qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-11-19 22:04:44 -07:00
Code Releases Activity

image/gif: make Decode only keep the first frame in memory

Browse Source 
Decode decodes entire GIF image and returns the first frame as an
image.Image. There's no need for it to keep every decoded frame in
memory except for the one it returns.

Fixes #22199

Change-Id: I76b4bd31608ebc76a1a3df02e85c20eb80df7877
Reviewed-on: https://go-review.googlesource.com/69890
Reviewed-by: Nigel Tao <nigeltao@golang.org>
This commit is contained in:
Artyom Pervukhin 2017-10-11 11:19:44 +03:00 committed by Nigel Tao
parent 58c7b1d160
commit 9ce43ce667
1 changed files with 9 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
src/image/gif/reader.go
View File

@ -150,7 +150,7 @@ func (b *blockReader) Read(p []byte) (int, error) {
}
// decode reads a GIF image from r and stores the result in d.
func (d *decoder) decode(r io.Reader, configOnly bool) error {
func (d *decoder) decode(r io.Reader, configOnly, keepAllFrames bool) error {
// Add buffering if r does not provide ReadByte.
if rr, ok := r.(reader); ok {
d.r = rr
@ -279,9 +279,11 @@ func (d *decoder) decode(r io.Reader, configOnly bool) error {
uninterlace(m)
}
d.image = append(d.image, m)
d.delay = append(d.delay, d.delayTime)
d.disposal = append(d.disposal, d.disposalMethod)
if keepAllFrames || len(d.image) == 0 {
d.image = append(d.image, m)
d.delay = append(d.delay, d.delayTime)
d.disposal = append(d.disposal, d.disposalMethod)
}
// The GIF89a spec, Section 23 (Graphic Control Extension) says:
// "The scope of this extension is the first graphic rendering block
// to follow." We therefore reset the GCE fields to zero.
@ -491,7 +493,7 @@ func uninterlace(m *image.Paletted) {
// image as an image.Image.
func Decode(r io.Reader) (image.Image, error) {
var d decoder
if err := d.decode(r, false); err != nil {
if err := d.decode(r, false, false); err != nil {
return nil, err
}
return d.image[0], nil
@ -526,7 +528,7 @@ type GIF struct {
// and timing information.
func DecodeAll(r io.Reader) (*GIF, error) {
var d decoder
if err := d.decode(r, false); err != nil {
if err := d.decode(r, false, true); err != nil {
return nil, err
}
gif := &GIF{
@ -548,7 +550,7 @@ func DecodeAll(r io.Reader) (*GIF, error) {
// without decoding the entire image.
func DecodeConfig(r io.Reader) (image.Config, error) {
var d decoder
if err := d.decode(r, true); err != nil {
if err := d.decode(r, true, false); err != nil {
return image.Config{}, err
}
return image.Config{