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    // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
    // file at the top-level directory of this distribution and at
    // http://rust-lang.org/COPYRIGHT.
    //
    // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
    // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
    // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
    // option. This file may not be copied, modified, or distributed
    // except according to those terms.

    //! Windows-specific extensions for the primitives in the `std::fs` module.

    #![stable(feature = "rust1", since = "1.0.0")]

    use fs::{self, OpenOptions, Metadata};
    use io;
    use path::Path;
    use sys;
    use sys_common::{AsInnerMut, AsInner};

    /// Windows-specific extensions to [`File`].
    ///
    /// [`File`]: ../../../fs/struct.File.html
    #[stable(feature = "file_offset", since = "1.15.0")]
    pub trait FileExt {
        /// Seeks to a given position and reads a number of bytes.
        ///
        /// Returns the number of bytes read.
        ///
        /// The offset is relative to the start of the file and thus independent
        /// from the current cursor. The current cursor **is** affected by this
        /// function, it is set to the end of the read.
        ///
        /// Reading beyond the end of the file will always return with a length of
        /// 0\.
        ///
        /// Note that similar to `File::read`, it is not an error to return with a
        /// short read. When returning from such a short read, the file pointer is
        /// still updated.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::io;
        /// use std::fs::File;
        /// use std::os::windows::prelude::*;
        ///
        /// # fn foo() -> io::Result<()> {
        /// let mut file = File::open("foo.txt")?;
        /// let mut buffer = [0; 10];
        ///
        /// // Read 10 bytes, starting 72 bytes from the
        /// // start of the file.
        /// file.seek_read(&mut buffer[..], 72)?;
        /// # Ok(())
        /// # }
        /// ```
        #[stable(feature = "file_offset", since = "1.15.0")]
        fn seek_read(&self, buf: &mut [u8], offset: u64) -> io::Result<usize>;

        /// Seeks to a given position and writes a number of bytes.
        ///
        /// Returns the number of bytes written.
        ///
        /// The offset is relative to the start of the file and thus independent
        /// from the current cursor. The current cursor **is** affected by this
        /// function, it is set to the end of the write.
        ///
        /// When writing beyond the end of the file, the file is appropriately
        /// extended and the intermediate bytes are left uninitialized.
        ///
        /// Note that similar to `File::write`, it is not an error to return a
        /// short write. When returning from such a short write, the file pointer
        /// is still updated.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::fs::File;
        /// use std::os::windows::prelude::*;
        ///
        /// # fn foo() -> std::io::Result<()> {
        /// let mut buffer = File::create("foo.txt")?;
        ///
        /// // Write a byte string starting 72 bytes from
        /// // the start of the file.
        /// buffer.seek_write(b"some bytes", 72)?;
        /// # Ok(())
        /// # }
        /// ```
        #[stable(feature = "file_offset", since = "1.15.0")]
        fn seek_write(&self, buf: &[u8], offset: u64) -> io::Result<usize>;
    }

    #[stable(feature = "file_offset", since = "1.15.0")]
    impl FileExt for fs::File {
        fn seek_read(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> {
            self.as_inner().read_at(buf, offset)
        }

        fn seek_write(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
            self.as_inner().write_at(buf, offset)
        }
    }

    /// Windows-specific extensions to [`OpenOptions`].
    ///
    /// [`OpenOptions`]: ../../../fs/struct.OpenOptions.html
    #[stable(feature = "open_options_ext", since = "1.10.0")]
    pub trait OpenOptionsExt {
        /// Overrides the `dwDesiredAccess` argument to the call to [`CreateFile`]
        /// with the specified value.
        ///
        /// This will override the `read`, `write`, and `append` flags on the
        /// `OpenOptions` structure. This method provides fine-grained control over
        /// the permissions to read, write and append data, attributes (like hidden
        /// and system), and extended attributes.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::fs::OpenOptions;
        /// use std::os::windows::prelude::*;
        ///
        /// // Open without read and write permission, for example if you only need
        /// // to call `stat` on the file
        /// let file = OpenOptions::new().access_mode(0).open("foo.txt");
        /// ```
        ///
        /// [`CreateFile`]: https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858.aspx
        #[stable(feature = "open_options_ext", since = "1.10.0")]
        fn access_mode(&mut self, access: u32) -> &mut Self;

        /// Overrides the `dwShareMode` argument to the call to [`CreateFile`] with
        /// the specified value.
        ///
        /// By default `share_mode` is set to
        /// `FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE`. This allows
        /// other processes to to read, write, and delete/rename the same file
        /// while it is open. Removing any of the flags will prevent other
        /// processes from performing the corresponding operation until the file
        /// handle is closed.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::fs::OpenOptions;
        /// use std::os::windows::prelude::*;
        ///
        /// // Do not allow others to read or modify this file while we have it open
        /// // for writing.
        /// let file = OpenOptions::new()
        ///     .write(true)
        ///     .share_mode(0)
        ///     .open("foo.txt");
        /// ```
        ///
        /// [`CreateFile`]: https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858.aspx
        #[stable(feature = "open_options_ext", since = "1.10.0")]
        fn share_mode(&mut self, val: u32) -> &mut Self;

        /// Sets extra flags for the `dwFileFlags` argument to the call to
        /// [`CreateFile2`] to the specified value (or combines it with
        /// `attributes` and `security_qos_flags` to set the `dwFlagsAndAttributes`
        /// for [`CreateFile`]).
        ///
        /// Custom flags can only set flags, not remove flags set by Rust's options.
        /// This option overwrites any previously set custom flags.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # #[cfg(for_demonstration_only)]
        /// extern crate winapi;
        /// # mod winapi { pub const FILE_FLAG_DELETE_ON_CLOSE: u32 = 0x04000000; }
        ///
        /// use std::fs::OpenOptions;
        /// use std::os::windows::prelude::*;
        ///
        /// let file = OpenOptions::new()
        ///     .create(true)
        ///     .write(true)
        ///     .custom_flags(winapi::FILE_FLAG_DELETE_ON_CLOSE)
        ///     .open("foo.txt");
        /// ```
        ///
        /// [`CreateFile`]: https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858.aspx
        /// [`CreateFile2`]: https://msdn.microsoft.com/en-us/library/windows/desktop/hh449422.aspx
        #[stable(feature = "open_options_ext", since = "1.10.0")]
        fn custom_flags(&mut self, flags: u32) -> &mut Self;

        /// Sets the `dwFileAttributes` argument to the call to [`CreateFile2`] to
        /// the specified value (or combines it with `custom_flags` and
        /// `security_qos_flags` to set the `dwFlagsAndAttributes` for
        /// [`CreateFile`]).
        ///
        /// If a _new_ file is created because it does not yet exist and
        /// `.create(true)` or `.create_new(true)` are specified, the new file is
        /// given the attributes declared with `.attributes()`.
        ///
        /// If an _existing_ file is opened with `.create(true).truncate(true)`, its
        /// existing attributes are preserved and combined with the ones declared
        /// with `.attributes()`.
        ///
        /// In all other cases the attributes get ignored.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # #[cfg(for_demonstration_only)]
        /// extern crate winapi;
        /// # mod winapi { pub const FILE_ATTRIBUTE_HIDDEN: u32 = 2; }
        ///
        /// use std::fs::OpenOptions;
        /// use std::os::windows::prelude::*;
        ///
        /// let file = OpenOptions::new()
        ///     .write(true)
        ///     .create(true)
        ///     .attributes(winapi::FILE_ATTRIBUTE_HIDDEN)
        ///     .open("foo.txt");
        /// ```
        ///
        /// [`CreateFile`]: https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858.aspx
        /// [`CreateFile2`]: https://msdn.microsoft.com/en-us/library/windows/desktop/hh449422.aspx
        #[stable(feature = "open_options_ext", since = "1.10.0")]
        fn attributes(&mut self, val: u32) -> &mut Self;

        /// Sets the `dwSecurityQosFlags` argument to the call to [`CreateFile2`] to
        /// the specified value (or combines it with `custom_flags` and `attributes`
        /// to set the `dwFlagsAndAttributes` for [`CreateFile`]).
        ///
        /// By default, `security_qos_flags` is set to `SECURITY_ANONYMOUS`. For
        /// information about possible values, see [Impersonation Levels] on the
        /// Windows Dev Center site.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::fs::OpenOptions;
        /// use std::os::windows::prelude::*;
        ///
        /// let file = OpenOptions::new()
        ///     .write(true)
        ///     .create(true)
        ///
        ///     // Sets the flag value to `SecurityIdentification`.
        ///     .security_qos_flags(1)
        ///
        ///     .open("foo.txt");
        /// ```
        ///
        /// [`CreateFile`]: https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858.aspx
        /// [`CreateFile2`]: https://msdn.microsoft.com/en-us/library/windows/desktop/hh449422.aspx
        /// [Impersonation Levels]:
        ///     https://msdn.microsoft.com/en-us/library/windows/desktop/aa379572.aspx
        #[stable(feature = "open_options_ext", since = "1.10.0")]
        fn security_qos_flags(&mut self, flags: u32) -> &mut OpenOptions;
    }

    #[stable(feature = "open_options_ext", since = "1.10.0")]
    impl OpenOptionsExt for OpenOptions {
        fn access_mode(&mut self, access: u32) -> &mut OpenOptions {
            self.as_inner_mut().access_mode(access); self
        }

        fn share_mode(&mut self, share: u32) -> &mut OpenOptions {
            self.as_inner_mut().share_mode(share); self
        }

        fn custom_flags(&mut self, flags: u32) -> &mut OpenOptions {
            self.as_inner_mut().custom_flags(flags); self
        }

        fn attributes(&mut self, attributes: u32) -> &mut OpenOptions {
            self.as_inner_mut().attributes(attributes); self
        }

        fn security_qos_flags(&mut self, flags: u32) -> &mut OpenOptions {
            self.as_inner_mut().security_qos_flags(flags); self
        }
    }

    /// Extension methods for [`fs::Metadata`] to access the raw fields contained
    /// within.
    ///
    /// The data members that this trait exposes correspond to the members
    /// of the [`BY_HANDLE_FILE_INFORMATION`] structure.
    ///
    /// [`fs::Metadata`]: ../../../fs/struct.Metadata.html
    /// [`BY_HANDLE_FILE_INFORMATION`]:
    ///     https://msdn.microsoft.com/en-us/library/windows/desktop/aa363788.aspx
    #[stable(feature = "metadata_ext", since = "1.1.0")]
    pub trait MetadataExt {
        /// Returns the value of the `dwFileAttributes` field of this metadata.
        ///
        /// This field contains the file system attribute information for a file
        /// or directory. For possible values and their descriptions, see
        /// [File Attribute Constants] in the Windows Dev Center.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::io;
        /// use std::fs;
        /// use std::os::windows::prelude::*;
        ///
        /// # fn foo() -> io::Result<()> {
        /// let metadata = fs::metadata("foo.txt")?;
        /// let attributes = metadata.file_attributes();
        /// # Ok(())
        /// # }
        /// ```
        ///
        /// [File Attribute Constants]:
        ///     https://msdn.microsoft.com/en-us/library/windows/desktop/gg258117.aspx
        #[stable(feature = "metadata_ext", since = "1.1.0")]
        fn file_attributes(&self) -> u32;

        /// Returns the value of the `ftCreationTime` field of this metadata.
        ///
        /// The returned 64-bit value is equivalent to a [`FILETIME`] struct,
        /// which represents the number of 100-nanosecond intervals since
        /// January 1, 1601 (UTC). The struct is automatically
        /// converted to a `u64` value, as that is the recommended way
        /// to use it.
        ///
        /// If the underlying filesystem does not support creation time, the
        /// returned value is 0.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::io;
        /// use std::fs;
        /// use std::os::windows::prelude::*;
        ///
        /// # fn foo() -> io::Result<()> {
        /// let metadata = fs::metadata("foo.txt")?;
        /// let creation_time = metadata.creation_time();
        /// # Ok(())
        /// # }
        /// ```
        ///
        /// [`FILETIME`]: https://msdn.microsoft.com/en-us/library/windows/desktop/ms724284.aspx
        #[stable(feature = "metadata_ext", since = "1.1.0")]
        fn creation_time(&self) -> u64;

        /// Returns the value of the `ftLastAccessTime` field of this metadata.
        ///
        /// The returned 64-bit value is equivalent to a [`FILETIME`] struct,
        /// which represents the number of 100-nanosecond intervals since
        /// January 1, 1601 (UTC). The struct is automatically
        /// converted to a `u64` value, as that is the recommended way
        /// to use it.
        ///
        /// For a file, the value specifies the last time that a file was read
        /// from or written to. For a directory, the value specifies when
        /// the directory was created. For both files and directories, the
        /// specified date is correct, but the time of day is always set to
        /// midnight.
        ///
        /// If the underlying filesystem does not support last access time, the
        /// returned value is 0.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::io;
        /// use std::fs;
        /// use std::os::windows::prelude::*;
        ///
        /// # fn foo() -> io::Result<()> {
        /// let metadata = fs::metadata("foo.txt")?;
        /// let last_access_time = metadata.last_access_time();
        /// # Ok(())
        /// # }
        /// ```
        ///
        /// [`FILETIME`]: https://msdn.microsoft.com/en-us/library/windows/desktop/ms724284.aspx
        #[stable(feature = "metadata_ext", since = "1.1.0")]
        fn last_access_time(&self) -> u64;

        /// Returns the value of the `ftLastWriteTime` field of this metadata.
        ///
        /// The returned 64-bit value is equivalent to a [`FILETIME`] struct,
        /// which represents the number of 100-nanosecond intervals since
        /// January 1, 1601 (UTC). The struct is automatically
        /// converted to a `u64` value, as that is the recommended way
        /// to use it.
        ///
        /// For a file, the value specifies the last time that a file was written
        /// to. For a directory, the structure specifies when the directory was
        /// created.
        ///
        /// If the underlying filesystem does not support the last write time,
        /// the returned value is 0.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::io;
        /// use std::fs;
        /// use std::os::windows::prelude::*;
        ///
        /// # fn foo() -> io::Result<()> {
        /// let metadata = fs::metadata("foo.txt")?;
        /// let last_write_time = metadata.last_write_time();
        /// # Ok(())
        /// # }
        /// ```
        ///
        /// [`FILETIME`]: https://msdn.microsoft.com/en-us/library/windows/desktop/ms724284.aspx
        #[stable(feature = "metadata_ext", since = "1.1.0")]
        fn last_write_time(&self) -> u64;

        /// Returns the value of the `nFileSize{High,Low}` fields of this
        /// metadata.
        ///
        /// The returned value does not have meaning for directories.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::io;
        /// use std::fs;
        /// use std::os::windows::prelude::*;
        ///
        /// # fn foo() -> io::Result<()> {
        /// let metadata = fs::metadata("foo.txt")?;
        /// let file_size = metadata.file_size();
        /// # Ok(())
        /// # }
        /// ```
        #[stable(feature = "metadata_ext", since = "1.1.0")]
        fn file_size(&self) -> u64;
    }

    #[stable(feature = "metadata_ext", since = "1.1.0")]
    impl MetadataExt for Metadata {
        fn file_attributes(&self) -> u32 { self.as_inner().attrs() }
        fn creation_time(&self) -> u64 { self.as_inner().created_u64() }
        fn last_access_time(&self) -> u64 { self.as_inner().accessed_u64() }
        fn last_write_time(&self) -> u64 { self.as_inner().modified_u64() }
        fn file_size(&self) -> u64 { self.as_inner().size() }
    }

    /// Creates a new file symbolic link on the filesystem.
    ///
    /// The `dst` path will be a file symbolic link pointing to the `src`
    /// path.
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::windows::fs;
    ///
    /// # fn foo() -> std::io::Result<()> {
    /// fs::symlink_file("a.txt", "b.txt")?;
    /// # Ok(())
    /// # }
    /// ```
    #[stable(feature = "symlink", since = "1.1.0")]
    pub fn symlink_file<P: AsRef<Path>, Q: AsRef<Path>>(src: P, dst: Q)
                                                        -> io::Result<()> {
        sys::fs::symlink_inner(src.as_ref(), dst.as_ref(), false)
    }

    /// Creates a new directory symlink on the filesystem.
    ///
    /// The `dst` path will be a directory symbolic link pointing to the `src`
    /// path.
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::windows::fs;
    ///
    /// # fn foo() -> std::io::Result<()> {
    /// fs::symlink_dir("a", "b")?;
    /// # Ok(())
    /// # }
    /// ```
    #[stable(feature = "symlink", since = "1.1.0")]
    pub fn symlink_dir<P: AsRef<Path>, Q: AsRef<Path>>(src: P, dst: Q)
                                                       -> io::Result<()> {
        sys::fs::symlink_inner(src.as_ref(), dst.as_ref(), true)
    }

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Prefix searches with a type followed by a colon (e.g. `fn:`) to restrict the search to a given type.

Accepted types are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.

Search functions by type signature (e.g. `vec -> usize` or `* -> vec`)