Simplify caching of directories retrieval.

anntzer · anntzer · commit 44aaa1bb1e81 · 2018-06-25T00:20:47.000+02:00
diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -386,27 +386,35 @@ def ge(self, level):
     verbose = Verbose()
 
 
-def _wrap(fmt, func, level=logging.DEBUG, always=True):
+def _logged_cached(fmt, func=None):
     """
-    return a callable function that wraps func and reports its
-    output through logger
+    Decorator that logs a function's return value, and memoizes that value.
 
-    if always is True, the report will occur on every function
-    call; otherwise only on the first time the function is called
+    After ::
+
+        @_logged_cached(fmt)
+        def func(): ...
+
+    the first call to *func* will log its return value at the DEBUG level using
+    %-format string *fmt*, and memoize it; later calls to *func* will directly
+    return that value.
     """
-    assert callable(func)
 
-    def wrapper(*args, **kwargs):
-        ret = func(*args, **kwargs)
+    if func is None:
+        return functools.partial(_logged_cached, fmt)
+
+    called = False
+    ret = None
 
-        if (always or not wrapper._spoke):
-            _log.log(level, fmt % ret)
-            spoke = True
-            if not wrapper._spoke:
-                wrapper._spoke = spoke
+    @functools.wraps(func)
+    def wrapper():
+        nonlocal called, ret
+        if not called:
+            ret = func()
+            called = True
+            _log.debug(fmt, ret)
         return ret
-    wrapper._spoke = False
-    wrapper.__doc__ = func.__doc__
+
     return wrapper
 
 
@@ -544,7 +552,8 @@ def checkdep_usetex(s):
     return flag
 
 
-def _get_home():
+@_logged_cached('$HOME=%s')
+def get_home():
     """
     Return the user's home directory.
 
@@ -555,8 +564,6 @@ def _get_home():
     except Exception:
         return None
 
-get_home = _wrap('$HOME=%s', _get_home, always=False)
-
 
 def _create_tmp_config_dir():
     """
@@ -575,7 +582,7 @@ def _get_xdg_config_dir():
     <http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html>`_.
     """
     return (os.environ.get('XDG_CONFIG_HOME')
-            or (Path(get_home(), ".config")
+            or (str(Path(get_home(), ".config"))
                 if get_home()
                 else None))
 
@@ -587,21 +594,21 @@ def _get_xdg_cache_dir():
     <http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html>`_.
     """
     return (os.environ.get('XDG_CACHE_HOME')
-            or (Path(get_home(), ".cache")
+            or (str(Path(get_home(), ".cache"))
                 if get_home()
                 else None))
 
 
 def _get_config_or_cache_dir(xdg_base):
     configdir = os.environ.get('MPLCONFIGDIR')
-    configdir = (
-        Path(configdir).resolve()
-        if configdir
-        else Path(xdg_base, "matplotlib")
-        if sys.platform.startswith(('linux', 'freebsd')) and xdg_base
-        else Path(get_home(), ".matplotlib")
-        if get_home()
-        else None)
+    if configdir:
+        configdir = Path(configdir).resolve()
+    elif sys.platform.startswith(('linux', 'freebsd')) and xdg_base:
+        configdir = Path(xdg_base, "matplotlib")
+    elif get_home():
+        configdir = Path(get_home(), ".matplotlib")
+    else:
+        configdir = None
 
     if configdir:
         try:
@@ -615,7 +622,9 @@ def _get_config_or_cache_dir(xdg_base):
     return _create_tmp_config_dir()
 
 
-def _get_configdir():
+
+@_logged_cached('CONFIGDIR=%s')
+def get_configdir():
     """
     Return the string representing the configuration directory.
 
@@ -633,10 +642,9 @@ def _get_configdir():
     """
     return _get_config_or_cache_dir(_get_xdg_config_dir())
 
-get_configdir = _wrap('CONFIGDIR=%s', _get_configdir, always=False)
-
 
-def _get_cachedir():
+@_logged_cached('CACHEDIR=%s')
+def get_cachedir():
     """
     Return the location of the cache directory.
 
@@ -645,8 +653,6 @@ def _get_cachedir():
     """
     return _get_config_or_cache_dir(_get_xdg_cache_dir())
 
-get_cachedir = _wrap('CACHEDIR=%s', _get_cachedir, always=False)
-
 
 def _decode_filesystem_path(path):
     if not isinstance(path, str):
@@ -698,14 +704,12 @@ def _get_data_path():
     raise RuntimeError('Could not find the matplotlib data files')
 
 
-def _get_data_path_cached():
+@_logged_cached('matplotlib data path: %s')
+def get_data_path():
     if defaultParams['datapath'][0] is None:
         defaultParams['datapath'][0] = _get_data_path()
     return defaultParams['datapath'][0]
 
-get_data_path = _wrap('matplotlib data path %s', _get_data_path_cached,
-                      always=False)
-
 
 def get_py2exe_datafiles():
     data_path = Path(get_data_path())
@@ -756,7 +760,7 @@ def gen_candidates():
         else:
             yield matplotlibrc
             yield os.path.join(matplotlibrc, 'matplotlibrc')
-        yield os.path.join(_get_configdir(), 'matplotlibrc')
+        yield os.path.join(get_configdir(), 'matplotlibrc')
         yield os.path.join(get_data_path(), 'matplotlibrc')
 
     for fname in gen_candidates():
diff --git a/lib/matplotlib/style/core.py b/lib/matplotlib/style/core.py
@@ -25,7 +25,7 @@
 
 BASE_LIBRARY_PATH = os.path.join(mpl.get_data_path(), 'stylelib')
 # Users may want multiple library paths, so store a list of paths.
-USER_LIBRARY_PATHS = [os.path.join(mpl._get_configdir(), 'stylelib')]
+USER_LIBRARY_PATHS = [os.path.join(mpl.get_configdir(), 'stylelib')]
 STYLE_EXTENSION = 'mplstyle'
 STYLE_FILE_PATTERN = re.compile(r'([\S]+).%s$' % STYLE_EXTENSION)
 
diff --git a/lib/matplotlib/testing/compare.py b/lib/matplotlib/testing/compare.py
@@ -18,9 +18,7 @@
 
 import matplotlib
 from matplotlib.testing.exceptions import ImageComparisonFailure
-from matplotlib import _png
-from matplotlib import _get_cachedir
-from matplotlib import cbook
+from matplotlib import _png, cbook
 
 __all__ = ['compare_float', 'compare_images', 'comparable_formats']
 
@@ -79,7 +77,7 @@ def compare_float(expected, actual, relTol=None, absTol=None):
 
 
 def get_cache_dir():
-    cachedir = _get_cachedir()
+    cachedir = matplotlib.get_cachedir()
     if cachedir is None:
         raise RuntimeError('Could not find a suitable configuration directory')
     cache_dir = os.path.join(cachedir, 'test_cache')
@@ -293,15 +291,12 @@ def comparable_formats():
 
 def convert(filename, cache):
     """
-    Convert the named file into a png file.  Returns the name of the
-    created file.
+    Convert the named file to png; return the name of the created file.
 
     If *cache* is True, the result of the conversion is cached in
-    `matplotlib._get_cachedir() + '/test_cache/'`.  The caching is based
-    on a hash of the exact contents of the input file.  The is no limit
-    on the size of the cache, so it may need to be manually cleared
-    periodically.
-
+    `matplotlib.get_cachedir() + '/test_cache/'`.  The caching is based on a
+    hash of the exact contents of the input file.  There is no limit on the
+    size of the cache, so it may need to be manually cleared periodically.
     """
     base, extension = filename.rsplit('.', 1)
     if extension not in converter:
