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Diffstat (limited to 'vendor/codeberg.org/superseriousbusiness/exif-terminator/terminator.go')
-rw-r--r--vendor/codeberg.org/superseriousbusiness/exif-terminator/terminator.go158
1 files changed, 0 insertions, 158 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 7dd3d9ad7..000000000
--- a/vendor/codeberg.org/superseriousbusiness/exif-terminator/terminator.go
+++ /dev/null
@@ -1,158 +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, fileSize int, mediaType string) (io.Reader, error) {
- // To avoid keeping too much stuff
- // in memory we want to pipe data
- // directly to the reader.
- pipeReader, pipeWriter := io.Pipe()
-
- // We don't know ahead of time how long
- // segments might be: they could be as
- // large as the file itself, so we need
- // a buffer with generous overhead.
- scanner := bufio.NewScanner(in)
- scanner.Buffer([]byte{}, fileSize)
-
- var err error
- switch mediaType {
- case "image/jpeg", "jpeg", "jpg":
- err = terminateJpeg(scanner, pipeWriter, fileSize)
-
- case "image/webp", "webp":
- err = terminateWebp(scanner, pipeWriter)
-
- 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 {
- err = headerError
- break
- }
-
- if !bytes.Equal(header, pngstructure.PngSignature[:]) {
- err = errors.New("could not decode png: invalid header")
- break
- }
-
- err = terminatePng(scanner, pipeWriter)
- default:
- err = fmt.Errorf("mediaType %s cannot be processed", mediaType)
- }
-
- return pipeReader, err
-}
-
-func terminateJpeg(scanner *bufio.Scanner, writer *io.PipeWriter, expectedFileSize int) error {
- v := &jpegVisitor{
- writer: writer,
- expectedFileSize: expectedFileSize,
- }
-
- // 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)
-
- go scanAndClose(scanner, writer)
- return nil
-}
-
-func terminateWebp(scanner *bufio.Scanner, writer *io.PipeWriter) error {
- v := &webpVisitor{
- writer: writer,
- }
-
- // Webp visitor's 'split' function
- // satisfies bufio.SplitFunc{}.
- scanner.Split(v.split)
-
- go scanAndClose(scanner, writer)
- return nil
-}
-
-func terminatePng(scanner *bufio.Scanner, writer *io.PipeWriter) error {
- ps := pngstructure.NewPngSplitter()
-
- // Don't bother checking CRC;
- // we're overwriting it anyway.
- ps.DoCheckCrc(false)
-
- v := &pngVisitor{
- ps: ps,
- writer: writer,
- lastWrittenChunk: -1,
- }
-
- // Png visitor's 'split' function
- // satisfies bufio.SplitFunc{}.
- scanner.Split(v.split)
-
- go scanAndClose(scanner, writer)
- return nil
-}
-
-// scanAndClose scans through the given scanner until there's
-// nothing left to scan, and then closes the writer so that the
-// reader on the other side of the pipe knows that we're done.
-//
-// Any error encountered when scanning will be logged by terminator.
-//
-// Due to the nature of io.Pipe, writing won't actually work
-// until the pipeReader starts being read by the caller, which
-// is why this function should always be called asynchronously.
-func scanAndClose(scanner *bufio.Scanner, writer *io.PipeWriter) {
- 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).
- writer.CloseWithError(err)
- }()
-
- for scanner.Scan() {
- }
-
- // Set error on return.
- err = scanner.Err()
-}