annotate rust/hg-core/src/narrow.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.

use std::path::Path;

use crate::{
    errors::HgError,
    exit_codes,
    filepatterns::parse_pattern_file_contents,
    matchers::{
        AlwaysMatcher, DifferenceMatcher, IncludeMatcher, Matcher,
        NeverMatcher,
    },
    repo::Repo,
    requirements::NARROW_REQUIREMENT,
    sparse::{self, SparseConfigError, SparseWarning},
};

/// The file in .hg/store/ that indicates which paths exit in the store
const FILENAME: &str = "narrowspec";
/// The file in .hg/ that indicates which paths exit in the dirstate
const DIRSTATE_FILENAME: &str = "narrowspec.dirstate";

/// Pattern prefixes that are allowed in narrow patterns. This list MUST
/// only contain patterns that are fast and safe to evaluate. Keep in mind
/// that patterns are supplied by clients and executed on remote servers
/// as part of wire protocol commands. That means that changes to this
/// data structure influence the wire protocol and should not be taken
/// lightly - especially removals.
const VALID_PREFIXES: [&str; 2] = ["path:", "rootfilesin:"];

/// Return the matcher for the current narrow spec, and all configuration
/// warnings to display.
pub fn matcher(
    repo: &Repo,
) -> Result<(Box<dyn Matcher + Sync>, Vec<SparseWarning>), SparseConfigError> {
    let mut warnings = vec![];
    if !repo.requirements().contains(NARROW_REQUIREMENT) {
        return Ok((Box::new(AlwaysMatcher), warnings));
    }
    // Treat "narrowspec does not exist" the same as "narrowspec file exists
    // and is empty".
    let store_spec = repo.store_vfs().try_read(FILENAME)?.unwrap_or_default();
    let working_copy_spec = repo
        .hg_vfs()
        .try_read(DIRSTATE_FILENAME)?
        .unwrap_or_default();
    if store_spec != working_copy_spec {
        return Err(HgError::abort(
            "abort: working copy's narrowspec is stale",
            exit_codes::STATE_ERROR,
            Some("run 'hg tracked --update-working-copy'".into()),
        )
        .into());
    }

    let config = sparse::parse_config(
        &store_spec,
        sparse::SparseConfigContext::Narrow,
    )?;

    warnings.extend(config.warnings);

    if !config.profiles.is_empty() {
        // TODO (from Python impl) maybe do something with profiles?
        return Err(SparseConfigError::IncludesInNarrow);
    }
    validate_patterns(&config.includes)?;
    validate_patterns(&config.excludes)?;

    if config.includes.is_empty() {
        return Ok((Box::new(NeverMatcher), warnings));
    }

    let (patterns, subwarnings) = parse_pattern_file_contents(
        &config.includes,
        Path::new(""),
        None,
        false,
        true,
    )?;
    warnings.extend(subwarnings.into_iter().map(From::from));

    let mut m: Box<dyn Matcher + Sync> =
        Box::new(IncludeMatcher::new(patterns)?);

    let (patterns, subwarnings) = parse_pattern_file_contents(
        &config.excludes,
        Path::new(""),
        None,
        false,
        true,
    )?;
    if !patterns.is_empty() {
        warnings.extend(subwarnings.into_iter().map(From::from));
        let exclude_matcher = Box::new(IncludeMatcher::new(patterns)?);
        m = Box::new(DifferenceMatcher::new(m, exclude_matcher));
    }

    Ok((m, warnings))
}

fn validate_patterns(patterns: &[u8]) -> Result<(), SparseConfigError> {
    for pattern in patterns.split(|c| *c == b'\n') {
        if pattern.is_empty() {
            continue;
        }
        for prefix in VALID_PREFIXES.iter() {
            if pattern.starts_with(prefix.as_bytes()) {
                return Ok(());
            }
        }
        return Err(SparseConfigError::InvalidNarrowPrefix(
            pattern.to_owned(),
        ));
    }
    Ok(())
}