1 // dagops.rs

     2 //

     3 // Copyright 2019 Georges Racinet <georges.racinet@octobus.net>

     4 //

     5 // This software may be used and distributed according to the terms of the

     6 // GNU General Public License version 2 or any later version.

     7 

     8 //! Bindings for the `hg::dagops` module provided by the

     9 //! `hg-core` package.

    10 //!

    11 //! From Python, this will be seen as `mercurial.rustext.dagop`

    12 use cindex::Index;

    13 use cpython::{PyDict, PyModule, PyObject, PyResult, Python};

    14 use crate::conversion::{py_set, rev_pyiter_collect};

    15 use exceptions::GraphError;

    16 use hg::dagops;

    17 use hg::Revision;

    18 use std::collections::HashSet;

    19 

    20 /// Using the the `index`, return heads out of any Python iterable of Revisions

    21 ///

    22 /// This is the Rust counterpart for `mercurial.dagop.headrevs`

    23 pub fn headrevs(

    24     py: Python,

    25     index: PyObject,

    26     revs: PyObject,

    27 ) -> PyResult<PyObject> {

    28     let mut as_set: HashSet<Revision> = rev_pyiter_collect(py, &revs)?;

    29     dagops::retain_heads(&Index::new(py, index)?, &mut as_set)

    30         .map_err(|e| GraphError::pynew(py, e))?;

    31     py_set(py, &as_set)

    32 }

    33 

    34 /// Create the module, with `__package__` given from parent

    35 pub fn init_module(py: Python, package: &str) -> PyResult<PyModule> {

    36     let dotted_name = &format!("{}.dagop", package);

    37     let m = PyModule::new(py, dotted_name)?;

    38     m.add(py, "__package__", package)?;

    39     m.add(py, "__doc__", "DAG operations - Rust implementation")?;

    40     m.add(

    41         py,

    42         "headrevs",

    43         py_fn!(py, headrevs(index: PyObject, revs: PyObject)),

    44     )?;

    45 

    46     let sys = PyModule::import(py, "sys")?;

    47     let sys_modules: PyDict = sys.get(py, "modules")?.extract(py)?;

    48     sys_modules.set_item(py, dotted_name, &m)?;

    49     // Example C code (see pyexpat.c and import.c) will "give away the

    50     // reference", but we won't because it will be consumed once the

    51     // Rust PyObject is dropped.

    52     Ok(m)

    53 }