add Uuid replacement

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

proxmox-tools/src/lib.rs

@@ -9,8 +9,12 @@ pub mod fd;
 pub mod fs;
 pub mod io;
 pub mod serde;
+pub mod uuid;
 pub mod vec;
 
+#[doc(inline)]
+pub use uuid::Uuid;
+
 /// Evaluates to the offset (in bytes) of a given member within a struct
 #[macro_export]
 macro_rules! offsetof {

proxmox-tools/src/uuid.rs

@@ -0,0 +1,160 @@
+//! Simple bindings to libuuid's `uuid_generate`.
+
+use std::borrow::{Borrow, BorrowMut};
+use std::fmt;
+use std::os::raw::c_int;
+
+use failure::{bail, Error};
+
+#[link(name = "uuid")]
+extern "C" {
+    fn uuid_generate(out: *mut [u8; 16]);
+    fn uuid_unparse_lower(input: *const [u8; 16], out: *mut u8);
+    fn uuid_unparse_upper(input: *const [u8; 16], out: *mut u8);
+    fn uuid_parse(input: *const u8, out: *mut [u8; 16]) -> c_int;
+}
+
+/// Uuid generated with the system's native libuuid.
+///
+/// ```
+/// use proxmox_tools::uuid::Uuid;
+///
+/// let uuid = Uuid::generate();
+/// println!("Generated uuid: {}", uuid);
+/// // prints somethign like:
+/// //    Generated uuid: d79191c-724-415f-a1bf-2256b8ea76e
+///
+/// let bytes: &[u8] = uuid.as_ref();
+/// println!("raw byte string: {:?}", bytes);
+/// //    raw byte string: [215, 9, 25, 28, 114, 4, 65, 95, 161, 191, 34, 86, 184, 234, 118, 14]
+///
+/// let text = format!("{}", uuid);
+/// let parsed: Uuid = text.parse().unwrap();
+/// assert_eq!(uuid, parsed);
+/// ```
+#[derive(Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
+pub struct Uuid(Box<[u8; 16]>);
+
+impl Uuid {
+    /// Generate a uuid with `uuid_generate(3)`.
+    pub fn generate() -> Self {
+        use std::alloc::{alloc, Layout};
+        let uuid = unsafe { alloc(Layout::new::<[u8; 16]>()) as *mut [u8; 16] };
+        unsafe { uuid_generate(uuid) };
+        Self(unsafe { Box::from_raw(uuid) })
+    }
+
+    /// Get a reference to the internal 16 byte array.
+    pub fn as_bytes(&self) -> &[u8; 16] {
+        &*self.0
+    }
+
+    /// Take out the inner boxed 16 byte array.
+    pub fn into_inner(self) -> Box<[u8; 16]> {
+        self.0
+    }
+
+    /// Parse a uuid in optionally-hyphenated format.
+    ///
+    /// ```
+    /// use proxmox_tools::uuid::Uuid;
+    ///
+    /// let gen = Uuid::generate();
+    /// let text = format!("{}", gen);
+    /// let parsed: Uuid = text.parse().unwrap();
+    /// assert_eq!(gen, parsed);
+    /// ```
+    pub fn parse_str(src: &str) -> Result<Self, Error> {
+        use std::alloc::{alloc, Layout};
+        let uuid = unsafe { alloc(Layout::new::<[u8; 16]>()) as *mut [u8; 16] };
+        let rc = unsafe { uuid_parse(src.as_bytes().as_ptr(), uuid) };
+        if rc != 0 {
+            bail!("failed to parse uuid");
+        }
+        Ok(Self(unsafe { Box::from_raw(uuid) }))
+    }
+}
+
+impl AsRef<[u8]> for Uuid {
+    #[inline]
+    fn as_ref(&self) -> &[u8] {
+        self.as_bytes()
+    }
+}
+
+impl AsMut<[u8]> for Uuid {
+    #[inline]
+    fn as_mut(&mut self) -> &mut [u8] {
+        &mut (self.0)[..]
+    }
+}
+
+impl Borrow<[u8]> for Uuid {
+    #[inline]
+    fn borrow(&self) -> &[u8] {
+        &(self.0)[..]
+    }
+}
+
+impl BorrowMut<[u8]> for Uuid {
+    #[inline]
+    fn borrow_mut(&mut self) -> &mut [u8] {
+        &mut (self.0)[..]
+    }
+}
+
+impl From<[u8; 16]> for Uuid {
+    fn from(data: [u8; 16]) -> Self {
+        Self(Box::new(data))
+    }
+}
+
+impl From<Box<[u8; 16]>> for Uuid {
+    fn from(data: Box<[u8; 16]>) -> Self {
+        Self(data)
+    }
+}
+
+impl Into<[u8; 16]> for Uuid {
+    fn into(self) -> [u8; 16] {
+        *self.0
+    }
+}
+
+impl fmt::Display for Uuid {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::LowerHex::fmt(self, f)
+    }
+}
+
+impl fmt::LowerHex for Uuid {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let mut buf = [0u8; 37];
+        unsafe {
+            uuid_unparse_lower(self.as_bytes(), buf.as_mut_ptr());
+        }
+        write!(f, "{}", unsafe {
+            std::str::from_utf8_unchecked(&buf[..36])
+        })
+    }
+}
+
+impl fmt::UpperHex for Uuid {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let mut buf = [0u8; 37];
+        unsafe {
+            uuid_unparse_upper(self.as_bytes(), buf.as_mut_ptr());
+        }
+        write!(f, "{}", unsafe {
+            std::str::from_utf8_unchecked(&buf[..36])
+        })
+    }
+}
+
+impl std::str::FromStr for Uuid {
+    type Err = Error;
+
+    fn from_str(src: &str) -> Result<Self, Error> {
+        Self::parse_str(src)
+    }
+}