dffml: source: file: Added Gzip support

* dffml: source: file: Added Gzip support
* tests: source: file: Added test for gzip file source
* CHANGELOG: Added Gzip support

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - New Feature creation tutorial
 - New Model creation tutorial
 - Added update functionality to the CSV source
+- Added support for Gzip file source
 ### Changed
 - Restructured documentation to docs folder and moved from rST to markdown
 - Git feature cloc logs if no binaries are in path

dffml/source/file.py

@@ -3,7 +3,7 @@
 import os
 import abc
 import asyncio
-
+import gzip
 from .source import Source
 from .log import LOGGER
 
@@ -40,15 +40,23 @@ async def _open(self):
                          self.filename)
             self.mem = {}
             return
-        with open(self.filename, 'r') as fd:
+        if self.filename[::-1].startswith(('.gz')[::-1]):
+            opener = gzip.open(self.filename, 'rt')
+        else:
+            opener = open(self.filename, 'r')
+        with opener as fd:
             await self.load_fd(fd)
 
     async def close(self):
         await asyncio.shield(self._close())
 
     async def _close(self):
         if not self.readonly:
-            with open(self.filename, 'w') as fd:
+            if self.filename[::-1].startswith(('.gz')[::-1]):
+                close = gzip.open(self.filename, 'wt')
+            else:
+                close = open(self.filename, 'w')
+            with close as fd:
                 await self.dump_fd(fd)
 
     @abc.abstractmethod

tests/source/test_file.py

@@ -63,6 +63,14 @@ async def test_open(self):
             await source.open()
             m_open.assert_called_once_with('testfile', 'r')
 
+    async def test_open_gz(self):
+        source = FakeFileSource('testfile.gz')
+        m_open = mock_open()
+        with patch('os.path.exists', return_value=True), \
+                patch('builtins.open', m_open):
+            await source.open()
+            m_open.assert_called_once_with('testfile.gz', 'rb')    
+
     async def test_open_no_file(self):
         source = FakeFileSource('testfile')
         with patch('os.path.isfile', return_value=False):
@@ -76,6 +84,13 @@ async def test_close(self):
             await source.close()
             m_open.assert_called_once_with('testfile', 'w')
 
+    async def test_close_gz(self):
+        source = FakeFileSource('testfile.gz')
+        m_open = mock_open()
+        with patch('builtins.open', m_open):
+            await source.close()
+            m_open.assert_called_once_with('testfile.gz', 'wb')
+
     async def test_close_readonly(self):
         source = FakeFileSource('testfile:ro')
         m_open = mock_open()