NixPath -> NixString and Error -> Errno

Author: arcnmx

src/cstr.rs

@@ -0,0 +1,80 @@
+use std::ffi::{OsStr, OsString, CString, NulError};
+use std::path::{Path, PathBuf};
+use std::os::unix::ffi::{OsStrExt, OsStringExt};
+
+pub trait ToCString {
+    fn to_cstring(&self) -> Result<CString, NulError>;
+    fn into_cstring(self) -> Result<CString, NulError> where Self: Sized { unimplemented!() }
+}
+
+impl ToCString for [u8] {
+    fn to_cstring(&self) -> Result<CString, NulError> {
+        CString::new(self)
+    }
+}
+
+impl ToCString for Vec<u8> {
+    fn to_cstring(&self) -> Result<CString, NulError> {
+        ToCString::to_cstring(&**self)
+    }
+
+    fn into_cstring(self) -> Result<CString, NulError> {
+        CString::new(self)
+    }
+}
+
+impl ToCString for str {
+    fn to_cstring(&self) -> Result<CString, NulError> {
+        CString::new(self.as_bytes())
+    }
+}
+
+impl ToCString for String {
+    fn to_cstring(&self) -> Result<CString, NulError> {
+        ToCString::to_cstring(&**self)
+    }
+
+    fn into_cstring(self) -> Result<CString, NulError> {
+        CString::new(self.into_bytes())
+    }
+}
+
+impl ToCString for OsStr {
+    fn to_cstring(&self) -> Result<CString, NulError> {
+        CString::new(self.as_bytes())
+    }
+}
+
+impl ToCString for OsString {
+    fn to_cstring(&self) -> Result<CString, NulError> {
+        ToCString::to_cstring(&**self)
+    }
+
+    fn into_cstring(self) -> Result<CString, NulError> {
+        CString::new(self.into_vec())
+    }
+}
+
+impl ToCString for Path {
+    fn to_cstring(&self) -> Result<CString, NulError> {
+        ToCString::to_cstring(self.as_os_str())
+    }
+}
+
+impl ToCString for PathBuf {
+    fn to_cstring(&self) -> Result<CString, NulError> {
+        ToCString::to_cstring(self.as_os_str())
+    }
+
+    fn into_cstring(self) -> Result<CString, NulError> {
+        ToCString::into_cstring(self.into_os_string())
+    }
+}
+
+// TODO: allow this in consts/statics
+#[macro_export]
+macro_rules! cstr {
+    ($s:expr) => {
+        unsafe { ::std::ffi::CStr::from_ptr(concat!($s, "\0").as_ptr() as *const _) }
+    }
+}

src/errno.rs

@@ -1,6 +1,5 @@
 use libc::c_int;
-use std::{fmt, io, error};
-use {Error, Result};
+use std::{fmt, io, error, result};
 
 pub use self::consts::*;
 pub use self::consts::Errno::*;
@@ -74,7 +73,7 @@ impl Errno {
     /// should not be used when `-1` is not the errno sentinel value.
     pub fn result<S: ErrnoSentinel + PartialEq<S>>(value: S) -> Result<S> {
         if value == S::sentinel() {
-            Err(Error::Sys(Self::last()))
+            Err(Self::last())
         } else {
             Ok(value)
         }
@@ -117,6 +116,8 @@ impl From<Errno> for io::Error {
     }
 }
 
+pub type Result<T> = result::Result<T, Errno>;
+
 fn last() -> Errno {
     Errno::from_i32(errno())
 }

src/fcntl.rs

@@ -1,4 +1,4 @@
-use {Errno, Result, NixPath};
+use {Errno, Result, NixString};
 use libc::{c_int, c_uint};
 use sys::stat::Mode;
 use std::os::unix::io::RawFd;
@@ -96,10 +96,10 @@ mod ffi {
     }
 }
 
-pub fn open<P: ?Sized + NixPath>(path: &P, oflag: OFlag, mode: Mode) -> Result<RawFd> {
-    let fd = try!(path.with_nix_path(|cstr| {
-        unsafe { ffi::open(cstr.as_ptr(), oflag.bits(), mode.bits() as c_uint) }
-    }));
+pub fn open<P: NixString>(path: P, oflag: OFlag, mode: Mode) -> Result<RawFd> {
+    let fd = unsafe {
+        ffi::open(path.as_ref().as_ptr(), oflag.bits(), mode.bits() as c_uint)
+    };
 
     Errno::result(fd)
 }

src/lib.rs

@@ -20,7 +20,13 @@ extern crate nix_test as nixtest;
 
 // Re-exports
 pub use libc::{c_int, c_void};
-pub use errno::Errno;
+pub use errno::{Errno, Result};
+pub use nix_string::NixString;
+
+mod nix_string;
+
+#[macro_use]
+pub mod cstr;
 
 pub mod errno;
 pub mod features;
@@ -42,186 +48,3 @@ pub mod sched;
 
 pub mod sys;
 pub mod unistd;
-
-/*
- *
- * ===== Result / Error =====
- *
- */
-
-use libc::c_char;
-use std::{ptr, result};
-use std::ffi::{CStr, OsStr};
-use std::path::{Path, PathBuf};
-use std::os::unix::ffi::OsStrExt;
-use std::io;
-use std::fmt;
-use std::error;
-use libc::PATH_MAX;
-
-pub type Result<T> = result::Result<T, Error>;
-
-#[derive(Clone, Copy, Debug, PartialEq)]
-pub enum Error {
-    Sys(errno::Errno),
-    InvalidPath,
-}
-
-impl Error {
-    pub fn from_errno(errno: errno::Errno) -> Error {
-        Error::Sys(errno)
-    }
-
-    pub fn last() -> Error {
-        Error::Sys(errno::Errno::last())
-    }
-
-    pub fn invalid_argument() -> Error {
-        Error::Sys(errno::EINVAL)
-    }
-
-    pub fn errno(&self) -> errno::Errno {
-        match *self {
-            Error::Sys(errno) => errno,
-            Error::InvalidPath => errno::Errno::EINVAL,
-        }
-    }
-}
-
-impl From<errno::Errno> for Error {
-    fn from(errno: errno::Errno) -> Error { Error::from_errno(errno) }
-}
-
-impl error::Error for Error {
-    fn description(&self) -> &str {
-        match self {
-            &Error::InvalidPath => "Invalid path",
-            &Error::Sys(ref errno) => errno.desc(),
-        }
-    }
-}
-
-impl fmt::Display for Error {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            &Error::InvalidPath => write!(f, "Invalid path"),
-            &Error::Sys(errno) => write!(f, "{:?}: {}", errno, errno.desc()),
-        }
-    }
-}
-
-impl From<Error> for io::Error {
-    fn from(err: Error) -> Self {
-        match err {
-            Error::InvalidPath => io::Error::new(io::ErrorKind::InvalidInput, err),
-            Error::Sys(errno) => io::Error::from_raw_os_error(errno as i32),
-        }
-    }
-}
-
-pub trait NixPath {
-    fn len(&self) -> usize;
-
-    fn with_nix_path<T, F>(&self, f: F) -> Result<T>
-        where F: FnOnce(&CStr) -> T;
-}
-
-impl NixPath for str {
-    fn len(&self) -> usize {
-        NixPath::len(OsStr::new(self))
-    }
-
-    fn with_nix_path<T, F>(&self, f: F) -> Result<T>
-        where F: FnOnce(&CStr) -> T {
-            OsStr::new(self).with_nix_path(f)
-        }
-}
-
-impl NixPath for OsStr {
-    fn len(&self) -> usize {
-        self.as_bytes().len()
-    }
-
-    fn with_nix_path<T, F>(&self, f: F) -> Result<T>
-        where F: FnOnce(&CStr) -> T {
-            self.as_bytes().with_nix_path(f)
-        }
-}
-
-impl NixPath for CStr {
-    fn len(&self) -> usize {
-        self.to_bytes().len()
-    }
-
-    fn with_nix_path<T, F>(&self, f: F) -> Result<T>
-            where F: FnOnce(&CStr) -> T {
-        // Equivalence with the [u8] impl.
-        if self.len() >= PATH_MAX as usize {
-            return Err(Error::InvalidPath);
-        }
-
-        Ok(f(self))
-    }
-}
-
-impl NixPath for [u8] {
-    fn len(&self) -> usize {
-        self.len()
-    }
-
-    fn with_nix_path<T, F>(&self, f: F) -> Result<T>
-            where F: FnOnce(&CStr) -> T {
-        let mut buf = [0u8; PATH_MAX as usize];
-
-        if self.len() >= PATH_MAX as usize {
-            return Err(Error::InvalidPath);
-        }
-
-        match self.iter().position(|b| *b == 0) {
-            Some(_) => Err(Error::InvalidPath),
-            None => {
-                unsafe {
-                    // TODO: Replace with bytes::copy_memory. rust-lang/rust#24028
-                    ptr::copy_nonoverlapping(self.as_ptr(), buf.as_mut_ptr(), self.len());
-                    Ok(f(CStr::from_ptr(buf.as_ptr() as *const c_char)))
-                }
-
-            }
-        }
-    }
-}
-
-impl NixPath for Path {
-    fn len(&self) -> usize {
-        NixPath::len(self.as_os_str())
-    }
-
-    fn with_nix_path<T, F>(&self, f: F) -> Result<T> where F: FnOnce(&CStr) -> T {
-        self.as_os_str().with_nix_path(f)
-    }
-}
-
-impl NixPath for PathBuf {
-    fn len(&self) -> usize {
-        NixPath::len(self.as_os_str())
-    }
-
-    fn with_nix_path<T, F>(&self, f: F) -> Result<T> where F: FnOnce(&CStr) -> T {
-        self.as_os_str().with_nix_path(f)
-    }
-}
-
-/// Treats `None` as an empty string.
-impl<'a, NP: ?Sized + NixPath>  NixPath for Option<&'a NP> {
-    fn len(&self) -> usize {
-        self.map_or(0, NixPath::len)
-    }
-
-    fn with_nix_path<T, F>(&self, f: F) -> Result<T> where F: FnOnce(&CStr) -> T {
-        if let Some(nix_path) = *self {
-            nix_path.with_nix_path(f)
-        } else {
-            unsafe { CStr::from_ptr("\0".as_ptr() as *const _).with_nix_path(f) }
-        }
-    }
-}