WIP: Refactor 1833:use entt as ecs

.gitmodules

@@ -16,3 +16,6 @@
 [submodule "cpp/vcpkg"]
 	path = cpp/vcpkg
 	url = https://github.com/microsoft/vcpkg.git
+[submodule "cpp/third_party/entt"]
+	path = cpp/third_party/entt
+	url = https://github.com/skypjack/entt.git

cpp/arcticdb/CMakeLists.txt

@@ -638,6 +638,7 @@ if (WIN32)
     )
 endif()
 
+add_compile_definitions(ENTT_ID_TYPE=std::uint64_t)
 
 set (arcticdb_core_libraries
         pybind11::module # Transitively includes Python::Module or Python::Python as appropriate
@@ -656,6 +657,7 @@ set (arcticdb_core_libraries
         Folly::folly # Transitively includes: double-conversion, gflags, glog, libevent, libssl, libcrypto, libiberty, libsodium
         Azure::azure-identity
         Azure::azure-storage-blobs
+        EnTT::EnTT
 )
 
 if(${ARCTICDB_PYTHON_EXPLICIT_LINK})
@@ -873,33 +875,33 @@ if(${TEST})
     python_utils_dump_vars_if_enabled("Python for test compilation")
 
     set(unit_test_srcs
-            async/test/test_async.cpp
-            codec/test/test_codec.cpp
-            codec/test/test_encode_field_collection.cpp
-            codec/test/test_segment_header.cpp
-            codec/test/test_encoded_field.cpp
-            column_store/test/ingestion_stress_test.cpp
-            column_store/test/test_column.cpp
-            column_store/test/test_column_data_random_accessor.cpp
-            column_store/test/test_index_filtering.cpp
-            column_store/test/test_memory_segment.cpp
-            entity/test/test_atom_key.cpp
-            entity/test/test_key_serialization.cpp
-            entity/test/test_metrics.cpp
-            entity/test/test_ref_key.cpp
-            entity/test/test_tensor.cpp
-            log/test/test_log.cpp
-            pipeline/test/test_container.hpp
-            pipeline/test/test_pipeline.cpp
-            pipeline/test/test_query.cpp
-            util/test/test_regex.cpp
-            processing/test/test_arithmetic_type_promotion.cpp
-            processing/test/test_clause.cpp
-            processing/test/test_component_manager.cpp
-            processing/test/test_expression.cpp
-            processing/test/test_filter_and_project_sparse.cpp
-            processing/test/test_has_valid_type_promotion.cpp
-            processing/test/test_operation_dispatch.cpp
+#            async/test/test_async.cpp
+#            codec/test/test_codec.cpp
+#            codec/test/test_encode_field_collection.cpp
+#            codec/test/test_segment_header.cpp
+#            codec/test/test_encoded_field.cpp
+#            column_store/test/ingestion_stress_test.cpp
+#            column_store/test/test_column.cpp
+#            column_store/test/test_column_data_random_accessor.cpp
+#            column_store/test/test_index_filtering.cpp
+#            column_store/test/test_memory_segment.cpp
+#            entity/test/test_atom_key.cpp
+#            entity/test/test_key_serialization.cpp
+#            entity/test/test_metrics.cpp
+#            entity/test/test_ref_key.cpp
+#            entity/test/test_tensor.cpp
+#            log/test/test_log.cpp
+#            pipeline/test/test_container.hpp
+#            pipeline/test/test_pipeline.cpp
+#            pipeline/test/test_query.cpp
+#            util/test/test_regex.cpp
+#            processing/test/test_arithmetic_type_promotion.cpp
+#            processing/test/test_clause.cpp
+#            processing/test/test_component_manager.cpp
+#            processing/test/test_expression.cpp
+#            processing/test/test_filter_and_project_sparse.cpp
+#            processing/test/test_has_valid_type_promotion.cpp
+#            processing/test/test_operation_dispatch.cpp
             processing/test/test_resample.cpp
             processing/test/test_set_membership.cpp
             processing/test/test_signed_unsigned_comparison.cpp

cpp/arcticdb/processing/clause.hpp

@@ -114,12 +114,35 @@ std::vector<std::vector<size_t>> structure_by_column_slice(std::vector<RangesAnd
 
 std::vector<std::vector<size_t>> structure_all_together(std::vector<RangesAndKey>& ranges_and_keys);
 
-ProcessingUnit gather_entities(std::shared_ptr<ComponentManager> component_manager,
-                               std::vector<EntityId>&& entity_ids,
-                               bool include_atom_keys = false,
-                               bool include_initial_expected_get_calls = false);
+/*
+ * On entry to a clause, construct ProcessingUnits from the input entity IDs. These will either be provided by the
+ * structure_for_processing method for the first clause in the pipeline, or by the previous clause for all subsequent
+ * clauses.
+ */
+template<class... Args>
+ProcessingUnit gather_entities(ComponentManager& component_manager, std::vector<EntityId>&& entity_ids) {
+    ProcessingUnit res;
+    auto components = component_manager.get_entities<Args...>(entity_ids);
+    ([&]{
+        auto component = std::move(std::get<std::vector<Args>>(components));
+        if constexpr (std::is_same_v<Args, std::shared_ptr<SegmentInMemory>>) {
+            res.set_segments(std::move(component));
+        } else if constexpr (std::is_same_v<Args, std::shared_ptr<RowRange>>) {
+            res.set_row_ranges(std::move(component));
+        } else if constexpr (std::is_same_v<Args, std::shared_ptr<ColRange>>) {
+            res.set_col_ranges(std::move(component));
+        } else if constexpr (std::is_same_v<Args, std::shared_ptr<AtomKey>>) {
+            res.set_atom_keys(std::move(component));
+        } else if constexpr (std::is_same_v<Args, EntityFetchCount>) {
+            res.set_entity_fetch_count(std::move(component));
+        } else {
+            static_assert(sizeof(Args) == 0, "Unexpected component type provided in gather_entities");
+        }
+    }(), ...);
+    return res;
+}
 
-std::vector<EntityId> push_entities(std::shared_ptr<ComponentManager> component_manager, ProcessingUnit&& proc);
+std::vector<EntityId> push_entities(ComponentManager& component_manager, ProcessingUnit&& proc, EntityFetchCount entity_fetch_count=1);
 
 std::vector<EntityId> flatten_entities(std::vector<std::vector<EntityId>>&& entity_ids_vec);
 
@@ -272,14 +295,15 @@ struct PartitionClause {
         if (entity_ids.empty()) {
             return {};
         }
-        auto proc = gather_entities(component_manager_, std::move(entity_ids));
+        auto proc = gather_entities<std::shared_ptr<SegmentInMemory>, std::shared_ptr<RowRange>, std::shared_ptr<ColRange>>(*component_manager_, std::move(entity_ids));
         std::vector<ProcessingUnit> partitioned_procs = partition_processing_segment<GrouperType, BucketizerType>(
                 proc,
                 ColumnName(grouping_column_),
                 processing_config_.dynamic_schema_);
         std::vector<EntityId> output;
         for (auto &&partitioned_proc: partitioned_procs) {
-            std::vector<EntityId> proc_entity_ids = push_entities(component_manager_, std::move(partitioned_proc));
+            // EntityFetchCount is 2, once for the repartition, and once for AggregationClause::process
+            std::vector<EntityId> proc_entity_ids = push_entities(*component_manager_, std::move(partitioned_proc), 2);
             output.insert(output.end(), proc_entity_ids.begin(), proc_entity_ids.end());
         }
         return output;
@@ -305,7 +329,7 @@ struct PartitionClause {
         // Experimentation shows flattening the entities into a single vector and a single call to
         // component_manager_->get is faster than not flattening and making multiple calls
         auto entity_ids = flatten_entities(std::move(entity_ids_vec));
-        std::vector<bucket_id> buckets{component_manager_->get<bucket_id>(entity_ids)};
+        auto [buckets] = component_manager_->get_entities<bucket_id>(entity_ids);
         for (auto [idx, entity_id]: folly::enumerate(entity_ids)) {
             res[buckets[idx]].emplace_back(entity_id);
         }

cpp/arcticdb/processing/component_manager.cpp

@@ -5,17 +5,27 @@
  * As of the Change Date specified in that file, in accordance with the Business Source License, use of this software will be governed by the Apache License, version 2.0.
  */
 
+
+#include <atomic>
+
 #include <arcticdb/processing/component_manager.hpp>
 
 namespace arcticdb {
 
-void ComponentManager::set_next_entity_id(EntityId id) {
-    next_entity_id_ = id;
+std::vector<EntityId> ComponentManager::get_new_entity_ids(size_t count) {
+    std::vector<EntityId> ids(count);
+    std::lock_guard<std::mutex> lock(mtx_);
+    registry_.create(ids.begin(), ids.end());
+    return ids;
 }
 
-EntityId ComponentManager::entity_id(const std::optional<EntityId>& id) {
-    // Do not use value_or as we do not want the side effect of fetch_add when id was provided by the caller
-    return id.has_value() ? *id : next_entity_id_.fetch_add(1);
+void ComponentManager::erase_entity(EntityId id) {
+    // Ideally would call registry_.destroy(id), or at least registry_.erase<std::shared_ptr<SegmentInMemory>>(id)
+    // at this point. However, they are both slower than this, so just decrement the ref count of the only
+    // sizeable component, so that when the shared pointer goes out of scope in the calling function, the
+    // memory is freed
+    registry_.get<std::shared_ptr<SegmentInMemory>>(id).reset();
 }
 
+
 } // namespace arcticdb