From 4c8b64d2a62b78e635a50f8c57c170681a542b30 Mon Sep 17 00:00:00 2001
From: Conner Fromknecht <conner@lightning.engineering>
Date: Fri, 4 Jan 2019 17:34:58 -0800
Subject: [PATCH] netann/log: add NANN logger

---
 netann/log.go | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 netann/log.go

diff --git a/netann/log.go b/netann/log.go
new file mode 100644
index 00000000..f19e212c
--- /dev/null
+++ b/netann/log.go
@@ -0,0 +1,45 @@
+package netann
+
+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("NANN", nil))
+}
+
+// DisableLog disables all library log output.  Logging output is disabled by
+// 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)
+}