Add debug package for memory reporting

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

debug/debug.go

@@ -0,0 +1,66 @@
+package debug
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// Smaps prints the smaps to a file
+func Smaps(note, file string) error {
+	smaps, err := getMaps(os.Getpid())
+	if err != nil {
+		return err
+	}
+	f, err := os.OpenFile(file, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	fmt.Fprintf(f, "%s: rss %d\n", note, smaps["rss"])
+	fmt.Fprintf(f, "%s: pss %d\n", note, smaps["pss"])
+	return nil
+}
+
+func getMaps(pid int) (map[string]int, error) {
+	f, err := os.Open(fmt.Sprintf("/proc/%d/smaps", pid))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	var (
+		smaps = make(map[string]int)
+		s     = bufio.NewScanner(f)
+	)
+	for s.Scan() {
+		var (
+			fields = strings.Fields(s.Text())
+			name   = fields[0]
+		)
+		name = strings.TrimSuffix(strings.ToLower(name), ":")
+		if len(fields) < 2 {
+			continue
+		}
+		n, err := strconv.Atoi(fields[1])
+		if err != nil {
+			continue
+		}
+		smaps[name] += n
+	}
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+	return smaps, nil
+}
+
+func keys(smaps map[string]int) []string {
+	var o []string
+	for k := range smaps {
+		o = append(o, k)
+	}
+	sort.Strings(o)
+	return o
+}