view rust/hg-core/src/revlog.rs @ 46209:a51d345f1404

upgrade: move optimization addition to determineactions() The documentation of `determineactions()` mention that it is given a list returned from `findoptimizations()` however it was not true before this patch. The code extending actions with optimizations also mentioned about it that this should be in determineactions. So let's do what comments at couple of places say. Differential Revision: https://phab.mercurial-scm.org/D9615
author Pulkit Goyal <7895pulkit@gmail.com>
date Wed, 16 Dec 2020 14:06:24 +0530
parents 9eb07ab3f2d4
children 5893706af3de
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// 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

pub mod node;
pub mod nodemap;
mod nodemap_docket;
pub mod path_encode;
pub use node::{Node, NodeError, NodePrefix, NodePrefixRef};
pub mod changelog;
pub mod index;
pub mod manifest;
pub mod patch;
pub mod revlog;

/// 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
/// to be smaller than all existing revisions.
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`
#[allow(clippy::unreadable_literal)]
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,
}

/// The Mercurial Revlog Index
///
/// This is currently limited to the minimal interface that is needed for
/// the [`nodemap`](nodemap/index.html) module
pub trait RevlogIndex {
    /// Total number of Revisions referenced in this index
    fn len(&self) -> usize;

    fn is_empty(&self) -> bool {
        self.len() == 0
    }

    /// Return a reference to the Node or `None` if rev is out of bounds
    ///
    /// `NULL_REVISION` is not considered to be out of bounds.
    fn node(&self, rev: Revision) -> Option<&Node>;
}