view rust/hg-core/src/lib.rs @ 41246:619ee4039bd4

rust: MissingAncestors.basesheads()

This new API method on `MissingAncestors` leverages directly the
Rust implementation for relative heads of a set, and also
lowers the cost of returning the results to Python in the context of
discovery.

These interchange costs can probably be further reduced by implementing
the `partialdiscovery` class in Rust, but that will be investigated in the
5.0 development cycle.

Differential Revision: https://phab.mercurial-scm.org/D5584

// Copyright 2018 Georges Racinet <[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.
mod ancestors;
pub mod dagops;
pub use ancestors::{AncestorsIterator, LazyAncestors, MissingAncestors};
#[cfg(test)]
pub mod testing;

/// Mercurial revision numbers
///
/// As noted in revlog.c, revision numbers are actually encoded in
/// 4 bytes, and are liberally converted to ints, whence the i32
pub type Revision = i32;

pub const NULL_REVISION: Revision = -1;

/// The simplest expression of what we need of Mercurial DAGs.
pub trait Graph {
    /// Return the two parents of the given `Revision`.
    ///
    /// Each of the parents can be independently `NULL_REVISION`
    fn parents(&self, Revision) -> Result<[Revision; 2], GraphError>;
}

#[derive(Clone, Debug, PartialEq)]
pub enum GraphError {
    ParentOutOfRange(Revision),
}