From 0af302f50745b93e90a4507993a555d246acef45 Mon Sep 17 00:00:00 2001 From: Brad Fitzpatrick Date: Wed, 15 May 2013 17:23:40 -0700 Subject: [PATCH] time: add Time.FormatAppend This is a version of Time.Format that doesn't require allocation. Fixes #5192 Update #5195 R=r CC=gobot, golang-dev https://golang.org/cl/8478044 --- src/pkg/time/format.go | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/src/pkg/time/format.go b/src/pkg/time/format.go index 7fe0402312..e40911aa53 100644 --- a/src/pkg/time/format.go +++ b/src/pkg/time/format.go @@ -380,6 +380,22 @@ func (t Time) String() string { // about the formats and the definition of the reference time, see the // documentation for ANSIC and the other constants defined by this package. func (t Time) Format(layout string) string { + const bufSize = 64 + var b []byte + max := len(layout) + 10 + if max <= bufSize { + var buf [bufSize]byte + b = buf[:0] + } else { + b = make([]byte, 0, max) + } + b = t.FormatAppend(layout, b) + return string(b) +} + +// FormatAppend works like Format but appends the textual +// representation to b and returns the extended buffer. +func (t Time) FormatAppend(layout string, b []byte) []byte { var ( name, offset, abs = t.locabs() @@ -389,16 +405,7 @@ func (t Time) Format(layout string) string { hour int = -1 min int sec int - - b []byte - buf [64]byte ) - max := len(layout) + 10 - if max <= len(buf) { - b = buf[:0] - } else { - b = make([]byte, 0, max) - } // Each iteration generates one std value. for layout != "" { prefix, std, suffix := nextStdChunk(layout) @@ -546,7 +553,7 @@ func (t Time) Format(layout string) string { b = formatNano(b, uint(t.Nanosecond()), std>>stdArgShift, std&stdMask == stdFracSecond9) } } - return string(b) + return b } var errBad = errors.New("bad value for field") // placeholder not passed to user -- 2.48.1