Reinstate deleted functions

With a deprecation decorator
matplotlib · jkseppan · Jan 7, 2017 · Jan 21, 2017 · Jan 21, 2017 · Jan 22, 2017
commit 33f2528cf9e68b5adcf5f6a94de54f5e07450c25
diff --git a/lib/matplotlib/testing/compare.py b/lib/matplotlib/testing/compare.py
@@ -12,6 +12,7 @@
 import matplotlib
 from matplotlib import cbook
 from matplotlib.compat import subprocess
+from matplotlib.testing import conversion_cache as ccache
 from matplotlib.testing.exceptions import ImageComparisonFailure
 from matplotlib import _png
 
@@ -120,6 +121,25 @@ def comparable_formats():
     return ['png'] + list(converter)
 
 
+@cbook.deprecated('2.1', addendum='Use ConversionCache instead')
+def get_cache_dir():
+    return ccache.ConversionCache.get_cache_dir()
+
+
+@cbook.deprecated('2.1', addendum='Use ConversionCache instead')
+def get_file_hash(path, block_size=2 ** 20):
+    if path.endswith('.pdf'):
+        from matplotlib import checkdep_ghostscript
+        version_tag = checkdep_ghostscript()[1].encode('utf-8')
+    elif path.endswith('.svg'):
+        from matplotlib import checkdep_inkscape
+        version_tag = checkdep_inkscape().encode('utf-8')
+    else:
+        version_tag = None
+    return ccache.ConversionCache._get_file_hash_static(
+        path, block_size, version_tag)
+
+
 def convert(filename, cache=None):
     """
     Convert the named file into a png file.  Returns the name of the

diff --git a/lib/matplotlib/testing/conversion_cache.py b/lib/matplotlib/testing/conversion_cache.py
@@ -115,25 +115,32 @@ def put(self, original, converted):
     def _get_file_hash(self, path, block_size=2 ** 20):
         if path in self.hash_cache:
             return self.hash_cache[path]
+        _, ext = os.path.splitext(path)
+        version_tag = self.converter_version.get(ext)
+        if version_tag is None:
+            warnings.warn(
+                ("Don't know the external converter for files with extension "
+                 "%s, cannot ensure cache invalidation on version update.")
+                % ext)
+        result = self._get_file_hash_static(path, block_size, version_tag)
+        self.hash_cache[path] = result
+        return result
+
+    @staticmethod
+    def _get_file_hash_static(path, block_size, version_tag):
+        # the parts of _get_file_hash that are called from the deprecated
+        # compare.get_file_hash; can merge into _get_file_hash once that
+        # function is removed
         md5 = hashlib.md5()
         with open(path, 'rb') as fd:
             while True:
                 data = fd.read(block_size)
                 if not data:
                     break
                 md5.update(data)
-        _, ext = os.path.splitext(path)
-        version_tag = self.converter_version.get(ext)
-        if version_tag:
+        if version_tag is not None:
             md5.update(version_tag)
-        else:
-            warnings.warn(("Don't know the external converter for %s, cannot "
-                           "ensure cache invalidation on version update.")
-                          % path)
-
-        result = md5.hexdigest()
-        self.hash_cache[path] = result
-        return result
+        return md5.hexdigest()
 
     def report(self):
         """Return information about the cache.