remove prefix, add remote storage

go.mod

@@ -1,3 +1,21 @@
 module github.com/tenrok/filestore
 
-go 1.23.4
+go 1.23.6
+
+require github.com/minio/minio-go/v7 v7.0.90
+
+require (
+	github.com/dustin/go-humanize v1.0.1 // indirect
+	github.com/go-ini/ini v1.67.0 // indirect
+	github.com/goccy/go-json v0.10.5 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/klauspost/compress v1.18.0 // indirect
+	github.com/klauspost/cpuid/v2 v2.2.10 // indirect
+	github.com/minio/crc64nvme v1.0.1 // indirect
+	github.com/minio/md5-simd v1.1.2 // indirect
+	github.com/rs/xid v1.6.0 // indirect
+	golang.org/x/crypto v0.36.0 // indirect
+	golang.org/x/net v0.38.0 // indirect
+	golang.org/x/sys v0.31.0 // indirect
+	golang.org/x/text v0.23.0 // indirect
+)

go.sum

@@ -0,0 +1,29 @@
+github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
+github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
+github.com/go-ini/ini v1.67.0 h1:z6ZrTEZqSWOTyH2FlglNbNgARyHG8oLW9gMELqKr06A=
+github.com/go-ini/ini v1.67.0/go.mod h1:ByCAeIL28uOIIG0E3PJtZPDL8WnHpFKFOtgjp+3Ies8=
+github.com/goccy/go-json v0.10.5 h1:Fq85nIqj+gXn/S5ahsiTlK3TmC85qgirsdTP/+DeaC4=
+github.com/goccy/go-json v0.10.5/go.mod h1:oq7eo15ShAhp70Anwd5lgX2pLfOS3QCiwU/PULtXL6M=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/klauspost/compress v1.18.0 h1:c/Cqfb0r+Yi+JtIEq73FWXVkRonBlf0CRNYc8Zttxdo=
+github.com/klauspost/compress v1.18.0/go.mod h1:2Pp+KzxcywXVXMr50+X0Q/Lsb43OQHYWRCY2AiWywWQ=
+github.com/klauspost/cpuid/v2 v2.0.1/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
+github.com/klauspost/cpuid/v2 v2.2.10 h1:tBs3QSyvjDyFTq3uoc/9xFpCuOsJQFNPiAhYdw2skhE=
+github.com/klauspost/cpuid/v2 v2.2.10/go.mod h1:hqwkgyIinND0mEev00jJYCxPNVRVXFQeu1XKlok6oO0=
+github.com/minio/crc64nvme v1.0.1 h1:DHQPrYPdqK7jQG/Ls5CTBZWeex/2FMS3G5XGkycuFrY=
+github.com/minio/crc64nvme v1.0.1/go.mod h1:eVfm2fAzLlxMdUGc0EEBGSMmPwmXD5XiNRpnu9J3bvg=
+github.com/minio/md5-simd v1.1.2 h1:Gdi1DZK69+ZVMoNHRXJyNcxrMA4dSxoYHZSQbirFg34=
+github.com/minio/md5-simd v1.1.2/go.mod h1:MzdKDxYpY2BT9XQFocsiZf/NKVtR7nkE4RoEpN+20RM=
+github.com/minio/minio-go/v7 v7.0.90 h1:TmSj1083wtAD0kEYTx7a5pFsv3iRYMsOJ6A4crjA1lE=
+github.com/minio/minio-go/v7 v7.0.90/go.mod h1:uvMUcGrpgeSAAI6+sD3818508nUyMULw94j2Nxku/Go=
+github.com/rs/xid v1.6.0 h1:fV591PaemRlL6JfRxGDEPl69wICngIQ3shQtzfy2gxU=
+github.com/rs/xid v1.6.0/go.mod h1:7XoLgs4eV+QndskICGsho+ADou8ySMSjJKDIan90Nz0=
+golang.org/x/crypto v0.36.0 h1:AnAEvhDddvBdpY+uR+MyHmuZzzNqXSe/GvuDeob5L34=
+golang.org/x/crypto v0.36.0/go.mod h1:Y4J0ReaxCR1IMaabaSMugxJES1EpwhBHhv2bDHklZvc=
+golang.org/x/net v0.38.0 h1:vRMAPTMaeGqVhG5QyLJHqNDwecKTomGeqbnfZyKlBI8=
+golang.org/x/net v0.38.0/go.mod h1:ivrbrMbzFq5J41QOQh0siUuly180yBYtLp+CKbEaFx8=
+golang.org/x/sys v0.31.0 h1:ioabZlmFYtWhL+TRYpcnNlLwhyxaM9kWTDEmfnprqik=
+golang.org/x/sys v0.31.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
+golang.org/x/text v0.23.0 h1:D71I7dUrlY+VX0gQShAThNGHFxZ13dGLBHQLVl1mJlY=
+golang.org/x/text v0.23.0/go.mod h1:/BLNzu4aZCJ1+kcD0DNRotWKage4q2rGVAg4o22unh4=

httpfs.go

@@ -0,0 +1,53 @@
+package filestore
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/tenrok/filestore/remote"
+)
+
+var _ http.FileSystem = (*HttpFS)(nil)
+
+type HttpFS struct {
+	store         *Store
+	remoteStorage remote.Storage
+}
+
+type Option func(*HttpFS)
+
+// WithRemoteStorage
+func WithRemoteStorage(storage remote.Storage) Option {
+	return func(httpFS *HttpFS) {
+		httpFS.remoteStorage = storage
+	}
+}
+
+// NewHttpFS
+func NewHttpFS(dir string, opts ...Option) (*HttpFS, error) {
+	store, err := NewStore(dir)
+	if err != nil {
+		return nil, err
+	}
+	f := &HttpFS{store: store}
+	for _, opt := range opts {
+		if opt != nil {
+			opt(f)
+		}
+	}
+	return f, nil
+}
+
+// Open
+func (f *HttpFS) Open(name string) (http.File, error) {
+	n := strings.TrimPrefix(name, "/")
+	if f.remoteStorage != nil {
+		return f.remoteStorage.Open(name)
+	}
+	return f.store.Open(n)
+}
+
+// RemoteStorage
+func (f *HttpFS) RemoteStorage() remote.Storage {
+	return f.remoteStorage
+}

remote/helper.go

@@ -0,0 +1,23 @@
+package remote
+
+import (
+	"errors"
+	"strings"
+)
+
+var (
+	ErrNoScheme = errors.New("no scheme")
+	ErrEmptyURL = errors.New("URL cannot be empty")
+)
+
+// schemeFromURL returns the scheme from a URL string
+func schemeFromURL(url string) (string, error) {
+	if url == "" {
+		return "", ErrEmptyURL
+	}
+	i := strings.Index(url, ":")
+	if i < 1 {
+		return "", ErrNoScheme
+	}
+	return url[:i], nil
+}

remote/miniostorage/file.go

@@ -0,0 +1,299 @@
+package miniostorage
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"io/fs"
+	"net/http"
+	"os"
+	"sort"
+	"syscall"
+
+	"github.com/minio/minio-go/v7"
+)
+
+var (
+	ErrOutOfRange   = errors.New("out of range")
+	ErrNotSupported = errors.New("doesn't support this operation")
+)
+
+var _ http.File = (*MinioFile)(nil)
+
+type MinioFile struct {
+	openFlags int
+	offset    int64
+	closed    bool
+	resource  *minioFileResource
+}
+
+// NewMinioFile
+func NewMinioFile(ctx context.Context, storage *MinioStorage, openFlags int, fileMode os.FileMode, name string) *MinioFile {
+	return &MinioFile{
+		openFlags: openFlags,
+		// offset:    0,
+		// closed:    false,
+		resource: &minioFileResource{
+			ctx:           ctx,
+			storage:       storage,
+			name:          name,
+			fileMode:      fileMode,
+			currentIoSize: 0,
+			offset:        0,
+			reader:        nil,
+			writer:        nil,
+		},
+	}
+}
+
+// Close
+func (f *MinioFile) Close() error {
+	if f.closed {
+		return os.ErrClosed
+	}
+	f.closed = true
+	return f.resource.Close()
+}
+
+// Read
+func (f *MinioFile) Read(p []byte) (int, error) {
+	if f.closed {
+		return 0, os.ErrClosed
+	}
+	readed, err := f.resource.ReadAt(p, f.offset)
+	f.offset += int64(readed)
+	return readed, err
+}
+
+// Seek
+func (f *MinioFile) Seek(offset int64, whence int) (int64, error) {
+	if f.closed {
+		return 0, os.ErrClosed
+	}
+	// Since this is an expensive operation; let's make sure we need it
+	if (whence == 0 && offset == f.offset) || (whence == 1 && offset == 0) {
+		return f.offset, nil
+	}
+	// Fore the reader/writers to be reopened (at correct offset)
+	if err := f.Sync(); err != nil {
+		return 0, err
+	}
+	stat, err := f.Stat()
+	if err != nil {
+		return 0, nil
+	}
+	switch whence {
+	case io.SeekStart:
+		f.offset = offset
+	case io.SeekCurrent:
+		f.offset += offset
+	case io.SeekEnd:
+		f.offset = stat.Size() + offset
+	}
+	return f.offset, nil
+}
+
+// Write
+func (f *MinioFile) Write(p []byte) (int, error) {
+	return f.WriteAt(p, f.offset)
+}
+
+// WriteAt
+func (f *MinioFile) WriteAt(b []byte, off int64) (int, error) {
+	if f.closed {
+		return 0, os.ErrClosed
+	}
+	if f.openFlags&os.O_RDONLY != 0 {
+		return 0, fmt.Errorf("file is opened as read only")
+	}
+	written, err := f.resource.WriteAt(b, off)
+	f.offset += int64(written)
+	return written, err
+}
+
+// readdirImpl
+func (f *MinioFile) readdirImpl(count int) ([]*MinioFileInfo, error) {
+	if err := f.Sync(); err != nil {
+		return nil, err
+	}
+	ownInfo, err := f.Stat()
+	if err != nil {
+		return nil, err
+	}
+	if !ownInfo.IsDir() {
+		return nil, syscall.ENOTDIR
+	}
+	var res []*MinioFileInfo
+	objs := f.resource.storage.client.ListObjects(f.resource.ctx, f.resource.storage.bucket, minio.ListObjectsOptions{
+		Recursive: true,
+		Prefix:    f.resource.name,
+	})
+	for obj := range objs {
+		tmp := NewFileInfoFromAttrs(obj, f.resource.fileMode)
+		if tmp.Name() == "" {
+			// neither object.Name, not object.Prefix were present - so let's skip this unknown thing
+			continue
+		}
+		res = append(res, tmp)
+	}
+	if count > 0 && len(res) > 0 {
+		sort.Sort(ByName(res))
+		res = res[:count]
+	}
+	return res, nil
+}
+
+// Readdir
+func (f *MinioFile) Readdir(count int) ([]fs.FileInfo, error) {
+	fi, err := f.readdirImpl(count)
+	if err != nil {
+		return nil, err
+	}
+	var res []fs.FileInfo
+	for _, v := range fi {
+		res = append(res, v)
+	}
+	return res, nil
+}
+
+// Readdirnames
+func (f *MinioFile) Readdirnames(n int) ([]string, error) {
+	fi, err := f.Readdir(n)
+	if err != nil && err != io.EOF {
+		return nil, err
+	}
+	names := make([]string, len(fi))
+	for i, v := range fi {
+		names[i] = v.Name()
+	}
+	return names, err
+}
+
+// Stat
+func (f *MinioFile) Stat() (os.FileInfo, error) {
+	if err := f.Sync(); err != nil {
+		return nil, err
+	}
+	stat, err := f.resource.storage.client.StatObject(f.resource.ctx, f.resource.storage.bucket, f.resource.name, minio.StatObjectOptions{})
+	if err != nil {
+		return nil, err
+	}
+	return NewFileInfoFromAttrs(stat, f.resource.fileMode), nil
+}
+
+// Sync
+func (f *MinioFile) Sync() error {
+	return f.resource.maybeCloseIo()
+}
+
+// Truncate
+func (f *MinioFile) Truncate(_ int64) error {
+	return ErrNotSupported
+}
+
+// WriteString
+func (f *MinioFile) WriteString(s string) (int, error) {
+	return f.Write([]byte(s))
+}
+
+type readerAtCloser interface {
+	io.ReadCloser
+	io.ReaderAt
+}
+
+type minioFileResource struct {
+	ctx           context.Context
+	storage       *MinioStorage
+	name          string
+	fileMode      os.FileMode
+	currentIoSize int64
+	offset        int64
+	reader        readerAtCloser
+	writer        io.WriteCloser
+	closed        bool
+}
+
+// Close
+func (r *minioFileResource) Close() error {
+	r.closed = true
+	return r.maybeCloseIo()
+}
+
+// maybeCloseIo
+func (r *minioFileResource) maybeCloseIo() error {
+	if r.reader != nil {
+		if err := r.reader.Close(); err != nil {
+			return fmt.Errorf("error closing reader: %v", err)
+		}
+		r.reader = nil
+	}
+	if r.writer != nil {
+		if err := r.writer.Close(); err != nil {
+			return fmt.Errorf("error closing writer: %v", err)
+		}
+		r.writer = nil
+	}
+	return nil
+}
+
+// ReadAt
+func (r *minioFileResource) ReadAt(p []byte, offset int64) (int, error) {
+	if cap(p) == 0 {
+		return 0, nil
+	}
+	// Assume that if the reader is open; it is at the correct offset a good performance assumption that we must ensure holds
+	if offset == r.offset && r.reader != nil {
+		readed, err := r.reader.ReadAt(p, offset)
+		r.offset += int64(readed)
+		return readed, err
+	}
+	// If any writers have written anything; commit it first so we can read it back.
+	if err := r.maybeCloseIo(); err != nil {
+		return 0, err
+	}
+	obj, err := r.storage.client.GetObject(r.ctx, r.storage.bucket, r.name, minio.GetObjectOptions{})
+	if err != nil {
+		return 0, err
+	}
+	r.reader = obj
+	r.offset = offset
+	readed, err := obj.ReadAt(p, offset)
+	r.offset += int64(readed)
+	return readed, err
+}
+
+// WriteAt
+func (r *minioFileResource) WriteAt(b []byte, offset int64) (int, error) {
+	// If the writer is opened and at the correct offset we're good!
+	if offset == r.offset && r.writer != nil {
+		written, err := r.writer.Write(b)
+		r.offset += int64(written)
+		return written, err
+	}
+	// Ensure readers must be re-opened and that if a writer is active at another offset it is first committed before we do a "seek" below
+	if err := r.maybeCloseIo(); err != nil {
+		return 0, err
+	}
+	// WriteAt to a non existing file
+	if offset > r.currentIoSize {
+		return 0, ErrOutOfRange
+	}
+	r.offset = offset
+	buffer := bytes.NewReader(b)
+	opts := minio.PutObjectOptions{
+		ContentType: http.DetectContentType(b),
+	}
+	if offset > 0 {
+		opts.PartSize = uint64(offset)
+		opts.NumThreads = 8
+		opts.ConcurrentStreamParts = false
+		opts.DisableMultipart = true
+	}
+	if _, err := r.storage.client.PutObject(r.ctx, r.storage.bucket, r.name, buffer, buffer.Size(), opts); err != nil {
+		return 0, err
+	}
+	r.offset += int64(buffer.Len())
+	return buffer.Len(), nil
+}

remote/miniostorage/fileinfo.go

@@ -0,0 +1,96 @@
+package miniostorage
+
+import (
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/minio/minio-go/v7"
+)
+
+const folderSize = 42
+
+var _ fs.FileInfo = (*MinioFileInfo)(nil)
+
+type MinioFileInfo struct {
+	ETag     string
+	name     string
+	size     int64
+	updated  time.Time
+	isDir    bool
+	fileMode os.FileMode
+}
+
+// NewFileInfoFromAttrs
+func NewFileInfoFromAttrs(obj minio.ObjectInfo, fileMode os.FileMode) *MinioFileInfo {
+	res := &MinioFileInfo{
+		ETag:     obj.ETag,
+		name:     obj.Key,
+		size:     obj.Size,
+		updated:  obj.LastModified,
+		isDir:    false,
+		fileMode: fileMode,
+	}
+
+	if res.name == "" {
+		// deals with them at the moment
+		//res.name = "folder"
+		res.size = folderSize
+		res.isDir = true
+	}
+
+	return res
+}
+
+// Name
+func (fi *MinioFileInfo) Name() string {
+	return filepath.Base(filepath.FromSlash(fi.name))
+}
+
+// Size
+func (fi *MinioFileInfo) Size() int64 {
+	return fi.size
+}
+
+// Mode
+func (fi *MinioFileInfo) Mode() os.FileMode {
+	if fi.IsDir() {
+		return os.ModeDir | fi.fileMode
+	}
+	return fi.fileMode
+}
+
+// ModTime
+func (fi *MinioFileInfo) ModTime() time.Time {
+	return fi.updated
+}
+
+// IsDir
+func (fi *MinioFileInfo) IsDir() bool {
+	return fi.isDir
+}
+
+// Sys
+func (fi *MinioFileInfo) Sys() any {
+	return nil
+}
+
+type ByName []*MinioFileInfo
+
+// Len
+func (a ByName) Len() int { return len(a) }
+
+// Swap
+func (a ByName) Swap(i, j int) {
+	a[i].name, a[j].name = a[j].name, a[i].name
+	a[i].size, a[j].size = a[j].size, a[i].size
+	a[i].updated, a[j].updated = a[j].updated, a[i].updated
+	a[i].isDir, a[j].isDir = a[j].isDir, a[i].isDir
+}
+
+// Less
+func (a ByName) Less(i, j int) bool {
+	return strings.Compare(a[i].Name(), a[j].Name()) == -1
+}

remote/miniostorage/helper.go

@@ -0,0 +1,15 @@
+package miniostorage
+
+import "net/url"
+
+// getUserPassword
+func getUserPassword(u *url.URL) (string, string) {
+	var user, password string
+	if u.User != nil {
+		user = u.User.Username()
+		if p, ok := u.User.Password(); ok {
+			password = p
+		}
+	}
+	return user, password
+}

remote/miniostorage/miniostorage.go

@@ -0,0 +1,148 @@
+package miniostorage
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"net/url"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/minio/minio-go/v7"
+	"github.com/minio/minio-go/v7/pkg/credentials"
+	"github.com/tenrok/filestore/remote"
+)
+
+const defaultFileMode = 0o755
+
+var _ remote.Storage = (*MinioStorage)(nil)
+
+func init() {
+	remote.Register("minio", &MinioStorage{})
+}
+
+type MinioStorage struct {
+	ctx       context.Context
+	client    *minio.Client
+	bucket    string
+	separator string
+}
+
+// NewStorage
+func (s *MinioStorage) NewStorage(ctx context.Context, connString string) (remote.Storage, error) {
+	u, err := url.Parse(connString)
+	if err != nil {
+		return nil, err
+	}
+	queries := u.Query()
+	username, password := getUserPassword(u)
+	token := queries.Get("token")
+	opts := &minio.Options{
+		Creds:  credentials.NewStaticV4(username, password, token),
+		Region: "us-east-1",
+	}
+	if queries.Has("secure") {
+		secure, err := strconv.ParseBool(queries.Get("secure"))
+		if err != nil {
+			return nil, err
+		}
+		opts.Secure = secure
+	}
+	if queries.Has("region") {
+		opts.Region = queries.Get("region")
+	}
+	client, err := minio.New(u.Host, opts)
+	if err != nil {
+		return nil, err
+	}
+	s.ctx = ctx
+	s.client = client
+	s.bucket = u.Path[1:]
+	s.separator = "/"
+	return s, nil
+}
+
+// normSeparators will normalize all "\\" and "/" to the provided separator
+func (s *MinioStorage) normSeparators(str string) string {
+	return strings.Replace(strings.Replace(str, "\\", s.separator, -1), "/", s.separator, -1)
+}
+
+// Create
+func (s *MinioStorage) Create(name string) (http.File, error) {
+	return s.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0)
+}
+
+// Open
+func (s *MinioStorage) Open(name string) (http.File, error) {
+	return s.OpenFile(name, os.O_RDONLY, 0)
+}
+
+// OpenFile
+func (s *MinioStorage) OpenFile(name string, flag int, fileMode os.FileMode) (http.File, error) {
+	if flag&os.O_APPEND != 0 {
+		return nil, errors.New("appending files will lead to trouble")
+	}
+	name = strings.TrimPrefix(s.normSeparators(name), s.separator)
+	file := NewMinioFile(s.ctx, s, flag, fileMode, name)
+	var err error
+	if flag&os.O_CREATE != 0 {
+		_, err = file.WriteString("")
+	}
+	return file, err
+}
+
+// Remove
+func (s *MinioStorage) Remove(name string) error {
+	name = strings.TrimPrefix(s.normSeparators(name), s.separator)
+	return s.client.RemoveObject(s.ctx, s.bucket, name, minio.RemoveObjectOptions{GovernanceBypass: true})
+}
+
+// RemoveAll
+func (s *MinioStorage) RemoveAll(path string) error {
+	path = strings.TrimPrefix(s.normSeparators(path), s.separator)
+	objectsCh := make(chan minio.ObjectInfo)
+	go func() {
+		defer close(objectsCh)
+		opts := minio.ListObjectsOptions{Prefix: path, Recursive: true}
+		for object := range s.client.ListObjects(s.ctx, s.bucket, opts) {
+			if object.Err != nil {
+				panic(object.Err)
+			}
+			objectsCh <- object
+		}
+	}()
+	errorCh := s.client.RemoveObjects(s.ctx, s.bucket, objectsCh, minio.RemoveObjectsOptions{})
+	for e := range errorCh {
+		return errors.New("Failed to remove " + e.ObjectName + ", error: " + e.Err.Error())
+	}
+	return nil
+}
+
+// Rename
+func (s *MinioStorage) Rename(oldName, newName string) error {
+	if oldName == newName {
+		return nil
+	}
+	oldName = strings.TrimPrefix(s.normSeparators(oldName), s.separator)
+	newName = strings.TrimPrefix(s.normSeparators(newName), s.separator)
+	src := minio.CopySrcOptions{
+		Bucket: s.bucket,
+		Object: oldName,
+	}
+	dst := minio.CopyDestOptions{
+		Bucket: s.bucket,
+		Object: newName,
+	}
+	if _, err := s.client.CopyObject(s.ctx, dst, src); err != nil {
+		return err
+	}
+	return s.Remove(oldName)
+}
+
+// Stat
+func (s *MinioStorage) Stat(name string) (os.FileInfo, error) {
+	name = strings.TrimPrefix(s.normSeparators(name), s.separator)
+	file := NewMinioFile(s.ctx, s, os.O_RDWR, defaultFileMode, name)
+	return file.Stat()
+}

remote/storage.go

@@ -0,0 +1,52 @@
+package remote
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"sync"
+)
+
+var (
+	storagesMu sync.RWMutex
+	storages   = make(map[string]Storage)
+)
+
+type Storage interface {
+	NewStorage(ctx context.Context, connString string) (Storage, error)
+	// Create(name string) (http.File, error)
+	Open(name string) (http.File, error)
+	// OpenFile(name string, flag int, fileMode os.FileMode) (http.File, error)
+	// Remove(name string) error
+	// RemoveAll(path string) error
+	// Rename(oldName, newName string) error
+	// Stat(name string) (os.FileInfo, error)
+}
+
+// NewStorage returns a new remote storage instance.
+func NewStorage(ctx context.Context, connString string) (Storage, error) {
+	scheme, err := schemeFromURL(connString)
+	if err != nil {
+		return nil, err
+	}
+	storagesMu.RLock()
+	s, ok := storages[scheme]
+	storagesMu.RUnlock()
+	if !ok {
+		return nil, fmt.Errorf("unknown storage %v (forgotten import?)", scheme)
+	}
+	return s.NewStorage(ctx, connString)
+}
+
+// Register globally registers a storage
+func Register(name string, storage Storage) {
+	storagesMu.Lock()
+	defer storagesMu.Unlock()
+	if storage == nil {
+		panic("Register storage is nil")
+	}
+	if _, exists := storages[name]; exists {
+		panic("Register called twice for storage " + name)
+	}
+	storages[name] = storage
+}

store.go

@@ -19,7 +19,7 @@ const tmpfileName = "<temporary file>"
 
 // Store описывает хранилище файлов.
 type Store struct {
-	root string
+	dir string
 
 	mutexes struct {
 		sync.Mutex
@@ -28,15 +28,6 @@ type Store struct {
 	}
 }
 
-// Open открывает и возвращает хранилище файлов.
-func Open(root string) (*Store, error) {
-	// Создаём каталог, если он ещё не создан
-	if err := os.MkdirAll(root, 0700); err != nil {
-		return nil, err
-	}
-	return &Store{root: root}, nil
-}
-
 // FileInfo описывает информацию о сохраненном файле.
 type FileInfo struct {
 	Location string `json:"location"`
@@ -47,24 +38,23 @@ type FileInfo struct {
 	MD5      string `json:"md5"`
 }
 
-// Create сохраняет файл в хранилище. В качестве имени файла используется комбинация из двух хешей. Файл сохраняется в подкаталоге prefix,
-// если он задан, но данный prefix не учитывается в возвращаемой информации в имени файла.
-func (s *Store) Create(prefix string, r io.Reader) (*FileInfo, error) {
-	// Добавляем префикс к корню и создаём каталог
-	root := filepath.Join(s.root, prefix)
-	if err := os.MkdirAll(root, 0700); err != nil {
+// NewStore открывает и возвращает хранилище файлов.
+func NewStore(dir string) (*Store, error) {
+	// Создаём каталог, если он ещё не создан
+	if err := os.MkdirAll(dir, 0700); err != nil {
 		return nil, err
 	}
+	return &Store{dir: dir}, nil
+}
 
+// Create сохраняет файл в хранилище. В качестве имени файла используется комбинация из двух хешей.
+func (s *Store) Create(r io.Reader) (*FileInfo, error) {
 	// Создаём временный файл в корневом каталоге
-	tmpfile, err := os.CreateTemp(root, "~tmp")
+	tmpfile, err := os.CreateTemp(s.dir, "~tmp")
 	if err != nil {
-		err.(*os.PathError).Path = tmpfileName // Подменяем имя файла
+		err.(*os.PathError).Path = tmpfileName // Подмениваем имя файла
 		return nil, err
 	}
-
-	// В любом случае временный файл должен быть удален, если он не был переименован, т.е. на момент окончания функции существует под
-	// временным именем
 	defer os.Remove(tmpfile.Name())
 
 	// Копируем содержимое во временный файл
@@ -77,7 +67,7 @@ func (s *Store) Create(prefix string, r io.Reader) (*FileInfo, error) {
 		err = &os.PathError{Op: "create", Path: tmpfileName, Err: err}
 		return nil, err
 	}
-	mimetype := http.DetectContentType(data) // Определяем тип содержимого
+	mimetype := http.DetectContentType(data)
 
 	// Одновременно с сохранением в файл считаем две хеш-суммы
 	hashCRC32, hashMD5 := crc32.NewIEEE(), md5.New()
@@ -92,7 +82,7 @@ func (s *Store) Create(prefix string, r io.Reader) (*FileInfo, error) {
 	sumMD5 := hashMD5.Sum(nil)
 	name := base32.StdEncoding.EncodeToString(append(hashCRC32.Sum(nil), sumMD5...))
 	fi := &FileInfo{
-		Location: s.GetFullName(prefix, name),
+		Location: s.GetFullName(name),
 		Name:     name,
 		Mimetype: mimetype,
 		Size:     size,
@@ -133,9 +123,9 @@ func (s *Store) Create(prefix string, r io.Reader) (*FileInfo, error) {
 }
 
 // Open открывает файл из каталога.
-func (s *Store) Open(prefix, name string) (*os.File, error) {
+func (s *Store) Open(name string) (*os.File, error) {
 	// Полное имя для доступа к файлу
-	fullName := s.GetFullName(prefix, name)
+	fullName := s.GetFullName(name)
 	if fullName == "" {
 		return nil, os.ErrNotExist
 	}
@@ -169,13 +159,13 @@ func (s *Store) Open(prefix, name string) (*os.File, error) {
 }
 
 // Remove удаляет файл из хранилища.
-func (s *Store) Remove(prefix, name string) error {
+func (s *Store) Remove(name string) error {
 	mu := s.getMutex(name)
 	mu.Lock()
 	defer mu.Unlock()
 
 	// Полное имя для доступа к файлу
-	fullName := s.GetFullName(prefix, name)
+	fullName := s.GetFullName(name)
 	if fullName == "" {
 		return os.ErrNotExist
 	}
@@ -186,7 +176,7 @@ func (s *Store) Remove(prefix, name string) error {
 	}
 
 	// Пытаемся удалить пустые каталоги, если они образовались
-	for i := 0; i < 2; i++ {
+	for range 2 {
 		fullName = filepath.Dir(fullName)
 		if err := os.Remove(fullName); err != nil {
 			break // Если не получилось, значит каталог не пустой
@@ -200,7 +190,7 @@ func (s *Store) Remove(prefix, name string) error {
 func (s *Store) Clean(lifetime time.Duration) error {
 	// Удаляем вообще все файлы, если время жизни не задано
 	if lifetime <= 0 {
-		files, err := filepath.Glob(filepath.Join(s.root, "*"))
+		files, err := filepath.Glob(filepath.Join(s.dir, "*"))
 		if err != nil {
 			return err
 		}
@@ -214,7 +204,7 @@ func (s *Store) Clean(lifetime time.Duration) error {
 	// Вычисляем крайнюю дату валидности файлов
 	valid := time.Now().Add(-lifetime)
 
-	err := filepath.Walk(s.root,
+	err := filepath.Walk(s.dir,
 		func(filename string, info os.FileInfo, err error) error {
 			if err != nil {
 				return err
@@ -231,7 +221,7 @@ func (s *Store) Clean(lifetime time.Duration) error {
 			}
 
 			// Пытаемся удалить пустые каталоги
-			for i := 0; i < 2; i++ {
+			for range 2 {
 				filename = filepath.Dir(filename)
 				if err = os.Remove(filename); err != nil {
 					break // Каталог не пустой
@@ -265,17 +255,16 @@ func (s *Store) getMutex(name string) *sync.Mutex {
 }
 
 // GetFullName возвращает полный путь к файлу в хранилище.
-func (s *Store) GetFullName(prefix, name string) string {
+func (s *Store) GetFullName(name string) string {
 	if len(name) < 27 {
 		return ""
 	}
-	return filepath.Join(s.root, prefix, name[:1], name[1:3], name[3:])
+	return filepath.Join(s.dir, name[:1], name[1:3], name[3:])
 }
 
 // IsExists проверяет: существует ли файл в хранилище?
-func (s *Store) IsExists(prefix, name string) bool {
-	// Полное имя файла
-	fullName := s.GetFullName(prefix, name)
+func (s *Store) IsExists(name string) bool {
+	fullName := s.GetFullName(name)
 	if fullName == "" {
 		return false
 	}