Mercurial > hg
view rust/hg-core/src/revlog/filelog.rs @ 47963:001d747c2baf
rust: Return HgError instead of RevlogError in revlog constructors
This leaves fewer cases for callers to handle, as RevlogError is more general
Differential Revision: https://phab.mercurial-scm.org/D11410
author | Simon Sapin <simon.sapin@octobus.net> |
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date | Mon, 13 Sep 2021 18:02:45 +0200 |
parents | 4d2a5ca060e3 |
children | 6f579618ea7b |
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use crate::errors::HgError; use crate::repo::Repo; use crate::revlog::path_encode::path_encode; use crate::revlog::revlog::{Revlog, RevlogError}; use crate::revlog::NodePrefix; use crate::revlog::Revision; use crate::utils::files::get_path_from_bytes; use crate::utils::hg_path::HgPath; use crate::utils::SliceExt; use std::borrow::Cow; use std::path::PathBuf; /// A specialized `Revlog` to work with file data logs. pub struct Filelog { /// The generic `revlog` format. revlog: Revlog, } impl Filelog { pub fn open(repo: &Repo, file_path: &HgPath) -> Result<Self, HgError> { let index_path = store_path(file_path, b".i"); let data_path = store_path(file_path, b".d"); let revlog = Revlog::open(repo, index_path, Some(&data_path))?; Ok(Self { revlog }) } /// The given node ID is that of the file as found in a manifest, not of a /// changeset. pub fn get_node( &self, file_node: impl Into<NodePrefix>, ) -> Result<FilelogEntry, RevlogError> { let file_rev = self.revlog.get_node_rev(file_node.into())?; self.get_rev(file_rev) } /// The given revision is that of the file as found in a manifest, not of a /// changeset. pub fn get_rev( &self, file_rev: Revision, ) -> Result<FilelogEntry, RevlogError> { let data = self.revlog.get_rev_data(file_rev)?; Ok(FilelogEntry(data.into())) } } 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() } pub struct FilelogEntry<'filelog>(Cow<'filelog, [u8]>); impl<'filelog> FilelogEntry<'filelog> { /// Split into metadata and data pub fn split(&self) -> Result<(Option<&[u8]>, &[u8]), HgError> { const DELIMITER: &[u8; 2] = &[b'\x01', b'\n']; if let Some(rest) = self.0.drop_prefix(DELIMITER) { if let Some((metadata, data)) = rest.split_2_by_slice(DELIMITER) { Ok((Some(metadata), data)) } else { Err(HgError::corrupted( "Missing metadata end delimiter in filelog entry", )) } } else { Ok((None, &self.0)) } } /// Returns the file contents at this revision, stripped of any metadata pub fn data(&self) -> Result<&[u8], HgError> { let (_metadata, data) = self.split()?; Ok(data) } }