Create wrapper class so data.json is only loaded once [RHELDST-4863]

This commit includes the creation of a CdnData class, which holds
methods related to the Python implementation of the data. The
CdnData class allows for the data set to be loaded once.

src/cdn_definitions/__init__.py

@@ -1,3 +1,4 @@
-from ._impl import PathAlias, origin_aliases, rhui_aliases, load_data
+from ._impl import PathAlias, load_data
+from ._impl.cdn_data import CdnData
 
-__all__ = ["PathAlias", "origin_aliases", "rhui_aliases", "load_data"]
+__all__ = ["PathAlias", "load_data", "CdnData"]

src/cdn_definitions/_impl/__init__.py

@@ -26,9 +26,6 @@ def load_data(source=None):
     raise RuntimeError("Could not load data")
 
 
-DATA = load_data()
-
-
 class PathAlias(object):
     """Represents an alias between one CDN path and another, generally
     used to make two directory trees on CDN serve identical content."""
@@ -48,19 +45,3 @@ def __init__(self, **kwargs):
         # Equal src/dest is nonsensical
         if self.src == self.dest:
             raise ValueError("%s cannot alias itself!" % self.src)
-
-
-def rhui_aliases():
-    """Returns:
-        list[:class:`~PathAlias`]
-            A list of aliases relating to RHUI paths.
-    """
-    return [PathAlias(**elem) for elem in DATA["rhui_alias"]]
-
-
-def origin_aliases():
-    """Returns:
-        list[:class:`~PathAlias`]
-            A list of aliases relating to origin paths.
-    """
-    return [PathAlias(**elem) for elem in DATA["origin_alias"]]

src/cdn_definitions/_impl/cdn_data.py

@@ -0,0 +1,26 @@
+from . import load_data, PathAlias
+
+
+class CdnData(object):
+    def __init__(self, source=None):
+        self._source = source
+        self._data = None
+
+    def data(self):
+        if not self._data:
+            self._data = load_data(self._source)
+        return self._data
+
+    def rhui_aliases(self):
+        """Returns:
+        list[:class:`~PathAlias`]
+            A list of aliases relating to RHUI paths.
+        """
+        return [PathAlias(**elem) for elem in self.data()["rhui_alias"]]
+
+    def origin_aliases(self):
+        """Returns:
+        list[:class:`~PathAlias`]
+            A list of aliases relating to origin paths.
+        """
+        return [PathAlias(**elem) for elem in self.data()["origin_alias"]]

tests/test_alias.py

@@ -1,11 +1,12 @@
 import pytest
 
-from cdn_definitions import PathAlias, origin_aliases, rhui_aliases
+from cdn_definitions import PathAlias, CdnData
 
 
 def test_rhui_sanity():
     """rhui_aliases must exist with expected properties"""
-    paths = rhui_aliases()
+    data = CdnData()
+    paths = data.rhui_aliases()
 
     # There should be some items
     assert paths
@@ -18,7 +19,8 @@ def test_rhui_sanity():
 
 def test_origin_sanity():
     """origin_aliases must exist with expected properties"""
-    paths = origin_aliases()
+    data = CdnData()
+    paths = data.origin_aliases()
 
     # There should be some items
     assert paths

tests/test_api.py

@@ -23,4 +23,3 @@ def test_load_data_api(tmpdir):
     json_file.write('{"hello": "world"}')
     data = api.data(source=str(json_file))
     assert data == {"hello": "world"}
-