Mercurial > hg
view rust/hg-core/src/revlog.rs @ 48851:d739cd69bb6a
revlog: return 0 for the fast_rank of nullrev
By convention, the rank of the null revision is 0. This particular revision is
never "physically" stored in the changelog, so it is a special case.
For consistency, the value `None` is still being returned for revlogs which do
not store the fast_rank property for any revision.
Differential Revision: https://phab.mercurial-scm.org/D12208
author | pacien <pacien.trangirard@pacien.net> |
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date | Mon, 21 Feb 2022 15:53:03 +0100 |
parents | 4d2a5ca060e3 |
children |
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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::{FromHexError, Node, NodePrefix}; pub mod changelog; pub mod filelog; 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; pub const WORKING_DIRECTORY_HEX: &str = "ffffffffffffffffffffffffffffffffffffffff"; /// 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>; }