annotate rust/hg-core/src/operations/cat.rs @ 51470:406b413e3cf2 stable

rust-filepatterns: export glob_to_re function

Making this function public should not risk freezing the internal API,
and it can be useful for all downstream code that needs to perform
glob matching against byte strings, such as RHGitaly where it will
be useful to match on branches and tags.

// list_tracked_files.rs
//
// Copyright 2020 Antoine Cezar <[e-mail]>
//
// 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::Node;
use crate::revlog::RevlogError;

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()?)),
                }
            }
        }
    }
}

// Tuple of (missing, found) paths in the manifest
type ManifestQueryResponse<'a> = (Vec<(&'a HgPath, Node)>, Vec<&'a HgPath>);

fn find_files_in_manifest<'query>(
    manifest: &Manifest,
    query: impl Iterator<Item = &'query HgPath>,
) -> Result<ManifestQueryResponse<'query>, 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)),
        }
    }
    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.into())?;
    let node = *repo
        .changelog()?
        .node_from_rev(rev.into())
        .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())?;

    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,
    })
}