[disk][host]: move back Warnings from internal to disk and host.

fix #1377

disk/disk_windows.go

@@ -80,7 +80,7 @@ func UsageWithContext(ctx context.Context, path string) (*UsageStat, error) {
 }
 
 func PartitionsWithContext(ctx context.Context, all bool) ([]PartitionStat, error) {
-	warnings := common.Warnings{
+	warnings := Warnings{
 		Verbose: true,
 	}
 	var ret []PartitionStat

disk/warnings.go

@@ -1,4 +1,4 @@
-package common
+package disk
 
 import "fmt"
 

host/host_linux.go

@@ -395,7 +395,7 @@ func SensorsTemperaturesWithContext(ctx context.Context) ([]TemperatureStat, err
 		}
 	}
 
-	var warns common.Warnings
+	var warns Warnings
 
 	if len(files) == 0 { // handle distributions without hwmon, like raspbian #391, parse legacy thermal_zone files
 		files, err = filepath.Glob(common.HostSys("/class/thermal/thermal_zone*/"))

host/warnings.go

@@ -0,0 +1,30 @@
+package host
+
+import "fmt"
+
+type Warnings struct {
+	List    []error
+	Verbose bool
+}
+
+func (w *Warnings) Add(err error) {
+	w.List = append(w.List, err)
+}
+
+func (w *Warnings) Reference() error {
+	if len(w.List) > 0 {
+		return w
+	}
+	return nil
+}
+
+func (w *Warnings) Error() string {
+	if w.Verbose {
+		str := ""
+		for i, e := range w.List {
+			str += fmt.Sprintf("\tError %d: %s\n", i, e.Error())
+		}
+		return str
+	}
+	return fmt.Sprintf("Number of warnings: %v", len(w.List))
+}