New static configuration loading system.

Co-authored-by: Mathieu Lonjaret <mathieu.lonjaret@gmail.com>

pkg/types/duration.go

@@ -0,0 +1,69 @@
+package types
+
+import (
+	"encoding/json"
+	"strconv"
+	"time"
+)
+
+// Duration is a custom type suitable for parsing duration values.
+// It supports `time.ParseDuration`-compatible values and suffix-less digits; in
+// the latter case, seconds are assumed.
+type Duration time.Duration
+
+// Set sets the duration from the given string value.
+func (d *Duration) Set(s string) error {
+	if v, err := strconv.ParseInt(s, 10, 64); err == nil {
+		*d = Duration(time.Duration(v) * time.Second)
+		return nil
+	}
+
+	v, err := time.ParseDuration(s)
+	*d = Duration(v)
+	return err
+}
+
+// Get returns the duration value.
+func (d *Duration) Get() interface{} { return time.Duration(*d) }
+
+// String returns a string representation of the duration value.
+func (d *Duration) String() string { return (*time.Duration)(d).String() }
+
+// SetValue sets the duration from the given Duration-asserted value.
+func (d *Duration) SetValue(val interface{}) {
+	*d = val.(Duration)
+}
+
+// MarshalText serialize the given duration value into a text.
+func (d *Duration) MarshalText() ([]byte, error) {
+	return []byte(d.String()), nil
+}
+
+// UnmarshalText deserializes the given text into a duration value.
+// It is meant to support TOML decoding of durations.
+func (d *Duration) UnmarshalText(text []byte) error {
+	return d.Set(string(text))
+}
+
+// MarshalJSON serializes the given duration value.
+func (d *Duration) MarshalJSON() ([]byte, error) {
+	return json.Marshal(time.Duration(*d))
+}
+
+// UnmarshalJSON deserializes the given text into a duration value.
+func (d *Duration) UnmarshalJSON(text []byte) error {
+	if v, err := strconv.ParseInt(string(text), 10, 64); err == nil {
+		*d = Duration(time.Duration(v))
+		return nil
+	}
+
+	// We use json unmarshal on value because we have the quoted version
+	var value string
+	err := json.Unmarshal(text, &value)
+	if err != nil {
+		return err
+	}
+	v, err := time.ParseDuration(value)
+	*d = Duration(v)
+	return err
+}