add blazingly fast instance_cache implementation for K2 - #1683
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denisichh wants to merge 29 commits into
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add blazingly fast instance_cache implementation for K2#1683denisichh wants to merge 29 commits into
denisichh wants to merge 29 commits into
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denisichh
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PetrShumilov
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Sep 9, 2026
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| void ClassDeclaration::compile_class_name_hash(CodeGenerator& W, ClassPtr klass) { | ||
| // hash of the class name, computed once at compile time -- same for every instance, |
Contributor
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I see that it would be better not to introduce a new field. We already have get_hash in class_instance, which can be helpful, but it has a specific corner case: class_instance<T>{}.get_hash() == nullptr, while class_instance<T>{}.alloc().get_hash() != nullptr. I think you have two possible options:
- Adjust the existing get_hash to provide the required semantics.
- Add a new method (e.g., get_type_hash or similar).
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| compile_class_method(FunctionSignatureGenerator(W).set_const_this(), klass, "size_t virtual_builtin_sizeof()", "sizeof(*this)"); | ||
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| compile_class_method(FunctionSignatureGenerator(W).set_const_this(), klass, "size_t virtual_builtin_alignof()", "alignof(" + klass->src_name + ")"); |
| // memory must be aligned to alignof(T) and >= estimate_memory_usage() bytes | ||
| // caller must pin it with a special ExtraRefCnt (e.g. for_instance_cache), since the instance never frees it. | ||
| // Returns a null instance if memory is unfit. | ||
| inline class_instance clone_in(vk::span<std::byte> memory) const noexcept; |
Contributor
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Do we have an ability to return something like variant?
| // constructs an instance in externally provided memory (no allocation/ownership) | ||
| // leaves it null if memory is smaller than sizeof(T) or misaligned | ||
| template<class... Args> | ||
| inline class_instance<T> alloc(vk::span<std::byte> memory, Args&&... args) noexcept __attribute__((always_inline)); |
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I think that would be better to rename into alloc_in based on 2 reasons:
- More regular and coherent with clone_in
- Do not produce a new overload
| std::enable_if_t<std::is_polymorphic<S>{}, class_instance> virtual_builtin_clone_in(vk::span<std::byte> memory) const noexcept { | ||
| class_instance res; | ||
| if (o) { | ||
| if (unlikely(memory.size() < o->virtual_builtin_sizeof() || reinterpret_cast<std::uintptr_t>(memory.data()) % o->virtual_builtin_alignof() != 0)) { |
Contributor
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I recommend to add nullptr check for memory.data()
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Rewrites instance_cache_store/fetch/update_ttl/delete in the K2 runtime: instead of msgpack-serializing and shipping instances to a separate cache process over RPC, instances are now deep-copied directly into shared memory via the platform's k2::alloc_shared_memory/publish_shared_memory/get_shared_memory.
Storage layout: class_name_hash(u64) | class_instance shell | inner data. On fetch, the block is reinterpreted in place rather than deserialized.
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