1 files changed, 122 insertions, 0 deletions
diff --git a/vendor/gix-hash/src/kind.rs b/vendor/gix-hash/src/kind.rs
new file mode 100644
index 000000000..86faddda2
--- /dev/null
+++ b/vendor/gix-hash/src/kind.rs
@@ -0,0 +1,122 @@
+use std::{convert::TryFrom, str::FromStr};
+
+use crate::{oid, Kind, ObjectId};
+
+impl Default for Kind {
+    fn default() -> Self {
+        Kind::Sha1
+    }
+}
+
+impl TryFrom<u8> for Kind {
+    type Error = u8;
+
+    fn try_from(value: u8) -> Result<Self, Self::Error> {
+        Ok(match value {
+            1 => Kind::Sha1,
+            unknown => return Err(unknown),
+        })
+    }
+}
+
+impl FromStr for Kind {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(match s {
+            "sha1" | "SHA1" => Kind::Sha1,
+            other => return Err(other.into()),
+        })
+    }
+}
+
+impl std::fmt::Display for Kind {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Kind::Sha1 => f.write_str("SHA1"),
+        }
+    }
+}
+
+impl Kind {
+    /// Returns the shortest hash we support
+    #[inline]
+    pub const fn shortest() -> Self {
+        Self::Sha1
+    }
+
+    /// Returns the longest hash we support
+    #[inline]
+    pub const fn longest() -> Self {
+        Self::Sha1
+    }
+
+    /// Returns a buffer suitable to hold the longest possible hash in hex.
+    #[inline]
+    pub const fn hex_buf() -> [u8; Kind::longest().len_in_hex()] {
+        [0u8; Kind::longest().len_in_hex()]
+    }
+
+    /// Returns a buffer suitable to hold the longest possible hash as raw bytes.
+    #[inline]
+    pub const fn buf() -> [u8; Kind::longest().len_in_bytes()] {
+        [0u8; Kind::longest().len_in_bytes()]
+    }
+
+    /// Returns the amount of ascii-characters needed to encode this has in hex
+    #[inline]
+    pub const fn len_in_hex(&self) -> usize {
+        match self {
+            Kind::Sha1 => 40,
+        }
+    }
+    /// Returns the amount of bytes taken up by the hash of the current kind
+    #[inline]
+    pub const fn len_in_bytes(&self) -> usize {
+        match self {
+            Kind::Sha1 => 20,
+        }
+    }
+
+    /// Returns the kind of hash that would fit the given `hex_len`, or `None` if there is no fitting hash.
+    /// Note that 0 as `hex_len` fits always yields Sha1.
+    #[inline]
+    pub const fn from_hex_len(hex_len: usize) -> Option<Self> {
+        Some(match hex_len {
+            0..=40 => Kind::Sha1,
+            _ => return None,
+        })
+    }
+
+    /// Converts a size in bytes as obtained by `Kind::len_in_bytes()` into the corresponding hash kind, if possible.
+    ///
+    /// **Panics** if the hash length doesn't match a known hash.
+    ///
+    /// NOTE that this method isn't public as it shouldn't be encouraged to assume all hashes have the same length.
+    /// However, if there should be such a thing, our `oid` implementation will have to become an enum and it's pretty breaking
+    /// to the way it's currently being used as auto-dereffing doesn't work anymore. Let's hope it won't happen.
+    // TODO: make 'const' once Rust 1.57 is more readily available in projects using 'gitoxide'.
+    #[inline]
+    pub(crate) fn from_len_in_bytes(bytes: usize) -> Self {
+        match bytes {
+            20 => Kind::Sha1,
+            _ => panic!("BUG: must be called only with valid hash lengths produced by len_in_bytes()"),
+        }
+    }
+
+    /// Create a null-id of our hash kind.
+    #[inline]
+    pub fn null_ref(&self) -> &'static oid {
+        match self {
+            Kind::Sha1 => oid::null_sha1(),
+        }
+    }
+
+    /// Create a null-id of our hash kind.
+    #[inline]
+    pub const fn null(&self) -> ObjectId {
+        match self {
+            Kind::Sha1 => ObjectId::null_sha1(),
+        }
+    }
+}