Add fs module

src/fs.rs

+use c_str::CStr;
+use header::fcntl::O_CREAT;
+use header::unistd::{SEEK_SET, SEEK_CUR, SEEK_END};
+use io;
+use platform;
+use platform::{Pal, Sys};
+use platform::types::*;
+
+fn last_os_error() -> io::Error {
+    let errno = unsafe { platform::errno };
+    io::Error::from_raw_os_error(errno)
+}
+
+pub struct File(c_int);
+
+impl File {
+    pub fn open(path: &CStr, oflag: c_int) -> io::Result<Self> {
+        match Sys::open(path, oflag, 0) {
+            -1 => Err(last_os_error()),
+            ok => Ok(File(ok)),
+        }
+    }
+
+    pub fn create(path: &CStr, oflag: c_int, mode: mode_t) -> io::Result<Self> {
+        match Sys::open(path, oflag | O_CREAT, mode) {
+            -1 => Err(last_os_error()),
+            ok => Ok(File(ok)),
+        }
+    }
+
+    pub fn sync_all(&self) -> io::Result<()> {
+        match Sys::fsync(self.0) {
+            -1 => Err(last_os_error()),
+            _ok => Ok(()),
+        }
+    }
+
+    pub fn set_len(&self, size: u64) -> io::Result<()> {
+        match Sys::ftruncate(self.0, size as off_t) {
+            -1 => Err(last_os_error()),
+            _ok => Ok(()),
+        }
+    }
+
+    pub fn try_clone(&self) -> io::Result<Self> {
+        match Sys::dup(self.0) {
+            -1 => Err(last_os_error()),
+            ok => Ok(File(ok)),
+        }
+    }
+}
+
+impl io::Read for File {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        match Sys::read(self.0, buf) {
+            -1 => Err(last_os_error()),
+            ok => Ok(ok as usize),
+        }
+    }
+}
+
+impl io::Write for File {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        match Sys::write(self.0, buf) {
+            -1 => Err(last_os_error()),
+            ok => Ok(ok as usize),
+        }
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+impl io::Seek for File {
+    fn seek(&mut self, pos: io::SeekFrom) -> io::Result<u64> {
+        let (offset, whence) = match pos {
+            io::SeekFrom::Start(start) => (start as off_t, SEEK_SET),
+            io::SeekFrom::Current(current) => (current as off_t, SEEK_CUR),
+            io::SeekFrom::End(end) => (end as off_t, SEEK_END),
+        };
+
+        match Sys::lseek(self.0, offset, whence) {
+            -1 => Err(last_os_error()),
+            ok => Ok(ok as u64),
+        }
+    }
+}

src/io.rs

+pub use core_io::*;

src/lib.rs

@@ -37,7 +37,9 @@ extern crate spin;
 #[macro_use]
 mod macros;
 pub mod c_str;
+pub mod fs;
 pub mod header;
+pub mod io;
 pub mod platform;
 pub mod start;