chromium/third_party/dawn/src/dawn/common/ContentLessObjectCache.h

// Copyright 2023 The Dawn & Tint Authors
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#ifndef SRC_DAWN_COMMON_CONTENTLESSOBJECTCACHE_H_
#define SRC_DAWN_COMMON_CONTENTLESSOBJECTCACHE_H_

#include <mutex>
#include <type_traits>
#include <utility>

#include "absl/container/flat_hash_set.h"
#include "absl/container/inlined_vector.h"
#include "dawn/common/ContentLessObjectCacheable.h"
#include "dawn/common/Ref.h"
#include "dawn/common/RefCounted.h"
#include "dawn/common/WeakRef.h"
#include "partition_alloc/pointers/raw_ptr.h"

namespace dawn {

template <typename RefCountedT>
class ContentLessObjectCache;

namespace detail {

// Tagged-type to force special path for EqualityFunc when dealing with Erase. When erasing, we only
// care about pointer equality, not value equality. This is also particularly important because
// trying to promote on the Erase path can cause failures as the object's last ref could've been
// dropped already.
template <typename RefCountedT>
struct ForErase { … };

// All cached WeakRefs must have an immutable hash value determined at insertion. This ensures that
// even if the last ref of the cached value is dropped, we still get the same hash in the set for
// erasing.
template <typename RefCountedT>
struct WeakRefAndHash { … };

template <typename RefCountedT>
struct ContentLessObjectCacheKeyFuncs { … };

}  // namespace detail

template <typename RefCountedT>
class ContentLessObjectCache { … };

}  // namespace dawn

#endif  // SRC_DAWN_COMMON_CONTENTLESSOBJECTCACHE_H_