Generate indexes for message registries

Being able to index into the message registry constexpr arrays will be
useful in the future, so update the parse_registries script to generate
an Index enum class, that allows directly indexing into the constexpr
table when necessary.

These indexes are used in the patchset here:
https://gerrit.openbmc-project.xyz/c/openbmc/bmcweb/+/50950
to avoid a binary search lookup for each entry.

Tested: No-op change, code inspection only.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: I345cc26a2b17b5bcd8cfb0055642f4ae443caad4

1 files changed, 14 insertions, 2 deletions

diff --git a/scripts/parse_registries.py b/scripts/parse_registries.py
index d64e540de2..8334eaefd9 100755
--- a/scripts/parse_registries.py
+++ b/scripts/parse_registries.py
@@ -91,7 +91,9 @@ for file, json_dict, namespace, url in files:
         registry.write(
             "constexpr std::array<MessageEntry, {}> registry = {{".format(
                 len(json_dict["Messages"])))
-        for messageId, message in sorted(json_dict["Messages"].items()):
+
+        messages_sorted = sorted(json_dict["Messages"].items())
+        for messageId, message in messages_sorted:
             registry.write("MessageEntry{")
             registry.write("\"{}\",".format(messageId))
             registry.write("{")
@@ -108,7 +110,17 @@ for file, json_dict, namespace, url in files:
             registry.write("},")
             registry.write("\"{}\",".format(message["Resolution"]))
             registry.write("}},")
-        registry.write("};}\n")
+
+        registry.write("\n};")
+
+        registry.write("\n\nenum class Index {\n")
+        for index, (messageId, message) in enumerate(messages_sorted):
+            messageId = messageId[0].lower() + messageId[1:]
+            registry.write(
+                "{} = {},\n".format(messageId, index))
+        registry.write("};")
+        registry.write("}")
+
     clang_format(file)