postgresql_statement.hpp 3.52 KB
Newer Older
louiz’'s avatar
louiz’ committed
1 2 3 4 5 6 7 8
#pragma once

#include <database/statement.hpp>

#include <logger/logger.hpp>

#include <libpq-fe.h>

9 10
#include <cstring>

louiz’'s avatar
louiz’ committed
11 12 13 14 15 16 17 18
class PostgresqlStatement: public Statement
{
 public:
  PostgresqlStatement(std::string body, PGconn*const conn):
      body(std::move(body)),
      conn(conn)
  {}
  ~PostgresqlStatement()
19 20 21 22
  {
    PQclear(this->result);
    this->result = nullptr;
  }
louiz’'s avatar
louiz’ committed
23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80
  PostgresqlStatement(const PostgresqlStatement&) = delete;
  PostgresqlStatement& operator=(const PostgresqlStatement&) = delete;
  PostgresqlStatement(PostgresqlStatement&& other) = delete;
  PostgresqlStatement& operator=(PostgresqlStatement&& other) = delete;

  StepResult step() override final
  {
    if (!this->executed)
      {
        this->current_tuple = 0;
        this->executed = true;
        if (!this->execute())
          return StepResult::Error;
      }
    else
      {
        this->current_tuple++;
      }
    if (this->current_tuple < PQntuples(this->result))
      return StepResult::Row;
    return StepResult::Done;
  }

  int64_t get_column_int64(const int col) override
  {
    const char* result = PQgetvalue(this->result, this->current_tuple, col);
    std::istringstream iss;
    iss.str(result);
    int64_t res;
    iss >> res;
    return res;
  }
  std::string get_column_text(const int col) override
  {
    const char* result = PQgetvalue(this->result, this->current_tuple, col);
    return result;
  }
  int get_column_int(const int col) override
  {
    const char* result = PQgetvalue(this->result, this->current_tuple, col);
    std::istringstream iss;
    iss.str(result);
    int res;
    iss >> res;
    return res;
  }

  void bind(std::vector<std::string> params) override
  {

    this->params = std::move(params);
  }

  bool bind_text(const int, const std::string& data) override
  {
    this->params.push_back(data);
    return true;
  }
louiz’'s avatar
louiz’ committed
81
  bool bind_int64(const int, const std::int64_t value) override
louiz’'s avatar
louiz’ committed
82 83 84 85
  {
    this->params.push_back(std::to_string(value));
    return true;
  }
louiz’'s avatar
louiz’ committed
86
  bool bind_null(const int) override
louiz’'s avatar
louiz’ committed
87 88 89 90 91 92 93 94
  {
    this->params.push_back("NULL");
    return true;
  }

 private:

private:
95
  bool execute(const bool second_attempt=false)
louiz’'s avatar
louiz’ committed
96 97 98 99 100
  {
    std::vector<const char*> params;
    params.reserve(this->params.size());

    for (const auto& param: this->params)
louiz’'s avatar
louiz’ committed
101
      params.push_back(param.data());
louiz’'s avatar
louiz’ committed
102
    const int param_size = static_cast<int>(this->params.size());
louiz’'s avatar
louiz’ committed
103
    this->result = PQexecParams(this->conn, this->body.data(),
louiz’'s avatar
louiz’ committed
104
                                param_size,
louiz’'s avatar
louiz’ committed
105 106 107 108 109 110
                                nullptr,
                                params.data(),
                                nullptr,
                                nullptr,
                                0);
    const auto status = PQresultStatus(this->result);
louiz’'s avatar
louiz’ committed
111
    if (status != PGRES_TUPLES_OK && status != PGRES_COMMAND_OK)
louiz’'s avatar
louiz’ committed
112
      {
113 114 115
        const char* original = PQerrorMessage(this->conn);
        if (original && std::strlen(original) > 0)
          log_error("Failed to execute command: ", std::string{original, std::strlen(original) - 1});
116 117 118 119 120 121 122 123 124 125 126
        if (PQstatus(this->conn) != CONNECTION_OK && !second_attempt)
          {
            log_info("Trying to reconnect to PostgreSQL server and execute the query again.");
            PQreset(this->conn);
            return this->execute(true);
          }
        else
          {
            log_error("Givin up.");
            return false;
          }
louiz’'s avatar
louiz’ committed
127 128 129 130 131 132 133 134 135 136 137
      }
    return true;
  }

  bool executed{false};
  std::string body;
  PGconn*const conn;
  std::vector<std::string> params;
  PGresult* result{nullptr};
  int current_tuple{0};
};