Complete lib

Cargo.toml

@@ -7,3 +7,4 @@ edition = "2021"
 
 [dependencies]
 getrandom = "0.2.10"
+serde = "1.0.188"

src/error.rs

@@ -0,0 +1,102 @@
+use std::fmt::{Display, Formatter};
+use std::str;
+
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
+pub struct Error(pub(crate) ErrorKind);
+
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
+pub(crate) enum ErrorKind {
+    ByteLength { len: usize },
+    Char { character: char, index: usize },
+    GroupCount { count: usize },
+    GroupLength { group: usize, len: usize, index: usize },
+    InvalidUtf8,
+}
+
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
+pub struct InvalidUuid<'a>(pub(crate) &'a [u8]);
+
+impl<'a> InvalidUuid<'a> {
+    pub fn into_err(self) -> Error {
+        // Check if the string is valid UTF-8
+        let uuid_str = match str::from_utf8(self.0) {
+            Ok(s) => s,
+            Err(_) => return Error(ErrorKind::InvalidUtf8)
+        };
+
+        let mut hyphen_count = 0;
+        let mut group_bounds = [0; 4];
+
+        let uuid_str = unsafe { str::from_utf8_unchecked(uuid_str.as_bytes()) };
+
+        for (index, character) in uuid_str.char_indices() {
+            let byte = character as u8;
+            if character as u32 - byte as u32 > 0 {
+                // The char is more than one byte
+                return Error(ErrorKind::Char {
+                    character,
+                    index: index + 1,
+                });
+            } else if byte == b'-' {
+                // Search for the groups bounds
+                if hyphen_count < 4 {
+                    group_bounds[hyphen_count] = index;
+                }
+                hyphen_count += 1;
+            } else if !matches!(byte, b'0'..=b'9' | b'a'..=b'f' | b'A'..=b'F') {
+                // Non hex char
+                return Error(ErrorKind::Char {
+                    character,
+                    index: index + 1,
+                });
+            }
+        }
+
+        if hyphen_count != 4 {
+            // There is more or less than 5 groups
+            Error(ErrorKind::GroupCount {
+                count: hyphen_count + 1
+            })
+        } else {
+            // One of the groups as an invalid length
+            const BLOCK_STARTS: [usize; 5] = [0, 9, 14, 19, 24];
+            for i in 0..4 {
+                if group_bounds[i] != BLOCK_STARTS[i + 1] - 1 {
+                    return Error(ErrorKind::GroupLength {
+                        group: i,
+                        len: group_bounds[i] - BLOCK_STARTS[i],
+                        index: BLOCK_STARTS[i] + 1,
+                    });
+                }
+            }
+
+            // The last group is too long
+            Error(ErrorKind::GroupLength {
+                group: 4,
+                len: uuid_str.len() - BLOCK_STARTS[4],
+                index: BLOCK_STARTS[4] + 1,
+            })
+        }
+    }
+}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        match self.0 {
+            ErrorKind::ByteLength { len } => {
+                write!(f, "invalid length: expected 16 bytes, found {}", len)
+            }
+            ErrorKind::Char { character, index, .. } => {
+                write!(f, "invalid character: expected a sequence of [0-9a-fA-F-], found `{}` at {}", character, index)
+            }
+            ErrorKind::GroupCount { count } => {
+                write!(f, "invalid group count: expected 5, found {}", count)
+            }
+            ErrorKind::GroupLength { group, len, .. } => {
+                let expected = [8, 4, 4, 4, 12][group];
+                write!(f, "invalid group length in group {}: epected {}, found {}", group, expected, len)
+            }
+            ErrorKind::InvalidUtf8 => write!(f, "non UTF-8 input"),
+        }
+    }
+}

src/fmt.rs

@@ -0,0 +1,75 @@
+use std::{ptr, str};
+use std::fmt::{Formatter, LowerHex, UpperHex};
+use crate::{Uuid};
+
+pub const UUID_STR_LEN: usize = 36;
+const LOWER_LUT: [u8; 16] = [
+    b'0', b'1', b'2', b'3', b'4', b'5', b'6', b'7', b'8', b'9', b'a', b'b', b'c', b'd', b'e', b'f'
+];
+const UPPER_LUT: [u8; 16] = [
+    b'0', b'1', b'2', b'3', b'4', b'5', b'6', b'7', b'8', b'9', b'A', b'B', b'C', b'D', b'E', b'F'
+];
+const GROUPS: [(usize, usize); 5] = [
+    (0, 8), (9, 13), (14, 18), (19, 23), (24, 36)
+];
+
+impl LowerHex for Uuid {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        f.write_str(encode(self.as_bytes(), &mut [0; UUID_STR_LEN], false))
+    }
+}
+
+impl UpperHex for Uuid {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        f.write_str(encode(self.as_bytes(), &mut [0; UUID_STR_LEN], true))
+    }
+}
+
+impl Uuid {
+    #[inline]
+    pub fn encode_lower<'buf>(&self, buffer: &'buf mut [u8]) -> &'buf mut str {
+        encode(self.as_bytes(), buffer, false)
+    }
+
+    #[inline]
+    pub fn encode_upper<'buf>(&self, buffer: &'buf mut [u8]) -> &'buf mut str {
+        encode(self.as_bytes(), buffer, true)
+    }
+}
+
+pub(crate) fn encode<'a>(data: &[u8], buffer: &'a mut [u8], upper: bool) -> &'a mut str {
+    let buf = &mut buffer[..UUID_STR_LEN];
+    let dst = buf.as_mut_ptr();
+
+    unsafe {
+        ptr::write(dst.cast(), format(data, upper));
+        str::from_utf8_unchecked_mut(buf)
+    }
+}
+
+fn format(data: &[u8], upper: bool) -> [u8; UUID_STR_LEN] {
+    let lut = if upper { UPPER_LUT } else { LOWER_LUT };
+
+    let mut dst = [0u8; UUID_STR_LEN];
+    let mut i = 0;
+
+    for j in 0..GROUPS.len() {
+        let (start, end) = GROUPS[j];
+
+        let mut k = start;
+        while k < end {
+            let x = data[i];
+            i += 1;
+
+            dst[k] = lut[(x >> 4) as usize];
+            dst[k + 1] = lut[(x & 0x0f) as usize];
+            k += 2;
+        }
+
+        if j < GROUPS.len() - 1 {
+            dst[end] = b'-';
+        }
+    }
+
+    dst
+}

src/lib.rs

@@ -1,8 +1,20 @@
-pub mod v4;
+use crate::error::{Error, ErrorKind};
+
+// UUID (RFC 4122) v4 implementation
+// Heavily based on the 'uuid' crate: https://docs.rs/uuid/latest/uuid/
+
+mod error;
+mod parse;
 mod rng;
 
-pub(crate) type Bytes = [u8; 16];
+pub mod fmt;
+pub mod serde;
+pub mod v4;
 
+pub type Bytes = [u8; 16];
+
+#[derive(Clone, Copy, Eq, Hash, Ord, PartialEq, PartialOrd)]
+#[repr(transparent)]
 pub struct Uuid(Bytes);
 
 #[derive(Clone, Copy, Debug, PartialEq)]
@@ -15,6 +27,7 @@ pub enum Variant {
 }
 
 #[derive(Clone, Copy, Debug, PartialEq)]
+#[non_exhaustive]
 #[repr(u8)]
 pub enum Version {
     Nil = 0,
@@ -23,25 +36,26 @@ pub enum Version {
     MD5 = 3,
     Random = 4,
     SHA1 = 5,
-    Unknown = u8::MAX
+    Unknown = u8::MAX,
 }
 
 impl Uuid {
-    pub fn new(version: Version) -> Self {
-        match version {
-            Version::Nil => Self::new_nil(),
-            Version::Random => Self::new_random(),
-            _ => panic!("Unsupported UUID version: {:?}", version)
-        }
-    }
-
     pub fn new_nil() -> Self {
         Uuid(Uuid::nil_bytes())
     }
 
-    #[inline]
-    pub const fn as_bytes(&self) -> &[u8] {
-        &self.0
+    pub fn from_bytes(bytes: Bytes) -> Self {
+        Uuid(bytes)
+    }
+
+    pub fn from_slice(b: &[u8]) -> Result<Uuid, Error> {
+        if b.len() != 16 {
+            return Err(Error(ErrorKind::ByteLength { len: b.len() }));
+        }
+
+        let mut bytes: Bytes = Uuid::nil_bytes();
+        bytes.copy_from_slice(b);
+        Ok(Uuid::from_bytes(bytes))
     }
 
     pub const fn get_variant(&self) -> Variant {
@@ -69,6 +83,28 @@ impl Uuid {
         }
     }
 
+    pub const fn as_u128(&self) -> u128 {
+        u128::from_be_bytes(*self.as_bytes())
+    }
+
+    #[inline]
+    pub const fn as_bytes(&self) -> &Bytes {
+        &self.0
+    }
+
+    #[inline]
+    pub const fn into_bytes(self) -> Bytes {
+        self.0
+    }
+
+    pub const fn is_nil(&self) -> bool {
+        self.as_u128() == u128::MIN
+    }
+
+    pub const fn encode_buffer() -> [u8; fmt::UUID_STR_LEN] {
+        [0; fmt::UUID_STR_LEN]
+    }
+
     #[inline]
     const fn nil_bytes() -> Bytes {
         [0u8; 16]
@@ -79,12 +115,15 @@ impl Uuid {
         let variant = variant as u8;
         let byte = bytes[8] & 0xf;
 
-        bytes[8] = variant & byte;
+        bytes[8] = variant | byte;
     }
 
     #[inline]
     fn set_version(bytes: &mut Bytes, version: Version) {
-        bytes[6] |= (version as u8) << 4;
+        let version = (version as u8) << 4;
+        let byte = bytes[6] & 0xf;
+
+        bytes[6] = version | byte;
     }
 }
 
@@ -94,8 +133,15 @@ impl Default for Uuid {
     }
 }
 
-// impl AsRef<Bytes> for Uuid {
-//     fn as_ref(&self) -> &Bytes {
-//         &self.0
-//     }
-// }
+impl AsRef<[u8]> for Uuid {
+    #[inline]
+    fn as_ref(&self) -> &[u8] {
+        &self.0
+    }
+}
+
+impl ToString for Uuid {
+    fn to_string(&self) -> String {
+        format!("{:02x}", self)
+    }
+}

src/parse.rs

@@ -0,0 +1,121 @@
+use std::str::FromStr;
+use crate::error::{Error, InvalidUuid};
+use crate::Uuid;
+
+impl FromStr for Uuid {
+    type Err = Error;
+
+    fn from_str(value: &str) -> Result<Self, Self::Err> {
+        Uuid::parse_str(value)
+    }
+}
+
+impl TryFrom<&'_ str> for Uuid {
+    type Error = Error;
+
+    fn try_from(value: &'_ str) -> Result<Self, Self::Error> {
+        Uuid::parse_str(value)
+    }
+}
+
+impl Uuid {
+    pub fn parse_str(value: &str) -> Result<Self, Error> {
+        try_parse(value.as_bytes())
+            .map(Uuid::from_bytes)
+            .map_err(InvalidUuid::into_err)
+    }
+}
+
+const fn try_parse(input: &[u8]) -> Result<[u8; 16], InvalidUuid> {
+    let result = match (input.len(), input) {
+        (36, s) => parse(s),
+        _ => Err(())
+    };
+
+    match result {
+        Ok(b) => Ok(b),
+        Err(()) => Err(InvalidUuid(input))
+    }
+}
+
+const fn parse(s: &[u8]) -> Result<[u8; 16], ()> {
+    if s.len() != 36 {
+        return Err(());
+    }
+
+    // Checks that the string looks like a valid UUID
+    match [s[8], s[13], s[18], s[23]] {
+        [b'-', b'-', b'-', b'-'] => {}
+        _ => return Err(())
+    }
+
+    let positions: [u8; 8] = [0, 4, 9, 14, 19, 24, 28, 32];
+    let mut buf: [u8; 16] = [0; 16];
+    let mut j = 0;
+
+    while j < 8 {
+        let i = positions[j];
+
+        let h1 = HEX_TABLE[s[i as usize] as usize];
+        let h2 = HEX_TABLE[s[(i + 1) as usize] as usize];
+        let h3 = HEX_TABLE[s[(i + 2) as usize] as usize];
+        let h4 = HEX_TABLE[s[(i + 3) as usize] as usize];
+
+        if h1 | h2 | h3 | h4 == 0xff {
+            return Err(());
+        }
+
+        buf[j * 2] = SHL4_TABLE[h1 as usize] | h2;
+        buf[j * 2 + 1] = SHL4_TABLE[h3 as usize] | h4;
+        j += 1;
+    }
+
+    Ok(buf)
+}
+
+const HEX_TABLE: &[u8; 256] = &{
+    let mut buf = [0u8; 256];
+    let mut i = 0u8;
+
+    loop {
+        buf[i as usize] = match i {
+            b'0'..=b'9' => i - b'0',
+            b'a'..=b'f' => i - b'a' + 10,
+            b'A'..=b'F' => i - b'A' + 10,
+            _ => 0xff
+        };
+
+        if i == 255 {
+            break buf;
+        }
+
+        i += 1
+    }
+};
+
+// Shift left 4 bits lookup table
+const SHL4_TABLE: &[u8; 256] = &{
+    let mut buf = [0u8; 256];
+    let mut i = 0u8;
+
+    loop {
+        buf[i as usize] = i.wrapping_shl(4);
+
+        if i == 255 {
+            break buf;
+        }
+
+        i += 1;
+    }
+};
+
+#[cfg(test)]
+mod tests {
+    use crate::Uuid;
+
+    #[test]
+    fn test_parse_uuid_v4() {
+        let uuid = Uuid::parse_str("67e55044-10b1-426f-9247-bb680e5fe0c8").unwrap();
+        print!("var: {:?}, ver: {:?}, uuid: {}", uuid.get_variant(), uuid.get_version(), uuid.to_string());
+    }
+}

src/serde.rs

@@ -0,0 +1,84 @@
+use std::fmt::{Formatter};
+use serde::{de::{self, Error as _}, Deserialize, Deserializer, Serialize, Serializer};
+use serde::de::SeqAccess;
+use crate::{error::*, Uuid};
+
+impl Serialize for Uuid {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer {
+        if serializer.is_human_readable() {
+            serializer.serialize_str(self.encode_lower(&mut Uuid::encode_buffer()))
+        } else {
+            serializer.serialize_bytes(self.as_bytes())
+        }
+    }
+}
+
+impl<'de> Deserialize<'de> for Uuid {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where D: Deserializer<'de> {
+        fn de_error<E: de::Error>(e: Error) -> E {
+            E::custom(format_args!("UUID parsing failed: {}", e))
+        }
+
+        if deserializer.is_human_readable() {
+            struct UuidVisitor;
+
+            impl<'vi> de::Visitor<'vi> for UuidVisitor {
+                type Value = Uuid;
+
+                fn expecting(&self, formatter: &mut Formatter) -> std::fmt::Result {
+                    write!(formatter, "a UUID string")
+                }
+
+                fn visit_str<E>(self, value: &str) -> Result<Self::Value, E> where E: de::Error {
+                   value.parse::<Uuid>().map_err(de_error)
+                }
+
+                fn visit_bytes<E>(self, value: &[u8]) -> Result<Self::Value, E> where E: de::Error {
+                    Uuid::from_slice(value).map_err(de_error)
+                }
+
+                fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error> where A: SeqAccess<'vi> {
+                    #[rustfmt::skip]
+                    let bytes = [
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) },
+                        match seq.next_element()? { Some(e) => e, None => return Err(A::Error::invalid_length(16, &self)) }
+                    ];
+
+                    Ok(Uuid::from_bytes(bytes))
+                }
+            }
+
+            deserializer.deserialize_str(UuidVisitor)
+        } else {
+            struct UuidBytesVisitor;
+
+            impl<'vi> de::Visitor<'vi> for UuidBytesVisitor {
+                type Value = Uuid;
+
+                fn expecting(&self, formatter: &mut Formatter) -> std::fmt::Result {
+                    write!(formatter, "bytes")
+                }
+
+                fn visit_bytes<E>(self, value: &[u8]) -> Result<Self::Value, E> where E: de::Error {
+                    Uuid::from_slice(value).map_err(de_error)
+                }
+            }
+
+            deserializer.deserialize_bytes(UuidBytesVisitor)
+        }
+    }
+}

src/v4.rs

@@ -19,10 +19,24 @@ impl Uuid {
 
 #[cfg(test)]
 mod tests {
-    use crate::{Uuid, Variant};
+    use crate::{Uuid, Variant, Version};
 
     #[test]
-    fn new_v4__variant() {
+    fn test_new_v4_version() {
+        let uuid = Uuid::new_v4();
+
+        assert_eq!(uuid.get_version(), Version::Random);
+    }
+
+    #[test]
+    fn test_new_v4_version_num() {
+        let uuid = Uuid::new_v4();
+
+        assert_eq!(uuid.get_version_num(), 4);
+    }
+
+    #[test]
+    fn test_new_v4_variant() {
         let uuid = Uuid::new_v4();
 
         assert_eq!(uuid.get_variant(), Variant::Default);