Mercurial > hg
view rust/hg-core/src/operations/cat.rs @ 46431:645ee7225fab
rust: Make NodePrefix allocation-free and Copy, remove NodePrefixRef
The `*Ref` struct only existed to avoid allocating `Vec`s
when cloning `NodePrefix`, but we can avoid having `Vec`
in the first place by using an inline array instead.
This makes `NodePrefix` 21 bytes (with 1 for the length)
which is smaller than before as `Vec` alone is 24 bytes.
Differential Revision: https://phab.mercurial-scm.org/D9863
author | Simon Sapin <simon.sapin@octobus.net> |
---|---|
date | Mon, 25 Jan 2021 11:48:47 +0100 |
parents | 8a4914397d02 |
children | 4b381dbbf8b7 |
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// list_tracked_files.rs // // Copyright 2020 Antoine Cezar <antoine.cezar@octobus.net> // // This software may be used and distributed according to the terms of the // GNU General Public License version 2 or any later version. use std::convert::From; use std::path::PathBuf; use crate::repo::Repo; use crate::revlog::changelog::Changelog; use crate::revlog::manifest::Manifest; use crate::revlog::path_encode::path_encode; use crate::revlog::revlog::Revlog; use crate::revlog::revlog::RevlogError; use crate::revlog::Node; use crate::revlog::NodePrefix; use crate::revlog::Revision; use crate::utils::files::get_path_from_bytes; use crate::utils::hg_path::{HgPath, HgPathBuf}; const METADATA_DELIMITER: [u8; 2] = [b'\x01', b'\n']; /// Kind of error encountered by `CatRev` #[derive(Debug)] pub enum CatRevErrorKind { /// Error when reading a `revlog` file. IoError(std::io::Error), /// The revision has not been found. InvalidRevision, /// Found more than one revision whose ID match the requested prefix AmbiguousPrefix, /// A `revlog` file is corrupted. CorruptedRevlog, /// The `revlog` format version is not supported. UnsuportedRevlogVersion(u16), /// The `revlog` data format is not supported. UnknowRevlogDataFormat(u8), } /// A `CatRev` error #[derive(Debug)] pub struct CatRevError { /// Kind of error encountered by `CatRev` pub kind: CatRevErrorKind, } impl From<CatRevErrorKind> for CatRevError { fn from(kind: CatRevErrorKind) -> Self { CatRevError { kind } } } impl From<RevlogError> for CatRevError { fn from(err: RevlogError) -> Self { match err { RevlogError::IoError(err) => CatRevErrorKind::IoError(err), RevlogError::UnsuportedVersion(version) => { CatRevErrorKind::UnsuportedRevlogVersion(version) } RevlogError::InvalidRevision => CatRevErrorKind::InvalidRevision, RevlogError::AmbiguousPrefix => CatRevErrorKind::AmbiguousPrefix, RevlogError::Corrupted => CatRevErrorKind::CorruptedRevlog, RevlogError::UnknowDataFormat(format) => { CatRevErrorKind::UnknowRevlogDataFormat(format) } } .into() } } /// List files under Mercurial control at a given revision. /// /// * `root`: Repository root /// * `rev`: The revision to cat the files from. /// * `files`: The files to output. pub fn cat( repo: &Repo, rev: &str, files: &[HgPathBuf], ) -> Result<Vec<u8>, CatRevError> { let changelog = Changelog::open(repo)?; let manifest = Manifest::open(repo)?; let changelog_entry = match rev.parse::<Revision>() { Ok(rev) => changelog.get_rev(rev)?, _ => { let changelog_node = NodePrefix::from_hex(&rev) .map_err(|_| CatRevErrorKind::InvalidRevision)?; changelog.get_node(changelog_node)? } }; let manifest_node = Node::from_hex(&changelog_entry.manifest_node()?) .map_err(|_| CatRevErrorKind::CorruptedRevlog)?; let manifest_entry = manifest.get_node(manifest_node.into())?; let mut bytes = vec![]; for (manifest_file, node_bytes) in manifest_entry.files_with_nodes() { for cat_file in files.iter() { if cat_file.as_bytes() == manifest_file.as_bytes() { let index_path = store_path(manifest_file, b".i"); let data_path = store_path(manifest_file, b".d"); let file_log = Revlog::open(repo, &index_path, Some(&data_path))?; let file_node = Node::from_hex(node_bytes) .map_err(|_| CatRevErrorKind::CorruptedRevlog)?; let file_rev = file_log.get_node_rev(file_node.into())?; let data = file_log.get_rev_data(file_rev)?; if data.starts_with(&METADATA_DELIMITER) { let end_delimiter_position = data [METADATA_DELIMITER.len()..] .windows(METADATA_DELIMITER.len()) .position(|bytes| bytes == METADATA_DELIMITER); if let Some(position) = end_delimiter_position { let offset = METADATA_DELIMITER.len() * 2; bytes.extend(data[position + offset..].iter()); } } else { bytes.extend(data); } } } } Ok(bytes) } fn store_path(hg_path: &HgPath, suffix: &[u8]) -> PathBuf { let encoded_bytes = path_encode(&[b"data/", hg_path.as_bytes(), suffix].concat()); get_path_from_bytes(&encoded_bytes).into() }