SNOW-270946 Progress percentage computation to handle the case when file size is zero (#628)

Author: sfc-gh-cshi

src/snowflake/connector/file_transfer_agent.py

@@ -171,7 +171,12 @@ def _update_progress(
     return progress == 1.0
 
 
-class SnowflakeProgressPercentage:
+def percent(seen_so_far: int, size: float) -> float:
+    return 1.0 if seen_so_far >= size or size <= 0\
+                else float(seen_so_far / size)
+
+
+class SnowflakeProgressPercentage():
     """Built-in Progress bar for PUT commands."""
 
     def __init__(
@@ -208,7 +213,7 @@ def __call__(self, bytes_amount: int):
         with self._lock:
             if self._output_stream:
                 self._seen_so_far += bytes_amount
-                percentage = float(self._seen_so_far / self._size)
+                percentage = percent(self._seen_so_far, self._size)
                 if not self._done:
                     self._done = _update_progress(
                         self._filename, self._start_time,
@@ -234,7 +239,7 @@ def __call__(self, current: int):
         with self._lock:
             if self._output_stream:
                 self._seen_so_far = current
-                percentage = float(self._seen_so_far / self._size)
+                percentage = percent(self._seen_so_far, self._size)
                 if not self._done:
                     self._done = _update_progress(
                         self._filename, self._start_time,

test/unit/test_put_get.py

@@ -11,7 +11,12 @@
 
 from snowflake.connector.compat import IS_WINDOWS
 from snowflake.connector.errors import Error
-from snowflake.connector.file_transfer_agent import SnowflakeFileTransferAgent
+from snowflake.connector.file_transfer_agent import (
+    SnowflakeAzureProgressPercentage,
+    SnowflakeFileTransferAgent,
+    SnowflakeS3ProgressPercentage,
+    percent,
+)
 
 
 @pytest.mark.skipif(IS_WINDOWS, reason='permission model is different')
@@ -74,3 +79,18 @@ def test_put_error(tmpdir):
         sf_file_transfer_agent.result()
 
     chmod(file1, 0o700)
+
+
+def test_percentage(tmp_path):
+    """Tests for ProgressPercentage classes."""
+    assert 1.0 == percent(0, 0)
+    assert 1.0 == percent(20, 0)
+    assert 1.0 == percent(40, 20)
+    assert 0.5 == percent(14, 28)
+
+    file_path = tmp_path / 'zero_file1'
+    file_path.touch()
+    func_callback = SnowflakeS3ProgressPercentage(str(file_path), 0)
+    func_callback(1)
+    func_callback = SnowflakeAzureProgressPercentage(str(file_path), 0)
+    func_callback(1)