diff options
Diffstat (limited to 'vendor/codeberg.org/superseriousbusiness/exif-terminator/terminator.go')
-rw-r--r-- | vendor/codeberg.org/superseriousbusiness/exif-terminator/terminator.go | 146 |
1 files changed, 0 insertions, 146 deletions
diff --git a/vendor/codeberg.org/superseriousbusiness/exif-terminator/terminator.go b/vendor/codeberg.org/superseriousbusiness/exif-terminator/terminator.go deleted file mode 100644 index 5793b8599..000000000 --- a/vendor/codeberg.org/superseriousbusiness/exif-terminator/terminator.go +++ /dev/null @@ -1,146 +0,0 @@ -/* - exif-terminator - Copyright (C) 2022 SuperSeriousBusiness admin@gotosocial.org - - This program is free software: you can redistribute it and/or modify - it under the terms of the GNU Affero General Public License as published by - the Free Software Foundation, either version 3 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU Affero General Public License for more details. - - You should have received a copy of the GNU Affero General Public License - along with this program. If not, see <http://www.gnu.org/licenses/>. -*/ - -package terminator - -import ( - "bufio" - "bytes" - "errors" - "fmt" - "io" - - jpegstructure "github.com/superseriousbusiness/go-jpeg-image-structure/v2" - pngstructure "github.com/superseriousbusiness/go-png-image-structure/v2" -) - -func Terminate(in io.Reader, mediaType string) (io.Reader, error) { - // To avoid keeping too much stuff - // in memory we want to pipe data - // directly to the reader. - pr, pw := io.Pipe() - - // Setup scanner to terminate exif into pipe writer. - scanner, err := terminatingScanner(pw, in, mediaType) - if err != nil { - _ = pw.Close() - return nil, err - } - - go func() { - var err error - - defer func() { - // Always close writer, using returned - // scanner error (if any). If err is nil - // then the standard io.EOF will be used. - // (this will not overwrite existing). - pw.CloseWithError(err) - }() - - // Scan through input. - for scanner.Scan() { - } - - // Set error on return. - err = scanner.Err() - }() - - return pr, nil -} - -func TerminateInto(out io.Writer, in io.Reader, mediaType string) error { - // Setup scanner to terminate exif from 'in' to 'out'. - scanner, err := terminatingScanner(out, in, mediaType) - if err != nil { - return err - } - - // Scan through input. - for scanner.Scan() { - } - - // Return scan errors. - return scanner.Err() -} - -func terminatingScanner(out io.Writer, in io.Reader, mediaType string) (*bufio.Scanner, error) { - scanner := bufio.NewScanner(in) - - // 40mb buffer size should be enough - // to scan through most file chunks - // without running into issues, they're - // usually chunked smaller than this... - scanner.Buffer(nil, 40*1024*1024) - - switch mediaType { - case "image/jpeg", "jpeg", "jpg": - v := &jpegVisitor{ - writer: out, - } - - // Provide the visitor to the splitter so - // that it triggers on every section scan. - js := jpegstructure.NewJpegSplitter(v) - - // The visitor also needs to read back the - // list of segments: for this it needs to - // know what jpeg splitter it's attached to, - // so give it a pointer to the splitter. - v.js = js - - // Jpeg visitor's 'split' function - // satisfies bufio.SplitFunc{}. - scanner.Split(js.Split) - - case "image/webp", "webp": - // Webp visitor's 'split' function - // satisfies bufio.SplitFunc{}. - scanner.Split((&webpVisitor{ - writer: out, - }).split) - - case "image/png", "png": - // For pngs we need to skip the header bytes, so read - // them in and check we're really dealing with a png. - header := make([]byte, len(pngstructure.PngSignature)) - if _, headerError := in.Read(header); headerError != nil { - return nil, headerError - } else if !bytes.Equal(header, pngstructure.PngSignature[:]) { - return nil, errors.New("could not decode png: invalid header") - } - - // Don't bother checking CRC; - // we're overwriting it anyway. - ps := pngstructure.NewPngSplitter() - ps.DoCheckCrc(false) - - // Png visitor's 'split' function - // satisfies bufio.SplitFunc{}. - scanner.Split((&pngVisitor{ - ps: ps, - writer: out, - lastWrittenChunk: -1, - }).split) - - default: - return nil, fmt.Errorf("mediaType %s cannot be processed", mediaType) - } - - return scanner, nil -} |