std: Expose SystemTime accessors on fs::Metadata

src/libstd/fs.rs

@@ -25,6 +25,7 @@ use sys::fs as fs_imp;
 use sys_common::io::read_to_end_uninitialized;
 use sys_common::{AsInnerMut, FromInner, AsInner, IntoInner};
 use vec::Vec;
+use time::SystemTime;
 
 /// A reference to an open file on the filesystem.
 ///
@@ -660,6 +661,52 @@ impl Metadata {
     pub fn permissions(&self) -> Permissions {
         Permissions(self.0.perm())
     }
+
+    /// Returns the last modification time listed in this metadata.
+    ///
+    /// The returned value corresponds to the `mtime` field of `stat` on Unix
+    /// platforms and the `ftLastWriteTime` field on Windows platforms.
+    ///
+    /// # Errors
+    ///
+    /// This field may not be available on all platforms, and will return an
+    /// `Err` on platforms where it is not available.
+    #[unstable(feature = "fs_time", issue = "31399")]
+    pub fn modified(&self) -> io::Result<SystemTime> {
+        self.0.modified().map(FromInner::from_inner)
+    }
+
+    /// Returns the last access time of this metadata.
+    ///
+    /// The returned value corresponds to the `atime` field of `stat` on Unix
+    /// platforms and the `ftLastAccessTime` field on Windows platforms.
+    ///
+    /// Note that not all platforms will keep this field update in a file's
+    /// metadata, for example Windows has an option to disable updating this
+    /// time when files are accessed and Linux similarly has `noatime`.
+    ///
+    /// # Errors
+    ///
+    /// This field may not be available on all platforms, and will return an
+    /// `Err` on platforms where it is not available.
+    #[unstable(feature = "fs_time", issue = "31399")]
+    pub fn accessed(&self) -> io::Result<SystemTime> {
+        self.0.accessed().map(FromInner::from_inner)
+    }
+
+    /// Returns the creation time listed in the this metadata.
+    ///
+    /// The returned value corresponds to the `birthtime` field of `stat` on
+    /// Unix platforms and the `ftCreationTime` field on Windows platforms.
+    ///
+    /// # Errors
+    ///
+    /// This field may not be available on all platforms, and will return an
+    /// `Err` on platforms where it is not available.
+    #[unstable(feature = "fs_time", issue = "31399")]
+    pub fn created(&self) -> io::Result<SystemTime> {
+        self.0.created().map(FromInner::from_inner)
+    }
 }
 
 impl AsInner<fs_imp::FileAttr> for Metadata {
@@ -2468,4 +2515,24 @@ mod tests {
         assert!(link.is_dir());
         assert!(d.exists());
     }
+
+    #[test]
+    fn metadata_access_times() {
+        let tmpdir = tmpdir();
+
+        let b = tmpdir.join("b");
+        File::create(&b).unwrap();
+
+        let a = check!(fs::metadata(&tmpdir.path()));
+        let b = check!(fs::metadata(&b));
+
+        assert_eq!(check!(a.accessed()), check!(a.accessed()));
+        assert_eq!(check!(a.modified()), check!(a.modified()));
+        assert_eq!(check!(b.accessed()), check!(b.modified()));
+
+        if cfg!(target_os = "macos") || cfg!(target_os = "windows") {
+            check!(a.created());
+            check!(b.created());
+        }
+    }
 }

src/libstd/sys/unix/fs.rs

@@ -22,6 +22,7 @@ use ptr;
 use sync::Arc;
 use sys::fd::FileDesc;
 use sys::platform::raw;
+use sys::time::SystemTime;
 use sys::{cvt, cvt_r};
 use sys_common::{AsInner, FromInner};
 
@@ -86,6 +87,67 @@ impl FileAttr {
     }
 }
 
+#[cfg(any(target_os = "ios", target_os = "macos"))]
+// FIXME: update SystemTime to store a timespec and don't lose precision
+impl FileAttr {
+    pub fn modified(&self) -> io::Result<SystemTime> {
+        Ok(SystemTime::from(libc::timeval {
+            tv_sec: self.stat.st_mtime,
+            tv_usec: (self.stat.st_mtime_nsec / 1000) as libc::suseconds_t,
+        }))
+    }
+
+    pub fn accessed(&self) -> io::Result<SystemTime> {
+        Ok(SystemTime::from(libc::timeval {
+            tv_sec: self.stat.st_atime,
+            tv_usec: (self.stat.st_atime_nsec / 1000) as libc::suseconds_t,
+        }))
+    }
+
+    pub fn created(&self) -> io::Result<SystemTime> {
+        Ok(SystemTime::from(libc::timeval {
+            tv_sec: self.stat.st_birthtime,
+            tv_usec: (self.stat.st_birthtime_nsec / 1000) as libc::suseconds_t,
+        }))
+    }
+}
+
+#[cfg(not(any(target_os = "ios", target_os = "macos")))]
+impl FileAttr {
+    pub fn modified(&self) -> io::Result<SystemTime> {
+        Ok(SystemTime::from(libc::timespec {
+            tv_sec: self.stat.st_mtime,
+            tv_nsec: self.stat.st_mtime_nsec as libc::c_long,
+        }))
+    }
+
+    pub fn accessed(&self) -> io::Result<SystemTime> {
+        Ok(SystemTime::from(libc::timespec {
+            tv_sec: self.stat.st_atime,
+            tv_nsec: self.stat.st_atime_nsec as libc::c_long,
+        }))
+    }
+
+    #[cfg(any(target_os = "bitrig",
+              target_os = "freebsd",
+              target_os = "openbsd"))]
+    pub fn created(&self) -> io::Result<SystemTime> {
+        Ok(SystemTime::from(libc::timespec {
+            tv_sec: self.stat.st_birthtime,
+            tv_nsec: self.stat.st_birthtime_nsec as libc::c_long,
+        }))
+    }
+
+    #[cfg(not(any(target_os = "bitrig",
+                  target_os = "freebsd",
+                  target_os = "openbsd")))]
+    pub fn created(&self) -> io::Result<SystemTime> {
+        Err(io::Error::new(io::ErrorKind::Other,
+                           "creation time is not available on this platform \
+                            currently"))
+    }
+}
+
 impl AsInner<raw::stat> for FileAttr {
     fn as_inner(&self) -> &raw::stat { &self.stat }
 }

src/libstd/sys/unix/time.rs

@@ -146,6 +146,12 @@ mod inner {
         }
     }
 
+    impl From<libc::timeval> for SystemTime {
+        fn from(t: libc::timeval) -> SystemTime {
+            SystemTime { t: t }
+        }
+    }
+
     impl PartialEq for SystemTime {
         fn eq(&self, other: &SystemTime) -> bool {
             self.t.tv_sec == other.t.tv_sec && self.t.tv_usec == other.t.tv_usec
@@ -282,6 +288,12 @@ mod inner {
         }
     }
 
+    impl From<libc::timespec> for SystemTime {
+        fn from(t: libc::timespec) -> SystemTime {
+            SystemTime { t: Timespec { t: t } }
+        }
+    }
+
     impl fmt::Debug for SystemTime {
         fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
             f.debug_struct("SystemTime")

src/libstd/sys/windows/ext/fs.rs

@@ -196,9 +196,9 @@ pub trait MetadataExt {
 #[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() }
-    fn last_access_time(&self) -> u64 { self.as_inner().accessed() }
-    fn last_write_time(&self) -> u64 { self.as_inner().modified() }
+    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() }
 }
 

src/libstd/sys/windows/fs.rs

@@ -20,6 +20,7 @@ use ptr;
 use slice;
 use sync::Arc;
 use sys::handle::Handle;
+use sys::time::SystemTime;
 use sys::{c, cvt};
 use sys_common::FromInner;
 
@@ -421,19 +422,39 @@ impl FileAttr {
         FileType::new(self.data.dwFileAttributes, self.reparse_tag)
     }
 
-    pub fn created(&self) -> u64 { self.to_u64(&self.data.ftCreationTime) }
-    pub fn accessed(&self) -> u64 { self.to_u64(&self.data.ftLastAccessTime) }
-    pub fn modified(&self) -> u64 { self.to_u64(&self.data.ftLastWriteTime) }
+    pub fn modified(&self) -> io::Result<SystemTime> {
+        Ok(SystemTime::from(self.data.ftLastWriteTime))
+    }
+
+    pub fn accessed(&self) -> io::Result<SystemTime> {
+        Ok(SystemTime::from(self.data.ftLastAccessTime))
+    }
 
-    fn to_u64(&self, ft: &c::FILETIME) -> u64 {
-        (ft.dwLowDateTime as u64) | ((ft.dwHighDateTime as u64) << 32)
+    pub fn created(&self) -> io::Result<SystemTime> {
+        Ok(SystemTime::from(self.data.ftCreationTime))
+    }
+
+    pub fn modified_u64(&self) -> u64 {
+        to_u64(&self.data.ftLastWriteTime)
+    }
+
+    pub fn accessed_u64(&self) -> u64 {
+        to_u64(&self.data.ftLastAccessTime)
+    }
+
+    pub fn created_u64(&self) -> u64 {
+        to_u64(&self.data.ftCreationTime)
     }
 
     fn is_reparse_point(&self) -> bool {
         self.data.dwFileAttributes & c::FILE_ATTRIBUTE_REPARSE_POINT != 0
     }
 }
 
+fn to_u64(ft: &c::FILETIME) -> u64 {
+    (ft.dwLowDateTime as u64) | ((ft.dwHighDateTime as u64) << 32)
+}
+
 impl FilePermissions {
     pub fn readonly(&self) -> bool {
         self.attrs & c::FILE_ATTRIBUTE_READONLY != 0

src/libstd/sys/windows/time.rs

@@ -166,6 +166,12 @@ impl fmt::Debug for SystemTime {
     }
 }
 
+impl From<c::FILETIME> for SystemTime {
+    fn from(t: c::FILETIME) -> SystemTime {
+        SystemTime { t: t }
+    }
+}
+
 fn dur2intervals(d: &Duration) -> i64 {
     d.as_secs().checked_mul(INTERVALS_PER_SEC).and_then(|i| {
         i.checked_add(d.subsec_nanos() as u64 / 100)

src/libstd/time/mod.rs

@@ -16,6 +16,7 @@ use error::Error;
 use fmt;
 use ops::{Add, Sub};
 use sys::time;
+use sys_common::FromInner;
 
 #[stable(feature = "time", since = "1.3.0")]
 pub use self::duration::Duration;
@@ -227,6 +228,12 @@ impl fmt::Display for SystemTimeError {
     }
 }
 
+impl FromInner<time::SystemTime> for SystemTime {
+    fn from_inner(time: time::SystemTime) -> SystemTime {
+        SystemTime(time)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::{Instant, SystemTime, Duration, UNIX_EPOCH};