rust/hg-core/src/operations/cat.rs
author Mads Kiilerich <mads@kiilerich.com>
Mon, 11 Jul 2022 22:47:56 +0200
branchstable
changeset 49416 1bad05cfc818
parent 48540 20d0d896183e
child 49925 49131579db62
permissions -rw-r--r--
rust: bump to memmap2 0.5.3, micro-timer 0.4.0, and crossbeam-channel 0.5.0 The merge in 12adf8c695ed had conflicts in rust/Cargo.lock and rust/hg-core/Cargo.toml . Let's ignore rust/Cargo.lock - it is regenerated. For rust/hg-core/Cargo.toml, stable had dd6b67d5c256 "rust: fix unsound `OwningDirstateMap`" which introduced ouroboros (and dropped stable_deref_trait). Default had ec8d9b5a5e7c "rust-hg-core: upgrade dependencies" which had a lot of churn bumping minimum versions - also patch versions. It is indeed a good idea to bump to *allow* use of latest package. That means that major versions should be bumped for packages after 1.0, and for packages below 1.0 minor versions should be bumped too. But it doesn't work to try enforce a policy of using latest patch by bumping versions at arbitrary times. For good or bad, the merge doesn't seem to have resolved the conflicts correctly, and many of the minor "upgrade dependencies" were lost again. Unfortunately, it also lost the bump of memmap2 to 0.5.3, which is needed for Fedora packaging where 0.4 isn't available. Same with micro-timer bump to 0.4 (which already is used in rhg). crossbeam-channel bump was also lost. This change fixes that regression by redoing these "important" lines of the merge "correctly". I propose this for stable, even though dependency changes on stable branches are annoying.

// 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 crate::repo::Repo;
use crate::revlog::revlog::RevlogError;
use crate::revlog::Node;

use crate::utils::hg_path::HgPath;

use crate::errors::HgError;
use crate::manifest::Manifest;
use crate::manifest::ManifestEntry;
use itertools::put_back;
use itertools::PutBack;
use std::cmp::Ordering;

pub struct CatOutput<'a> {
    /// Whether any file in the manifest matched the paths given as CLI
    /// arguments
    pub found_any: bool,
    /// The contents of matching files, in manifest order
    pub results: Vec<(&'a HgPath, Vec<u8>)>,
    /// Which of the CLI arguments did not match any manifest file
    pub missing: Vec<&'a HgPath>,
    /// The node ID that the given revset was resolved to
    pub node: Node,
}

// Find an item in an iterator over a sorted collection.
fn find_item<'a>(
    i: &mut PutBack<impl Iterator<Item = Result<ManifestEntry<'a>, HgError>>>,
    needle: &HgPath,
) -> Result<Option<Node>, HgError> {
    loop {
        match i.next() {
            None => return Ok(None),
            Some(result) => {
                let entry = result?;
                match needle.as_bytes().cmp(entry.path.as_bytes()) {
                    Ordering::Less => {
                        i.put_back(Ok(entry));
                        return Ok(None);
                    }
                    Ordering::Greater => continue,
                    Ordering::Equal => return Ok(Some(entry.node_id()?)),
                }
            }
        }
    }
}

fn find_files_in_manifest<'query>(
    manifest: &Manifest,
    query: impl Iterator<Item = &'query HgPath>,
) -> Result<(Vec<(&'query HgPath, Node)>, Vec<&'query HgPath>), HgError> {
    let mut manifest = put_back(manifest.iter());
    let mut res = vec![];
    let mut missing = vec![];

    for file in query {
        match find_item(&mut manifest, file)? {
            None => missing.push(file),
            Some(item) => res.push((file, item)),
        }
    }
    return Ok((res, missing));
}

/// Output the given revision of files
///
/// * `root`: Repository root
/// * `rev`: The revision to cat the files from.
/// * `files`: The files to output.
pub fn cat<'a>(
    repo: &Repo,
    revset: &str,
    mut files: Vec<&'a HgPath>,
) -> Result<CatOutput<'a>, RevlogError> {
    let rev = crate::revset::resolve_single(revset, repo)?;
    let manifest = repo.manifest_for_rev(rev)?;
    let node = *repo
        .changelog()?
        .node_from_rev(rev)
        .expect("should succeed when repo.manifest did");
    let mut results: Vec<(&'a HgPath, Vec<u8>)> = vec![];
    let mut found_any = false;

    files.sort_unstable();

    let (found, missing) = find_files_in_manifest(
        &manifest,
        files.into_iter().map(|f| f.as_ref()),
    )?;

    for (file_path, file_node) in found {
        found_any = true;
        let file_log = repo.filelog(file_path)?;
        results.push((
            file_path,
            file_log.data_for_node(file_node)?.into_file_data()?,
        ));
    }

    Ok(CatOutput {
        found_any,
        results,
        missing,
        node,
    })
}