lnd.xprv/monitoring/log.go

46 lines
1.3 KiB
Go

package monitoring
import (
"github.com/btcsuite/btclog"
"github.com/lightningnetwork/lnd/build"
)
// log is a logger that is initialized with no output filters. This means the
// package will not perform any logging by default until the caller requests
// it.
var log btclog.Logger
// The default amount of logging is none.
func init() {
UseLogger(build.NewSubLogger("PROM", nil))
}
// DisableLog disables all library log output. Logging output is disabled by
// default until UseLogger is called.
func DisableLog() {
UseLogger(btclog.Disabled)
}
// UseLogger uses a specified Logger to output package logging info. This
// should be used in preference to SetLogWriter if the caller is also using
// btclog.
func UseLogger(logger btclog.Logger) {
log = logger
}
// logClosure is used to provide a closure over expensive logging operations so
// don't have to be performed when the logging level doesn't warrant it.
type logClosure func() string
// String invokes the underlying function and returns the result.
func (c logClosure) String() string {
return c()
}
// newLogClosure returns a new closure over a function that returns a string
// which itself provides a Stringer interface so that it can be used with the
// logging system.
func newLogClosure(c func() string) logClosure {
return logClosure(c)
}