maskMemoizer.h

Go to the documentation of this file.

//
// Copyright 2025 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
#ifndef PXR_EXEC_VDF_MASK_MEMOIZER_H
#define PXR_EXEC_VDF_MASK_MEMOIZER_H
 
 
#include "pxr/pxr.h"
 
#include "pxr/exec/vdf/mask.h"
 
#include "pxr/base/tf/hash.h"
 
#include <utility>
 
PXR_NAMESPACE_OPEN_SCOPE
 
template <template <typename...> class MapType>
class VdfMaskMemoizer
{
public:
    const VdfMask &Append(const VdfMask &lhs, const VdfMask &rhs) {
        _Key key{lhs, rhs};
 
        typename _Cache::iterator it = _appended.find(key);
        if (it != _appended.end()) {
            return it->second;
        }
 
        return _appended.insert({std::move(key), lhs | rhs}).first->second;
    }
 
private:
 
    // Operations are keyed off of the lhs and rhs operands.
    using _Key = std::pair<VdfMask, VdfMask>;
 
    // Produce a combination of lhs and rhs hash values as the hash for the
    // key.
    struct _Hash {
        size_t operator()(const _Key &v) const {
            return TfHash::Combine(v.first.GetHash(), v.second.GetHash());
        }
    };
 
    // The cache for append operations.
    using _Cache = MapType<_Key, VdfMask, _Hash>;
    _Cache _appended;
};
 
PXR_NAMESPACE_CLOSE_SCOPE
 
#endif