//
// SPDX-License-Identifier: AGPL-3.0
-package main
+package keepweb
import (
"crypto/rand"
"errors"
"fmt"
+ "io"
prand "math/rand"
"os"
"path"
"sync/atomic"
"time"
- "git.curoverse.com/arvados.git/sdk/go/arvados"
+ "git.arvados.org/arvados.git/sdk/go/arvados"
"golang.org/x/net/context"
"golang.org/x/net/webdav"
// existence automatically so sequences like "mkcol foo; put foo/bar"
// work as expected.
type webdavFS struct {
- collfs arvados.CollectionFileSystem
- update func() error
+ collfs arvados.FileSystem
+ // prefix works like fs.Sub: Stat(name) calls
+ // Stat(prefix+name) in the wrapped filesystem.
+ prefix string
+ writing bool
+ // webdav PROPFIND reads the first few bytes of each file
+ // whose filename extension isn't recognized, which is
+ // prohibitively expensive: we end up fetching multiple 64MiB
+ // blocks. Avoid this by returning EOF on all reads when
+ // handling a PROPFIND.
+ alwaysReadEOF bool
}
func (fs *webdavFS) makeparents(name string) {
- dir, name := path.Split(name)
+ if !fs.writing {
+ return
+ }
+ dir, _ := path.Split(name)
if dir == "" || dir == "/" {
return
}
dir = dir[:len(dir)-1]
fs.makeparents(dir)
- fs.collfs.Mkdir(dir, 0755)
+ fs.collfs.Mkdir(fs.prefix+dir, 0755)
}
func (fs *webdavFS) Mkdir(ctx context.Context, name string, perm os.FileMode) error {
- if fs.update == nil {
+ if !fs.writing {
return errReadOnly
}
name = strings.TrimRight(name, "/")
fs.makeparents(name)
- if err := fs.collfs.Mkdir(name, 0755); err != nil {
- return err
- }
- return fs.update()
+ return fs.collfs.Mkdir(fs.prefix+name, 0755)
}
func (fs *webdavFS) OpenFile(ctx context.Context, name string, flag int, perm os.FileMode) (f webdav.File, err error) {
- writing := flag&(os.O_WRONLY|os.O_RDWR) != 0
+ writing := flag&(os.O_WRONLY|os.O_RDWR|os.O_TRUNC) != 0
if writing {
- if fs.update == nil {
- return nil, errReadOnly
- }
fs.makeparents(name)
}
- f, err = fs.collfs.OpenFile(name, flag, perm)
- if writing && err == nil {
- f = writingFile{File: f, update: fs.update}
+ f, err = fs.collfs.OpenFile(fs.prefix+name, flag, perm)
+ if !fs.writing {
+ // webdav module returns 404 on all OpenFile errors,
+ // but returns 405 Method Not Allowed if OpenFile()
+ // succeeds but Write() or Close() fails. We'd rather
+ // have 405. writeFailer ensures Close() fails if the
+ // file is opened for writing *or* Write() is called.
+ var err error
+ if writing {
+ err = errReadOnly
+ }
+ f = writeFailer{File: f, err: err}
+ }
+ if fs.alwaysReadEOF {
+ f = readEOF{File: f}
}
return
}
func (fs *webdavFS) RemoveAll(ctx context.Context, name string) error {
- if err := fs.collfs.RemoveAll(name); err != nil {
- return err
- }
- return fs.update()
+ return fs.collfs.RemoveAll(fs.prefix + name)
}
func (fs *webdavFS) Rename(ctx context.Context, oldName, newName string) error {
- if fs.update == nil {
+ if !fs.writing {
return errReadOnly
}
- fs.makeparents(newName)
- if err := fs.collfs.Rename(oldName, newName); err != nil {
- return err
+ if strings.HasSuffix(oldName, "/") {
+ // WebDAV "MOVE foo/ bar/" means rename foo to bar.
+ oldName = oldName[:len(oldName)-1]
+ newName = strings.TrimSuffix(newName, "/")
}
- return fs.update()
+ fs.makeparents(newName)
+ return fs.collfs.Rename(fs.prefix+oldName, fs.prefix+newName)
}
func (fs *webdavFS) Stat(ctx context.Context, name string) (os.FileInfo, error) {
- if fs.update != nil {
+ if fs.writing {
fs.makeparents(name)
}
- return fs.collfs.Stat(name)
+ return fs.collfs.Stat(fs.prefix + name)
}
-type writingFile struct {
+type writeFailer struct {
webdav.File
- update func() error
+ err error
+}
+
+func (wf writeFailer) Write([]byte) (int, error) {
+ wf.err = errReadOnly
+ return 0, wf.err
}
-func (f writingFile) Close() error {
- if err := f.File.Close(); err != nil || f.update == nil {
- return err
+func (wf writeFailer) Close() error {
+ err := wf.File.Close()
+ if err != nil {
+ wf.err = err
}
- return f.update()
+ return wf.err
+}
+
+type readEOF struct {
+ webdav.File
+}
+
+func (readEOF) Read(p []byte) (int, error) {
+ return 0, io.EOF
}
// noLockSystem implements webdav.LockSystem by returning success for