      1
      2
      3
      4
      5
      6
      7
      8
      9
     10
     11
     12
     13
     14
     15
     16
     17
     18
     19
     20
     21
     22
     23
     24
     25
     26
     27
     28
     29
     30
     31
     32
     33
     34
     35
     36
     37
     38
     39
     40
     41
     42
     43
     44
     45
     46
     47
     48
     49
     50
     51
     52
     53
     54
     55
     56
     57
     58
     59
     60
     61
     62
     63
     64
     65
     66
     67
     68
     69
     70
     71
     72
     73
     74
     75
     76
     77
     78
     79
     80
     81
     82
     83
     84
     85
     86
     87
     88
     89
     90
     91
     92
     93
     94
     95
     96
     97
     98
     99
    100
    101
    102
    103
    104
    105
    106
    107
    108
    109
    110
    111
    112
    113
    114
    115
    116
    117
    118
    119
    120
    121
    122
    123
    124
    125
    126
    127
    128
    129
    130
    131
    132
    133
    134
    135
    136
    137
    138
    139
    140
    141
    142
    143
    144
    145
    146
    147
    148
    149
    150
    151
    152
    153
    154
    155
    156
    157
    158
    159
    160
    161
    162
    163
    164
    165
    166
    167
    168
    169
    170
    171
    172
    173
    174
    175
    176
    177
    178
    179
    180
    181
    182
    183
    184
    185
    186
    187
    188
    189
    190
    191
    192
    193
    194
    195
    196
    197
    198
    199
    200
    201
    202
    203
    204
    205
    206
    207
    208
    209
    210
    211
    212
    213
    214
    215
    216
    217
    218
    219
    220
    221
    222
    223
    224
    225
    226
    227
    228
    229
    230
    231
    232
    233
    234
    235
    236
    237
    238
    239
    240
    241
    242
    243
    244
    245
    246
    247
    248
    249
    250
    251
    252
    253
    254
    255
    256
    257
    258
    259
    260
    261
    262
    263
    264
    265
    266
    267
    268
    269
    270
    271
    272
    273
    274
    275
    276
    277

    use crate::fs::{asyncify, sys};

    use std::ffi::OsString;
    use std::fs::{FileType, Metadata};
    use std::future::Future;
    use std::io;
    use std::path::{Path, PathBuf};
    use std::pin::Pin;
    use std::sync::Arc;
    use std::task::Context;
    use std::task::Poll;

    /// Returns a stream over the entries within a directory.
    ///
    /// This is an async version of [`std::fs::read_dir`](std::fs::read_dir)
    pub async fn read_dir(path: impl AsRef<Path>) -> io::Result<ReadDir> {
        let path = path.as_ref().to_owned();
        let std = asyncify(|| std::fs::read_dir(path)).await?;

        Ok(ReadDir(State::Idle(Some(std))))
    }

    /// Read the the entries in a directory.
    ///
    /// This struct is returned from the [`read_dir`] function of this module and
    /// will yield instances of [`DirEntry`]. Through a [`DirEntry`] information
    /// like the entry's path and possibly other metadata can be learned.
    ///
    /// A `ReadDir` can be turned into a `Stream` with [`ReadDirStream`].
    ///
    /// [`ReadDirStream`]: https://docs.rs/tokio-stream/0.1/tokio_stream/wrappers/struct.ReadDirStream.html
    ///
    /// # Errors
    ///
    /// This stream will return an [`Err`] if there's some sort of intermittent
    /// IO error during iteration.
    ///
    /// [`read_dir`]: read_dir
    /// [`DirEntry`]: DirEntry
    /// [`Err`]: std::result::Result::Err
    #[derive(Debug)]
    #[must_use = "streams do nothing unless polled"]
    pub struct ReadDir(State);

    #[derive(Debug)]
    enum State {
        Idle(Option<std::fs::ReadDir>),
        Pending(sys::Blocking<(Option<io::Result<std::fs::DirEntry>>, std::fs::ReadDir)>),
    }

    impl ReadDir {
        /// Returns the next entry in the directory stream.
        pub async fn next_entry(&mut self) -> io::Result<Option<DirEntry>> {
            use crate::future::poll_fn;
            poll_fn(|cx| self.poll_next_entry(cx)).await
        }

        /// Polls for the next directory entry in the stream.
        ///
        /// This method returns:
        ///
        ///  * `Poll::Pending` if the next directory entry is not yet available.
        ///  * `Poll::Ready(Ok(Some(entry)))` if the next directory entry is available.
        ///  * `Poll::Ready(Ok(None))` if there are no more directory entries in this
        ///    stream.
        ///  * `Poll::Ready(Err(err))` if an IO error occurred while reading the next
        ///    directory entry.
        ///
        /// When the method returns `Poll::Pending`, the `Waker` in the provided
        /// `Context` is scheduled to receive a wakeup when the next directory entry
        /// becomes available on the underlying IO resource.
        ///
        /// Note that on multiple calls to `poll_next_entry`, only the `Waker` from
        /// the `Context` passed to the most recent call is scheduled to receive a
        /// wakeup.
        pub fn poll_next_entry(&mut self, cx: &mut Context<'_>) -> Poll<io::Result<Option<DirEntry>>> {
            loop {
                match self.0 {
                    State::Idle(ref mut std) => {
                        let mut std = std.take().unwrap();

                        self.0 = State::Pending(sys::run(move || {
                            let ret = std.next();
                            (ret, std)
                        }));
                    }
                    State::Pending(ref mut rx) => {
                        let (ret, std) = ready!(Pin::new(rx).poll(cx))?;
                        self.0 = State::Idle(Some(std));

                        let ret = match ret {
                            Some(Ok(std)) => Ok(Some(DirEntry(Arc::new(std)))),
                            Some(Err(e)) => Err(e),
                            None => Ok(None),
                        };

                        return Poll::Ready(ret);
                    }
                }
            }
        }
    }

    feature! {
        #![unix]

        use std::os::unix::fs::DirEntryExt;

        impl DirEntry {
            /// Returns the underlying `d_ino` field in the contained `dirent`
            /// structure.
            ///
            /// # Examples
            ///
            /// ```
            /// use tokio::fs;
            ///
            /// # #[tokio::main]
            /// # async fn main() -> std::io::Result<()> {
            /// let mut entries = fs::read_dir(".").await?;
            /// while let Some(entry) = entries.next_entry().await? {
            ///     // Here, `entry` is a `DirEntry`.
            ///     println!("{:?}: {}", entry.file_name(), entry.ino());
            /// }
            /// # Ok(())
            /// # }
            /// ```
            pub fn ino(&self) -> u64 {
                self.as_inner().ino()
            }
        }
    }

    /// Entries returned by the [`ReadDir`] stream.
    ///
    /// [`ReadDir`]: struct@ReadDir
    ///
    /// This is a specialized version of [`std::fs::DirEntry`] for usage from the
    /// Tokio runtime.
    ///
    /// An instance of `DirEntry` represents an entry inside of a directory on the
    /// filesystem. Each entry can be inspected via methods to learn about the full
    /// path or possibly other metadata through per-platform extension traits.
    #[derive(Debug)]
    pub struct DirEntry(Arc<std::fs::DirEntry>);

    impl DirEntry {
        /// Returns the full path to the file that this entry represents.
        ///
        /// The full path is created by joining the original path to `read_dir`
        /// with the filename of this entry.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use tokio::fs;
        ///
        /// # async fn dox() -> std::io::Result<()> {
        /// let mut entries = fs::read_dir(".").await?;
        ///
        /// while let Some(entry) = entries.next_entry().await? {
        ///     println!("{:?}", entry.path());
        /// }
        /// # Ok(())
        /// # }
        /// ```
        ///
        /// This prints output like:
        ///
        /// ```text
        /// "./whatever.txt"
        /// "./foo.html"
        /// "./hello_world.rs"
        /// ```
        ///
        /// The exact text, of course, depends on what files you have in `.`.
        pub fn path(&self) -> PathBuf {
            self.0.path()
        }

        /// Returns the bare file name of this directory entry without any other
        /// leading path component.
        ///
        /// # Examples
        ///
        /// ```
        /// use tokio::fs;
        ///
        /// # async fn dox() -> std::io::Result<()> {
        /// let mut entries = fs::read_dir(".").await?;
        ///
        /// while let Some(entry) = entries.next_entry().await? {
        ///     println!("{:?}", entry.file_name());
        /// }
        /// # Ok(())
        /// # }
        /// ```
        pub fn file_name(&self) -> OsString {
            self.0.file_name()
        }

        /// Returns the metadata for the file that this entry points at.
        ///
        /// This function will not traverse symlinks if this entry points at a
        /// symlink.
        ///
        /// # Platform-specific behavior
        ///
        /// On Windows this function is cheap to call (no extra system calls
        /// needed), but on Unix platforms this function is the equivalent of
        /// calling `symlink_metadata` on the path.
        ///
        /// # Examples
        ///
        /// ```
        /// use tokio::fs;
        ///
        /// # async fn dox() -> std::io::Result<()> {
        /// let mut entries = fs::read_dir(".").await?;
        ///
        /// while let Some(entry) = entries.next_entry().await? {
        ///     if let Ok(metadata) = entry.metadata().await {
        ///         // Now let's show our entry's permissions!
        ///         println!("{:?}: {:?}", entry.path(), metadata.permissions());
        ///     } else {
        ///         println!("Couldn't get file type for {:?}", entry.path());
        ///     }
        /// }
        /// # Ok(())
        /// # }
        /// ```
        pub async fn metadata(&self) -> io::Result<Metadata> {
            let std = self.0.clone();
            asyncify(move || std.metadata()).await
        }

        /// Returns the file type for the file that this entry points at.
        ///
        /// This function will not traverse symlinks if this entry points at a
        /// symlink.
        ///
        /// # Platform-specific behavior
        ///
        /// On Windows and most Unix platforms this function is free (no extra
        /// system calls needed), but some Unix platforms may require the equivalent
        /// call to `symlink_metadata` to learn about the target file type.
        ///
        /// # Examples
        ///
        /// ```
        /// use tokio::fs;
        ///
        /// # async fn dox() -> std::io::Result<()> {
        /// let mut entries = fs::read_dir(".").await?;
        ///
        /// while let Some(entry) = entries.next_entry().await? {
        ///     if let Ok(file_type) = entry.file_type().await {
        ///         // Now let's show our entry's file type!
        ///         println!("{:?}: {:?}", entry.path(), file_type);
        ///     } else {
        ///         println!("Couldn't get file type for {:?}", entry.path());
        ///     }
        /// }
        /// # Ok(())
        /// # }
        /// ```
        pub async fn file_type(&self) -> io::Result<FileType> {
            let std = self.0.clone();
            asyncify(move || std.file_type()).await
        }

        /// Returns a reference to the underlying `std::fs::DirEntry`
        #[cfg(unix)]
        pub(super) fn as_inner(&self) -> &std::fs::DirEntry {
            &self.0
        }
    }