//! This crate provides types for identifying git objects using a hash digest.//!//! These are provided in borrowed versions as well as owned ones.//! ## Feature Flags#![cfg_attr( feature = "document-features", cfg_attr(doc, doc = ::document_features::document_features!()))]#![cfg_attr(docsrs, feature(doc_cfg, doc_auto_cfg))]#![deny(missing_docs, rust_2018_idioms, unsafe_code)] mod borrowed; use std::{convert::TryFrom, str::FromStr}; pub use borrowed::oid; mod owned;pub use owned::{prefix, ObjectId, Prefix}; #[allow(missing_docs)]pub mod decode { use std::str::FromStr; use quick_error::quick_error; use crate::owned::ObjectId; quick_error! { /// An error returned by [`ObjectId::from_40_bytes_in_hex()`] #[derive(Debug)] #[allow(missing_docs)] pub enum Error { InvalidHexEncodingLength(length: usize) { display("A hash sized {} hexadecimal characters is invalid", length) } } } /// Hash decoding impl ObjectId { /// Create an instance from a `buffer` of 40 bytes encoded with hexadecimal notation. /// /// Such a buffer can be obtained using [`oid::write_hex_to(buffer)`][super::oid::write_hex_to()] pub fn from_hex(buffer: &[u8]) -> Result<ObjectId, Error> { use hex::FromHex; match buffer.len() { 40 => Ok(ObjectId::Sha1( <[u8; 20]>::from_hex(buffer).expect("our length check is correct thus we can decode hex"), )), len => Err(Error::InvalidHexEncodingLength(len)), } } } impl FromStr for ObjectId { type Err = Error; fn from_str(s: &str) -> Result<Self, Self::Err> { Self::from_hex(s.as_bytes()) } }} /// The size of a SHA1 hash digest in bytesconst SIZE_OF_SHA1_DIGEST: usize = 20; /// Denotes the kind of function to produce a `Id`#[derive(PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone, Copy)]#[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]pub enum Kind { /// The Sha1 hash with 160 bits. Sha1 = 1,} 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(), } }}
//! This crate provides types for identifying git objects using a hash digest.
//!
//! These are provided in borrowed versions as well as owned ones.
//! ## Feature Flags
#![cfg_attr(
feature = "document-features",
cfg_attr(doc, doc = ::document_features::document_features!())
)]
#![cfg_attr(docsrs, feature(doc_cfg, doc_auto_cfg))]
#![deny(missing_docs, rust_2018_idioms, unsafe_code)]
mod borrowed;
use std::{convert::TryFrom, str::FromStr};
pub use borrowed::oid;
mod owned;
pub use owned::{prefix, ObjectId, Prefix};
#[allow(missing_docs)]
pub mod decode {
use std::str::FromStr;
use quick_error::quick_error;
use crate::owned::ObjectId;
quick_error! {
/// An error returned by [`ObjectId::from_40_bytes_in_hex()`]
#[derive(Debug)]
#[allow(missing_docs)]
pub enum Error {
InvalidHexEncodingLength(length: usize) {
display("A hash sized {} hexadecimal characters is invalid", length)
}
}
}
/// Hash decoding
impl ObjectId {
/// Create an instance from a `buffer` of 40 bytes encoded with hexadecimal notation.
///
/// Such a buffer can be obtained using [`oid::write_hex_to(buffer)`][super::oid::write_hex_to()]
pub fn from_hex(buffer: &[u8]) -> Result<ObjectId, Error> {
use hex::FromHex;
match buffer.len() {
40 => Ok(ObjectId::Sha1(
<[u8; 20]>::from_hex(buffer).expect("our length check is correct thus we can decode hex"),
)),
len => Err(Error::InvalidHexEncodingLength(len)),
}
}
}
impl FromStr for ObjectId {
type Err = Error;
fn from_str(s: &str) -> Result<Self, Self::Err> {
Self::from_hex(s.as_bytes())
}
}
}
/// The size of a SHA1 hash digest in bytes
const SIZE_OF_SHA1_DIGEST: usize = 20;
/// Denotes the kind of function to produce a `Id`
#[derive(PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone, Copy)]
#[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]
pub enum Kind {
/// The Sha1 hash with 160 bits.
Sha1 = 1,
}
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(),
}
}
}