PerfectJoinHashTable.h

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/*
 * Copyright 2022 HEAVY.AI, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include "Analyzer/Analyzer.h"
#include "DataMgr/Allocators/ThrustAllocator.h"
#include "DataMgr/Chunk/Chunk.h"
#include "QueryEngine/ColumnarResults.h"
#include "QueryEngine/DataRecycler/HashingSchemeRecycler.h"
#include "QueryEngine/DataRecycler/HashtableRecycler.h"
#include "QueryEngine/Descriptors/InputDescriptors.h"
#include "QueryEngine/Descriptors/RowSetMemoryOwner.h"
#include "QueryEngine/ExpressionRange.h"
#include "QueryEngine/InputMetadata.h"
#include "QueryEngine/JoinHashTable/HashJoin.h"
#include "QueryEngine/JoinHashTable/PerfectHashTable.h"

#include <llvm/IR/Value.h>

#ifdef HAVE_CUDA
#include <cuda.h>
#endif
#include <functional>
#include <memory>
#include <mutex>
#include <stdexcept>

struct BucketizedHashEntryInfo;

class PerfectJoinHashTable : public HashJoin {
 public:
  static std::shared_ptr<PerfectJoinHashTable> getInstance(
      const std::shared_ptr<Analyzer::BinOper> qual_bin_oper,
      const std::vector<InputTableInfo>& query_infos,
      const Data_Namespace::MemoryLevel memory_level,
      const JoinType join_type,
      const HashType preferred_hash_type,
      const int device_count,
      ColumnCacheMap& column_cache,
      Executor* executor,
      const HashTableBuildDagMap& hashtable_build_dag_map,
      const RegisteredQueryHint& query_hints,
      const TableIdToNodeMap& table_id_to_node_map);

  std::string toString(const ExecutorDeviceType device_type,
                       const int device_id = 0,
                       bool raw = false) const override;

  std::set<DecodedJoinHashBufferEntry> toSet(const ExecutorDeviceType device_type,
                                             const int device_id) const override;

  llvm::Value* codegenSlot(const CompilationOptions&, const size_t) override;

  HashJoinMatchingSet codegenMatchingSet(const CompilationOptions&,
                                         const size_t) override;

  shared::TableKey getInnerTableId() const noexcept override {
    return col_var_->getTableKey();
  };

  int getInnerTableRteIdx() const noexcept override {
    return col_var_.get()->get_rte_idx();
  };

  HashType getHashType() const noexcept override { return hash_type_; }

  Data_Namespace::MemoryLevel getMemoryLevel() const noexcept override {
    return memory_level_;
  };

  int getDeviceCount() const noexcept override { return device_count_; };

  size_t offsetBufferOff() const noexcept override;

  size_t countBufferOff() const noexcept override;

  size_t payloadBufferOff() const noexcept override;

  std::string getHashJoinType() const final { return "Perfect"; }

  static HashtableRecycler* getHashTableCache() {
    CHECK(hash_table_cache_);
    return hash_table_cache_.get();
  }
  static HashingSchemeRecycler* getHashingSchemeCache() {
    CHECK(hash_table_layout_cache_);
    return hash_table_layout_cache_.get();
  }

  static void invalidateCache() {
    CHECK(hash_table_layout_cache_);
    hash_table_layout_cache_->clearCache();

    CHECK(hash_table_cache_);
    hash_table_cache_->clearCache();
  }

  static void markCachedItemAsDirty(size_t table_key) {
    CHECK(hash_table_layout_cache_);
    CHECK(hash_table_cache_);
    auto candidate_table_keys =
        hash_table_cache_->getMappedQueryPlanDagsWithTableKey(table_key);
    if (candidate_table_keys.has_value()) {
      hash_table_layout_cache_->markCachedItemAsDirty(
          table_key,
          *candidate_table_keys,
          CacheItemType::HT_HASHING_SCHEME,
          DataRecyclerUtil::CPU_DEVICE_IDENTIFIER);
      hash_table_cache_->markCachedItemAsDirty(table_key,
                                               *candidate_table_keys,
                                               CacheItemType::PERFECT_HT,
                                               DataRecyclerUtil::CPU_DEVICE_IDENTIFIER);
    }
  }

  const RegisteredQueryHint& getRegisteredQueryHint() { return query_hints_; }

  BucketizedHashEntryInfo getHashEntryInfo() const { return hash_entry_info_; }

  size_t getNormalizedHashEntryCount() const {
    return hash_entry_info_.getNormalizedHashEntryCount();
  }

  virtual ~PerfectJoinHashTable() {}

 private:
  // Equijoin API
  bool isOneToOneHashPossible(
      const std::vector<ColumnsForDevice>& columns_per_device) const;

  ColumnsForDevice fetchColumnsForDevice(
      const std::vector<Fragmenter_Namespace::FragmentInfo>& fragments,
      const int device_id,
      DeviceAllocator* dev_buff_owner);

  void reifyForDevice(const ChunkKey& hash_table_key,
                      const ColumnsForDevice& columns_for_device,
                      const HashType layout,
                      const int device_id,
                      const logger::ThreadLocalIds);

  int initHashTableForDevice(const ChunkKey& chunk_key,
                             const JoinColumn& join_column,
                             const InnerOuter& cols,
                             const HashType layout,
                             const Data_Namespace::MemoryLevel effective_memory_level,
                             const int device_id);

  Data_Namespace::MemoryLevel getEffectiveMemoryLevel(
      const std::vector<InnerOuter>& inner_outer_pairs) const;

  std::vector<InnerOuter> inner_outer_pairs_;

  PerfectJoinHashTable(const std::shared_ptr<Analyzer::BinOper> qual_bin_oper,
                       const Analyzer::ColumnVar* col_var,
                       const std::vector<InputTableInfo>& query_infos,
                       const Data_Namespace::MemoryLevel memory_level,
                       const JoinType join_type,
                       const HashType preferred_hash_type,
                       const ExpressionRange& col_range,
                       const ExpressionRange& rhs_source_col_range,
                       const BucketizedHashEntryInfo hash_entry_info,
                       ColumnCacheMap& column_cache,
                       Executor* executor,
                       const int device_count,
                       const RegisteredQueryHint& query_hints,
                       const HashTableBuildDagMap& hashtable_build_dag_map,
                       const TableIdToNodeMap& table_id_to_node_map,
                       const InnerOuterStringOpInfos& inner_outer_string_op_infos = {})
      : qual_bin_oper_(qual_bin_oper)
      , join_type_(join_type)
      , col_var_(std::dynamic_pointer_cast<Analyzer::ColumnVar>(col_var->deep_copy()))
      , query_infos_(query_infos)
      , memory_level_(memory_level)
      , hash_type_(preferred_hash_type)
      , col_range_(col_range)
      , rhs_source_col_range_(rhs_source_col_range)
      , hash_entry_info_(hash_entry_info)
      , executor_(executor)
      , column_cache_(column_cache)
      , device_count_(device_count)
      , query_hints_(query_hints)
      , needs_dict_translation_(false)
      , hashtable_build_dag_map_(hashtable_build_dag_map)
      , table_id_to_node_map_(table_id_to_node_map)
      , inner_outer_string_op_infos_(inner_outer_string_op_infos) {
    CHECK(col_range.getType() == ExpressionRangeType::Integer);
    CHECK_GT(device_count_, 0);
    hash_tables_for_device_.resize(device_count_);
  }

  ChunkKey genChunkKey(const std::vector<Fragmenter_Namespace::FragmentInfo>& fragments,
                       const Analyzer::Expr* outer_col,
                       const Analyzer::ColumnVar* inner_col) const;

  void reify();
  std::shared_ptr<PerfectHashTable> initHashTableOnCpuFromCache(
      QueryPlanHash key,
      CacheItemType item_type,
      DeviceIdentifier device_identifier);
  void putHashTableOnCpuToCache(QueryPlanHash key,
                                CacheItemType item_type,
                                std::shared_ptr<PerfectHashTable> hashtable_ptr,
                                DeviceIdentifier device_identifier,
                                size_t hashtable_building_time);

  const InputTableInfo& getInnerQueryInfo(const Analyzer::ColumnVar* inner_col) const;

  size_t shardCount() const;

  llvm::Value* codegenHashTableLoad(const size_t table_idx);

  std::vector<llvm::Value*> getHashJoinArgs(llvm::Value* hash_ptr,
                                            llvm::Value* key_lvs,
                                            const Analyzer::Expr* key_col,
                                            const int shard_count,
                                            const CompilationOptions& co);

  bool isBitwiseEq() const override;

  size_t getComponentBufferSize() const noexcept override;

  HashTable* getHashTableForDevice(const size_t device_id) const;

  void copyCpuHashTableToGpu(std::shared_ptr<PerfectHashTable>& cpu_hash_table,
                             const int device_id,
                             Data_Namespace::DataMgr* data_mgr);

  struct AlternativeCacheKeyForPerfectHashJoin {
    const ExpressionRange col_range;
    const Analyzer::ColumnVar* inner_col;
    const Analyzer::ColumnVar* outer_col;
    InnerOuterStringOpInfos inner_outer_string_op_infos;
    const ChunkKey chunk_key;
    const size_t num_elements;
    const SQLOps optype;
    const JoinType join_type;
  };

  static QueryPlanHash getAlternativeCacheKey(
      AlternativeCacheKeyForPerfectHashJoin& info) {
    auto hash = boost::hash_value(::toString(info.chunk_key));
    boost::hash_combine(hash, info.inner_col->toString());
    if (info.inner_col->get_type_info().is_string()) {
      boost::hash_combine(hash, info.outer_col->toString());
    }
    boost::hash_combine(hash, ::toString(info.inner_outer_string_op_infos));
    boost::hash_combine(hash, info.col_range.toString());
    boost::hash_combine(hash, info.num_elements);
    boost::hash_combine(hash, info.optype);
    boost::hash_combine(hash, info.join_type);
    return hash;
  }

  std::shared_ptr<Analyzer::BinOper> qual_bin_oper_;
  const JoinType join_type_;
  std::shared_ptr<Analyzer::ColumnVar> col_var_;
  const std::vector<InputTableInfo>& query_infos_;
  const Data_Namespace::MemoryLevel memory_level_;
  HashType hash_type_;
  std::mutex cpu_hash_table_buff_mutex_;
  std::mutex str_proxy_translation_mutex_;
  const StringDictionaryProxy::IdMap* str_proxy_translation_map_{nullptr};
  ExpressionRange col_range_;
  ExpressionRange rhs_source_col_range_;
  mutable BucketizedHashEntryInfo hash_entry_info_;
  Executor* executor_;
  ColumnCacheMap& column_cache_;
  const int device_count_;
  RegisteredQueryHint query_hints_;
  mutable bool needs_dict_translation_;
  HashTableBuildDagMap hashtable_build_dag_map_;
  // per-device cache key to cover hash table for sharded table
  std::vector<QueryPlanHash> hashtable_cache_key_;
  HashtableCacheMetaInfo hashtable_cache_meta_info_;
  std::unordered_set<size_t> table_keys_;
  const TableIdToNodeMap table_id_to_node_map_;
  const InnerOuterStringOpInfos inner_outer_string_op_infos_;

  static std::unique_ptr<HashtableRecycler> hash_table_cache_;
  static std::unique_ptr<HashingSchemeRecycler> hash_table_layout_cache_;
};

bool needs_dictionary_translation(
    const InnerOuter& inner_outer_col_pair,
    const InnerOuterStringOpInfos& inner_outer_string_op_infos,
    const Executor* executor);

inline Data_Namespace::MemoryLevel get_effective_memory_level(
    const Data_Namespace::MemoryLevel memory_level,
    const bool needs_dict_translation) {
  if (needs_dict_translation) {
    return Data_Namespace::CPU_LEVEL;
  }
  return memory_level;
}

std::vector<Fragmenter_Namespace::FragmentInfo> only_shards_for_device(
    const std::vector<Fragmenter_Namespace::FragmentInfo>& fragments,
    const int device_id,
    const int device_count);

const InputTableInfo& get_inner_query_info(
    const shared::TableKey& inner_table_key,
    const std::vector<InputTableInfo>& query_infos);

size_t get_entries_per_device(const size_t total_entries,
                              const size_t shard_count,
                              const size_t device_count,
                              const Data_Namespace::MemoryLevel memory_level);