diff mbox

[v7,03/14] qapi: Provide nicer array names in introspection

Message ID 1445056549-7815-4-git-send-email-eblake@redhat.com
State New
Headers show

Commit Message

Eric Blake Oct. 17, 2015, 4:35 a.m. UTC 
For the sake of humans reading introspection output, it is nice
to have the name of implicit array types be recognizable as
arrays of the underlying type.  However, while this patch allows
humans to skip from a command with return type "[123]" straight
to the definition of type "123" without having to first inspect
type "[123]", document that this shortcut should not be taken by
client apps.

This makes the resulting introspection string slightly larger by
default, but slightly smaller when -u is in use (as '[FOO]' is
nicer than 'FOOList' for expressing 'array of FOO').

Signed-off-by: Eric Blake <eblake@redhat.com>

---
v7: no change
v6: no change
---
 docs/qapi-code-gen.txt     | 7 +++++--
 scripts/qapi-introspect.py | 8 +++++---
 2 files changed, 10 insertions(+), 5 deletions(-)

Comments

Markus Armbruster Oct. 22, 2015, 4:12 p.m. UTC | #1 
Eric Blake <eblake@redhat.com> writes:

> For the sake of humans reading introspection output, it is nice
> to have the name of implicit array types be recognizable as
> arrays of the underlying type.  However, while this patch allows
> humans to skip from a command with return type "[123]" straight
> to the definition of type "123" without having to first inspect
> type "[123]", document that this shortcut should not be taken by
> client apps.

Personally, I still don't see much value in special-casing array names.
On the other hand, the patch is really simple.

> This makes the resulting introspection string slightly larger by
> default, but slightly smaller when -u is in use (as '[FOO]' is
> nicer than 'FOOList' for expressing 'array of FOO').

Size with -u is unimportant.

If we don't want to pay the prize in size without -u, we can make it
conditional on -u.  But with -u, [FOO] isn't much of an improvement over
FooList.

Anyway, if you want the feature, I'll take the patch.
diff mbox

Patch

diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt
index df2d198..15a1c70 100644
--- a/docs/qapi-code-gen.txt
+++ b/docs/qapi-code-gen.txt
@@ -662,11 +662,14 @@  Example: the SchemaInfo for BlockRef from section Alternate types

 The SchemaInfo for an array type has meta-type "array", and variant
 member "element-type", which names the array's element type.  Array
-types are implicitly defined.
+types are implicitly defined.  For convenience, the array's name may
+resemble the element type; however, clients should examine member
+"element-type" instead of making assumptions based on parsing member
+"name".

 Example: the SchemaInfo for ['str']

-    { "name": "strList", "meta-type": "array",
+    { "name": "[str]", "meta-type": "array",
       "element-type": "str" }

 The SchemaInfo for an enumeration type has meta-type "enum" and
diff --git a/scripts/qapi-introspect.py b/scripts/qapi-introspect.py
index c0dad66..64f2cd0 100644
--- a/scripts/qapi-introspect.py
+++ b/scripts/qapi-introspect.py
@@ -107,10 +107,12 @@  const char %(c_name)s[] = %(c_string)s;
         # characters.
         if isinstance(typ, QAPISchemaBuiltinType):
             return typ.name
+        if isinstance(typ, QAPISchemaArrayType):
+            return '[' + self._use_type(typ.element_type) + ']'
         return self._name(typ.name)

     def _gen_json(self, name, mtype, obj):
-        if mtype != 'command' and mtype != 'event' and mtype != 'builtin':
+        if mtype not in ('command', 'event', 'builtin', 'array'):
             name = self._name(name)
         obj['name'] = name
         obj['meta-type'] = mtype
@@ -136,8 +138,8 @@  const char %(c_name)s[] = %(c_string)s;
         self._gen_json(name, 'enum', {'values': values})

     def visit_array_type(self, name, info, element_type):
-        self._gen_json(name, 'array',
-                       {'element-type': self._use_type(element_type)})
+        element = self._use_type(element_type)
+        self._gen_json('[' + element + ']', 'array', {'element-type': element})

     def visit_object_type_flat(self, name, info, members, variants):
         obj = {'members': [self._gen_member(m) for m in members]}