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path: root/vendor/github.com/dsoprea/go-jpeg-image-structure/media_parser.go
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Diffstat (limited to 'vendor/github.com/dsoprea/go-jpeg-image-structure/media_parser.go')
-rw-r--r--vendor/github.com/dsoprea/go-jpeg-image-structure/media_parser.go128
1 files changed, 128 insertions, 0 deletions
diff --git a/vendor/github.com/dsoprea/go-jpeg-image-structure/media_parser.go b/vendor/github.com/dsoprea/go-jpeg-image-structure/media_parser.go
new file mode 100644
index 000000000..dd4c73af9
--- /dev/null
+++ b/vendor/github.com/dsoprea/go-jpeg-image-structure/media_parser.go
@@ -0,0 +1,128 @@
+package jpegstructure
+
+import (
+ "bufio"
+ "bytes"
+ "io"
+ "os"
+
+ "github.com/dsoprea/go-logging"
+ "github.com/dsoprea/go-utility/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
+}
+
+var (
+ // Enforce interface conformance.
+ _ riimage.MediaParser = new(JpegMediaParser)
+)