[Qemu-devel] [PATCH RFC v2 47/47] qapi-introspect: Hide type names

[Markus Armbruster]

To eliminate the temptation for clients to look up types by name
(which are not ABI), replace all type names by meaningless strings.

Reduces output of query-schema by 9 out of 80KiB.

Signed-off-by: Markus Armbruster <address@hidden>
---
 scripts/qapi-introspect.py | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/scripts/qapi-introspect.py b/scripts/qapi-introspect.py
index 961fe88..efb34ff 100644
--- a/scripts/qapi-introspect.py
+++ b/scripts/qapi-introspect.py
@@ -9,13 +9,18 @@
 # This work is licensed under the terms of the GNU GPL, version 2.
 # See the COPYING file in the top-level directory.
 
+import string
 from qapi import *
 
+def _b32digit(num):
+    return (string.lowercase + string.digits[2:])[num]
+
 class QAPISchemaGenIntrospectVisitor(QAPISchemaVisitor):
     def __init__(self):
         self.schema = None
         self.jsons = None
         self.used_types = None
+        self.name_map = None
         self.defn = None
         self.decl = None
 
@@ -23,13 +28,17 @@ class QAPISchemaGenIntrospectVisitor(QAPISchemaVisitor):
         self.schema = schema
         self.jsons = []
         self.used_types = []
+        self.name_map = {}
         return QAPISchemaType   # don't visit types for now
 
     def visit_end(self):
         # visit the types that are actually used
+        jsons = self.jsons
+        self.jsons = []
         for typ in self.used_types:
             typ.visit(self)
         self.jsons.sort()
+        jsons.extend(self.jsons)
         name = prefix + 'qmp_schema_json'
         self.decl = mcgen('''
 extern char %(c_name)s[];
@@ -40,10 +49,19 @@ char %(c_name)s[] = "["
     "%(c_jsons)s]";
 ''',
                           c_name=c_name(name),
-                          c_jsons=', "\n    "'.join(self.jsons))
+                          c_jsons=', "\n    "'.join(jsons))
         self.schema = None
         self.jsons = None
         self.used_types = None
+        self.name_map = None
+
+    def _name(self, name):
+        if name not in self.name_map:
+            n = len(self.name_map)
+            self.name_map[name] = ':' + _b32digit(n / 32 / 32) \
+                                  + _b32digit(n / 32 % 32) \
+                                  + _b32digit(n % 32)
+        return self.name_map[name]
 
     def _use_type(self, typ):
         # Map the various integer types to plain int
@@ -55,9 +73,14 @@ char %(c_name)s[] = "["
         # Add type to work queue if new
         if typ not in self.used_types:
             self.used_types.append(typ)
-        return typ.name
+        # Clients should examine commands and events, not types.  Hide
+        # type names to reduce the temptation.  Also saves a few
+        # characters.
+        return self._name(typ.name)
 
     def _gen_json(self, name, mtype, extra):
+        if mtype != 'command' and mtype != 'event':
+            name = self._name(name)
         self.jsons.append("{ 'name': '%s', 'meta-type': '%s', %s }"
                           % (name, mtype, extra))
 
-- 
1.9.3