1 //
2 // Copyright 2020 Pixar
3 //
4 // Licensed under the Apache License, Version 2.0 (the "Apache License")
5 // with the following modification; you may not use this file except in
6 // compliance with the Apache License and the following modification to it:
7 // Section 6. Trademarks. is deleted and replaced with:
8 //
9 // 6. Trademarks. This License does not grant permission to use the trade
10 //    names, trademarks, service marks, or product names of the Licensor
11 //    and its affiliates, except as required to comply with Section 4(c) of
12 //    the License and to reproduce the content of the NOTICE file.
13 //
14 // You may obtain a copy of the Apache License at
15 //
16 //     http://www.apache.org/licenses/LICENSE-2.0
17 //
18 // Unless required by applicable law or agreed to in writing, software
19 // distributed under the Apache License with the above modification is
20 // distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
21 // KIND, either express or implied. See the Apache License for the specific
22 // language governing permissions and limitations under the Apache License.
23 //
24 #include "pxr/pxr.h"
25 #include "pxr/usd/usd/primTypeInfo.h"
26 
27 PXR_NAMESPACE_OPEN_SCOPE
28 
UsdPrimTypeInfo(_TypeId && typeId)29 UsdPrimTypeInfo::UsdPrimTypeInfo(_TypeId &&typeId)
30     : _typeId(std::move(typeId))
31     , _primDefinition(nullptr)
32 {
33     // Helper for initializing the schema type from either the mapped type
34     // name or the prim type name.
35     auto _SetSchemaType = [this](const TfToken &typeName)
36     {
37         // Empty type name returns false.
38         if (typeName.IsEmpty()) {
39             return false;
40         }
41         _schemaType =
42             UsdSchemaRegistry::GetConcreteTypeFromSchemaTypeName(typeName);
43         if (_schemaType) {
44             _schemaTypeName = typeName;
45         }
46         // Return true even if the schema type is invalid since the type name
47         // is not empty.
48         return true;
49     };
50 
51     // Set the schema type using the mapped type name over the prim type
52     // name if we have a mapped type name.
53     _SetSchemaType(_typeId.mappedTypeName) ||
54         _SetSchemaType(_typeId.primTypeName);
55 }
56 
57 const UsdPrimDefinition *
_FindOrCreatePrimDefinition() const58 UsdPrimTypeInfo::_FindOrCreatePrimDefinition() const
59 {
60     const UsdPrimDefinition *primDef = nullptr;
61     const UsdSchemaRegistry &reg = UsdSchemaRegistry::GetInstance();
62     if (_typeId.appliedAPISchemas.empty()) {
63         // With no applied schemas we can just get the concrete typed prim
64         // definition from the schema registry. Prim definitions for all
65         // concrete types are created with the schema registry when it is
66         // instantiated so if the type exists, the definition will be there.
67         primDef = reg.FindConcretePrimDefinition(_schemaTypeName);
68         if (!primDef) {
69             // For invalid types, we use the empty prim definition so we don't
70             // have to check again.
71             primDef = reg.GetEmptyPrimDefinition();
72         }
73         // Cache the prim definition pointer. The schema registry created the
74         // prim definition and will continue to own it so the pointer value
75         // will be constant. Thus, we don't have to check if another thread
76         // cached it first as all threads would store the same pointer.
77         _primDefinition.store(primDef, std::memory_order_relaxed);
78     } else {
79         // If we have applied schemas, then we need ask the schema registry to
80         // compose a prim definition for us from the list of types. The schema
81         // registry does NOT take ownership of this new prim definition; this
82         // type info will own it instead.
83         std::unique_ptr<UsdPrimDefinition> composedPrimDef =
84             reg.BuildComposedPrimDefinition(_schemaTypeName,
85                                             _typeId.appliedAPISchemas);
86         // Try to cache the new prim definition, but if another thread beat us
87         // to it, we'll use its definition instead and just let ours get
88         // deleted.
89         if (_primDefinition.compare_exchange_strong(
90                 primDef, composedPrimDef.get(), std::memory_order_acq_rel)) {
91             // Since we succeeded, transfer ownership of the new prim definition
92             // to this type info.
93             _ownedPrimDefinition = std::move(composedPrimDef);
94             primDef = _ownedPrimDefinition.get();
95         }
96     }
97     return primDef;
98 }
99 
100 /*static*/
101 const UsdPrimTypeInfo &
GetEmptyPrimType()102 UsdPrimTypeInfo::GetEmptyPrimType()
103 {
104     static const UsdPrimTypeInfo empty;
105     return empty;
106 }
107 
108 PXR_NAMESPACE_CLOSE_SCOPE
109 
110