Refine

db/db.go

@@ -0,0 +1,86 @@
+package db
+
+import (
+	"database/sql"
+	"fmt"
+	"net/url"
+	"strconv"
+	"time"
+
+	_ "github.com/jackc/pgx/v5/stdlib" // PostgreSQL driver
+)
+
+const defaultMaxOpenConns = 10
+
+// Open opens a PostgreSQL database connection pool from a DSN string. It supports custom
+// query parameters for pool configuration: pool_max_conns (default 10), pool_max_idle_conns,
+// pool_conn_max_lifetime, and pool_conn_max_idle_time. These parameters are stripped from
+// the DSN before passing it to the driver.
+func Open(dsn string) (*sql.DB, error) {
+	u, err := url.Parse(dsn)
+	if err != nil {
+		return nil, fmt.Errorf("invalid database URL: %w", err)
+	}
+	q := u.Query()
+	maxOpenConns, err := extractIntParam(q, "pool_max_conns", defaultMaxOpenConns)
+	if err != nil {
+		return nil, err
+	}
+	maxIdleConns, err := extractIntParam(q, "pool_max_idle_conns", 0)
+	if err != nil {
+		return nil, err
+	}
+	connMaxLifetime, err := extractDurationParam(q, "pool_conn_max_lifetime", 0)
+	if err != nil {
+		return nil, err
+	}
+	connMaxIdleTime, err := extractDurationParam(q, "pool_conn_max_idle_time", 0)
+	if err != nil {
+		return nil, err
+	}
+	u.RawQuery = q.Encode()
+	db, err := sql.Open("pgx", u.String())
+	if err != nil {
+		return nil, err
+	}
+	db.SetMaxOpenConns(maxOpenConns)
+	if maxIdleConns > 0 {
+		db.SetMaxIdleConns(maxIdleConns)
+	}
+	if connMaxLifetime > 0 {
+		db.SetConnMaxLifetime(connMaxLifetime)
+	}
+	if connMaxIdleTime > 0 {
+		db.SetConnMaxIdleTime(connMaxIdleTime)
+	}
+	if err := db.Ping(); err != nil {
+		return nil, fmt.Errorf("ping failed: %w", err)
+	}
+	return db, nil
+}
+
+func extractIntParam(q url.Values, key string, defaultValue int) (int, error) {
+	s := q.Get(key)
+	if s == "" {
+		return defaultValue, nil
+	}
+	q.Del(key)
+	v, err := strconv.Atoi(s)
+	if err != nil {
+		return 0, fmt.Errorf("invalid %s value %q: %w", key, s, err)
+	}
+	return v, nil
+}
+
+func extractDurationParam(q url.Values, key string, defaultValue time.Duration) (time.Duration, error) {
+	s := q.Get(key)
+	if s == "" {
+		return defaultValue, nil
+	}
+	q.Del(key)
+	d, err := time.ParseDuration(s)
+	if err != nil {
+		return 0, fmt.Errorf("invalid %s value %q: %w", key, s, err)
+	}
+	return d, nil
+}