Change duration -> internal and implement private gopsutil methods

internal/internal.go

@@ -0,0 +1,63 @@
+package internal
+
+import (
+	"bufio"
+	"errors"
+	"os"
+	"strings"
+	"time"
+)
+
+// Duration just wraps time.Duration
+type Duration struct {
+	time.Duration
+}
+
+// UnmarshalTOML parses the duration from the TOML config file
+func (d *Duration) UnmarshalTOML(b []byte) error {
+	dur, err := time.ParseDuration(string(b[1 : len(b)-1]))
+	if err != nil {
+		return err
+	}
+
+	d.Duration = dur
+
+	return nil
+}
+
+var NotImplementedError = errors.New("not implemented yet")
+
+// ReadLines reads contents from a file and splits them by new lines.
+// A convenience wrapper to ReadLinesOffsetN(filename, 0, -1).
+func ReadLines(filename string) ([]string, error) {
+	return ReadLinesOffsetN(filename, 0, -1)
+}
+
+// ReadLines reads contents from file and splits them by new line.
+// The offset tells at which line number to start.
+// The count determines the number of lines to read (starting from offset):
+//   n >= 0: at most n lines
+//   n < 0: whole file
+func ReadLinesOffsetN(filename string, offset uint, n int) ([]string, error) {
+	f, err := os.Open(filename)
+	if err != nil {
+		return []string{""}, err
+	}
+	defer f.Close()
+
+	var ret []string
+
+	r := bufio.NewReader(f)
+	for i := 0; i < n+int(offset) || n < 0; i++ {
+		line, err := r.ReadString('\n')
+		if err != nil {
+			break
+		}
+		if i < int(offset) {
+			continue
+		}
+		ret = append(ret, strings.Trim(line, "\n"))
+	}
+
+	return ret, nil
+}