view rust/hg-core/src/testing.rs @ 42748:7cae6bc29ff9

rust-parsers: switch to parse/pack_dirstate to mutate-on-loop

Both `parse_dirstate` and `pack_dirstate` can operate directly on the data
they're passed, which prevents the creation of intermediate data structures,
simplifies the function signatures and reduces boilerplate. They are exposed
directly to the Python for now, but a later patch will make use of them inside
`hg-core`.

Differential Revision: https://phab.mercurial-scm.org/D6628

// testing.rs
//
// 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.

use crate::{Graph, GraphError, Revision, NULL_REVISION};

/// A stub `Graph`, same as the one from `test-ancestor.py`
///
/// o  13
/// |
/// | o  12
/// | |
/// | | o    11
/// | | |\
/// | | | | o  10
/// | | | | |
/// | o---+ |  9
/// | | | | |
/// o | | | |  8
///  / / / /
/// | | o |  7
/// | | | |
/// o---+ |  6
///  / / /
/// | | o  5
/// | |/
/// | o  4
/// | |
/// o |  3
/// | |
/// | o  2
/// |/
/// o  1
/// |
/// o  0
#[derive(Clone, Debug)]
pub struct SampleGraph;

impl Graph for SampleGraph {
    fn parents(&self, rev: Revision) -> Result<[Revision; 2], GraphError> {
        match rev {
            0 => Ok([NULL_REVISION, NULL_REVISION]),
            1 => Ok([0, NULL_REVISION]),
            2 => Ok([1, NULL_REVISION]),
            3 => Ok([1, NULL_REVISION]),
            4 => Ok([2, NULL_REVISION]),
            5 => Ok([4, NULL_REVISION]),
            6 => Ok([4, NULL_REVISION]),
            7 => Ok([4, NULL_REVISION]),
            8 => Ok([NULL_REVISION, NULL_REVISION]),
            9 => Ok([6, 7]),
            10 => Ok([5, NULL_REVISION]),
            11 => Ok([3, 7]),
            12 => Ok([9, NULL_REVISION]),
            13 => Ok([8, NULL_REVISION]),
            r => Err(GraphError::ParentOutOfRange(r)),
        }
    }
}

// A Graph represented by a vector whose indices are revisions
// and values are parents of the revisions
pub type VecGraph = Vec<[Revision; 2]>;

impl Graph for VecGraph {
    fn parents(&self, rev: Revision) -> Result<[Revision; 2], GraphError> {
        Ok(self[rev as usize])
    }
}