Merge pull request #191 from pycompression/makesurestreamsarenotclosed

igzip_threaded.open no longer closes streams that are passed to it

Author: rhpvorderman

CHANGELOG.rst

@@ -7,6 +7,10 @@ Changelog
 .. This document is user facing. Please word the changes in such a way
 .. that users understand how the changes affect the new version.
 
+version 1.6.1
+-----------------
++ Fix a bug where streams that were passed to igzip_threaded.open where closed.
+
 version 1.6.0
 -----------------
 + Fix a bug where compression levels for IGzipFile where checked in read mode.

src/isal/igzip_threaded.py

@@ -78,16 +78,18 @@ def open(filename, mode="rb", compresslevel=igzip._COMPRESS_LEVEL_TRADEOFF,
 def open_as_binary_stream(filename, open_mode):
     if isinstance(filename, (str, bytes)) or hasattr(filename, "__fspath__"):
         binary_file = builtins.open(filename, open_mode)
+        closefd = True
     elif hasattr(filename, "read") or hasattr(filename, "write"):
         binary_file = filename
+        closefd = False
     else:
         raise TypeError("filename must be a str or bytes object, or a file")
-    return binary_file
+    return binary_file, closefd
 
 
 class _ThreadedGzipReader(io.RawIOBase):
     def __init__(self, filename, queue_size=2, block_size=1024 * 1024):
-        self.raw = open_as_binary_stream(filename, "rb")
+        self.raw, self.closefd = open_as_binary_stream(filename, "rb")
         self.fileobj = igzip._IGzipReader(self.raw, buffersize=8 * block_size)
         self.pos = 0
         self.read_file = False
@@ -155,7 +157,8 @@ def close(self) -> None:
         self.running = False
         self.worker.join()
         self.fileobj.close()
-        self.raw.close()
+        if self.closefd:
+            self.raw.close()
         self._closed = True
 
     @property
@@ -246,7 +249,7 @@ def __init__(self,
         self._crc = 0
         self.running = False
         self._size = 0
-        self.raw = open_as_binary_stream(filename, mode)
+        self.raw, self.closefd = open_as_binary_stream(filename, mode)
         self._closed = False
         self._write_gzip_header()
         self.start()
@@ -329,7 +332,8 @@ def close(self) -> None:
         trailer = struct.pack("<II", self._crc, self._size & 0xFFFFFFFF)
         self.raw.write(trailer)
         self.raw.flush()
-        self.raw.close()
+        if self.closefd:
+            self.raw.close()
         self._closed = True
 
     @property

tests/test_igzip_threaded.py

@@ -199,3 +199,22 @@ def test_igzip_threaded_open_compresslevel_and_reading(tmp_path):
     with igzip_threaded.open(test_file, compresslevel=5) as f:
         text = f.read()
     assert text == b"thisisatest"
+
+
+def test_threaded_reader_does_not_close_stream():
+    test_stream = io.BytesIO()
+    test_stream.write(gzip.compress(b"thisisatest"))
+    test_stream.seek(0)
+    with igzip_threaded.open(test_stream, "rb") as f:
+        text = f.read()
+    assert not test_stream.closed
+    assert text == b"thisisatest"
+
+
+def test_threaded_writer_does_not_close_stream():
+    test_stream = io.BytesIO()
+    with igzip_threaded.open(test_stream, "wb") as f:
+        f.write(b"thisisatest")
+    assert not test_stream.closed
+    test_stream.seek(0)
+    assert gzip.decompress(test_stream.read()) == b"thisisatest"