1 files changed, 58 insertions, 0 deletions
diff --git a/codegen/vulkan/scripts/spec_tools/data_structures.py b/codegen/vulkan/scripts/spec_tools/data_structures.py
new file mode 100644
index 00000000..f2808cf1
--- /dev/null
+++ b/codegen/vulkan/scripts/spec_tools/data_structures.py
@@ -0,0 +1,58 @@
+#!/usr/bin/python3 -i
+#
+# Copyright (c) 2019 Collabora, Ltd.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+# Author(s):    Ryan Pavlik <ryan.pavlik@collabora.com>
+"""Provides general-purpose data structures."""
+
+
+class DictOfStringSets:
+    """A dictionary where the values are sets of strings.
+
+    Has some convenience functions to allow easier maintenance via
+    the .add method."""
+
+    def __init__(self, d=None):
+        self.d = {}
+        if d:
+            for k, v in d.items():
+                self.add(k, v)
+
+    def __getitem__(self, k):
+        return self.d[k]
+
+    def __contains__(self, k):
+        return k in self.d
+
+    def get(self, k, default=None):
+        return self.d.get(k, default)
+
+    def get_dict(self):
+        return self.d
+
+    def items(self):
+        """Return an iterator like dict().items()."""
+        return self.d.items()
+
+    def keys(self):
+        """Return an iterator over keys."""
+        return self.d.keys()
+
+    def values(self):
+        """Return an iterator over values."""
+        return self.d.values()
+
+    def add_key(self, k):
+        """Ensure the set for the given key exists."""
+        if k not in self.d:
+            self.d[k] = set()
+
+    def add(self, k, v):
+        self.add_key(k)
+        if isinstance(v, str):
+            v = (v, )
+        if not isinstance(v, set):
+            v = set(v)
+        self.d[k].update(v)