1 files changed, 88 insertions, 0 deletions
diff --git a/python/mozbuild/mozbuild/dotproperties.py b/python/mozbuild/mozbuild/dotproperties.py
new file mode 100644
index 0000000000..3028a4187e
--- /dev/null
+++ b/python/mozbuild/mozbuild/dotproperties.py
@@ -0,0 +1,88 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# This file contains utility functions for reading .properties files, like
+# region.properties.
+
+from __future__ import absolute_import, print_function, unicode_literals
+
+import codecs
+import re
+import six
+import sys
+
+if sys.version_info[0] == 3:
+    str_type = str
+else:
+    str_type = basestring
+
+
+class DotProperties:
+    r"""A thin representation of a key=value .properties file."""
+
+    def __init__(self, file=None):
+        self._properties = {}
+        if file:
+            self.update(file)
+
+    def update(self, file):
+        """Updates properties from a file name or file-like object.
+
+        Ignores empty lines and comment lines."""
+
+        if isinstance(file, str_type):
+            f = codecs.open(file, "r", "utf-8")
+        else:
+            f = file
+
+        for l in f.readlines():
+            line = l.strip()
+            if not line or line.startswith("#"):
+                continue
+            (k, v) = re.split("\s*=\s*", line, 1)
+            self._properties[k] = v
+
+    def get(self, key, default=None):
+        return self._properties.get(key, default)
+
+    def get_list(self, prefix):
+        """Turns {'list.0':'foo', 'list.1':'bar'} into ['foo', 'bar'].
+
+        Returns [] to indicate an empty or missing list."""
+
+        if not prefix.endswith("."):
+            prefix = prefix + "."
+        indexes = []
+        for k, v in six.iteritems(self._properties):
+            if not k.startswith(prefix):
+                continue
+            key = k[len(prefix) :]
+            if "." in key:
+                # We have something like list.sublist.0.
+                continue
+            indexes.append(int(key))
+        return [self._properties[prefix + str(index)] for index in sorted(indexes)]
+
+    def get_dict(self, prefix, required_keys=[]):
+        """Turns {'foo.title':'title', ...} into {'title':'title', ...}.
+
+        If ``|required_keys|`` is present, it must be an iterable of required key
+        names.  If a required key is not present, ValueError is thrown.
+
+        Returns {} to indicate an empty or missing dict."""
+
+        if not prefix.endswith("."):
+            prefix = prefix + "."
+
+        D = dict(
+            (k[len(prefix) :], v)
+            for k, v in six.iteritems(self._properties)
+            if k.startswith(prefix) and "." not in k[len(prefix) :]
+        )
+
+        for required_key in required_keys:
+            if required_key not in D:
+                raise ValueError("Required key %s not present" % required_key)
+
+        return D