annotate rust/hg-core/src/sparse.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::{collections::HashSet, path::Path};

use format_bytes::{write_bytes, DisplayBytes};

use crate::{
    errors::HgError,
    filepatterns::parse_pattern_file_contents,
    matchers::{
        AlwaysMatcher, DifferenceMatcher, IncludeMatcher, Matcher,
        UnionMatcher,
    },
    operations::cat,
    repo::Repo,
    requirements::SPARSE_REQUIREMENT,
    utils::{hg_path::HgPath, SliceExt},
    IgnorePattern, PatternError, PatternFileWarning, PatternSyntax, Revision,
    NULL_REVISION,
};

/// Command which is triggering the config read
#[derive(Copy, Clone, Debug)]
pub enum SparseConfigContext {
    Sparse,
    Narrow,
}

impl DisplayBytes for SparseConfigContext {
    fn display_bytes(
        &self,
        output: &mut dyn std::io::Write,
    ) -> std::io::Result<()> {
        match self {
            SparseConfigContext::Sparse => write_bytes!(output, b"sparse"),
            SparseConfigContext::Narrow => write_bytes!(output, b"narrow"),
        }
    }
}

/// Possible warnings when reading sparse configuration
#[derive(Debug, derive_more::From)]
pub enum SparseWarning {
    /// Warns about improper paths that start with "/"
    RootWarning {
        context: SparseConfigContext,
        line: Vec<u8>,
    },
    /// Warns about a profile missing from the given changelog revision
    ProfileNotFound { profile: Vec<u8>, rev: Revision },
    #[from]
    Pattern(PatternFileWarning),
}

/// Parsed sparse config
#[derive(Debug, Default)]
pub struct SparseConfig {
    // Line-separated
    pub(crate) includes: Vec<u8>,
    // Line-separated
    pub(crate) excludes: Vec<u8>,
    pub(crate) profiles: HashSet<Vec<u8>>,
    pub(crate) warnings: Vec<SparseWarning>,
}

/// All possible errors when reading sparse/narrow config
#[derive(Debug, derive_more::From)]
pub enum SparseConfigError {
    IncludesAfterExcludes {
        context: SparseConfigContext,
    },
    EntryOutsideSection {
        context: SparseConfigContext,
        line: Vec<u8>,
    },
    /// Narrow config does not support '%include' directives
    IncludesInNarrow,
    /// An invalid pattern prefix was given to the narrow spec. Includes the
    /// entire pattern for context.
    InvalidNarrowPrefix(Vec<u8>),
    #[from]
    HgError(HgError),
    #[from]
    PatternError(PatternError),
}

/// Parse sparse config file content.
pub(crate) fn parse_config(
    raw: &[u8],
    context: SparseConfigContext,
) -> Result<SparseConfig, SparseConfigError> {
    let mut includes = vec![];
    let mut excludes = vec![];
    let mut profiles = HashSet::new();
    let mut warnings = vec![];

    #[derive(PartialEq, Eq)]
    enum Current {
        Includes,
        Excludes,
        None,
    }

    let mut current = Current::None;
    let mut in_section = false;

    for line in raw.split(|c| *c == b'\n') {
        let line = line.trim();
        if line.is_empty() || line[0] == b'#' {
            // empty or comment line, skip
            continue;
        }
        if line.starts_with(b"%include ") {
            let profile = line[b"%include ".len()..].trim();
            if !profile.is_empty() {
                profiles.insert(profile.into());
            }
        } else if line == b"[include]" {
            if in_section && current == Current::Includes {
                return Err(SparseConfigError::IncludesAfterExcludes {
                    context,
                });
            }
            in_section = true;
            current = Current::Includes;
            continue;
        } else if line == b"[exclude]" {
            in_section = true;
            current = Current::Excludes;
        } else {
            if current == Current::None {
                return Err(SparseConfigError::EntryOutsideSection {
                    context,
                    line: line.into(),
                });
            }
            if line.trim().starts_with(b"/") {
                warnings.push(SparseWarning::RootWarning {
                    context,
                    line: line.into(),
                });
                continue;
            }
            match current {
                Current::Includes => {
                    includes.push(b'\n');
                    includes.extend(line.iter());
                }
                Current::Excludes => {
                    excludes.push(b'\n');
                    excludes.extend(line.iter());
                }
                Current::None => unreachable!(),
            }
        }
    }

    Ok(SparseConfig {
        includes,
        excludes,
        profiles,
        warnings,
    })
}

fn read_temporary_includes(
    repo: &Repo,
) -> Result<Vec<Vec<u8>>, SparseConfigError> {
    let raw = repo.hg_vfs().try_read("tempsparse")?.unwrap_or_default();
    if raw.is_empty() {
        return Ok(vec![]);
    }
    Ok(raw.split(|c| *c == b'\n').map(ToOwned::to_owned).collect())
}

/// Obtain sparse checkout patterns for the given revision
fn patterns_for_rev(
    repo: &Repo,
    rev: Revision,
) -> Result<Option<SparseConfig>, SparseConfigError> {
    if !repo.has_sparse() {
        return Ok(None);
    }
    let raw = repo.hg_vfs().try_read("sparse")?.unwrap_or_default();

    if raw.is_empty() {
        return Ok(None);
    }

    let mut config = parse_config(&raw, SparseConfigContext::Sparse)?;

    if !config.profiles.is_empty() {
        let mut profiles: Vec<Vec<u8>> = config.profiles.into_iter().collect();
        let mut visited = HashSet::new();

        while let Some(profile) = profiles.pop() {
            if visited.contains(&profile) {
                continue;
            }
            visited.insert(profile.to_owned());

            let output =
                cat(repo, &rev.to_string(), vec![HgPath::new(&profile)])
                    .map_err(|_| {
                        HgError::corrupted(
                            "dirstate points to non-existent parent node"
                                .to_string(),
                        )
                    })?;
            if output.results.is_empty() {
                config.warnings.push(SparseWarning::ProfileNotFound {
                    profile: profile.to_owned(),
                    rev,
                })
            }

            let subconfig = parse_config(
                &output.results[0].1,
                SparseConfigContext::Sparse,
            )?;
            if !subconfig.includes.is_empty() {
                config.includes.push(b'\n');
                config.includes.extend(&subconfig.includes);
            }
            if !subconfig.includes.is_empty() {
                config.includes.push(b'\n');
                config.excludes.extend(&subconfig.excludes);
            }
            config.warnings.extend(subconfig.warnings.into_iter());
            profiles.extend(subconfig.profiles.into_iter());
        }

        config.profiles = visited;
    }

    if !config.includes.is_empty() {
        config.includes.extend(b"\n.hg*");
    }

    Ok(Some(config))
}

/// Obtain a matcher for sparse working directories.
pub fn matcher(
    repo: &Repo,
) -> Result<(Box<dyn Matcher + Sync>, Vec<SparseWarning>), SparseConfigError> {
    let mut warnings = vec![];
    if !repo.requirements().contains(SPARSE_REQUIREMENT) {
        return Ok((Box::new(AlwaysMatcher), warnings));
    }

    let parents = repo.dirstate_parents()?;
    let mut revs = vec![];
    let p1_rev =
        repo.changelog()?
            .rev_from_node(parents.p1.into())
            .map_err(|_| {
                HgError::corrupted(
                    "dirstate points to non-existent parent node".to_string(),
                )
            })?;
    if p1_rev != NULL_REVISION {
        revs.push(p1_rev)
    }
    let p2_rev =
        repo.changelog()?
            .rev_from_node(parents.p2.into())
            .map_err(|_| {
                HgError::corrupted(
                    "dirstate points to non-existent parent node".to_string(),
                )
            })?;
    if p2_rev != NULL_REVISION {
        revs.push(p2_rev)
    }
    let mut matchers = vec![];

    for rev in revs.iter() {
        let config = patterns_for_rev(repo, *rev);
        if let Ok(Some(config)) = config {
            warnings.extend(config.warnings);
            let mut m: Box<dyn Matcher + Sync> = Box::new(AlwaysMatcher);
            if !config.includes.is_empty() {
                let (patterns, subwarnings) = parse_pattern_file_contents(
                    &config.includes,
                    Path::new(""),
                    Some(PatternSyntax::Glob),
                    false,
                    false,
                )?;
                warnings.extend(subwarnings.into_iter().map(From::from));
                m = Box::new(IncludeMatcher::new(patterns)?);
            }
            if !config.excludes.is_empty() {
                let (patterns, subwarnings) = parse_pattern_file_contents(
                    &config.excludes,
                    Path::new(""),
                    Some(PatternSyntax::Glob),
                    false,
                    false,
                )?;
                warnings.extend(subwarnings.into_iter().map(From::from));
                m = Box::new(DifferenceMatcher::new(
                    m,
                    Box::new(IncludeMatcher::new(patterns)?),
                ));
            }
            matchers.push(m);
        }
    }
    let result: Box<dyn Matcher + Sync> = match matchers.len() {
        0 => Box::new(AlwaysMatcher),
        1 => matchers.pop().expect("1 is equal to 0"),
        _ => Box::new(UnionMatcher::new(matchers)),
    };

    let matcher =
        force_include_matcher(result, &read_temporary_includes(repo)?)?;
    Ok((matcher, warnings))
}

/// Returns a matcher that returns true for any of the forced includes before
/// testing against the actual matcher
fn force_include_matcher(
    result: Box<dyn Matcher + Sync>,
    temp_includes: &[Vec<u8>],
) -> Result<Box<dyn Matcher + Sync>, PatternError> {
    if temp_includes.is_empty() {
        return Ok(result);
    }
    let forced_include_matcher = IncludeMatcher::new(
        temp_includes
            .iter()
            .map(|include| {
                IgnorePattern::new(PatternSyntax::Path, include, Path::new(""))
            })
            .collect(),
    )?;
    Ok(Box::new(UnionMatcher::new(vec![
        Box::new(forced_include_matcher),
        result,
    ])))
}