rust/hg-cpython/src/lib.rs

branchmap: update rev-branch-cache incrementally

Historically, the revision to branch mapping cache was updated on demand
and shared via bundle2 to avoid the cost of rebuilding on first use.

Use the new `register_changeset` callback and update rbc directly on
every change. Make the transfer of the bundle part redundant, but keep
it for the moment to avoid the test churn.

Over all, "hg unbundle" for large bundles is less than 1.8% slower for
different larger repositories and that seems to a reasonable trade off.

Differential Revision: https://phab.mercurial-scm.org/D9781

// lib.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.

//! Python bindings of `hg-core` objects using the `cpython` crate.
//! Once compiled, the resulting single shared library object can be placed in
//! the `mercurial` package directly as `rustext.so` or `rustext.dll`.
//! It holds several modules, so that from the point of view of Python,
//! it behaves as the `cext` package.
//!
//! Example:
//!
//! ```text
//! >>> from mercurial.rustext import ancestor
//! >>> ancestor.__doc__
//! 'Generic DAG ancestor algorithms - Rust implementation'
//! ```

/// This crate uses nested private macros, `extern crate` is still needed in
/// 2018 edition.
#[macro_use]
extern crate cpython;

pub mod ancestors;
mod cindex;
mod conversion;
#[macro_use]
pub mod ref_sharing;
pub mod copy_tracing;
pub mod dagops;
pub mod debug;
pub mod dirstate;
pub mod discovery;
pub mod exceptions;
pub mod parsers;
pub mod revlog;
pub mod utils;

py_module_initializer!(rustext, initrustext, PyInit_rustext, |py, m| {
    m.add(
        py,
        "__doc__",
        "Mercurial core concepts - Rust implementation",
    )?;

    let dotted_name: String = m.get(py, "__name__")?.extract(py)?;
    m.add(py, "ancestor", ancestors::init_module(py, &dotted_name)?)?;
    m.add(py, "dagop", dagops::init_module(py, &dotted_name)?)?;
    m.add(py, "debug", debug::init_module(py, &dotted_name)?)?;
    m.add(
        py,
        "copy_tracing",
        copy_tracing::init_module(py, &dotted_name)?,
    )?;
    m.add(py, "discovery", discovery::init_module(py, &dotted_name)?)?;
    m.add(py, "dirstate", dirstate::init_module(py, &dotted_name)?)?;
    m.add(py, "revlog", revlog::init_module(py, &dotted_name)?)?;
    m.add(
        py,
        "parsers",
        parsers::init_parsers_module(py, &dotted_name)?,
    )?;
    m.add(py, "GraphError", py.get_type::<exceptions::GraphError>())?;
    Ok(())
});

#[cfg(not(any(feature = "python27-bin", feature = "python3-bin")))]
#[test]
#[ignore]
fn libpython_must_be_linked_to_run_tests() {
    // stub function to tell that some tests wouldn't run
}