stageCache.h

//
// Copyright 2016 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
#ifndef PXR_USD_USD_STAGE_CACHE_H
#define PXR_USD_USD_STAGE_CACHE_H
 
#include "pxr/pxr.h"
#include "pxr/usd/usd/api.h"
#include "pxr/usd/sdf/declareHandles.h"
#include "pxr/base/tf/declarePtrs.h"
#include "pxr/base/tf/stringUtils.h"
 
#include <string>
#include <memory>
#include <mutex>
#include <vector>
 
PXR_NAMESPACE_OPEN_SCOPE
 
 
SDF_DECLARE_HANDLES(SdfLayer);
TF_DECLARE_REF_PTRS(UsdStage);
 
class ArResolverContext;
 
class UsdStageCacheRequest;
 
class UsdStageCache
{
public:
    struct Id {
        Id() : _value(-1) {}
 
        static Id FromLongInt(long int val) { return Id(val); }
 
        static Id FromString(const std::string &s) {
            bool overflow = false;
            const long int result = TfStringToLong(s, &overflow);
            if (overflow) {
                TF_CODING_ERROR(
                    "'%s' overflowed during conversion to int64_t.",
                    s.c_str()
                );
            }
            return FromLongInt(result);
        }
 
        long int ToLongInt() const { return _value; }
 
        std::string ToString() const {
            return TfStringify(ToLongInt());
        }
 
        bool IsValid() const { return _value != -1; }
 
        explicit operator bool() const { return IsValid(); }
 
    private:
        friend bool operator==(const Id &lhs, const Id &rhs) {
            return lhs.ToLongInt() == rhs.ToLongInt();
        }
        friend bool operator!=(const Id &lhs, const Id &rhs) {
            return !(lhs == rhs);
        }
        friend bool operator<(const Id &lhs, const Id &rhs) {
            return lhs.ToLongInt() < rhs.ToLongInt();
        }
        friend bool operator<=(const Id &lhs, const Id &rhs) {
            return !(rhs < lhs);
        }
        friend bool operator>(const Id &lhs, const Id &rhs) {
            return rhs < lhs;
        }
        friend bool operator>=(const Id &lhs, const Id &rhs) {
            return !(lhs < rhs);
        }
        friend size_t hash_value(Id id) {
            return ~size_t(id.ToLongInt());
        }
        
        explicit Id(long int val) : _value(val) {}
 
        long int _value;
    };
 
    USD_API
    UsdStageCache();
    
    USD_API
    UsdStageCache(const UsdStageCache &other);
 
    USD_API
    ~UsdStageCache();
 
    USD_API
    UsdStageCache &operator=(const UsdStageCache &other);
 
    USD_API
    void swap(UsdStageCache &other);
 
    USD_API
    std::vector<UsdStageRefPtr> GetAllStages() const;
 
    USD_API
    size_t Size() const;
 
    bool IsEmpty() const { return Size() == 0; }
 
    USD_API
    std::pair<UsdStageRefPtr, bool>
    RequestStage(UsdStageCacheRequest &&request);
 
    USD_API
    UsdStageRefPtr Find(Id id) const;
 
    USD_API
    UsdStageRefPtr FindOneMatching(const SdfLayerHandle &rootLayer) const;
 
    USD_API
    UsdStageRefPtr FindOneMatching(const SdfLayerHandle &rootLayer,
                                   const SdfLayerHandle &sessionLayer) const;
 
    USD_API
    UsdStageRefPtr FindOneMatching(
        const SdfLayerHandle &rootLayer,
        const ArResolverContext &pathResolverContext) const;
 
    USD_API
    UsdStageRefPtr FindOneMatching(
        const SdfLayerHandle &rootLayer,
        const SdfLayerHandle &sessionLayer,
        const ArResolverContext &pathResolverContext) const;
 
    USD_API
    std::vector<UsdStageRefPtr>
    FindAllMatching(const SdfLayerHandle &rootLayer) const;
 
    USD_API
    std::vector<UsdStageRefPtr>
    FindAllMatching(const SdfLayerHandle &rootLayer,
                    const SdfLayerHandle &sessionLayer) const;
 
    USD_API
    std::vector<UsdStageRefPtr>
    FindAllMatching(const SdfLayerHandle &rootLayer,
                    const ArResolverContext &pathResolverContext) const;
 
    USD_API
    std::vector<UsdStageRefPtr>
    FindAllMatching(const SdfLayerHandle &rootLayer,
                    const SdfLayerHandle &sessionLayer,
                    const ArResolverContext &pathResolverContext) const;
 
    USD_API
    Id GetId(const UsdStageRefPtr &stage) const;
 
    bool Contains(const UsdStageRefPtr &stage) const {
        return static_cast<bool>(GetId(stage));
    }
 
    bool Contains(Id id) const { return Find(id); }
 
    USD_API
    Id Insert(const UsdStageRefPtr &stage);
    
    USD_API
    bool Erase(Id id);
 
    USD_API
    bool Erase(const UsdStageRefPtr &stage);
 
    USD_API
    size_t EraseAll(const SdfLayerHandle &rootLayer);
 
    USD_API
    size_t EraseAll(const SdfLayerHandle &rootLayer,
                    const SdfLayerHandle &sessionLayer);
 
    USD_API
    size_t EraseAll(const SdfLayerHandle &rootLayer,
                    const SdfLayerHandle &sessionLayer,
                    const ArResolverContext &pathResolverContext);
    
    USD_API
    void Clear();
 
    USD_API
    void SetDebugName(const std::string &debugName);
 
    USD_API
    std::string GetDebugName() const;
 
private:
    friend void swap(UsdStageCache &lhs, UsdStageCache &rhs) {
        lhs.swap(rhs);
    }
 
    typedef struct Usd_StageCacheImpl _Impl;
    std::unique_ptr<_Impl> _impl;
    mutable std::mutex _mutex;
};
 
class UsdStageCacheRequest
{
public:
    USD_API
    virtual ~UsdStageCacheRequest();
 
    // Return true if the stage satisfies this request.
    virtual bool IsSatisfiedBy(UsdStageRefPtr const &stage) const = 0;
 
    // Return true if the pending request will satisfy this request, once
    // complete.
    virtual bool IsSatisfiedBy(UsdStageCacheRequest const &pending) const = 0;
 
    // Invoked to manufacture a stage to insert in the cache.  Postcondition:
    // IsSatisfiedBy() must return true for the resulting stage.
    virtual UsdStageRefPtr Manufacture() = 0;
 
private:
    friend class UsdStageCache;
 
    struct _Mailbox;
    void _Subscribe(_Mailbox *);
 
    struct _Data;
    struct _DataDeleter { void operator()(_Data *); };
    std::unique_ptr<_Data, _DataDeleter> _data;
};
 
 
PXR_NAMESPACE_CLOSE_SCOPE
 
#endif // PXR_USD_USD_STAGE_CACHE_H