registry.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_BASE_PLUG_REGISTRY_H
#define PXR_BASE_PLUG_REGISTRY_H

#include "pxr/pxr.h"
#include "pxr/base/plug/api.h"

#include "pxr/base/js/value.h"
#include "pxr/base/tf/declarePtrs.h"
#include "pxr/base/tf/hash.h"
#include "pxr/base/tf/hashset.h"
#include "pxr/base/tf/refPtr.h"
#include "pxr/base/tf/singleton.h"
#include "pxr/base/tf/type.h"
#include "pxr/base/tf/weakBase.h"
#include "pxr/base/tf/weakPtr.h"

#include <mutex>
#include <string>
#include <vector>

PXR_NAMESPACE_OPEN_SCOPE

TF_DECLARE_WEAK_PTRS(PlugPlugin);
class Plug_RegistrationMetadata;


class PlugRegistry : public TfWeakBase {
    PlugRegistry(PlugRegistry const &) = delete;
    PlugRegistry &operator=(PlugRegistry const &) = delete;
public:
    typedef PlugRegistry This;
    typedef std::vector<TfType> TypeVector;

    PLUG_API
    static PlugRegistry & GetInstance();

    PLUG_API
    PlugPluginPtrVector RegisterPlugins(const std::string & pathToPlugInfo);

    PLUG_API
    PlugPluginPtrVector
    RegisterPlugins(const std::vector<std::string> & pathsToPlugInfo);

    PLUG_API
    static TfType FindTypeByName(std::string const &typeName);

    PLUG_API
    static TfType
    FindDerivedTypeByName(TfType base, std::string const &typeName);

    template <class Base>
    static TfType
    FindDerivedTypeByName(std::string const &typeName) {
        return FindDerivedTypeByName(TfType::Find<Base>(), typeName);
    }

    PLUG_API
    static std::vector<TfType>
    GetDirectlyDerivedTypes(TfType base);

    PLUG_API
    static void
    GetAllDerivedTypes(TfType base, std::set<TfType> *result);

    template <class Base>
    static void
    GetAllDerivedTypes(std::set<TfType> *result) {
        return GetAllDerivedTypes(TfType::Find<Base>(), result);
    }

    PLUG_API
    PlugPluginPtr GetPluginForType(TfType t) const;

    PLUG_API
    PlugPluginPtrVector GetAllPlugins() const;

    PLUG_API
    PlugPluginPtr GetPluginWithName(const std::string& name) const;

    PLUG_API
    std::string GetStringFromPluginMetaData(TfType type, 
                                            const std::string &key) const;

    PLUG_API
    JsValue GetDataFromPluginMetaData(TfType type,
                                      const std::string &key) const;

private:
    // Private ctor and dtor since this is a constructed as a singleton.
    PLUG_LOCAL
    PlugRegistry();

    // Registers all plug-ins discovered in any of \a pathsToPlugInfo
    // but does not send a notice.  The priority order of paths is honored if
    // pathsAreOrdered.
    PLUG_LOCAL
    PlugPluginPtrVector
    _RegisterPlugins(const std::vector<std::string>& pathsToPlugInfo,
                     bool pathsAreOrdered);

    template <class ConcurrentVector>
    PLUG_LOCAL
    void _RegisterPlugin(const Plug_RegistrationMetadata&,
                         ConcurrentVector *newPlugins);
    PLUG_LOCAL
    bool _InsertRegisteredPluginPath(const std::string &path);

    friend class TfSingleton< PlugRegistry >;
    friend class PlugPlugin; // For _RegisterPlugins().

private:
    TfHashSet<std::string, TfHash> _registeredPluginPaths;

    std::mutex _mutex;
};

PLUG_API_TEMPLATE_CLASS(TfSingleton<PlugRegistry>);

PXR_NAMESPACE_CLOSE_SCOPE

#endif // PXR_BASE_PLUG_REGISTRY_H