151 lines · 4.7 KB · Rust
RawDownload
use std::convert::TryFrom; use bstr::BStr; use crate::{immutable::object, tree}; /// A directory snapshot containing files (blobs), directories (trees) and submodules (commits).#[derive(PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone)]#[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]pub struct Tree<'a> {    /// The directories and files contained in this tree.    #[cfg_attr(feature = "serde1", serde(borrow))]    pub entries: Vec<Entry<'a>>,} /// A directory snapshot containing files (blobs), directories (trees) and submodules (commits), lazily evaluated.#[derive(PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone)]#[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]pub struct TreeIter<'a> {    /// The directories and files contained in this tree.    #[cfg_attr(feature = "serde1", serde(borrow))]    data: &'a [u8],} impl<'a> TreeIter<'a> {    /// Instantiate an iterator from the given tree data.    pub fn from_bytes(data: &'a [u8]) -> TreeIter<'a> {        TreeIter { data }    }} /// An element of a [`Tree`][Tree::entries].#[derive(PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone)]#[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]pub struct Entry<'a> {    /// The kind of object to which `oid` is pointing.    pub mode: tree::EntryMode,    /// The name of the file in the parent tree.    pub filename: &'a BStr,    /// The id of the object representing the entry.    #[cfg_attr(feature = "serde1", serde(borrow))]    pub oid: &'a git_hash::oid,} impl<'a> Tree<'a> {    /// Deserialize a Tree from `data`.    pub fn from_bytes(data: &'a [u8]) -> Result<Tree<'a>, object::decode::Error> {        decode::tree(data).map(|(_, t)| t).map_err(object::decode::Error::from)    }     /// Create an instance of the empty tree.    ///    /// It's particularly useful as static part of a program.    pub const fn empty() -> Tree<'static> {        Tree { entries: Vec::new() }    }} impl<'a> TreeIter<'a> {    /// Consume self and return all parsed entries.    pub fn entries(self) -> Result<Vec<Entry<'a>>, object::decode::Error> {        self.collect()    }} impl<'a> Default for TreeIter<'a> {    fn default() -> Self {        TreeIter { data: &[] }    }} impl<'a> Iterator for TreeIter<'a> {    type Item = Result<Entry<'a>, object::decode::Error>;     fn next(&mut self) -> Option<Self::Item> {        if self.data.is_empty() {            return None;        }        match decode::entry(self.data) {            Ok((data_left, entry)) => {                self.data = data_left;                Some(Ok(entry))            }            Err(err) => {                self.data = &[];                Some(Err(err.into()))            }        }    }} impl<'a> TryFrom<&'a [u8]> for tree::EntryMode {    type Error = &'a [u8];     fn try_from(mode: &'a [u8]) -> Result<Self, Self::Error> {        Ok(match mode {            b"40000" => tree::EntryMode::Tree,            b"100644" => tree::EntryMode::Blob,            b"100664" => tree::EntryMode::Blob, // rare and found in the linux kernel            b"100640" => tree::EntryMode::Blob, // rare and found in the Rust repo            b"100755" => tree::EntryMode::BlobExecutable,            b"120000" => tree::EntryMode::Link,            b"160000" => tree::EntryMode::Commit,            _ => return Err(mode),        })    }} mod decode {    use std::convert::TryFrom;     use bstr::ByteSlice;    use nom::{        bytes::complete::{tag, take, take_while1, take_while_m_n},        character::is_digit,        combinator::all_consuming,        error::ParseError,        multi::many0,        sequence::terminated,        IResult,    };     use crate::{        immutable::{parse::SPACE, tree::Entry, Tree},        tree,    };     const NULL: &[u8] = b"\0";     pub fn entry<'a, E: ParseError<&'a [u8]>>(i: &'a [u8]) -> IResult<&[u8], Entry<'_>, E> {        let (i, mode) = terminated(take_while_m_n(5, 6, is_digit), tag(SPACE))(i)?;        let mode = tree::EntryMode::try_from(mode)            .map_err(|invalid| nom::Err::Error(E::from_error_kind(invalid, nom::error::ErrorKind::MapRes)))?;        let (i, filename) = terminated(take_while1(|b| b != NULL[0]), tag(NULL))(i)?;        let (i, oid) = take(20u8)(i)?;         Ok((            i,            Entry {                mode,                filename: filename.as_bstr(),                oid: git_hash::oid::try_from(oid).expect("we counted exactly 20 bytes"),            },        ))    }     pub fn tree<'a, E: ParseError<&'a [u8]>>(i: &'a [u8]) -> IResult<&'a [u8], Tree<'a>, E> {        let (i, entries) = all_consuming(many0(entry))(i)?;        Ok((i, Tree { entries }))    }}