crates/kernel/ents-anchor/src/util.rs
util.rshistorycomment on this file
| 1 | //! Small `gix` plumbing helpers shared by [`crate::capture`] and |
| 2 | //! [`crate::project`]/[`crate::project_exact`]/[`crate::project_from_context`]. |
| 3 | //! |
| 4 | //! Nothing here is public API; each function is a thin, single-purpose |
| 5 | //! wrapper over a `gix::Repository` lookup, kept out of the call sites that |
| 6 | //! use it so the projection and capture logic reads as policy rather than |
| 7 | //! plumbing. |
| 8 | |
| 9 | use gix::ObjectId; |
| 10 | use gix::bstr::ByteSlice as _; |
| 11 | |
| 12 | use crate::error::{Error, Result}; |
| 13 | |
| 14 | /// Resolve `revision` (a hex id, ref name, or revspec) to the commit it |
| 15 | /// names in `repo`. |
| 16 | pub(crate) fn resolve_commit<'repo>( |
| 17 | repo: &'repo gix::Repository, |
| 18 | revision: &str, |
| 19 | ) -> Result<gix::Commit<'repo>> { |
| 20 | let resolve = || Error::Resolve(revision.to_owned()); |
| 21 | repo.rev_parse_single(revision) |
| 22 | .map_err(|_error| resolve())? |
| 23 | .object() |
| 24 | .map_err(|_error| resolve())? |
| 25 | .peel_to_kind(gix::object::Kind::Commit) |
| 26 | .map_err(|_error| resolve())? |
| 27 | .try_into_commit() |
| 28 | .map_err(|_error| resolve()) |
| 29 | } |
| 30 | |
| 31 | /// Look up the commit `id` names directly, with no revision parsing — for an |
| 32 | /// [`crate::Anchor`]'s own recorded commit, which already names a concrete |
| 33 | /// object rather than an arbitrary revision. |
| 34 | pub(crate) fn commit_at(repo: &gix::Repository, id: ObjectId) -> Result<gix::Commit<'_>> { |
| 35 | let resolve = || Error::Resolve(id.to_string()); |
| 36 | repo.find_object(id) |
| 37 | .map_err(|_error| resolve())? |
| 38 | .peel_to_kind(gix::object::Kind::Commit) |
| 39 | .map_err(|_error| resolve())? |
| 40 | .try_into_commit() |
| 41 | .map_err(|_error| resolve()) |
| 42 | } |
| 43 | |
| 44 | /// Read the full contents of the blob at `id`. |
| 45 | pub(crate) fn read_blob(repo: &gix::Repository, id: ObjectId) -> Result<Vec<u8>> { |
| 46 | Ok(repo |
| 47 | .find_blob(id) |
| 48 | .map_err(|error| Error::Object(error.to_string()))? |
| 49 | .take_data()) |
| 50 | } |
| 51 | |
| 52 | /// The text of the 1-based inclusive `range` within `data`, or |
| 53 | /// [`Error::LinesOutOfRange`] (naming `path`) when the range does not fit. |
| 54 | pub(crate) fn lines_of(data: &[u8], path: &str, range: crate::LineRange) -> Result<String> { |
| 55 | let all: Vec<&[u8]> = data.lines_with_terminator().collect(); |
| 56 | let out_of_range = || Error::LinesOutOfRange { |
| 57 | path: path.to_owned(), |
| 58 | start: range.start, |
| 59 | end: range.end, |
| 60 | len: u64::try_from(all.len()).unwrap_or(u64::MAX), |
| 61 | }; |
| 62 | // One slice lookup validates the whole range: start == 0 dies in |
| 63 | // checked_sub, an inverted or oversized range dies in get. |
| 64 | let first = usize::try_from(range.start) |
| 65 | .ok() |
| 66 | .and_then(|start| start.checked_sub(1)) |
| 67 | .ok_or_else(out_of_range)?; |
| 68 | let last = usize::try_from(range.end).ok().ok_or_else(out_of_range)?; |
| 69 | let bytes = all.get(first..last).ok_or_else(out_of_range)?.concat(); |
| 70 | Ok(String::from_utf8_lossy(&bytes).into_owned()) |
| 71 | } |