schemaRegistry.h

//
// Copyright 2016 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
// Section 6. Trademarks. is deleted and replaced with:
//
// 6. Trademarks. This License does not grant permission to use the trade
//    names, trademarks, service marks, or product names of the Licensor
//    and its affiliates, except as required to comply with Section 4(c) of
//    the License and to reproduce the content of the NOTICE file.
//
// You may obtain a copy of the Apache License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the Apache License with the above modification is
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the Apache License for the specific
// language governing permissions and limitations under the Apache License.
//
#ifndef PXR_USD_USD_SCHEMA_REGISTRY_H
#define PXR_USD_USD_SCHEMA_REGISTRY_H

#include "pxr/pxr.h"
#include "pxr/usd/usd/api.h"
#include "pxr/usd/usd/common.h"

#include "pxr/usd/sdf/layer.h"
#include "pxr/usd/sdf/primSpec.h"

#include "pxr/base/tf/hash.h"
#include "pxr/base/tf/singleton.h"

#include <unordered_map>

PXR_NAMESPACE_OPEN_SCOPE

SDF_DECLARE_HANDLES(SdfAttributeSpec);
SDF_DECLARE_HANDLES(SdfRelationshipSpec);

class UsdPrimDefinition;

class UsdSchemaRegistry : public TfWeakBase, boost::noncopyable {
public:
    USD_API
    static UsdSchemaRegistry& GetInstance() {
        return TfSingleton<UsdSchemaRegistry>::GetInstance();
    }

    USD_API
    static TfToken GetSchemaTypeName(const TfType &schemaType);

    template <class SchemaType>
    static
    TfToken GetSchemaTypeName() {
        return GetSchemaTypeName(SchemaType::_GetStaticTfType());
    }

    USD_API
    static TfToken GetConcreteSchemaTypeName(const TfType &schemaType);

    USD_API
    static TfToken GetAPISchemaTypeName(const TfType &schemaType);

    USD_API
    static TfType GetTypeFromSchemaTypeName(const TfToken &typeName);

    USD_API
    static TfType GetConcreteTypeFromSchemaTypeName(const TfToken &typeName);

    USD_API
    static TfType GetAPITypeFromSchemaTypeName(const TfToken &typeName);

    USD_API
    static bool IsDisallowedField(const TfToken &fieldName);

    USD_API
    static bool IsTyped(const TfType& primType);

    USD_API 
    static UsdSchemaKind GetSchemaKind(const TfType &schemaType);

    USD_API 
    static UsdSchemaKind GetSchemaKind(const TfToken &typeName);

    USD_API
    static bool IsConcrete(const TfType& primType);

    USD_API
    static bool IsConcrete(const TfToken& primType);

    USD_API
    static bool IsAbstract(const TfType& primType);

    USD_API
    static bool IsAbstract(const TfToken& primType);

    USD_API
    static bool IsAppliedAPISchema(const TfType& apiSchemaType);

    USD_API
    static bool IsAppliedAPISchema(const TfToken& apiSchemaType);

    USD_API
    static bool IsMultipleApplyAPISchema(const TfType& apiSchemaType);
    
    USD_API
    static bool IsMultipleApplyAPISchema(const TfToken& apiSchemaType);
        
    USD_API
    static TfType GetTypeFromName(const TfToken& typeName);

    USD_API
    static std::pair<TfToken, TfToken> GetTypeNameAndInstance(
            const TfToken &apiSchemaName);

    USD_API
    static bool IsAllowedAPISchemaInstanceName(
        const TfToken &apiSchemaName,
        const TfToken &instanceName);

    USD_API
    static const TfTokenVector &GetAPISchemaCanOnlyApplyToTypeNames(
        const TfToken &apiSchemaName, 
        const TfToken &instanceName = TfToken());

    USD_API
    static const std::map<TfToken, TfTokenVector> &GetAutoApplyAPISchemas();

    USD_API
    static void CollectAddtionalAutoApplyAPISchemasFromPlugins(
        std::map<TfToken, TfTokenVector> *autoApplyAPISchemas);

    USD_API
    static TfToken MakeMultipleApplyNameTemplate(
        const std::string &namespacePrefix, 
        const std::string &baseName);

    USD_API
    static TfToken MakeMultipleApplyNameInstance(
        const std::string &nameTemplate,
        const std::string &instanceName);

    USD_API
    static TfToken GetMultipleApplyNameTemplateBaseName(
        const std::string &nameTemplate);

    USD_API
    static bool IsMultipleApplyNameTemplate(
        const std::string &nameTemplate);

    const UsdPrimDefinition* FindConcretePrimDefinition(
        const TfToken &typeName) const {
        const auto it = _concreteTypedPrimDefinitions.find(typeName);
        return it != _concreteTypedPrimDefinitions.end() ? it->second.get() : nullptr;
    }

    const UsdPrimDefinition *FindAppliedAPIPrimDefinition(
        const TfToken &typeName) const {
        // Check the single apply API schemas first then check for multiple
        // apply schemas. This function will most often be used to find a 
        // single apply schema's prim definition as the prim definitions for
        // multiple apply schemas aren't generally useful.
        const auto it = _appliedAPIPrimDefinitions.find(typeName);
        if (it != _appliedAPIPrimDefinitions.end()) {
            return it->second.get();
        }
        const auto multiIt = _multiApplyAPIPrimDefinitions.find(typeName);
        return multiIt != _multiApplyAPIPrimDefinitions.end() ? 
            multiIt->second : nullptr;
    }

    const UsdPrimDefinition *GetEmptyPrimDefinition() const {
        return _emptyPrimDefinition;
    }

    USD_API
    std::unique_ptr<UsdPrimDefinition>
    BuildComposedPrimDefinition(
        const TfToken &primType, const TfTokenVector &appliedAPISchemas) const;

    const VtDictionary &GetFallbackPrimTypes() const {
        return _fallbackPrimTypes;
    }

private:
    friend class TfSingleton<UsdSchemaRegistry>;

    UsdSchemaRegistry();

    // For the given full API schema name (which may be "type:instance" for 
    // multiple apply API schemas), finds and returns the prim definition for 
    // the API schema type. If the API schema is an instance of a multiple 
    // apply API, the instance name will be set in instanceName.
    const UsdPrimDefinition *_FindAPIPrimDefinitionByFullName(
        const TfToken &apiSchemaName, 
        TfToken *instanceName) const;

    void _ComposeAPISchemasIntoPrimDefinition(
        UsdPrimDefinition *primDef, 
        const TfTokenVector &appliedAPISchemas) const;

    // Private class for helping initialize the schema registry. Defined 
    // entirely in the implementation. Declared here for private access to the
    // registry.
    class _SchemaDefInitHelper;

    using _TypeNameToPrimDefinitionMap = std::unordered_map<
        TfToken, const std::unique_ptr<UsdPrimDefinition>, TfToken::HashFunctor>;

    SdfLayerRefPtr _schematics;

    _TypeNameToPrimDefinitionMap _concreteTypedPrimDefinitions;
    _TypeNameToPrimDefinitionMap _appliedAPIPrimDefinitions;

    // This is a mapping from multiple apply API schema name (e.g. 
    // "CollectionAPI") to the template prim definition stored for it in
    // _appliedAPIPrimDefinitions as the template prim definition is actually 
    // mapped to its template name (e.g. "CollectionAPI:__INSTANCE_NAME__") in
    // that map.
    std::unordered_map<TfToken, const UsdPrimDefinition *, TfToken::HashFunctor> 
        _multiApplyAPIPrimDefinitions;
    UsdPrimDefinition *_emptyPrimDefinition;

    VtDictionary _fallbackPrimTypes;

    friend class UsdPrimDefinition;
};

USD_API_TEMPLATE_CLASS(TfSingleton<UsdSchemaRegistry>);

// Utility function for extracting the metadata about applying API schemas from
// the plugin metadata for the schema's type. It is useful for certain clients
// to be able to access this plugin data in the same way that the 
// UsdSchemaRegistry does.
void Usd_GetAPISchemaPluginApplyToInfoForType(
    const TfType &apiSchemaType,
    const TfToken &apiSchemaName,
    std::map<TfToken, TfTokenVector> *autoApplyAPISchemasMap,
    TfHashMap<TfToken, TfTokenVector, TfHash> *canOnlyApplyAPISchemasMap,
    TfHashMap<TfToken, TfToken::Set, TfHash> *allowedInstanceNamesMap);

PXR_NAMESPACE_CLOSE_SCOPE

#endif //PXR_USD_USD_SCHEMA_REGISTRY_H