revlog.rs
38 lines
| 1.3 KiB
| application/rls-services+xml
|
RustLexer
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r44457 | // Copyright 2018-2020 Georges Racinet <georges.racinet@octobus.net> | ||
// 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. | ||||
//! Mercurial concepts for handling revision history | ||||
/// 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; | ||||
/// Marker expressing the absence of a parent | ||||
/// | ||||
/// Independently of the actual representation, `NULL_REVISION` is guaranteed | ||||
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r44547 | /// to be smaller than all existing revisions. | ||
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r44457 | pub const NULL_REVISION: Revision = -1; | ||
/// Same as `mercurial.node.wdirrev` | ||||
/// | ||||
/// This is also equal to `i32::max_value()`, but it's better to spell | ||||
/// it out explicitely, same as in `mercurial.node` | ||||
pub const WORKING_DIRECTORY_REVISION: Revision = 0x7fffffff; | ||||
/// 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, rev: Revision) -> Result<[Revision; 2], GraphError>; | ||||
} | ||||
#[derive(Clone, Debug, PartialEq)] | ||||
pub enum GraphError { | ||||
ParentOutOfRange(Revision), | ||||
WorkingDirectoryUnsupported, | ||||
} | ||||