small refactor*

plugins/archive/fs.go

@@ -0,0 +1,158 @@
+package archive
+
+import (
+	"context"
+	"io"
+	"io/fs"
+	"path"
+	"strings"
+	"sync"
+	"time"
+
+	"git.kmsign.ru/royalcat/tstor/server/src/vfs"
+)
+
+// Unlink implements Filesystem.
+func (a *ArchiveFS) Unlink(ctx context.Context, filename string) error {
+	return vfs.ErrNotImplemented
+}
+
+func (a *ArchiveFS) Open(ctx context.Context, filename string) (vfs.File, error) {
+	if filename == vfs.Separator {
+		return vfs.NewDirFile(filename), nil
+	}
+
+	f, ok := a.files[filename]
+	if ok {
+		return f.open(ctx)
+	}
+
+	for p := range a.files {
+		if strings.HasPrefix(p, filename) {
+			return vfs.NewDirFile(filename), nil
+		}
+	}
+
+	return nil, vfs.ErrNotExist
+}
+
+func (a *ArchiveFS) ReadDir(ctx context.Context, path string) ([]fs.DirEntry, error) {
+	infos := make(map[string]fs.FileInfo, len(a.files))
+	for k, v := range a.files {
+		infos[k] = v
+	}
+
+	return vfs.ListDirFromInfo(infos, path)
+}
+
+// Stat implements Filesystem.
+func (afs *ArchiveFS) Stat(ctx context.Context, filename string) (fs.FileInfo, error) {
+	if entry, ok := afs.files[filename]; ok {
+		return entry, nil
+	}
+
+	for p := range afs.files {
+		if strings.HasPrefix(p, filename) {
+			return vfs.NewDirInfo(path.Base(filename), time.Time{}), nil
+		}
+	}
+
+	return nil, vfs.ErrNotExist
+}
+
+// Info implements Filesystem.
+func (a *ArchiveFS) Info() (fs.FileInfo, error) {
+	return a, nil
+}
+
+// IsDir implements Filesystem.
+func (a *ArchiveFS) IsDir() bool {
+	return true
+}
+
+// Name implements Filesystem.
+func (a *ArchiveFS) Name() string {
+	return a.name
+}
+
+// Type implements Filesystem.
+func (a *ArchiveFS) Type() fs.FileMode {
+	return fs.ModeDir
+}
+
+var _ vfs.File = (*archiveFile)(nil)
+
+func newArchiveFile(name string, size int64, rr *randomReaderFromLinear) *archiveFile {
+	return &archiveFile{
+		name: name,
+		size: size,
+		rr:   rr,
+	}
+}
+
+type archiveFile struct {
+	name string
+	size int64
+
+	m      sync.Mutex
+	offset int64
+
+	rr *randomReaderFromLinear
+}
+
+// Seek implements File.
+func (d *archiveFile) Seek(offset int64, whence int) (int64, error) {
+	switch whence {
+	case io.SeekStart:
+		d.offset = offset
+
+	case io.SeekCurrent:
+		d.offset += offset
+	case io.SeekEnd:
+		d.offset = d.size + offset
+	}
+	return d.offset, nil
+}
+
+// Name implements File.
+func (d *archiveFile) Name() string {
+	return d.name
+}
+
+// Type implements File.
+func (d *archiveFile) Type() fs.FileMode {
+	return vfs.ModeFileRO
+}
+
+func (d *archiveFile) Info() (fs.FileInfo, error) {
+	return vfs.NewFileInfo(d.name, d.size, time.Time{}), nil
+}
+
+func (d *archiveFile) Size() int64 {
+	return d.size
+}
+
+func (d *archiveFile) IsDir() bool {
+	return false
+}
+
+func (d *archiveFile) Read(ctx context.Context, p []byte) (n int, err error) {
+	ctx, span := tracer.Start(ctx, "archive.File.Read")
+	defer span.End()
+
+	n, err = d.rr.ReadAt(ctx, p, d.offset)
+	d.offset += int64(n)
+	return n, err
+}
+
+func (d *archiveFile) ReadAt(ctx context.Context, p []byte, off int64) (n int, err error) {
+	d.m.Lock()
+	defer d.m.Unlock()
+
+	return d.rr.ReadAt(ctx, p, off)
+}
+
+func (d *archiveFile) Close(ctx context.Context) error {
+	// FIXME close should do nothing as archive fs currently reuse the same file instances
+	return nil
+}