From 3b6279ddf21ca58b8cf9469c04a249d69ea449cb Mon Sep 17 00:00:00 2001 From: Luke Shumaker Date: Wed, 18 Apr 2018 16:28:37 -0400 Subject: add comments, fiddle with function publicity --- influxdb.go | 2 ++ jwg.go | 6 ++++++ main.go | 26 +++++++++++++++----------- ping.go | 3 +++ tinc.go | 12 ++++++++---- 5 files changed, 34 insertions(+), 15 deletions(-) diff --git a/influxdb.go b/influxdb.go index 992bef3..7dd42bb 100644 --- a/influxdb.go +++ b/influxdb.go @@ -6,8 +6,10 @@ import ( client "github.com/influxdata/influxdb/client/v2" ) +// Point is a datapoint to be logged in to InfluxDB. type Point = *client.Point +// NewPoint is a convenience function to create a new Point. func NewPoint(name string, tags map[string]string, fields map[string]interface{}) Point { pt, err := client.NewPoint(name, tags, fields, time.Now()) if err != nil { diff --git a/jwg.go b/jwg.go index a7fd343..5b4f8a8 100644 --- a/jwg.go +++ b/jwg.go @@ -7,12 +7,15 @@ import ( "time" ) +// JobWaitGroup is like sync.WaitGroup, but keeps track of job status, +// and tracks how long each job took. type JobWaitGroup struct { lock sync.RWMutex jobs map[string]time.Duration wg sync.WaitGroup } +// Do a job. func (jwg *JobWaitGroup) Do(name string, fn func()) { jwg.lock.Lock() defer jwg.lock.Unlock() @@ -37,11 +40,14 @@ func (jwg *JobWaitGroup) Do(name string, fn func()) { }() } +// Wait for all jobs to finish, and return how long each job took. func (jwg *JobWaitGroup) Wait() map[string]time.Duration { jwg.wg.Wait() return jwg.jobs } +// Status returns the total number of jobs that have been started, and +// a list of still-running jobs. func (jwg *JobWaitGroup) Status() (int, []string) { jwg.lock.RLock() diff --git a/main.go b/main.go index a89dc46..9c86758 100644 --- a/main.go +++ b/main.go @@ -12,6 +12,8 @@ import ( "time" ) +// Given a host/node name and a port number, format a string suitable +// for net.Dial. func fmtAddress(node, port string) string { if isIPv6(node) { return fmt.Sprintf("[%s]:%s", node, port) @@ -27,33 +29,33 @@ func isIPv6(node string) bool { var jwg JobWaitGroup -func Emit(pt Point) { +func emit(pt Point) { if pt == nil { return } fmt.Println(pt) } -func DoHostfile(fname string) { +func doHostfile(fname string) { hostname := filepath.Base(fname) - cfg, err := readConfigFile(fname) + cfg, err := ReadConfigFile(fname) if err != nil { - Emit(NewPoint("public", map[string]string{"host": hostname}, map[string]interface{}{"error": err.Error()})) + emit(NewPoint("public", map[string]string{"host": hostname}, map[string]interface{}{"error": err.Error()})) return } addresses := make(map[string]struct{}) - for _, address := range getAddresses(cfg) { + for _, address := range GetAddresses(cfg) { addresses[fmtAddress(address.Node, address.Port)] = struct{}{} } for address := range addresses { - jwg.Do(hostname+"/"+address+"/tcp4", func() { Emit(DoAddress(hostname, "tcp4", address)) }) - jwg.Do(hostname+"/"+address+"/tcp6", func() { Emit(DoAddress(hostname, "tcp6", address)) }) + jwg.Do(hostname+"/"+address+"/tcp4", func() { emit(doAddress(hostname, "tcp4", address)) }) + jwg.Do(hostname+"/"+address+"/tcp6", func() { emit(doAddress(hostname, "tcp6", address)) }) } } -func DoAddress(host, network, address string) Point { +func doAddress(host, network, address string) Point { tags := map[string]string{ "host": host, "network": network, @@ -75,7 +77,7 @@ func DoAddress(host, network, address string) Point { var result_error error go func() { defer _wg.Done() - result_name, result_version, result_error = Hello(addr) + result_name, result_version, result_error = hello(addr) }() var result_ping float64 go func() { @@ -102,7 +104,9 @@ var dialer = net.Dialer{ Timeout: 10 * time.Second, } -func Hello(addr *net.TCPAddr) (name, version string, err error) { +// hello opens a TCP connection and waits for a Tinc server to say +// hello. +func hello(addr *net.TCPAddr) (name, version string, err error) { conn, err := dialer.Dial(addr.Network(), addr.String()) if err != nil { return "", "", err @@ -121,7 +125,7 @@ func Hello(addr *net.TCPAddr) (name, version string, err error) { func main() { for _, fname := range os.Args[1:] { - DoHostfile(fname) + doHostfile(fname) } watch(time.Second) } diff --git a/ping.go b/ping.go index a41b4ab..ba825e8 100644 --- a/ping.go +++ b/ping.go @@ -7,6 +7,9 @@ import ( "strings" ) +// Ping sends one ICMP echo packet to the given IP and times how long +// it takes to get a response, in milleseconds. Returns -1 if no +// response is received. func Ping(ip net.IP) float64 { cmd := exec.Command("ping", "-n", // numeric diff --git a/tinc.go b/tinc.go index 1bfefc6..d06a6d2 100644 --- a/tinc.go +++ b/tinc.go @@ -7,6 +7,7 @@ import ( "strings" ) +// Error is a parse error recording the filename and line number. type Error struct { File string Line int @@ -38,7 +39,10 @@ func parseConfigLine(line string) (key, val string) { return variable, value } -func readConfigFile(fname string) (map[string][]string, error) { +// ReadConfigFile opens and reads a Tinc configuration file, returning +// a map of settings. Since Tinc setting names are case-insensitive, +// the keys in the map are all lower-case. +func ReadConfigFile(fname string) (map[string][]string, error) { config_tree := make(map[string][]string) fp, err := os.Open(fname) @@ -89,9 +93,9 @@ func readConfigFile(fname string) (map[string][]string, error) { return config_tree, nil } -// Returns a list of public addresses for a host-config in Go -// "net.Dial" format. -func getAddresses(cfg map[string][]string) []struct{ Node, Port string } { +// GetAddresses inspects a tinc host-confing settings object and +// returns a list of public addresses in it. +func GetAddresses(cfg map[string][]string) []struct{ Node, Port string } { var result []struct{ Node, Port string } for _, node := range cfg["address"] { -- cgit v1.2.3