numerus/pkg/db.go

package pkg

import (
	"context"
	"log"

	"github.com/jackc/pgx/v4"
	"github.com/jackc/pgx/v4/pgxpool"
)

type Db struct {
	*pgxpool.Pool
}

func NewDatabase(ctx context.Context, connString string) (*Db, error) {
	config, err := pgxpool.ParseConfig(connString)
	if err != nil {
		log.Fatal(err)
	}

	config.AfterConnect = func(ctx context.Context, conn *pgx.Conn) error {
		_, err := conn.Exec(context.Background(), "SET search_path TO numerus, public")
		return err
	}

	config.BeforeAcquire = func(ctx context.Context, conn *pgx.Conn) bool {
		cookie := ""
		if value, ok := ctx.Value(ContextCookieKey).(string); ok {
			cookie = value
		}
		if _, err := conn.Exec(ctx, "select set_cookie($1)", cookie); err != nil {
                       log.Printf("ERROR - Failed to set role: %v", err)
                       return false
	       }
		return true
	}

	config.AfterRelease = func(conn *pgx.Conn) bool {
		if _, err := conn.Exec(context.Background(), "RESET ROLE"); err != nil {
			log.Printf("ERROR - Failed to reset role: %v", err)
			return false
		}
		return true
	}

	pool, err := pgxpool.ConnectConfig(ctx, config)
	if err != nil {
		return nil, err
	}
	return &Db{pool}, nil
}

func (db *Db) Acquire(ctx context.Context) (*Conn, error) {
	conn, err := db.Pool.Acquire(ctx)
	if err != nil {
		return nil, err
	}
	return &Conn{conn}, nil
}

type Conn struct {
	*pgxpool.Conn
}

func (c *Conn) Text(ctx context.Context, def string, sql string, args ...interface{}) string {
	var result string
	if err := c.Conn.QueryRow(ctx, sql, args...).Scan(&result); err != nil {
		if err == pgx.ErrNoRows {
			return def
		}
		panic(err)
	}

	return result
}

func (c *Conn) Exec(ctx context.Context, sql string, args ...interface{}) {
	if _, err := c.Conn.Exec(ctx, sql, args...); err != nil {
		panic(err)
	}
}