add comments in snapshot.go

snapshot.go

@@ -1,20 +1,25 @@
 package main
 
 import (
-	"fmt"
 	"time"
 )
 
+// basic conf.
+// TODO: find a good policy to do snapshot
 type snapshotConf struct {
-	// basic
+	// Etcd will check if snapshot is need every checkingInterval
 	checkingInterval time.Duration
-	lastWrites       uint64
-	writesThr        uint64
+	// The number of writes when the last snapshot happened
+	lastWrites uint64
+	// If the incremental number of writes since the last snapshot
+	// exceeds the write Threshold, etcd will do a snapshot
+	writesThr uint64
 }
 
 var snapConf *snapshotConf
 
 func newSnapshotConf() *snapshotConf {
+	// check snapshot every 3 seconds and the threshold is 20K
 	return &snapshotConf{time.Second * 3, etcdStore.TotalWrites(), 20 * 1000}
 }
 
@@ -26,9 +31,6 @@ func monitorSnapshot() {
 		if currentWrites > snapConf.writesThr {
 			raftServer.TakeSnapshot()
 			snapConf.lastWrites = etcdStore.TotalWrites()
-
-		} else {
-			fmt.Println(currentWrites)
 		}
 	}
 }

util.go

@@ -25,6 +25,7 @@ func durationToExpireTime(strDuration string) (time.Time, error) {
 			return time.Unix(0, 0), err
 		}
 		return time.Now().Add(time.Second * (time.Duration)(duration)), nil
+
 	} else {
 		return time.Unix(0, 0), nil
 	}