Scan refactor (#1816)

* Add file scanner
* Scan scene changes
* Split scan files
* Generalise scan
* Refactor ffprobe
* Refactor ffmpeg encoder
* Move scene scan code to scene package
* Move matchExtension to utils
* Refactor gallery scanning
* Refactor image scanning
* Prevent race conditions on identical hashes
* Refactor image thumbnail generation
* Perform count concurrently
* Allow progress increment before total set
* Make progress updates more frequent

pkg/file/zip.go

@@ -0,0 +1,64 @@
+package file
+
+import (
+	"archive/zip"
+	"io"
+	"io/fs"
+	"strings"
+)
+
+const zipSeparator = "\x00"
+
+type zipFile struct {
+	zipPath string
+	zf      *zip.File
+}
+
+func (f *zipFile) Open() (io.ReadCloser, error) {
+	return f.zf.Open()
+}
+
+func (f *zipFile) Path() string {
+	// TODO - fix this
+	return ZipFilename(f.zipPath, f.zf.Name)
+}
+
+func (f *zipFile) FileInfo() fs.FileInfo {
+	return f.zf.FileInfo()
+}
+
+func ZipFile(zipPath string, zf *zip.File) SourceFile {
+	return &zipFile{
+		zipPath: zipPath,
+		zf:      zf,
+	}
+}
+
+func ZipFilename(zipFilename, filenameInZip string) string {
+	return zipFilename + zipSeparator + filenameInZip
+}
+
+// IsZipPath returns true if the path includes the zip separator byte,
+// indicating it is within a zip file.
+func IsZipPath(p string) bool {
+	return strings.Contains(p, zipSeparator)
+}
+
+// ZipPathDisplayName converts an zip path for display. It translates the zip
+// file separator character into '/', since this character is also used for
+// path separators within zip files. It returns the original provided path
+// if it does not contain the zip file separator character.
+func ZipPathDisplayName(path string) string {
+	return strings.Replace(path, zipSeparator, "/", -1)
+}
+
+func ZipFilePath(path string) (zipFilename, filename string) {
+	nullIndex := strings.Index(path, zipSeparator)
+	if nullIndex != -1 {
+		zipFilename = path[0:nullIndex]
+		filename = path[nullIndex+1:]
+	} else {
+		filename = path
+	}
+	return
+}