add BeforeClose to pgxpool.Pool

pgxpool/pool.go

@@ -85,6 +85,7 @@ type Pool struct {
 	afterConnect          func(context.Context, *pgx.Conn) error
 	beforeAcquire         func(context.Context, *pgx.Conn) bool
 	afterRelease          func(*pgx.Conn) bool
+	beforeClose           func(*pgx.Conn)
 	minConns              int32
 	maxConns              int32
 	maxConnLifetime       time.Duration
@@ -111,7 +112,7 @@ type Config struct {
 	AfterConnect func(context.Context, *pgx.Conn) error
 
 	// BeforeAcquire is called before a connection is acquired from the pool. It must return true to allow the
-	// acquision or false to indicate that the connection should be destroyed and a different connection should be
+	// acquisition or false to indicate that the connection should be destroyed and a different connection should be
 	// acquired.
 	BeforeAcquire func(context.Context, *pgx.Conn) bool
 
@@ -119,6 +120,9 @@ type Config struct {
 	// return the connection to the pool or false to destroy the connection.
 	AfterRelease func(*pgx.Conn) bool
 
+	// BeforeClose is called right before a connection is closed and removed from the pool.
+	BeforeClose func(*pgx.Conn)
+
 	// MaxConnLifetime is the duration since creation after which a connection will be automatically closed.
 	MaxConnLifetime time.Duration
 
@@ -180,6 +184,7 @@ func NewWithConfig(ctx context.Context, config *Config) (*Pool, error) {
 		afterConnect:          config.AfterConnect,
 		beforeAcquire:         config.BeforeAcquire,
 		afterRelease:          config.AfterRelease,
+		beforeClose:           config.BeforeClose,
 		minConns:              config.MinConns,
 		maxConns:              config.MaxConns,
 		maxConnLifetime:       config.MaxConnLifetime,
@@ -236,6 +241,9 @@ func NewWithConfig(ctx context.Context, config *Config) (*Pool, error) {
 			Destructor: func(value *connResource) {
 				ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
 				conn := value.conn
+				if p.beforeClose != nil {
+					p.beforeClose(conn)
+				}
 				conn.Close(ctx)
 				select {
 				case <-conn.PgConn().CleanupDone():