1 files changed, 78 insertions, 0 deletions
diff --git a/field_time.go b/field_time.go
new file mode 100644
index 0000000..d8a1776
--- /dev/null
+++ b/field_time.go
@@ -0,0 +1,78 @@
+/******************************************************************************
+*
+*  Copyright 2018 Stefan Majewsky <majewsky@gmx.net>
+*
+*  Licensed under the Apache License, Version 2.0 (the "License");
+*  you may not use this file except in compliance with the License.
+*  You may obtain a copy of the License at
+*
+*      http://www.apache.org/licenses/LICENSE-2.0
+*
+*  Unless required by applicable law or agreed to in writing, software
+*  distributed under the License is distributed on an "AS IS" BASIS,
+*  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+*  See the License for the specific language governing permissions and
+*  limitations under the License.
+*
+******************************************************************************/
+
+package schwift
+
+import (
+	"math"
+	"strconv"
+	"time"
+)
+
+//FieldUnixTimeReadonly is a helper type that provides type-safe access to a
+//Swift header whose value is a UNIX timestamp. It cannot be directly
+//constructed, but methods on the Headers types return this type. For example:
+//
+//    //suppose you have:
+//    hdr, err := obj.Headers()
+//
+//    //you could do all this:
+//    sec, err := strconv.ParseFloat(hdr.Get("X-Timestamp"), 64)
+//    time := time.Unix(int64(sec), int64(1e9 * (sec - math.Floor(sec))))
+//
+//    //or you can just:
+//    time := hdr.Timestamp().Get()
+//
+//Don't worry about the missing `err` in the last line. When the X-Timestamp
+//header fails to parse, Object.Headers() already returns the corresponding
+//MalformedHeaderError.
+type FieldUnixTimeReadonly struct {
+	h headerInterface
+	k string
+}
+
+//Exists checks whether there is a value for this header.
+func (f FieldUnixTimeReadonly) Exists() bool {
+	return f.h.Get(f.k) != ""
+}
+
+//Get returns the value for this header, or the zero value if there is no value
+//(or if it is not a valid timestamp).
+func (f FieldUnixTimeReadonly) Get() time.Time {
+	v, err := strconv.ParseFloat(f.h.Get(f.k), 64)
+	if err != nil {
+		return time.Time{}
+	}
+	seconds := math.Floor(v)
+	return time.Unix(
+		int64(seconds),
+		int64(1e9*(v-seconds)),
+	)
+}
+
+func (f FieldUnixTimeReadonly) validate() error {
+	val := f.h.Get(f.k)
+	if val == "" {
+		return nil
+	}
+	_, err := strconv.ParseFloat(val, 64)
+	if err == nil {
+		return nil
+	}
+	return MalformedHeaderError{f.k, err}
+}