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forked from sneak/dcf

bring the repo up to org standards

Adopt the standard tooling: a Makefile of thin shims over a full
scripts-to-rule-them-all `script/` set, the canonical `.golangci.yml`
vendored byte-identical from `sneak/prompts`, docker-only linting via
`Dockerfile.lint`, a `Dockerfile` and Gitea workflow that gate every
push, and prettier/editorconfig/dockerignore config.

`make build` pointed at a `cmd/dcfinfo` that is not in the tree and
could never have succeeded; this repo is a library, so `build` is now
the compile check over every package.

Clear the 57 findings the canonical linter config reports on `pkg/dcf`.
Two were real: `findDCFMountPoints` checked a never-assigned `erro`
instead of the error from `findAllMountPoints`, discarding it, and
`privatePath` was computed twice so the first computation was dead.
Mountpoint selection otherwise behaves exactly as before; the defects
that survive are filed as issue #6, not fixed here.

Rename `DCFStore` to `Store` and `DCFObject` to `Object` (with its
`DCFStoreRoot` field to `StoreRoot`), which revive's stutter rule
requires and which the `fs.FS` rework in issue #4 will build on.

Replace the placeholder test with tests over the exported surface.
The filesystem walk stays uncovered: it is reachable only through
`GetDCFStores`, which needs real mounted media.

README keeps its content, reorganised into the required sections and
gaining Entrypoints.

(closes #1)
This commit is contained in:
2026-08-30 11:36:58 +00:00
parent f585e8fa34
commit ed95e66f7d
32 changed files with 1622 additions and 152 deletions

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@@ -1,177 +1,259 @@
// Package dcf reads DCF stores: the directory structures described by
// the "Design rule for Camera File system" (JEITA CP-3461) that digital
// cameras write to the root of removable media.
package dcf
import (
"crypto/sha256"
"encoding/hex"
"fmt"
"io"
"io/fs"
"os"
"path/filepath"
"slices"
"strings"
"github.com/dustin/go-humanize"
)
var imageExtensions = []string{".jpg", ".jpeg", ".png", ".gif", ".bmp", ".tiff", ".raw", ".arw"}
var videoExtensions = []string{".mp4", ".mov", ".avi", ".mkv", ".wmv"}
// DCFStore represents a DCF store, which is a directory sturcture that contains
// images and videos in the root of a mounted filesystem.
type DCFStore struct {
// Store represents a DCF store, which is a directory structure that
// contains images and videos in the root of a mounted filesystem.
type Store struct {
RootDirectory string
Images []*Image
Videos []*Video
}
// DCFObject represents a file in a DCF store. It is embedded in Image and Video types.
type DCFObject struct {
DCFStoreRoot string
Path string
Size int64
Extension string
// Object represents a file in a DCF store. It is embedded in the Image
// and Video types.
type Object struct {
StoreRoot string
Path string
Size int64
Extension string
}
// Image represents an image file on a DCF store.
type Image struct {
DCFObject
Object
}
// Video represents a video file on a DCF store.
type Video struct {
DCFObject
Object
}
func (d *DCFObject) FullFilePath() string {
return filepath.Join(d.DCFStoreRoot, d.Path)
// FullFilePath returns the path of the object on the local filesystem,
// which is its store-relative path resolved against the store root.
func (d *Object) FullFilePath() string {
return filepath.Join(d.StoreRoot, d.Path)
}
// VideosCount returns the number of videos in the DCF store.
func (d *DCFStore) VideosCount() int {
func (d *Store) VideosCount() int {
return len(d.Videos)
}
// ImagesCount returns the number of images in the DCF store.
func (d *DCFStore) ImagesCount() int {
func (d *Store) ImagesCount() int {
return len(d.Images)
}
func (d *DCFStore) TotalImageSize() int64 {
// TotalImageSize returns the summed size in bytes of the store's images.
func (d *Store) TotalImageSize() int64 {
totalSize := int64(0)
for _, image := range d.Images {
totalSize += image.Size
}
return totalSize
}
func (d *DCFStore) TotalVideoSize() int64 {
// TotalVideoSize returns the summed size in bytes of the store's videos.
func (d *Store) TotalVideoSize() int64 {
totalSize := int64(0)
for _, video := range d.Videos {
totalSize += video.Size
}
return totalSize
}
func (d *DCFStore) TotalSize() int64 {
// TotalSize returns the summed size in bytes of every object in the
// store.
func (d *Store) TotalSize() int64 {
return d.TotalImageSize() + d.TotalVideoSize()
}
func (d *DCFStore) String() string {
return fmt.Sprintf("DCFStore{RootDirectory: %s, Images: %d, Videos: %d, TotalSize: %s}",
// String renders the store as a single human-readable summary line.
func (d *Store) String() string {
return fmt.Sprintf(
"Store{RootDirectory: %s, Images: %d, Videos: %d, TotalSize: %s}",
d.RootDirectory,
d.ImagesCount(),
d.VideosCount(),
humanize.Bytes(uint64(d.TotalSize())),
humanize.Bytes(d.totalSizeBytes()),
)
}
// totalSizeBytes returns TotalSize as an unsigned byte count for
// formatting. Sizes come from the filesystem and are never negative,
// but the conversion is guarded rather than assumed.
func (d *Store) totalSizeBytes() uint64 {
total := d.TotalSize()
if total < 0 {
return 0
}
return uint64(total)
}
// String renders the video as a single human-readable line.
func (v *Video) String() string {
return fmt.Sprintf("Video{Path: %s, Size: %d, Extension: %s}", v.Path, v.Size, v.Extension)
return fmt.Sprintf(
"Video{Path: %s, Size: %d, Extension: %s}",
v.Path, v.Size, v.Extension,
)
}
// String renders the image as a single human-readable line.
func (i *Image) String() string {
return fmt.Sprintf("Image{Path: %s, Size: %d, Extension: %s}", i.Path, i.Size, i.Extension)
return fmt.Sprintf(
"Image{Path: %s, Size: %d, Extension: %s}",
i.Path, i.Size, i.Extension,
)
}
// Hash() returns the SHA256 hash of the file as a hex string.
func (d *DCFObject) Hash() (string, error) {
// Hash returns the SHA-256 digest of the object's file as a hex string.
func (d *Object) Hash() (string, error) {
return pathToSHA256(d.FullFilePath())
}
// pathToSHA256 returns the SHA-256 digest of the file at path as a hex
// string.
func pathToSHA256(path string) (string, error) {
file, err := os.Open(path)
// The path is supplied by the caller by design: this library exists
// to hash files the caller pointed it at.
file, err := os.Open(filepath.Clean(path))
if err != nil {
return "", err
}
defer file.Close()
defer func() { _ = file.Close() }()
hash := sha256.New()
if _, err := io.Copy(hash, file); err != nil {
_, err = io.Copy(hash, file)
if err != nil {
return "", err
}
return fmt.Sprintf("%x", hash.Sum(nil)), nil
return hex.EncodeToString(hash.Sum(nil)), nil
}
// GetDCFStores returns a list of DCF stores found on the system in the root of any mounted filesystems.
// the integer argument is the number of DCF stores to return. If the argument is 0, all DCF stores are returned.
// It does not mount filesystems or search outside of filesystem root directories. It does, however,
// walk the filesystems to find images and videos and populate the returned DCFStores.
func GetDCFStores(requestedCount int) (*[]DCFStore, error) {
dcfStorePaths, err := findDCFMountPoints(requestedCount)
// GetDCFStores returns the DCF stores found in the root directories of
// the system's mounted filesystems. requestedCount bounds how many
// stores are returned; 0 returns all of them.
//
// It neither mounts filesystems nor searches outside filesystem root
// directories. It does walk each store it finds, populating the
// returned stores with the images and videos they contain.
func GetDCFStores(requestedCount int) (*[]Store, error) {
storePaths, err := findDCFMountPoints(requestedCount)
if err != nil {
return nil, err
}
dcfStores := []DCFStore{}
for _, dcfStorePath := range dcfStorePaths {
dcfStore := DCFStore{
RootDirectory: dcfStorePath,
Images: make([]*Image, 0),
Videos: make([]*Video, 0),
}
err := filepath.Walk(dcfStorePath, func(path string, info os.FileInfo, err error) error {
if err != nil {
return err
}
if !info.IsDir() && isImageFile(path) {
image := Image{}
image.Path = strings.TrimPrefix(path, dcfStorePath+"/")
image.Size = info.Size()
image.Extension = filepath.Ext(path)
image.DCFStoreRoot = dcfStorePath
dcfStore.Images = append(dcfStore.Images, &image)
}
if !info.IsDir() && isVideoFile(path) {
video := Video{}
video.Path = strings.TrimPrefix(path, dcfStorePath+"/")
video.Size = info.Size()
video.Extension = filepath.Ext(path)
video.DCFStoreRoot = dcfStorePath
dcfStore.Videos = append(dcfStore.Videos, &video)
}
return nil
})
stores := []Store{}
for _, storePath := range storePaths {
store, err := scanStore(storePath)
if err != nil {
return nil, err
}
dcfStores = append(dcfStores, dcfStore)
stores = append(stores, *store)
}
return &dcfStores, nil
return &stores, nil
}
// scanStore walks root and returns a Store holding every image and
// video beneath it.
func scanStore(root string) (*Store, error) {
store := Store{
RootDirectory: root,
Images: make([]*Image, 0),
Videos: make([]*Video, 0),
}
walk := func(path string, entry fs.DirEntry, err error) error {
if err != nil {
return err
}
if entry.IsDir() {
return nil
}
return store.addFile(root, path, entry)
}
err := filepath.WalkDir(root, walk)
if err != nil {
return nil, err
}
return &store, nil
}
// addFile classifies path by extension and appends it to the store's
// images or videos. A file that is neither is ignored.
func (d *Store) addFile(root, path string, entry fs.DirEntry) error {
isImage := isImageFile(path)
if !isImage && !isVideoFile(path) {
return nil
}
info, err := entry.Info()
if err != nil {
return err
}
object := Object{
StoreRoot: root,
Path: strings.TrimPrefix(path, root+string(filepath.Separator)),
Size: info.Size(),
Extension: filepath.Ext(path),
}
if isImage {
d.Images = append(d.Images, &Image{Object: object})
return nil
}
d.Videos = append(d.Videos, &Video{Object: object})
return nil
}
// isImageFile reports whether path names a file this package treats as
// an image.
func isImageFile(path string) bool {
ext := strings.ToLower(filepath.Ext(path))
for _, imageExt := range imageExtensions {
if ext == imageExt {
return true
}
}
return false
return hasExtension(path,
".jpg", ".jpeg", ".png", ".gif", ".bmp", ".tiff", ".raw", ".arw")
}
// isVideoFile reports whether path names a file this package treats as
// a video.
func isVideoFile(path string) bool {
ext := strings.ToLower(filepath.Ext(path))
for _, videoExt := range videoExtensions {
if ext == videoExt {
return true
}
}
return false
return hasExtension(path, ".mp4", ".mov", ".avi", ".mkv", ".wmv")
}
// hasExtension reports whether path's extension, lowercased, is one of
// the given extensions. Extensions are given with their leading dot.
func hasExtension(path string, extensions ...string) bool {
return slices.Contains(extensions, strings.ToLower(filepath.Ext(path)))
}

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@@ -1,10 +1,177 @@
package dcf
package dcf_test
import (
"crypto/sha256"
"encoding/hex"
"os"
"path/filepath"
"strings"
"testing"
"git.eeqj.de/sneak/dcf/pkg/dcf"
)
func TestCompile(t *testing.T) {
// This is a placeholder test to ensure that the module compiles successfully.
// You can add more meaningful tests here once you start implementing your code.
// newStore builds a store with two images and one video of known sizes,
// so the count and size accessors have something deterministic to
// report.
func newStore(root string) *dcf.Store {
return &dcf.Store{
RootDirectory: root,
Images: []*dcf.Image{
{Object: dcf.Object{
StoreRoot: root,
Path: "DCIM/100MSDCF/DSC00001.ARW",
Size: 2000,
Extension: ".ARW",
}},
{Object: dcf.Object{
StoreRoot: root,
Path: "DCIM/100MSDCF/DSC00002.JPG",
Size: 500,
Extension: ".JPG",
}},
},
Videos: []*dcf.Video{
{Object: dcf.Object{
StoreRoot: root,
Path: "PRIVATE/M4ROOT/CLIP/C0001.MP4",
Size: 9000,
Extension: ".MP4",
}},
},
}
}
func TestObjectFullFilePath(t *testing.T) {
t.Parallel()
object := dcf.Object{
StoreRoot: filepath.Join("/mnt", "card"),
Path: filepath.Join("DCIM", "100MSDCF", "DSC00001.ARW"),
}
want := filepath.Join("/mnt", "card", "DCIM", "100MSDCF", "DSC00001.ARW")
if got := object.FullFilePath(); got != want {
t.Fatalf("FullFilePath() = %q, want %q", got, want)
}
}
func TestStoreCounts(t *testing.T) {
t.Parallel()
store := newStore("/mnt/card")
if got := store.ImagesCount(); got != 2 {
t.Errorf("ImagesCount() = %d, want 2", got)
}
if got := store.VideosCount(); got != 1 {
t.Errorf("VideosCount() = %d, want 1", got)
}
}
func TestStoreSizes(t *testing.T) {
t.Parallel()
store := newStore("/mnt/card")
if got := store.TotalImageSize(); got != 2500 {
t.Errorf("TotalImageSize() = %d, want 2500", got)
}
if got := store.TotalVideoSize(); got != 9000 {
t.Errorf("TotalVideoSize() = %d, want 9000", got)
}
if got := store.TotalSize(); got != 11500 {
t.Errorf("TotalSize() = %d, want 11500", got)
}
}
func TestEmptyStoreSizesAreZero(t *testing.T) {
t.Parallel()
store := dcf.Store{RootDirectory: "/mnt/empty"}
if got := store.TotalSize(); got != 0 {
t.Fatalf("TotalSize() = %d, want 0", got)
}
}
func TestStoreStringReportsHumanizedTotal(t *testing.T) {
t.Parallel()
got := newStore("/mnt/card").String()
for _, want := range []string{"/mnt/card", "Images: 2", "Videos: 1", "12 kB"} {
if !strings.Contains(got, want) {
t.Errorf("String() = %q, want it to contain %q", got, want)
}
}
}
func TestImageAndVideoString(t *testing.T) {
t.Parallel()
image := dcf.Image{Object: dcf.Object{
Path: "DCIM/100MSDCF/DSC00001.ARW",
Size: 2000,
Extension: ".ARW",
}}
want := "Image{Path: DCIM/100MSDCF/DSC00001.ARW, Size: 2000, " +
"Extension: .ARW}"
if got := image.String(); got != want {
t.Errorf("Image.String() = %q, want %q", got, want)
}
video := dcf.Video{Object: dcf.Object{
Path: "PRIVATE/M4ROOT/CLIP/C0001.MP4",
Size: 9000,
Extension: ".MP4",
}}
want = "Video{Path: PRIVATE/M4ROOT/CLIP/C0001.MP4, Size: 9000, " +
"Extension: .MP4}"
if got := video.String(); got != want {
t.Errorf("Video.String() = %q, want %q", got, want)
}
}
func TestObjectHashMatchesSHA256OfFile(t *testing.T) {
t.Parallel()
root := t.TempDir()
contents := []byte("DSC00001.ARW contents")
err := os.MkdirAll(filepath.Join(root, "DCIM"), 0o750)
if err != nil {
t.Fatalf("MkdirAll: %v", err)
}
err = os.WriteFile(filepath.Join(root, "DCIM", "a.arw"), contents, 0o600)
if err != nil {
t.Fatalf("WriteFile: %v", err)
}
object := dcf.Object{StoreRoot: root, Path: filepath.Join("DCIM", "a.arw")}
got, err := object.Hash()
if err != nil {
t.Fatalf("Hash() returned error: %v", err)
}
sum := sha256.Sum256(contents)
if want := hex.EncodeToString(sum[:]); got != want {
t.Fatalf("Hash() = %q, want %q", got, want)
}
}
func TestObjectHashOnMissingFileReturnsError(t *testing.T) {
t.Parallel()
object := dcf.Object{StoreRoot: t.TempDir(), Path: "absent.jpg"}
_, err := object.Hash()
if err == nil {
t.Fatal("Hash() on a missing file returned no error")
}
}

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@@ -1,75 +1,84 @@
package dcf
import (
"fmt"
"log/slog"
"os"
"path/filepath"
"runtime"
"slices"
"github.com/shirou/gopsutil/disk"
)
// dcfMarkerDirectories are the directory names whose presence in a
// filesystem root identifies that filesystem as a DCF store.
func dcfMarkerDirectories() []string {
return []string{"DCIM", "M4ROOT"}
}
// findAllMountPoints returns the distinct mountpoints of the system's
// physical filesystems.
func findAllMountPoints() ([]string, error) {
mountpoints := []string{}
partitions, err := disk.Partitions(false) // physical devices only, so false
partitions, err := disk.Partitions(false) // physical devices only
if err != nil {
return nil, err
}
mountpoints := []string{}
for _, partition := range partitions {
if !contains(mountpoints, partition.Mountpoint) {
if !slices.Contains(mountpoints, partition.Mountpoint) {
mountpoints = append(mountpoints, partition.Mountpoint)
}
}
return mountpoints, nil
}
func dump(x interface{}) {
_, file, line, _ := runtime.Caller(1)
slog.Debug(fmt.Sprintf("%s:%d %#v\n", file, line, x))
}
// findDCFMountPoints returns a list of strings of the paths of mountpoints that
// contain a DCIM or PRIVATE directory, which is how we detect DCF stores. Its
// only argument is an integer of how many mountpoints to return. If the
// argument is 0, all mountpoints are returned.
// findDCFMountPoints returns the paths of the mountpoints that contain
// one of the marker directories a DCF store is identified by. Its only
// argument is how many mountpoints to return; 0 returns all of them.
func findDCFMountPoints(requestedCount int) ([]string, error) {
filteredMountpoints := []string{}
var erro error
mountpoints, err := findAllMountPoints()
if erro != nil {
if err != nil {
return nil, err
}
filteredMountpoints := []string{}
for _, mountpoint := range mountpoints {
dcimPath := filepath.Join(mountpoint, "DCIM")
privatePath := filepath.Join(mountpoint, "PRIVATE")
privatePath = filepath.Join(mountpoint, "M4ROOT")
shouldKeep := false
if _, err := os.Stat(dcimPath); err == nil {
shouldKeep = true
slog.Debug(fmt.Sprintf("Found DCIM directory at %s\n", dcimPath))
if !isDCFMountPoint(mountpoint) {
continue
}
if _, err := os.Stat(privatePath); err == nil {
shouldKeep = true
slog.Debug(fmt.Sprintf("Found M4ROOT directory at %s\n", privatePath))
}
if shouldKeep {
slog.Debug(fmt.Sprintf("Keeping mountpoint %s\n", mountpoint))
filteredMountpoints = append(filteredMountpoints, mountpoint)
if (requestedCount > 0) && (len(filteredMountpoints)+1 >= requestedCount) {
break
}
slog.Debug("keeping mountpoint", "mountpoint", mountpoint)
filteredMountpoints = append(filteredMountpoints, mountpoint)
if requestedCount > 0 && len(filteredMountpoints)+1 >= requestedCount {
break
}
}
return filteredMountpoints, nil
}
func contains(slice []string, str string) bool {
for _, s := range slice {
if s == str {
return true
// isDCFMountPoint reports whether mountpoint holds any of the marker
// directories a DCF store is identified by.
func isDCFMountPoint(mountpoint string) bool {
found := false
for _, marker := range dcfMarkerDirectories() {
markerPath := filepath.Join(mountpoint, marker)
_, err := os.Stat(markerPath)
if err != nil {
continue
}
slog.Debug("found marker directory", "path", markerPath)
found = true
}
return false
return found
}