From 29bbc978760a4a56e27d5fdb41e78fee0f62e186 Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@sbcglobal.net>
Date: Thu, 26 Jan 2017 01:16:05 -0500
Subject: cgswap: tidy

---
 cgswap.go | 78 +++++++++++++++++++++++++++++++++++++++------------------------
 1 file changed, 49 insertions(+), 29 deletions(-)

diff --git a/cgswap.go b/cgswap.go
index 6fab8ae..696265a 100644
--- a/cgswap.go
+++ b/cgswap.go
@@ -6,6 +6,7 @@ package main
 import (
 	"bufio"
 	"fmt"
+	"io"
 	"os"
 	"sort"
 	"strconv"
@@ -29,7 +30,7 @@ func (l cginfos) Len() int           { return len(l) }
 func (l cginfos) Less(i, j int) bool { return l[i].VmSwap < l[j].VmSwap }
 func (l cginfos) Swap(i, j int)      { l[i], l[j] = l[j], l[i] }
 
-func in_array(needle string, haystack []string) bool {
+func inArray(needle string, haystack []string) bool {
 	for _, straw := range haystack {
 		if needle == straw {
 			return true
@@ -38,6 +39,38 @@ func in_array(needle string, haystack []string) bool {
 	return false
 }
 
+func getVmSwap(statusFile io.Reader) (int, bool) {
+	buf := bufio.NewScanner(statusFile)
+	for buf.Scan() {
+		line := buf.Text()
+		if strings.HasPrefix(line, "VmSwap:") {
+			swap, err := strconv.Atoi(strings.TrimSpace(strings.TrimSuffix(strings.TrimPrefix(line, "VmSwap:"), "kB")))
+			if err != nil {
+				return 0, false
+			}
+			return swap, true
+		}
+	}
+	return 0, false
+}
+
+func getCgroup(cgroupFile io.Reader) (string, bool) {
+	buf := bufio.NewScanner(cgroupFile)
+	for buf.Scan() {
+		parts := strings.SplitN(buf.Text(), ":", 3)
+		if len(parts) != 3 {
+			continue
+		}
+		heir := parts[0]
+		controllers := strings.Split(parts[1], ",")
+		cgroup := parts[2]
+		if heir == "0" || inArray("name=systemd", controllers) {
+			return cgroup, true
+		}
+	}
+	return "", false
+}
+
 func main() {
 	dir, err := os.Open("/proc")
 	if err != nil {
@@ -79,35 +112,22 @@ func main() {
 					return
 				}
 				cgroupFile, err := os.Open(fmt.Sprintf("/proc/%d/cgroup", pid))
-
-				buf := bufio.NewScanner(statusFile)
-				for buf.Scan() {
-					line := buf.Text()
-					if strings.HasPrefix(line, "VmSwap:") {
-						swap, err := strconv.Atoi(strings.TrimSpace(strings.TrimSuffix(strings.TrimPrefix(line, "VmSwap:"), "kB")))
-						if err != nil || swap == 0 {
-							return
-						}
-						buf := bufio.NewScanner(cgroupFile)
-						for buf.Scan() {
-							parts := strings.SplitN(buf.Text(), ":", 3)
-							if len(parts) != 3 {
-								continue
-							}
-							heir := parts[0]
-							controllers := strings.Split(parts[1], ",")
-							cgroup := parts[2]
-							if heir == "0" || in_array("name=systemd", controllers) {
-								ch <- cginfo{VmSwap: swap, Cgroup: cgroup}
-								return
-							}
-						}
-						return
-					}
+				if err != nil {
+					return
 				}
+				swap, ok := getVmSwap(statusFile)
+				if !ok || swap == 0 {
+					return
+				}
+				cgroup, ok := getCgroup(cgroupFile)
+				if !ok {
+					return
+				}
+				ch <- cginfo{VmSwap: swap, Cgroup: cgroup}
 			}(pid)
 		}
 	}
+
 	producers.Wait()
 	close(ch)
 	consumers.Wait()
@@ -118,10 +138,10 @@ func main() {
 	for _, info := range infos {
 		total += info.VmSwap
 	}
-	vmswap_width := len(strconv.Itoa(total))
+	vmswapWidth := len(strconv.Itoa(total))
 
 	for _, info := range infos {
-		fmt.Printf("%[1]*d kB  %s\n", vmswap_width, info.VmSwap, info.Cgroup)
+		fmt.Printf("%[1]*d kB  %s\n", vmswapWidth, info.VmSwap, info.Cgroup)
 	}
-	fmt.Printf("%[1]*d kB  %s\n", vmswap_width, total, "total")
+	fmt.Printf("%[1]*d kB  %s\n", vmswapWidth, total, "total")
 }
-- 
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