dbmetrics

Import path github.com/zweiundeins/lith/dbmetrics. Generated from the doc comments in dbmetrics/.

Wrap a connector (sql.OpenDB) or a driver (sql.Register): each query and exec goes to an Observer and, at or above the slow threshold, to the log with its SQL text, never its arguments. A query's time is the time spent in the driver, in the call and in every Next, not the caller's work between rows. The Prometheus Observer is the nested module dbmetrics/prom, so this package pulls in no metrics library.

Constants

const (
	OpQuery = "query"
	OpExec  = "exec"
)

The op an Observer receives: a statement that returns rows, or one that does not.

const DefaultSlowThreshold = 100 * time.Millisecond

DefaultSlowThreshold is the slow threshold when Options leaves it zero.

Functions

func Register

func Register(name, base string, opts Options) error

Register registers under name the driver registered as base, wrapped. It fails if name is taken or base is unknown. sqlite.Options.Driver opens a lith database through it.

func Wrap

func Wrap(d driver.Driver, opts Options) driver.Driver

Wrap returns a driver whose connections time their statements.

func WrapConnector

func WrapConnector(c driver.Connector, opts Options) driver.Connector

WrapConnector returns a connector whose connections time their statements:

c, err := sqlite.NewConnector(dsn)
...
db := sql.OpenDB(dbmetrics.WrapConnector(c, opts))

Types

type Observer

type Observer interface {
	Observe(op string, elapsed time.Duration, slow bool)
}

Observer receives the duration of every statement. slow reports whether it reached the slow threshold. Observe must be safe for concurrent use.

type Options

type Options struct {
	// Observer receives every statement; nil records nothing but the slow log.
	Observer Observer
	// SlowThreshold is the duration from which a statement is slow: logged at
	// Warn and flagged to the Observer. Zero means DefaultSlowThreshold, a
	// negative value turns the slow log off.
	SlowThreshold time.Duration
	// Logger receives the slow log; nil means slog.Default().
	Logger *slog.Logger
}

Options configure a wrapped driver or connector.