tokio_tar/
builder.rs

1use crate::{
2    header::{path2bytes, HeaderMode},
3    other, EntryType, Header,
4};
5use std::{fs::Metadata, path::Path, str};
6use tokio::{
7    fs,
8    io::{self, AsyncRead as Read, AsyncReadExt, AsyncWrite as Write, AsyncWriteExt},
9};
10
11/// A structure for building archives
12///
13/// This structure has methods for building up an archive from scratch into any
14/// arbitrary writer.
15pub struct Builder<W: Write + Unpin + Send> {
16    mode: HeaderMode,
17    follow: bool,
18    finished: bool,
19    obj: Option<W>,
20    cancellation: Option<tokio::sync::oneshot::Sender<W>>,
21}
22
23const TERMINATION: &[u8; 1024] = &[0; 1024];
24
25impl<W: Write + Unpin + Send + 'static> Builder<W> {
26    /// Create a new archive builder with the underlying object as the
27    /// destination of all data written. The builder will use
28    /// `HeaderMode::Complete` by default.
29    ///
30    /// On drop, would write [`TERMINATION`] into the end of the archive,
31    /// use `skip_termination` method to disable this.
32    pub fn new(obj: W) -> Builder<W> {
33        let (tx, rx) = tokio::sync::oneshot::channel::<W>();
34        tokio::spawn(async move {
35            if let Ok(mut w) = rx.await {
36                let _ = w.write_all(TERMINATION).await;
37            }
38        });
39        Builder {
40            mode: HeaderMode::Complete,
41            follow: true,
42            finished: false,
43            obj: Some(obj),
44            cancellation: Some(tx),
45        }
46    }
47}
48
49impl<W: Write + Unpin + Send> Builder<W> {
50    /// Create a new archive builder with the underlying object as the
51    /// destination of all data written. The builder will use
52    /// `HeaderMode::Complete` by default.
53    ///
54    /// The [`TERMINATION`] symbol would not be written to the archive in the end.
55    pub fn new_non_terminated(obj: W) -> Builder<W> {
56        Builder {
57            mode: HeaderMode::Complete,
58            follow: true,
59            finished: false,
60            obj: Some(obj),
61            cancellation: None,
62        }
63    }
64
65    /// Changes the HeaderMode that will be used when reading fs Metadata for
66    /// methods that implicitly read metadata for an input Path. Notably, this
67    /// does _not_ apply to `append(Header)`.
68    pub fn mode(&mut self, mode: HeaderMode) {
69        self.mode = mode;
70    }
71
72    /// Follow symlinks, archiving the contents of the file they point to rather
73    /// than adding a symlink to the archive. Defaults to true.
74    pub fn follow_symlinks(&mut self, follow: bool) {
75        self.follow = follow;
76    }
77
78    /// Skip writing final termination bytes into the archive.
79    pub fn skip_termination(&mut self) {
80        drop(self.cancellation.take());
81    }
82
83    /// Gets shared reference to the underlying object.
84    pub fn get_ref(&self) -> &W {
85        self.obj.as_ref().unwrap()
86    }
87
88    /// Gets mutable reference to the underlying object.
89    ///
90    /// Note that care must be taken while writing to the underlying
91    /// object. But, e.g. `get_mut().flush()` is claimed to be safe and
92    /// useful in the situations when one needs to be ensured that
93    /// tar entry was flushed to the disk.
94    pub fn get_mut(&mut self) -> &mut W {
95        self.obj.as_mut().unwrap()
96    }
97
98    /// Unwrap this archive, returning the underlying object.
99    ///
100    /// This function will finish writing the archive if the `finish` function
101    /// hasn't yet been called, returning any I/O error which happens during
102    /// that operation.
103    pub async fn into_inner(mut self) -> io::Result<W> {
104        if !self.finished {
105            self.finish().await?;
106        }
107        Ok(self.obj.take().unwrap())
108    }
109
110    /// Adds a new entry to this archive.
111    ///
112    /// This function will append the header specified, followed by contents of
113    /// the stream specified by `data`. To produce a valid archive the `size`
114    /// field of `header` must be the same as the length of the stream that's
115    /// being written. Additionally the checksum for the header should have been
116    /// set via the `set_cksum` method.
117    ///
118    /// Note that this will not attempt to seek the archive to a valid position,
119    /// so if the archive is in the middle of a read or some other similar
120    /// operation then this may corrupt the archive.
121    ///
122    /// Also note that after all entries have been written to an archive the
123    /// `finish` function needs to be called to finish writing the archive.
124    ///
125    /// # Errors
126    ///
127    /// This function will return an error for any intermittent I/O error which
128    /// occurs when either reading or writing.
129    ///
130    /// # Examples
131    ///
132    /// ```
133    /// # fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> { tokio::runtime::Runtime::new().unwrap().block_on(async {
134    /// #
135    /// use tokio_tar::{Builder, Header};
136    ///
137    /// let mut header = Header::new_gnu();
138    /// header.set_path("foo")?;
139    /// header.set_size(4);
140    /// header.set_cksum();
141    ///
142    /// let mut data: &[u8] = &[1, 2, 3, 4];
143    ///
144    /// let mut ar = Builder::new(Vec::new());
145    /// ar.append(&header, data).await?;
146    /// let data = ar.into_inner().await?;
147    /// #
148    /// # Ok(()) }) }
149    /// ```
150    pub async fn append<R: Read + Unpin>(
151        &mut self,
152        header: &Header,
153        mut data: R,
154    ) -> io::Result<()> {
155        append(self.get_mut(), header, &mut data).await?;
156
157        Ok(())
158    }
159
160    /// Adds a new entry to this archive with the specified path.
161    ///
162    /// This function will set the specified path in the given header, which may
163    /// require appending a GNU long-name extension entry to the archive first.
164    /// The checksum for the header will be automatically updated via the
165    /// `set_cksum` method after setting the path. No other metadata in the
166    /// header will be modified.
167    ///
168    /// Then it will append the header, followed by contents of the stream
169    /// specified by `data`. To produce a valid archive the `size` field of
170    /// `header` must be the same as the length of the stream that's being
171    /// written.
172    ///
173    /// Note that this will not attempt to seek the archive to a valid position,
174    /// so if the archive is in the middle of a read or some other similar
175    /// operation then this may corrupt the archive.
176    ///
177    /// Also note that after all entries have been written to an archive the
178    /// `finish` function needs to be called to finish writing the archive.
179    ///
180    /// # Errors
181    ///
182    /// This function will return an error for any intermittent I/O error which
183    /// occurs when either reading or writing.
184    ///
185    /// # Examples
186    ///
187    /// ```
188    /// # fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> { tokio::runtime::Runtime::new().unwrap().block_on(async {
189    /// #
190    /// use tokio_tar::{Builder, Header};
191    ///
192    /// let mut header = Header::new_gnu();
193    /// header.set_size(4);
194    /// header.set_cksum();
195    ///
196    /// let mut data: &[u8] = &[1, 2, 3, 4];
197    ///
198    /// let mut ar = Builder::new(Vec::new());
199    /// ar.append_data(&mut header, "really/long/path/to/foo", data).await?;
200    /// let data = ar.into_inner().await?;
201    /// #
202    /// # Ok(()) }) }
203    /// ```
204    pub async fn append_data<P: AsRef<Path>, R: Read + Unpin>(
205        &mut self,
206        header: &mut Header,
207        path: P,
208        data: R,
209    ) -> io::Result<()> {
210        prepare_header_path(self.get_mut(), header, path.as_ref()).await?;
211        header.set_cksum();
212        self.append(header, data).await?;
213
214        Ok(())
215    }
216
217    /// Adds a file on the local filesystem to this archive.
218    ///
219    /// This function will open the file specified by `path` and insert the file
220    /// into the archive with the appropriate metadata set, returning any I/O
221    /// error which occurs while writing. The path name for the file inside of
222    /// this archive will be the same as `path`, and it is required that the
223    /// path is a relative path.
224    ///
225    /// Note that this will not attempt to seek the archive to a valid position,
226    /// so if the archive is in the middle of a read or some other similar
227    /// operation then this may corrupt the archive.
228    ///
229    /// Also note that after all files have been written to an archive the
230    /// `finish` function needs to be called to finish writing the archive.
231    ///
232    /// # Examples
233    ///
234    /// ```no_run
235    /// # fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> { tokio::runtime::Runtime::new().unwrap().block_on(async {
236    /// #
237    /// use tokio_tar::Builder;
238    ///
239    /// let mut ar = Builder::new(Vec::new());
240    ///
241    /// ar.append_path("foo/bar.txt").await?;
242    /// #
243    /// # Ok(()) }) }
244    /// ```
245    pub async fn append_path<P: AsRef<Path>>(&mut self, path: P) -> io::Result<()> {
246        let mode = self.mode;
247        let follow = self.follow;
248        append_path_with_name(self.get_mut(), path.as_ref(), None, mode, follow).await?;
249        Ok(())
250    }
251
252    /// Adds a file on the local filesystem to this archive under another name.
253    ///
254    /// This function will open the file specified by `path` and insert the file
255    /// into the archive as `name` with appropriate metadata set, returning any
256    /// I/O error which occurs while writing. The path name for the file inside
257    /// of this archive will be `name` is required to be a relative path.
258    ///
259    /// Note that this will not attempt to seek the archive to a valid position,
260    /// so if the archive is in the middle of a read or some other similar
261    /// operation then this may corrupt the archive.
262    ///
263    /// Also note that after all files have been written to an archive the
264    /// `finish` function needs to be called to finish writing the archive.
265    ///
266    /// # Examples
267    ///
268    /// ```no_run
269    /// # fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> { tokio::runtime::Runtime::new().unwrap().block_on(async {
270    /// #
271    /// use tokio_tar::Builder;
272    ///
273    /// let mut ar = Builder::new(Vec::new());
274    ///
275    /// // Insert the local file "foo/bar.txt" in the archive but with the name
276    /// // "bar/foo.txt".
277    /// ar.append_path_with_name("foo/bar.txt", "bar/foo.txt").await?;
278    /// #
279    /// # Ok(()) }) }
280    /// ```
281    pub async fn append_path_with_name<P: AsRef<Path>, N: AsRef<Path>>(
282        &mut self,
283        path: P,
284        name: N,
285    ) -> io::Result<()> {
286        let mode = self.mode;
287        let follow = self.follow;
288        append_path_with_name(
289            self.get_mut(),
290            path.as_ref(),
291            Some(name.as_ref()),
292            mode,
293            follow,
294        )
295        .await?;
296        Ok(())
297    }
298
299    /// Adds a file to this archive with the given path as the name of the file
300    /// in the archive.
301    ///
302    /// This will use the metadata of `file` to populate a `Header`, and it will
303    /// then append the file to the archive with the name `path`.
304    ///
305    /// Note that this will not attempt to seek the archive to a valid position,
306    /// so if the archive is in the middle of a read or some other similar
307    /// operation then this may corrupt the archive.
308    ///
309    /// Also note that after all files have been written to an archive the
310    /// `finish` function needs to be called to finish writing the archive.
311    ///
312    /// # Examples
313    ///
314    /// ```no_run
315    /// # fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> { tokio::runtime::Runtime::new().unwrap().block_on(async {
316    /// #
317    /// use tokio::fs::File;
318    /// use tokio_tar::Builder;
319    ///
320    /// let mut ar = Builder::new(Vec::new());
321    ///
322    /// // Open the file at one location, but insert it into the archive with a
323    /// // different name.
324    /// let mut f = File::open("foo/bar/baz.txt").await?;
325    /// ar.append_file("bar/baz.txt", &mut f).await?;
326    /// #
327    /// # Ok(()) }) }
328    /// ```
329    pub async fn append_file<P: AsRef<Path>>(
330        &mut self,
331        path: P,
332        file: &mut fs::File,
333    ) -> io::Result<()> {
334        let mode = self.mode;
335        append_file(self.get_mut(), path.as_ref(), file, mode).await?;
336        Ok(())
337    }
338
339    /// Adds a directory to this archive with the given path as the name of the
340    /// directory in the archive.
341    ///
342    /// This will use `stat` to populate a `Header`, and it will then append the
343    /// directory to the archive with the name `path`.
344    ///
345    /// Note that this will not attempt to seek the archive to a valid position,
346    /// so if the archive is in the middle of a read or some other similar
347    /// operation then this may corrupt the archive.
348    ///
349    /// Also note that after all files have been written to an archive the
350    /// `finish` function needs to be called to finish writing the archive.
351    ///
352    /// # Examples
353    ///
354    /// ```
355    /// # fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> { tokio::runtime::Runtime::new().unwrap().block_on(async {
356    /// #
357    /// use tokio::fs;
358    /// use tokio_tar::Builder;
359    ///
360    /// let mut ar = Builder::new(Vec::new());
361    ///
362    /// // Use the directory at one location, but insert it into the archive
363    /// // with a different name.
364    /// ar.append_dir("bardir", ".").await?;
365    /// #
366    /// # Ok(()) }) }
367    /// ```
368    pub async fn append_dir<P, Q>(&mut self, path: P, src_path: Q) -> io::Result<()>
369    where
370        P: AsRef<Path>,
371        Q: AsRef<Path>,
372    {
373        let mode = self.mode;
374        append_dir(self.get_mut(), path.as_ref(), src_path.as_ref(), mode).await?;
375        Ok(())
376    }
377
378    /// Adds a directory and all of its contents (recursively) to this archive
379    /// with the given path as the name of the directory in the archive.
380    ///
381    /// Note that this will not attempt to seek the archive to a valid position,
382    /// so if the archive is in the middle of a read or some other similar
383    /// operation then this may corrupt the archive.
384    ///
385    /// Also note that after all files have been written to an archive the
386    /// `finish` function needs to be called to finish writing the archive.
387    ///
388    /// # Examples
389    ///
390    /// ```
391    /// # fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> { tokio::runtime::Runtime::new().unwrap().block_on(async {
392    /// #
393    /// use tokio::fs;
394    /// use tokio_tar::Builder;
395    ///
396    /// let mut ar = Builder::new(Vec::new());
397    ///
398    /// let td = tempfile::tempdir()?;
399    ///
400    /// // Use the directory at one location, but insert it into the archive
401    /// // with a different name.
402    /// ar.append_dir_all("bardir", td.path()).await?;
403    /// #
404    /// # Ok(()) }) }
405    /// ```
406    pub async fn append_dir_all<P, Q>(&mut self, path: P, src_path: Q) -> io::Result<()>
407    where
408        P: AsRef<Path>,
409        Q: AsRef<Path>,
410    {
411        let mode = self.mode;
412        let follow = self.follow;
413        append_dir_all(
414            self.get_mut(),
415            path.as_ref(),
416            src_path.as_ref(),
417            mode,
418            follow,
419        )
420        .await?;
421        Ok(())
422    }
423
424    /// Finish writing this archive, emitting the termination sections.
425    ///
426    /// This function should only be called when the archive has been written
427    /// entirely and if an I/O error happens the underlying object still needs
428    /// to be acquired.
429    ///
430    /// In most situations the `into_inner` method should be preferred.
431    pub async fn finish(&mut self) -> io::Result<()> {
432        if self.finished {
433            return Ok(());
434        }
435        self.finished = true;
436        self.get_mut().write_all(&[0; 1024]).await?;
437        Ok(())
438    }
439}
440
441async fn append<Dst: Write + Unpin + ?Sized, Data: Read + Unpin + ?Sized>(
442    mut dst: &mut Dst,
443    header: &Header,
444    mut data: &mut Data,
445) -> io::Result<()> {
446    dst.write_all(header.as_bytes()).await?;
447    let len = io::copy(&mut data, &mut dst).await?;
448
449    // Pad with zeros if necessary.
450    let buf = [0; 512];
451    let remaining = 512 - (len % 512);
452    if remaining < 512 {
453        dst.write_all(&buf[..remaining as usize]).await?;
454    }
455
456    Ok(())
457}
458
459async fn append_path_with_name<Dst: Write + Unpin + ?Sized>(
460    dst: &mut Dst,
461    path: &Path,
462    name: Option<&Path>,
463    mode: HeaderMode,
464    follow: bool,
465) -> io::Result<()> {
466    let stat = if follow {
467        fs::metadata(path).await.map_err(|err| {
468            io::Error::new(
469                err.kind(),
470                format!("{} when getting metadata for {}", err, path.display()),
471            )
472        })?
473    } else {
474        fs::symlink_metadata(path).await.map_err(|err| {
475            io::Error::new(
476                err.kind(),
477                format!("{} when getting metadata for {}", err, path.display()),
478            )
479        })?
480    };
481    let ar_name = name.unwrap_or(path);
482    if stat.is_file() {
483        append_fs(
484            dst,
485            ar_name,
486            &stat,
487            &mut fs::File::open(path).await?,
488            mode,
489            None,
490        )
491        .await?;
492        Ok(())
493    } else if stat.is_dir() {
494        append_fs(dst, ar_name, &stat, &mut io::empty(), mode, None).await?;
495        Ok(())
496    } else if stat.file_type().is_symlink() {
497        let link_name = fs::read_link(path).await?;
498        append_fs(
499            dst,
500            ar_name,
501            &stat,
502            &mut io::empty(),
503            mode,
504            Some(&link_name),
505        )
506        .await?;
507        Ok(())
508    } else {
509        #[cfg(unix)]
510        {
511            append_special(dst, path, &stat, mode).await
512        }
513        #[cfg(not(unix))]
514        {
515            Err(other(&format!("{} has unknown file type", path.display())))
516        }
517    }
518}
519
520#[cfg(unix)]
521async fn append_special<Dst: Write + Unpin + ?Sized>(
522    dst: &mut Dst,
523    path: &Path,
524    stat: &Metadata,
525    mode: HeaderMode,
526) -> io::Result<()> {
527    use ::std::os::unix::fs::{FileTypeExt, MetadataExt};
528
529    let file_type = stat.file_type();
530    let entry_type;
531    if file_type.is_socket() {
532        // sockets can't be archived
533        return Err(other(&format!(
534            "{}: socket can not be archived",
535            path.display()
536        )));
537    } else if file_type.is_fifo() {
538        entry_type = EntryType::Fifo;
539    } else if file_type.is_char_device() {
540        entry_type = EntryType::Char;
541    } else if file_type.is_block_device() {
542        entry_type = EntryType::Block;
543    } else {
544        return Err(other(&format!("{} has unknown file type", path.display())));
545    }
546
547    let mut header = Header::new_gnu();
548    header.set_metadata_in_mode(stat, mode);
549    prepare_header_path(dst, &mut header, path).await?;
550
551    header.set_entry_type(entry_type);
552    let dev_id = stat.rdev();
553    let dev_major = ((dev_id >> 32) & 0xffff_f000) | ((dev_id >> 8) & 0x0000_0fff);
554    let dev_minor = ((dev_id >> 12) & 0xffff_ff00) | ((dev_id) & 0x0000_00ff);
555    header.set_device_major(dev_major as u32)?;
556    header.set_device_minor(dev_minor as u32)?;
557
558    header.set_cksum();
559    dst.write_all(header.as_bytes()).await?;
560
561    Ok(())
562}
563
564async fn append_file<Dst: Write + Unpin + ?Sized>(
565    dst: &mut Dst,
566    path: &Path,
567    file: &mut fs::File,
568    mode: HeaderMode,
569) -> io::Result<()> {
570    let stat = file.metadata().await?;
571    append_fs(dst, path, &stat, file, mode, None).await?;
572    Ok(())
573}
574
575async fn append_dir<Dst: Write + Unpin + ?Sized>(
576    dst: &mut Dst,
577    path: &Path,
578    src_path: &Path,
579    mode: HeaderMode,
580) -> io::Result<()> {
581    let stat = fs::metadata(src_path).await?;
582    append_fs(dst, path, &stat, &mut io::empty(), mode, None).await?;
583    Ok(())
584}
585
586fn prepare_header(size: u64, entry_type: EntryType) -> Header {
587    let mut header = Header::new_gnu();
588    let name = b"././@LongLink";
589    header.as_gnu_mut().unwrap().name[..name.len()].clone_from_slice(&name[..]);
590    header.set_mode(0o644);
591    header.set_uid(0);
592    header.set_gid(0);
593    header.set_mtime(0);
594    // + 1 to be compliant with GNU tar
595    header.set_size(size + 1);
596    header.set_entry_type(entry_type);
597    header.set_cksum();
598    header
599}
600
601async fn prepare_header_path<Dst: Write + Unpin + ?Sized>(
602    dst: &mut Dst,
603    header: &mut Header,
604    path: &Path,
605) -> io::Result<()> {
606    // Try to encode the path directly in the header, but if it ends up not
607    // working (probably because it's too long) then try to use the GNU-specific
608    // long name extension by emitting an entry which indicates that it's the
609    // filename.
610    if let Err(e) = header.set_path(path) {
611        let data = path2bytes(path)?;
612        let max = header.as_old().name.len();
613        //  Since e isn't specific enough to let us know the path is indeed too
614        //  long, verify it first before using the extension.
615        if data.len() < max {
616            return Err(e);
617        }
618        let header2 = prepare_header(data.len() as u64, EntryType::GNULongName);
619        // null-terminated string
620        let mut data2 = data.chain(io::repeat(0).take(1));
621        append(dst, &header2, &mut data2).await?;
622
623        // Truncate the path to store in the header we're about to emit to
624        // ensure we've got something at least mentioned. Note that we use
625        // `str`-encoding to be compatible with Windows, but in general the
626        // entry in the header itself shouldn't matter too much since extraction
627        // doesn't look at it.
628        let truncated = match str::from_utf8(&data[..max]) {
629            Ok(s) => s,
630            Err(e) => str::from_utf8(&data[..e.valid_up_to()]).unwrap(),
631        };
632        header.set_truncated_path_for_gnu_header(truncated)?;
633    }
634    Ok(())
635}
636
637async fn prepare_header_link<Dst: Write + Unpin + ?Sized>(
638    dst: &mut Dst,
639    header: &mut Header,
640    link_name: &Path,
641) -> io::Result<()> {
642    // Same as previous function but for linkname
643    if let Err(e) = header.set_link_name(link_name) {
644        let data = path2bytes(link_name)?;
645        if data.len() < header.as_old().linkname.len() {
646            return Err(e);
647        }
648        let header2 = prepare_header(data.len() as u64, EntryType::GNULongLink);
649        let mut data2 = data.chain(io::repeat(0).take(1));
650        append(dst, &header2, &mut data2).await?;
651    }
652    Ok(())
653}
654
655async fn append_fs<Dst: Write + Unpin + ?Sized, R: Read + Unpin + ?Sized>(
656    dst: &mut Dst,
657    path: &Path,
658    meta: &Metadata,
659    read: &mut R,
660    mode: HeaderMode,
661    link_name: Option<&Path>,
662) -> io::Result<()> {
663    let mut header = Header::new_gnu();
664
665    prepare_header_path(dst, &mut header, path).await?;
666    header.set_metadata_in_mode(meta, mode);
667    if let Some(link_name) = link_name {
668        prepare_header_link(dst, &mut header, link_name).await?;
669    }
670    header.set_cksum();
671    append(dst, &header, read).await?;
672
673    Ok(())
674}
675
676async fn append_dir_all<Dst: Write + Unpin + ?Sized>(
677    dst: &mut Dst,
678    path: &Path,
679    src_path: &Path,
680    mode: HeaderMode,
681    follow: bool,
682) -> io::Result<()> {
683    let mut stack = vec![(src_path.to_path_buf(), true, false)];
684    while let Some((src, is_dir, is_symlink)) = stack.pop() {
685        let dest = path.join(src.strip_prefix(src_path).unwrap());
686
687        // In case of a symlink pointing to a directory, is_dir is false, but src.is_dir() will return true
688        if is_dir || (is_symlink && follow && src.is_dir()) {
689            let mut entries = fs::read_dir(&src).await?;
690            while let Some(entry) = entries.next_entry().await.transpose() {
691                let entry = entry?;
692                let file_type = entry.file_type().await?;
693                stack.push((entry.path(), file_type.is_dir(), file_type.is_symlink()));
694            }
695            if dest != Path::new("") {
696                append_dir(dst, &dest, &src, mode).await?;
697            }
698        } else if !follow && is_symlink {
699            let stat = fs::symlink_metadata(&src).await?;
700            let link_name = fs::read_link(&src).await?;
701            append_fs(dst, &dest, &stat, &mut io::empty(), mode, Some(&link_name)).await?;
702        } else {
703            #[cfg(unix)]
704            {
705                let stat = fs::metadata(&src).await?;
706                if !stat.is_file() {
707                    append_special(dst, &dest, &stat, mode).await?;
708                    continue;
709                }
710            }
711            append_file(dst, &dest, &mut fs::File::open(src).await?, mode).await?;
712        }
713    }
714    Ok(())
715}
716
717impl<W: Write + Unpin + Send> Drop for Builder<W> {
718    fn drop(&mut self) {
719        // TODO: proper async cancellation
720        if !self.finished {
721            if let Some(cancellation) = self.cancellation.take() {
722                cancellation.send(self.obj.take().unwrap()).ok();
723            }
724        }
725    }
726}