file_utils_test.py 文件源码

def test_get_from_cache(self):
        url = 'http://fake.datastore.com/glove.txt.gz'
        set_up_glove(url, self.glove_bytes, change_etag_every=2)

        filename = get_from_cache(url, cache_dir=self.TEST_DIR)
        assert filename == os.path.join(self.TEST_DIR, url_to_filename(url, etag="0"))

        # We should have made one HEAD request and one GET request.
        method_counts = Counter(call.request.method for call in responses.calls)
        assert len(method_counts) == 2
        assert method_counts['HEAD'] == 1
        assert method_counts['GET'] == 1

        # And the cached file should have the correct contents
        with open(filename, 'rb') as cached_file:
            assert cached_file.read() == self.glove_bytes

        # A second call to `get_from_cache` should make another HEAD call
        # but not another GET call.
        filename2 = get_from_cache(url, cache_dir=self.TEST_DIR)
        assert filename2 == filename

        method_counts = Counter(call.request.method for call in responses.calls)
        assert len(method_counts) == 2
        assert method_counts['HEAD'] == 2
        assert method_counts['GET'] == 1

        with open(filename2, 'rb') as cached_file:
            assert cached_file.read() == self.glove_bytes

        # A third call should have a different ETag and should force a new download,
        # which means another HEAD call and another GET call.
        filename3 = get_from_cache(url, cache_dir=self.TEST_DIR)
        assert filename3 == os.path.join(self.TEST_DIR, url_to_filename(url, etag="1"))

        method_counts = Counter(call.request.method for call in responses.calls)
        assert len(method_counts) == 2
        assert method_counts['HEAD'] == 3
        assert method_counts['GET'] == 2

        with open(filename3, 'rb') as cached_file:
            assert cached_file.read() == self.glove_bytes