From 493613b9b3b12d8d7235f2a187a1e3154c5dfa78 Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@lukeshu.com>
Date: Tue, 17 Apr 2018 18:26:53 -0400
Subject: cooler job tracking

---
 jwg.go  | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 main.go | 23 +++++++++--------
 2 files changed, 101 insertions(+), 10 deletions(-)
 create mode 100644 jwg.go

diff --git a/jwg.go b/jwg.go
new file mode 100644
index 0000000..6ef06d0
--- /dev/null
+++ b/jwg.go
@@ -0,0 +1,88 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+)
+
+type JobWaitGroup struct {
+	lock sync.RWMutex
+	jobs map[string]bool
+	wg   sync.WaitGroup
+}
+
+func (jwg *JobWaitGroup) Do(name string, fn func()) {
+	jwg.lock.Lock()
+	defer jwg.lock.Unlock()
+
+	if jwg.jobs == nil {
+		jwg.jobs = make(map[string]bool)
+	}
+	if _, dup := jwg.jobs[name]; dup {
+		panic(fmt.Sprintf("job %q already exists", name))
+	}
+	jwg.jobs[name] = true
+	//fmt.Fprintf(os.Stderr, "add %p %v\n", &jwg.wg, jwg.wg)
+	jwg.wg.Add(1)
+	go func() {
+		defer func() {
+			jwg.lock.Lock()
+			defer jwg.lock.Unlock()
+			jwg.jobs[name] = false
+			jwg.wg.Done()
+			//fmt.Fprintf(os.Stderr, "del %p %v\n", &jwg.wg, jwg.wg)
+		}()
+		fn()
+	}()
+}
+
+func (jwg *JobWaitGroup) Wait() {
+	jwg.wg.Wait()
+}
+
+func (jwg *JobWaitGroup) Status() (int, []string) {
+	jwg.lock.RLock()
+
+	n := len(jwg.jobs)
+	var jobs []string
+	for job, active := range jwg.jobs {
+		if active {
+			jobs = append(jobs, job)
+		}
+	}
+	defer jwg.lock.RUnlock()
+	sort.Strings(jobs)
+
+	return n, jobs
+}
+
+func (jwg *JobWaitGroup) Watch(d time.Duration) {
+	ticker := time.NewTicker(d)
+	done := make(chan struct{})
+	go func() {
+		jwg.Wait()
+		ticker.Stop()
+		done <- struct{}{}
+	}()
+	for {
+		select {
+		case <-ticker.C:
+			n, jobs := jwg.Status()
+			if len(jobs) == 0 {
+				panic("no active jobs, but wg still waiting")
+			}
+			line := fmt.Sprintf("%d/%d : %v", len(jobs), n, strings.Join(jobs, ", "))
+			if len(line) > 70 {
+				line = line[:67] + "..."
+			}
+			fmt.Fprintf(os.Stderr, "\r%-70s", line)
+		case <-done:
+			fmt.Fprintf(os.Stderr, "\r%-70s\n", "done")
+			return
+		}
+	}
+}
diff --git a/main.go b/main.go
index eba5024..4f4b983 100644
--- a/main.go
+++ b/main.go
@@ -8,6 +8,7 @@ import (
 	"path/filepath"
 	"strings"
 	"sync"
+	"time"
 )
 
 func fmtAddress(node, port string) string {
@@ -23,7 +24,7 @@ func isIPv6(node string) bool {
 	return ip != nil && ip.To4() == nil
 }
 
-var wg sync.WaitGroup
+var jwg JobWaitGroup
 
 func Emit(pt Point) {
 	if pt == nil {
@@ -33,23 +34,25 @@ func Emit(pt Point) {
 }
 
 func DoHostfile(fname string) {
-	defer wg.Done()
 	hostname := filepath.Base(fname)
+
 	cfg, err := readConfigFile(fname)
 	if err != nil {
 		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) {
-		addressStr := fmtAddress(address.Node, address.Port)
-		wg.Add(2)
-		go Emit(DoAddress(hostname, "tcp4", addressStr))
-		go Emit(DoAddress(hostname, "tcp6", addressStr))
+		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)) })
 	}
 }
 
 func DoAddress(host, network, address string) Point {
-	defer wg.Done()
 	tags := map[string]string{
 		"host":    host,
 		"network": network,
@@ -100,6 +103,7 @@ func Hello(addr *net.TCPAddr) (name, version string, err error) {
 		return "", "", err
 	}
 	defer conn.Close()
+	conn.SetDeadline(time.Now().Add(10 * time.Second))
 	conn.CloseWrite()
 	all, _ := ioutil.ReadAll(conn)
 	line := strings.TrimRight(string(all), "\n")
@@ -112,8 +116,7 @@ func Hello(addr *net.TCPAddr) (name, version string, err error) {
 
 func main() {
 	for _, fname := range os.Args[1:] {
-		wg.Add(1)
-		go DoHostfile(fname)
+		DoHostfile(fname)
 	}
-	wg.Wait()
+	jwg.Watch(time.Second)
 }
-- 
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