@ def get_tensor_dict(self, with_opt_vars=False):
             np.float32
         )
 
+        check_precision_loss(self.logger, latest_trees_float32_array, original_data=latest_trees)
+
         return {"local_tree": latest_trees_float32_array}
 
     def get_required_tensorkeys_for_function(self, func_name, **kwargs):

openfl/interface/aggregation_functions/fed_bagging.py

@@ -5,11 +5,11 @@
 """Federated Boostrap Aggregation for XGBoost module."""
 
 import json
-
+from logging import getLogger
 import numpy as np
 
 from openfl.interface.aggregation_functions.core import AggregationFunction
-
+from openfl.federated.task.runner_xgb import check_precision_loss
 
 def get_global_model(iterator, target_round):
     """
@@ -95,7 +95,7 @@ def call(self, local_tensors, db_iterator, tensor_name, fl_round, *_):
         Returns:
             bytearray: aggregated tensor
         """
-
+        logger = getLogger(__name__)
         global_model = get_global_model(db_iterator, fl_round)
 
         if (
@@ -127,4 +127,7 @@ def call(self, local_tensors, db_iterator, tensor_name, fl_round, *_):
         global_model_json = json.dumps(global_model)
         global_model_bytes = global_model_json.encode("utf-8")
 
-        return np.frombuffer(global_model_bytes, dtype=np.uint8).astype(np.float32)
+        global_model_float32_array = np.frombuffer(global_model_bytes, dtype=np.uint8).astype(np.float32)
+        check_precision_loss(logger, global_model_float32_array, global_model)
+
+        return global_model_float32_array