Implement archive.Apply on Windows

Signed-off-by: Darren Stahl <darst@microsoft.com>

archive/strconv.go

@@ -0,0 +1,52 @@
+// +build windows
+
+package archive
+
+import (
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/dmcgowan/go-tar"
+)
+
+// Forked from https://github.com/golang/go/blob/master/src/archive/tar/strconv.go
+// as archive/tar doesn't support CreationTime, but does handle PAX time parsing,
+// and there's no need to re-invent the wheel.
+
+// parsePAXTime takes a string of the form %d.%d as described in the PAX
+// specification. Note that this implementation allows for negative timestamps,
+// which is allowed for by the PAX specification, but not always portable.
+func parsePAXTime(s string) (time.Time, error) {
+	const maxNanoSecondDigits = 9
+
+	// Split string into seconds and sub-seconds parts.
+	ss, sn := s, ""
+	if pos := strings.IndexByte(s, '.'); pos >= 0 {
+		ss, sn = s[:pos], s[pos+1:]
+	}
+
+	// Parse the seconds.
+	secs, err := strconv.ParseInt(ss, 10, 64)
+	if err != nil {
+		return time.Time{}, tar.ErrHeader
+	}
+	if len(sn) == 0 {
+		return time.Unix(secs, 0), nil // No sub-second values
+	}
+
+	// Parse the nanoseconds.
+	if strings.Trim(sn, "0123456789") != "" {
+		return time.Time{}, tar.ErrHeader
+	}
+	if len(sn) < maxNanoSecondDigits {
+		sn += strings.Repeat("0", maxNanoSecondDigits-len(sn)) // Right pad
+	} else {
+		sn = sn[:maxNanoSecondDigits] // Right truncate
+	}
+	nsecs, _ := strconv.ParseInt(sn, 10, 64) // Must succeed
+	if len(ss) > 0 && ss[0] == '-' {
+		return time.Unix(secs, -1*int64(nsecs)), nil // Negative correction
+	}
+	return time.Unix(secs, int64(nsecs)), nil
+}