annotate rust/hg-core/src/lib.rs @ 52164:e01e84e5e426

rust-revlog: add a Rust-only `InnerRevlog`

This mirrors the Python `InnerRevlog` and will be used in a future patch
to replace said Python implementation. This allows us to start doing more
things in pure Rust, in particular reading and writing operations.

A lot of changes have to be introduced all at once, it wouldn't be very
useful to separate this patch IMO since all of them are either interlocked
or only useful with the rest.

// Copyright 2018-2020 Georges Racinet <[e-mail]>
//           and Mercurial contributors
//
// This software may be used and distributed according to the terms of the
// GNU General Public License version 2 or any later version.

mod ancestors;
pub mod dagops;
pub mod errors;
pub mod narrow;
pub mod sparse;
pub use ancestors::{AncestorsIterator, MissingAncestors};
pub mod dirstate;
pub mod dirstate_tree;
pub mod discovery;
pub mod exit_codes;
pub mod requirements;
pub mod testing; // unconditionally built, for use from integration tests
pub use dirstate::{
    dirs_multiset::{DirsMultiset, DirsMultisetIter},
    status::{
        BadMatch, BadType, DirstateStatus, HgPathCow, StatusError,
        StatusOptions,
    },
    DirstateEntry, DirstateParents, EntryState,
};
pub mod copy_tracing;
pub mod filepatterns;
pub mod matchers;
pub mod repo;
pub mod revlog;
pub use revlog::*;
pub mod checkexec;
pub mod config;
pub mod lock;
pub mod logging;
pub mod operations;
pub mod progress;
pub mod revset;
pub mod transaction;
pub mod update;
pub mod utils;
pub mod vfs;

use crate::utils::hg_path::{HgPathBuf, HgPathError};
pub use filepatterns::{
    parse_pattern_syntax_kind, read_pattern_file, IgnorePattern,
    PatternFileWarning, PatternSyntax,
};
use std::collections::HashMap;
use std::fmt;
use twox_hash::RandomXxHashBuilder64;

pub type LineNumber = usize;

/// Rust's default hasher is too slow because it tries to prevent collision
/// attacks. We are not concerned about those: if an ill-minded person has
/// write access to your repository, you have other issues.
pub type FastHashMap<K, V> = HashMap<K, V, RandomXxHashBuilder64>;

// TODO: should this be the default `FastHashMap` for all of hg-core, not just
// dirstate_tree? How does XxHash compare with AHash, hashbrown’s default?
pub type FastHashbrownMap<K, V> =
    hashbrown::HashMap<K, V, RandomXxHashBuilder64>;

#[derive(Debug, PartialEq)]
pub enum DirstateMapError {
    PathNotFound(HgPathBuf),
    InvalidPath(HgPathError),
}

impl From<HgPathError> for DirstateMapError {
    fn from(error: HgPathError) -> Self {
        Self::InvalidPath(error)
    }
}

impl fmt::Display for DirstateMapError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            DirstateMapError::PathNotFound(_) => {
                f.write_str("expected a value, found none")
            }
            DirstateMapError::InvalidPath(path_error) => path_error.fmt(f),
        }
    }
}

#[derive(Debug, derive_more::From)]
pub enum DirstateError {
    Map(DirstateMapError),
    Common(errors::HgError),
}

impl From<HgPathError> for DirstateError {
    fn from(error: HgPathError) -> Self {
        Self::Map(DirstateMapError::InvalidPath(error))
    }
}

impl fmt::Display for DirstateError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            DirstateError::Map(error) => error.fmt(f),
            DirstateError::Common(error) => error.fmt(f),
        }
    }
}

#[derive(Debug, derive_more::From)]
pub enum PatternError {
    #[from]
    Path(HgPathError),
    UnsupportedSyntax(String),
    UnsupportedSyntaxInFile(String, String, usize),
    TooLong(usize),
    #[from]
    IO(std::io::Error),
    /// Needed a pattern that can be turned into a regex but got one that
    /// can't. This should only happen through programmer error.
    NonRegexPattern(IgnorePattern),
}

impl fmt::Display for PatternError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            PatternError::UnsupportedSyntax(syntax) => {
                write!(f, "Unsupported syntax {}", syntax)
            }
            PatternError::UnsupportedSyntaxInFile(syntax, file_path, line) => {
                write!(
                    f,
                    "{}:{}: unsupported syntax {}",
                    file_path, line, syntax
                )
            }
            PatternError::TooLong(size) => {
                write!(f, "matcher pattern is too long ({} bytes)", size)
            }
            PatternError::IO(error) => error.fmt(f),
            PatternError::Path(error) => error.fmt(f),
            PatternError::NonRegexPattern(pattern) => {
                write!(f, "'{:?}' cannot be turned into a regex", pattern)
            }
        }
    }
}