File storage rewrite (#2676)

* Restructure data layer part 2 (#2599)
* Refactor and separate image model
* Refactor image query builder
* Handle relationships in image query builder
* Remove relationship management methods
* Refactor gallery model/query builder
* Add scenes to gallery model
* Convert scene model
* Refactor scene models
* Remove unused methods
* Add unit tests for gallery
* Add image tests
* Add scene tests
* Convert unnecessary scene value pointers to values
* Convert unnecessary pointer values to values
* Refactor scene partial
* Add scene partial tests
* Refactor ImagePartial
* Add image partial tests
* Refactor gallery partial update
* Add partial gallery update tests
* Use zero/null package for null values
* Add files and scan system
* Add sqlite implementation for files/folders
* Add unit tests for files/folders
* Image refactors
* Update image data layer
* Refactor gallery model and creation
* Refactor scene model
* Refactor scenes
* Don't set title from filename
* Allow galleries to freely add/remove images
* Add multiple scene file support to graphql and UI
* Add multiple file support for images in graphql/UI
* Add multiple file for galleries in graphql/UI
* Remove use of some deprecated fields
* Remove scene path usage
* Remove gallery path usage
* Remove path from image
* Move funscript to video file
* Refactor caption detection
* Migrate existing data
* Add post commit/rollback hook system
* Lint. Comment out import/export tests
* Add WithDatabase read only wrapper
* Prepend tasks to list
* Add 32 pre-migration
* Add warnings in release and migration notes

pkg/file/fingerprint.go

@@ -0,0 +1,43 @@
+package file
+
+var (
+	FingerprintTypeOshash = "oshash"
+	FingerprintTypeMD5    = "md5"
+	FingerprintTypePhash  = "phash"
+)
+
+// Fingerprint represents a fingerprint of a file.
+type Fingerprint struct {
+	Type        string
+	Fingerprint interface{}
+}
+
+type Fingerprints []Fingerprint
+
+func (f Fingerprints) Get(type_ string) interface{} {
+	for _, fp := range f {
+		if fp.Type == type_ {
+			return fp.Fingerprint
+		}
+	}
+
+	return nil
+}
+
+// AppendUnique appends a fingerprint to the list if a Fingerprint of the same type does not already exist in the list. If one does, then it is updated with o's Fingerprint value.
+func (f Fingerprints) AppendUnique(o Fingerprint) Fingerprints {
+	ret := f
+	for i, fp := range ret {
+		if fp.Type == o.Type {
+			ret[i] = o
+			return ret
+		}
+	}
+
+	return append(f, o)
+}
+
+// FingerprintCalculator calculates a fingerprint for the provided file.
+type FingerprintCalculator interface {
+	CalculateFingerprints(f *BaseFile, o Opener) ([]Fingerprint, error)
+}