mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-12-29 18:46:31 +00:00
140 lines
2.9 KiB
Go
140 lines
2.9 KiB
Go
package jpegstructure
|
|
|
|
import (
|
|
"bufio"
|
|
"bytes"
|
|
"image"
|
|
"io"
|
|
"os"
|
|
|
|
"image/jpeg"
|
|
|
|
"github.com/dsoprea/go-logging"
|
|
"github.com/dsoprea/go-utility/v2/image"
|
|
)
|
|
|
|
// JpegMediaParser is a `riimage.MediaParser` that knows how to parse JPEG
|
|
// images.
|
|
type JpegMediaParser struct {
|
|
}
|
|
|
|
// NewJpegMediaParser returns a new JpegMediaParser.
|
|
func NewJpegMediaParser() *JpegMediaParser {
|
|
|
|
// TODO(dustin): Add test
|
|
|
|
return new(JpegMediaParser)
|
|
}
|
|
|
|
// Parse parses a JPEG uses an `io.ReadSeeker`. Even if it fails, it will return
|
|
// the list of segments encountered prior to the failure.
|
|
func (jmp *JpegMediaParser) Parse(rs io.ReadSeeker, size int) (ec riimage.MediaContext, err error) {
|
|
defer func() {
|
|
if state := recover(); state != nil {
|
|
err = log.Wrap(state.(error))
|
|
}
|
|
}()
|
|
|
|
s := bufio.NewScanner(rs)
|
|
|
|
// Since each segment can be any size, our buffer must allowed to grow as
|
|
// large as the file.
|
|
buffer := []byte{}
|
|
s.Buffer(buffer, size)
|
|
|
|
js := NewJpegSplitter(nil)
|
|
s.Split(js.Split)
|
|
|
|
for s.Scan() != false {
|
|
}
|
|
|
|
// Always return the segments that were parsed, at least until there was an
|
|
// error.
|
|
ec = js.Segments()
|
|
|
|
log.PanicIf(s.Err())
|
|
|
|
return ec, nil
|
|
}
|
|
|
|
// ParseFile parses a JPEG file. Even if it fails, it will return the list of
|
|
// segments encountered prior to the failure.
|
|
func (jmp *JpegMediaParser) ParseFile(filepath string) (ec riimage.MediaContext, err error) {
|
|
defer func() {
|
|
if state := recover(); state != nil {
|
|
err = log.Wrap(state.(error))
|
|
}
|
|
}()
|
|
|
|
// TODO(dustin): Add test
|
|
|
|
f, err := os.Open(filepath)
|
|
log.PanicIf(err)
|
|
|
|
defer f.Close()
|
|
|
|
stat, err := f.Stat()
|
|
log.PanicIf(err)
|
|
|
|
size := stat.Size()
|
|
|
|
sl, err := jmp.Parse(f, int(size))
|
|
|
|
// Always return the segments that were parsed, at least until there was an
|
|
// error.
|
|
ec = sl
|
|
|
|
log.PanicIf(err)
|
|
|
|
return ec, nil
|
|
}
|
|
|
|
// ParseBytes parses a JPEG byte-slice. Even if it fails, it will return the
|
|
// list of segments encountered prior to the failure.
|
|
func (jmp *JpegMediaParser) ParseBytes(data []byte) (ec riimage.MediaContext, err error) {
|
|
defer func() {
|
|
if state := recover(); state != nil {
|
|
err = log.Wrap(state.(error))
|
|
}
|
|
}()
|
|
|
|
br := bytes.NewReader(data)
|
|
|
|
sl, err := jmp.Parse(br, len(data))
|
|
|
|
// Always return the segments that were parsed, at least until there was an
|
|
// error.
|
|
ec = sl
|
|
|
|
log.PanicIf(err)
|
|
|
|
return ec, nil
|
|
}
|
|
|
|
// LooksLikeFormat indicates whether the data looks like a JPEG image.
|
|
func (jmp *JpegMediaParser) LooksLikeFormat(data []byte) bool {
|
|
if len(data) < 4 {
|
|
return false
|
|
}
|
|
|
|
l := len(data)
|
|
if data[0] != 0xff || data[1] != MARKER_SOI || data[l-2] != 0xff || data[l-1] != MARKER_EOI {
|
|
return false
|
|
}
|
|
|
|
return true
|
|
}
|
|
|
|
// GetImage returns an image.Image-compatible struct.
|
|
func (jmp *JpegMediaParser) GetImage(r io.Reader) (img image.Image, err error) {
|
|
img, err = jpeg.Decode(r)
|
|
log.PanicIf(err)
|
|
|
|
return img, nil
|
|
}
|
|
|
|
var (
|
|
// Enforce interface conformance.
|
|
_ riimage.MediaParser = new(JpegMediaParser)
|
|
)
|