//! 特定于 Linux 的 [`std::fs`] 模块中的原语扩展。
//!
//! [`std::fs`]: crate::fs

#![stable(feature = "metadata_ext", since = "1.1.0")]

use crate::fs::Metadata;
use crate::sys_common::AsInner;

#[allow(deprecated)]
use crate::os::linux::raw;

/// 特定于操作系统的 [`fs::Metadata`] 扩展。
///
/// [`fs::Metadata`]: crate::fs::Metadata
#[stable(feature = "metadata_ext", since = "1.1.0")]
pub trait MetadataExt {
    /// 获得对底层 `stat` 结构的引用，该结构包含操作系统返回的原始信息。
    ///
    ///
    /// 返回的 [`stat`] 的内容在 Unix 平台上是不一致的。
    /// `os::unix::fs::MetadataExt` trait 包含原始统计信息中包含的跨 Unix 抽象。
    ///
    /// [`stat`]: struct@crate::os::linux::raw::stat
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     let stat = meta.as_raw_stat();
    ///     Ok(())
    /// }
    /// ```
    ///
    #[stable(feature = "metadata_ext", since = "1.1.0")]
    #[deprecated(since = "1.8.0", note = "other methods of this trait are now preferred")]
    #[allow(deprecated)]
    fn as_raw_stat(&self) -> &raw::stat;

    /// 返回此文件所在的设备 ID。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_dev());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_dev(&self) -> u64;
    /// 返回索引节点号。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_ino());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_ino(&self) -> u64;
    /// 返回文件类型和模式。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_mode());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_mode(&self) -> u32;
    /// 返回文件的硬链接数。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_nlink());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_nlink(&self) -> u64;
    /// 返回文件所有者的用户标识。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_uid());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_uid(&self) -> u32;
    /// 返回文件所有者的组 ID。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_gid());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_gid(&self) -> u32;
    /// 返回此文件表示的设备 ID。仅与特殊文件有关。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_rdev());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_rdev(&self) -> u64;
    /// 返回文件的大小 (如果是常规文件或符号链接)，以字节为单位。
    ///
    /// 符号链接的大小是它包含的路径名的长度，没有终止的空字节。
    ///
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_size());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_size(&self) -> u64;
    /// 返回文件的最后访问时间，以自 Unix 纪元以来的秒数为单位。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_atime());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_atime(&self) -> i64;
    /// 返回文件的最后访问时间，自 [`st_atime`] 起以纳秒为单位。
    ///
    /// [`st_atime`]: Self::st_atime
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_atime_nsec());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_atime_nsec(&self) -> i64;
    /// 返回文件的最后修改时间，以自 Unix 纪元以来的秒数为单位。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_mtime());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_mtime(&self) -> i64;
    /// 返回文件的最后修改时间，自 [`st_mtime`] 起以纳秒为单位。
    ///
    /// [`st_mtime`]: Self::st_mtime
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_mtime_nsec());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_mtime_nsec(&self) -> i64;
    /// 返回文件的最后状态更改时间，以自 Unix 纪元以来的秒数为单位。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_ctime());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_ctime(&self) -> i64;
    /// 返回文件的最后状态更改时间，自 [`st_ctime`] 起以纳秒为单位。
    ///
    /// [`st_ctime`]: Self::st_ctime
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_ctime_nsec());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_ctime_nsec(&self) -> i64;
    /// 返回有效文件系统 I/O 的 "preferred" 块大小。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_blksize());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_blksize(&self) -> u64;
    /// 返回分配给文件的块数，以 512 字节为单位。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::fs;
    /// use std::io;
    /// use std::os::linux::fs::MetadataExt;
    ///
    /// fn main() -> io::Result<()> {
    ///     let meta = fs::metadata("some_file")?;
    ///     println!("{}", meta.st_blocks());
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "metadata_ext2", since = "1.8.0")]
    fn st_blocks(&self) -> u64;
}

#[stable(feature = "metadata_ext", since = "1.1.0")]
impl MetadataExt for Metadata {
    #[allow(deprecated)]
    fn as_raw_stat(&self) -> &raw::stat {
        unsafe { &*(self.as_inner().as_inner() as *const libc::stat64 as *const raw::stat) }
    }
    fn st_dev(&self) -> u64 {
        self.as_inner().as_inner().st_dev as u64
    }
    fn st_ino(&self) -> u64 {
        self.as_inner().as_inner().st_ino as u64
    }
    fn st_mode(&self) -> u32 {
        self.as_inner().as_inner().st_mode as u32
    }
    fn st_nlink(&self) -> u64 {
        self.as_inner().as_inner().st_nlink as u64
    }
    fn st_uid(&self) -> u32 {
        self.as_inner().as_inner().st_uid as u32
    }
    fn st_gid(&self) -> u32 {
        self.as_inner().as_inner().st_gid as u32
    }
    fn st_rdev(&self) -> u64 {
        self.as_inner().as_inner().st_rdev as u64
    }
    fn st_size(&self) -> u64 {
        self.as_inner().as_inner().st_size as u64
    }
    fn st_atime(&self) -> i64 {
        let file_attr = self.as_inner();
        #[cfg(all(target_env = "gnu", target_pointer_width = "32"))]
        if let Some(atime) = file_attr.stx_atime() {
            return atime.tv_sec;
        }
        file_attr.as_inner().st_atime as i64
    }
    fn st_atime_nsec(&self) -> i64 {
        self.as_inner().as_inner().st_atime_nsec as i64
    }
    fn st_mtime(&self) -> i64 {
        let file_attr = self.as_inner();
        #[cfg(all(target_env = "gnu", target_pointer_width = "32"))]
        if let Some(mtime) = file_attr.stx_mtime() {
            return mtime.tv_sec;
        }
        file_attr.as_inner().st_mtime as i64
    }
    fn st_mtime_nsec(&self) -> i64 {
        self.as_inner().as_inner().st_mtime_nsec as i64
    }
    fn st_ctime(&self) -> i64 {
        let file_attr = self.as_inner();
        #[cfg(all(target_env = "gnu", target_pointer_width = "32"))]
        if let Some(ctime) = file_attr.stx_ctime() {
            return ctime.tv_sec;
        }
        file_attr.as_inner().st_ctime as i64
    }
    fn st_ctime_nsec(&self) -> i64 {
        self.as_inner().as_inner().st_ctime_nsec as i64
    }
    fn st_blksize(&self) -> u64 {
        self.as_inner().as_inner().st_blksize as u64
    }
    fn st_blocks(&self) -> u64 {
        self.as_inner().as_inner().st_blocks as u64
    }
}