Class: RDO::Postgres::Driver

Inherits:
Driver
  • Object
show all
Defined in:
lib/rdo/postgres/driver.rb

Overview

Driver for the Postgres server.

All default behaviour is overloaded.

Instance Method Summary collapse

Instance Method Details

#close ⇒ Object

Disconnect from the postgres server, and release memory



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# File 'ext/rdo_postgres/driver.c', line 77

static VALUE rdo_postgres_driver_close(VALUE self) {
  RDOPostgresDriver * driver;
  Data_Get_Struct(self, RDOPostgresDriver, driver);

  PQfinish(driver->conn_ptr);
  driver->conn_ptr   = NULL;
  driver->is_open    = 0;
  driver->stmt_count = 0;
  driver->encoding   = -1;

  return Qtrue;
}

#execute(stmt, *args) ⇒ RDO::Result

Internally this driver uses prepared statements.

Parameters:

  • stmt (String) —

    the statement to execute

  • *args (Object...) —

    bind parameters to execute with

Returns:

  • (RDO::Result) —

    a result containing any tuples and query info



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# File 'lib/rdo/postgres/driver.rb', line 26

def execute(stmt, *args)
  prepare(stmt).execute(*args)
end

#open ⇒ Object

Connect to the postgres server



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# File 'ext/rdo_postgres/driver.c', line 46

static VALUE rdo_postgres_driver_open(VALUE self) {
  RDOPostgresDriver * driver;
  Data_Get_Struct(self, RDOPostgresDriver, driver);

  if (driver->is_open) {
    return Qtrue;
  }

  driver->conn_ptr = PQconnectdb(
      RSTRING_PTR(rb_funcall(self, rb_intern("connect_db_string"), 0)));

  if (driver->conn_ptr == NULL || PQstatus(driver->conn_ptr) == CONNECTION_BAD) {
    RDO_ERROR("PostgreSQL connection failed: %s",
        PQerrorMessage(driver->conn_ptr));
  } else if (PQprotocolVersion(driver->conn_ptr) < 3) {
    RDO_ERROR("rdo-postgres requires PostgreSQL protocol version >= 3 (using %u). "
        "PostgreSQL >= 7.4 required.",
        PQprotocolVersion(driver->conn_ptr));
  } else {
    PQsetNoticeProcessor(driver->conn_ptr, &rdo_postgres_driver_notice_processor, NULL);
    driver->is_open    = 1;
    driver->stmt_count = 0;
    driver->encoding   = rb_enc_find_index(
        RSTRING_PTR(rb_funcall(self, rb_intern("encoding"), 0)));
    rb_funcall(self, rb_intern("after_open"), 0);
  }

  return Qtrue;
}

#open? ⇒ Boolean

Preciate test if connection is open

Returns:

  • (Boolean) 


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# File 'ext/rdo_postgres/driver.c', line 91

static VALUE rdo_postgres_driver_open_p(VALUE self) {
  RDOPostgresDriver * driver;
  Data_Get_Struct(self, RDOPostgresDriver, driver);
  return driver->is_open ? Qtrue : Qfalse;
}

#prepare(cmd) ⇒ Object

Prepare a statement for execution



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# File 'ext/rdo_postgres/driver.c', line 98

static VALUE rdo_postgres_driver_prepare(VALUE self, VALUE cmd) {
  Check_Type(cmd, T_STRING);

  RDOPostgresDriver * driver;
  Data_Get_Struct(self, RDOPostgresDriver, driver);

  if (!(driver->is_open)) {
    RDO_ERROR("Unable to prepare statement: connection is not open");
  }

  char name[32];
  sprintf(name, "rdo_stmt_%i", ++driver->stmt_count);

  return rdo_postgres_statement_executor_new(self, cmd, rb_str_new2(name));
}

#quote(str) ⇒ Object

Quote a string literal for safe insertion in a statement



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# File 'ext/rdo_postgres/driver.c', line 115

static VALUE rdo_postgres_driver_quote(VALUE self, VALUE str) {
  if (TYPE(str) == T_NIL) {
    return rb_str_new2("NULL");
  } else if (TYPE(str) != T_STRING) {
    str = RDO_OBJ_TO_S(str);
  }

  RDOPostgresDriver * driver;
  Data_Get_Struct(self, RDOPostgresDriver, driver);

  if (!(driver->is_open)) {
    RDO_ERROR("Unable to quote string: connection is not open");
  }

  char * quoted = malloc(sizeof(char) * RSTRING_LEN(str) * 2 + 1);
  PQescapeStringConn(driver->conn_ptr, quoted,
      RSTRING_PTR(str), RSTRING_LEN(str), NULL);

  VALUE newstr = rb_str_new2(quoted);

  free(quoted);

  return newstr;
}