graph_db_session.h

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#ifndef GRAPHSCOPE_DATABASE_GRAPH_DB_SESSION_H_
#define GRAPHSCOPE_DATABASE_GRAPH_DB_SESSION_H_
 
#include "flex/engines/graph_db/app/app_base.h"
#include "flex/engines/graph_db/database/compact_transaction.h"
#include "flex/engines/graph_db/database/insert_transaction.h"
#include "flex/engines/graph_db/database/read_transaction.h"
#include "flex/engines/graph_db/database/single_edge_insert_transaction.h"
#include "flex/engines/graph_db/database/single_vertex_insert_transaction.h"
#include "flex/engines/graph_db/database/transaction_utils.h"
#include "flex/engines/graph_db/database/update_transaction.h"
#include "flex/storages/rt_mutable_graph/mutable_property_fragment.h"
#include "flex/utils/property/column.h"
#include "flex/utils/result.h"
 
namespace gs {
 
class GraphDB;
class WalWriter;
 
class GraphDBSession {
 public:
  enum class InputFormat : uint8_t {
    kCppEncoder = 0,
    kCypherJson = 1,            // Json format for cypher query
    kCypherProtoAdhoc = 2,      // Protobuf format for adhoc query
    kCypherProtoProcedure = 3,  // Protobuf format for procedure query
  };
 
  static constexpr int32_t MAX_RETRY = 3;
  static constexpr int32_t MAX_PLUGIN_NUM = 256;  // 2^(sizeof(uint8_t)*8)
  static constexpr const char* kCppEncoderStr = "\x00";
  static constexpr const char* kCypherJsonStr = "\x01";
  static constexpr const char* kCypherProtoAdhocStr = "\x02";
  static constexpr const char* kCypherProtoProcedureStr = "\x03";
  GraphDBSession(GraphDB& db, Allocator& alloc, WalWriter& logger,
                 const std::string& work_dir, int thread_id)
      : db_(db),
        alloc_(alloc),
        logger_(logger),
        work_dir_(work_dir),
        thread_id_(thread_id),
        eval_duration_(0),
        query_num_(0) {
    for (auto& app : apps_) {
      app = nullptr;
    }
  }
  ~GraphDBSession() {}
 
  ReadTransaction GetReadTransaction() const;
 
  InsertTransaction GetInsertTransaction();
 
  SingleVertexInsertTransaction GetSingleVertexInsertTransaction();
 
  SingleEdgeInsertTransaction GetSingleEdgeInsertTransaction();
 
  UpdateTransaction GetUpdateTransaction();
 
  CompactTransaction GetCompactTransaction();
 
  bool BatchUpdate(UpdateBatch& batch);
 
  const MutablePropertyFragment& graph() const;
  MutablePropertyFragment& graph();
  const GraphDB& db() const;
 
  const Schema& schema() const;
 
  std::shared_ptr<ColumnBase> get_vertex_property_column(
      uint8_t label, const std::string& col_name) const;
 
  // Get vertex id column.
  std::shared_ptr<RefColumnBase> get_vertex_id_column(uint8_t label) const;
 
  Result<std::vector<char>> Eval(const std::string& input);
 
  void GetAppInfo(Encoder& result);
 
  int SessionId() const;
 
  bool Compact();
 
  double eval_duration() const;
 
  const AppMetric& GetAppMetric(int idx) const;
 
  int64_t query_num() const;
 
  AppBase* GetApp(int idx);
 
  AppBase* GetApp(const std::string& name);
 
 private:
  Result<std::pair<uint8_t, std::string_view>>
  parse_query_type_from_cypher_json(const std::string_view& input);
  Result<std::pair<uint8_t, std::string_view>>
  parse_query_type_from_cypher_internal(const std::string_view& input);
  inline Result<std::pair<uint8_t, std::string_view>> parse_query_type(
      const std::string& input) {
    const char* str_data = input.data();
    VLOG(10) << "parse query type for " << input << " size: " << input.size();
    char input_tag = input.back();
    VLOG(10) << "input tag: " << static_cast<int>(input_tag);
    size_t len = input.size();
    if (input_tag == static_cast<uint8_t>(InputFormat::kCppEncoder)) {
      // For cpp encoder, the query id is the second last byte, others are all
      // user-defined payload,
      return std::make_pair((uint8_t) input[len - 2],
                            std::string_view(str_data, len - 2));
    } else if (input_tag ==
               static_cast<uint8_t>(InputFormat::kCypherProtoAdhoc)) {
      // For cypher internal adhoc, the query id is the
      // second last byte,which is fixed to 255, and other bytes are a string
      // representing the path to generated dynamic lib.
      return std::make_pair((uint8_t) input[len - 2],
                            std::string_view(str_data, len - 2));
    } else if (input_tag == static_cast<uint8_t>(InputFormat::kCypherJson)) {
      // For cypherJson there is no query-id provided. The query name is
      // provided in the json string.
      // We don't discard the last byte, since we need it to determine the input
      // format when deserializing the input arguments in deserialize() function
      std::string_view str_view(input.data(), len);
      return parse_query_type_from_cypher_json(str_view);
    } else if (input_tag ==
               static_cast<uint8_t>(InputFormat::kCypherProtoProcedure)) {
      // For cypher internal procedure, the query_name is
      // provided in the protobuf message.
      // Same as cypherJson, we don't discard the last byte.
      std::string_view str_view(input.data(), len);
      return parse_query_type_from_cypher_internal(str_view);
    } else {
      return Result<std::pair<uint8_t, std::string_view>>(
          gs::Status(StatusCode::INVALID_ARGUMENT,
                     "Invalid input tag: " + std::to_string(input_tag)));
    }
  }
  GraphDB& db_;
  Allocator& alloc_;
  WalWriter& logger_;
  std::string work_dir_;
  int thread_id_;
 
  std::array<AppWrapper, MAX_PLUGIN_NUM> app_wrappers_;
  std::array<AppBase*, MAX_PLUGIN_NUM> apps_;
  std::array<AppMetric, MAX_PLUGIN_NUM> app_metrics_;
 
  std::atomic<int64_t> eval_duration_;
  std::atomic<int64_t> query_num_;
};
 
}  // namespace gs
 
#endif  // GRAPHSCOPE_DATABASE_GRAPH_DB_SESSION_H_