Mercurial > hg
view rust/hg-core/src/revlog/changelog.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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use crate::repo::Repo; use crate::revlog::revlog::{Revlog, RevlogError}; use crate::revlog::NodePrefix; use crate::revlog::Revision; /// A specialized `Revlog` to work with `changelog` data format. pub struct Changelog { /// The generic `revlog` format. revlog: Revlog, } impl Changelog { /// Open the `changelog` of a repository given by its root. pub fn open(repo: &Repo) -> Result<Self, RevlogError> { let revlog = Revlog::open(repo, "00changelog.i", None)?; Ok(Self { revlog }) } /// Return the `ChangelogEntry` a given node id. pub fn get_node( &self, node: NodePrefix, ) -> Result<ChangelogEntry, RevlogError> { let rev = self.revlog.get_node_rev(node)?; self.get_rev(rev) } /// Return the `ChangelogEntry` of a given node revision. pub fn get_rev( &self, rev: Revision, ) -> Result<ChangelogEntry, RevlogError> { let bytes = self.revlog.get_rev_data(rev)?; Ok(ChangelogEntry { bytes }) } } /// `Changelog` entry which knows how to interpret the `changelog` data bytes. #[derive(Debug)] pub struct ChangelogEntry { /// The data bytes of the `changelog` entry. bytes: Vec<u8>, } impl ChangelogEntry { /// Return an iterator over the lines of the entry. pub fn lines(&self) -> impl Iterator<Item = &[u8]> { self.bytes .split(|b| b == &b'\n') .filter(|line| !line.is_empty()) } /// Return the node id of the `manifest` referenced by this `changelog` /// entry. pub fn manifest_node(&self) -> Result<&[u8], RevlogError> { self.lines().next().ok_or(RevlogError::Corrupted) } }