labelsQuery.h

//
// Copyright 2024 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
#ifndef PXR_USDSEMANTICS_LABELSQUERY_H
#define PXR_USDSEMANTICS_LABELSQUERY_H
 
#include "pxr/pxr.h"
 
#include "pxr/usd/usdSemantics/labelsAPI.h"
#include "pxr/usd/usd/timeCode.h"
#include "pxr/base/gf/interval.h"
#include "pxr/base/tf/token.h"
 
#include <shared_mutex>
#include <set>
#include <unordered_map>
#include <variant>
 
 
PXR_NAMESPACE_OPEN_SCOPE
 
class UsdSemanticsLabelsQuery
{
public:
    UsdSemanticsLabelsQuery(const UsdSemanticsLabelsQuery&) = delete;
    UsdSemanticsLabelsQuery& operator=(
        const UsdSemanticsLabelsQuery&) = delete;
 
    USDSEMANTICS_API UsdSemanticsLabelsQuery(const TfToken& taxonomy,
                                             UsdTimeCode timeCode);
 
    USDSEMANTICS_API UsdSemanticsLabelsQuery(const TfToken& taxonomy,
                                             const GfInterval& interval);
 
    USDSEMANTICS_API
    VtTokenArray ComputeUniqueDirectLabels(const UsdPrim& prim) const;
 
    USDSEMANTICS_API
    VtTokenArray ComputeUniqueInheritedLabels(const UsdPrim& prim) const;
 
    USDSEMANTICS_API
    bool HasDirectLabel(const UsdPrim& prim, const TfToken& label) const;
 
    USDSEMANTICS_API
    bool HasInheritedLabel(const UsdPrim& prim, const TfToken& label) const;
 
    const std::variant<GfInterval, UsdTimeCode>& GetTime() const & { 
        return _time; }
    
    std::variant<GfInterval, UsdTimeCode> GetTime() && { 
        return std::move(_time); }
 
    const TfToken& GetTaxonomy() const & { return _taxonomy; }
 
    TfToken GetTaxonomy() && { return std::move(_taxonomy); }
 
private:
    // Return true if the prim has an entry in the cache
    bool _PopulateLabels(const UsdPrim& prim) const;
 
    // Return true if any of the prim's ancestors have an entry in the cache
    bool _PopulateInheritedLabels(const UsdPrim& prim) const;
 
    TfToken _taxonomy;
    std::variant<GfInterval, UsdTimeCode> _time;
 
    mutable std::shared_mutex _cachedLabelsMutex;
    using _UnorderedTokenSet = std::unordered_set<TfToken, TfHash>;
    mutable std::unordered_map<SdfPath, _UnorderedTokenSet, TfHash> _cachedLabels;
};
 
PXR_NAMESPACE_CLOSE_SCOPE
 
#endif