udemy-go-web-1/internal/repository/driverrepo/sqldriver.go

package driverrepo

import (
	"database/sql"
	"go-udemy-web-1/internal/repository"
	"time"

	_ "github.com/jackc/pgconn"
	_ "github.com/jackc/pgx/v5"
	_ "github.com/jackc/pgx/v5/stdlib"
)

var dbConn = &repository.DB{}

const (
	maxOpenDbConn = 10
	maxIdleDbConn = 5
	maxDbLifetime = 5 * time.Minute
)

// ConnectSQL creates SQL pool for Postgres
func (s *sqlDriverRepo) ConnectSQL(dsn string) (*repository.DB, error) {
	d, err := newDatabase(dsn)
	if err != nil {
		panic(err)
	}

	d.SetMaxOpenConns(maxOpenDbConn)
	d.SetMaxIdleConns(maxIdleDbConn)
	d.SetConnMaxLifetime(maxDbLifetime)

	dbConn.SQL = d

	err = testDB(d)
	if err != nil {
		return nil, err
	}
	return dbConn, nil
}

// testDB tries to ping the database
func testDB(d *sql.DB) error {
	err := d.Ping()
	if err != nil {
		return err
	}
	return nil
}

// newDatabase creates a new database for the application
func newDatabase(dsn string) (*sql.DB, error) {
	db, err := sql.Open("pgx", dsn)
	if err != nil {
		return nil, err
	}

	// Ping test the conn
	if err = db.Ping(); err != nil {
		return nil, err
	}

	return db, err
}