Check files can be closed

Author: rhpvorderman

src/isal/igzip_threaded.py

@@ -88,6 +88,10 @@ def __init__(self, fp, queue_size=4, block_size=8 * 1024 * 1024):
         self.running = True
         self.worker.start()
 
+    def _check_closed(self, msg = None):
+        if self._closed:
+            raise ValueError("I/O operation on closed file")
+
     def _decompress(self):
         block_size = self.block_size
         block_queue = self.queue
@@ -107,8 +111,7 @@ def _decompress(self):
                     pass
 
     def readinto(self, b):
-        if self._closed:
-            raise ValueError("I/O operation on closed file")
+        self._check_closed()
         result = self.buffer.readinto(b)
         if result == 0:
             while True:
@@ -130,11 +133,12 @@ def readable(self) -> bool:
         return True
 
     def tell(self) -> int:
-        if self._closed:
-            raise ValueError("I/O operation on closed file")
+        self._check_closed()
         return self.pos
 
     def close(self) -> None:
+        if self._closed:
+            return
         self.running = False
         self.worker.join()
         self.fileobj.close()
@@ -208,6 +212,10 @@ def __init__(self,
         self._write_gzip_header()
         self.start()
 
+    def _check_closed(self, msg = None):
+        if self._closed:
+            raise ValueError("I/O operation on closed file")
+
     def _write_gzip_header(self):
         """Simple gzip header. Only xfl flag is set according to level."""
         magic1 = 0x1f
@@ -234,11 +242,10 @@ def stop(self):
         self.output_worker.join()
 
     def write(self, b) -> int:
+        self._check_closed()
         with self.lock:
             if self.exception:
                 raise self.exception
-        if self._closed:
-            raise IOError("Can not write closed file")
         index = self.index
         data = bytes(b)
         zdict = memoryview(self.previous_block)[-DEFLATE_WINDOW_SIZE:]
@@ -249,8 +256,7 @@ def write(self, b) -> int:
         return len(data)
 
     def flush(self):
-        if self._closed:
-            raise IOError("Can not write closed file")
+        self._check_closed()
         # Wait for all data to be compressed
         for in_q in self.input_queues:
             in_q.join()

tests/test_igzip_threaded.py

@@ -106,13 +106,29 @@ def test_reader_not_writable():
 
 
 def test_writer_not_readable():
-    with tempfile.TemporaryFile(mode="wb") as tmp:
-        with igzip_threaded.open(tmp, "wb") as f:
-            assert not f.readable()
+    with igzip_threaded.open(io.BytesIO(), "wb") as f:
+        assert not f.readable()
 
 
 def test_writer_wrong_level():
     with pytest.raises(ValueError) as error:
-        igzip_threaded.open("test", mode="wb", compresslevel=42)
+        igzip_threaded._ThreadedGzipWriter(io.BytesIO(), level=42)
     error.match("Invalid compression level")
     error.match("42")
+
+
+def test_reader_read_after_close():
+    with open(TEST_FILE, "rb") as test_f:
+        f = igzip_threaded._ThreadedGzipReader(test_f)
+        f.close()
+        with pytest.raises(ValueError) as error:
+            f.read(1024)
+        error.match("closed")
+
+
+def test_writer_write_after_close():
+    f = igzip_threaded._ThreadedGzipWriter(io.BytesIO())
+    f.close()
+    with pytest.raises(ValueError) as error:
+        f.write(b"abc")
+    error.match("closed")