Mercurial > public > mercurial-scm > hg

annotate rust/hg-cpython/src/cindex.rs @ 41350:ab0d762d89ef stable

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
rust-cpython: raising error.WdirUnsupported The Graph implementation of hg-cpython returns the appropriate error upon encounter with the working directory special revision number, and this gives us in particular a code path to test from test-rust-ancestors.py In the current implementation, the exception is actually raised from the iterator instantiation; we are nonetheless consuming the iterator in the test with `list()` in order not to depend on implementation details.
author Georges Racinet <georges.racinet@octobus.net>
date Wed, 23 Jan 2019 07:49:36 -0500
parents ef54bd33b476
children 326fdce22fb2
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
41052
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
1 // cindex.rs
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
2 //
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
3 // Copyright 2018 Georges Racinet <gracinet@anybox.fr>
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
4 //
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
5 // This software may be used and distributed according to the terms of the
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
6 // GNU General Public License version 2 or any later version.
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
7
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
8 //! Bindings to use the Index defined by the parsers C extension
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
9 //!
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
10 //! Ideally, we should use an Index entirely implemented in Rust,
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
11 //! but this will take some time to get there.
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
12 #[cfg(feature = "python27")]
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
13 extern crate python27_sys as python_sys;
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
14 #[cfg(feature = "python3")]
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
15 extern crate python3_sys as python_sys;
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
16
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
17 use self::python_sys::PyCapsule_Import;
41054
ef54bd33b476 rust: core implementation for lazyancestors
Georges Racinet <gracinet@anybox.fr>
parents: 41052
diff changeset
18 use cpython::{PyClone, PyErr, PyObject, PyResult, Python};
41350
ab0d762d89ef rust-cpython: raising error.WdirUnsupported
Georges Racinet <georges.racinet@octobus.net>
parents: 41054
diff changeset
19 use hg::{Graph, GraphError, Revision, WORKING_DIRECTORY_REVISION};
41052
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
20 use libc::c_int;
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
21 use std::ffi::CStr;
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
22 use std::mem::transmute;
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
23
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
24 type IndexParentsFn = unsafe extern "C" fn(
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
25 index: *mut python_sys::PyObject,
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
26 rev: c_int,
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
27 ps: *mut [c_int; 2],
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
28 ) -> c_int;
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
29
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
30 /// A `Graph` backed up by objects and functions from revlog.c
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
31 ///
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
32 /// This implementation of the `Graph` trait, relies on (pointers to)
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
33 /// - the C index object (`index` member)
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
34 /// - the `index_get_parents()` function (`parents` member)
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
35 ///
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
36 /// # Safety
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
37 ///
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
38 /// The C index itself is mutable, and this Rust exposition is **not
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
39 /// protected by the GIL**, meaning that this construct isn't safe with respect
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
40 /// to Python threads.
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
41 ///
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
42 /// All callers of this `Index` must acquire the GIL and must not release it
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
43 /// while working.
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
44 ///
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
45 /// # TODO find a solution to make it GIL safe again.
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
46 ///
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
47 /// This is non trivial, and can wait until we have a clearer picture with
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
48 /// more Rust Mercurial constructs.
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
49 ///
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
50 /// One possibility would be to a `GILProtectedIndex` wrapper enclosing
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
51 /// a `Python<'p>` marker and have it be the one implementing the
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
52 /// `Graph` trait, but this would mean the `Graph` implementor would become
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
53 /// likely to change between subsequent method invocations of the `hg-core`
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
54 /// objects (a serious change of the `hg-core` API):
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
55 /// either exposing ways to mutate the `Graph`, or making it a non persistent
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
56 /// parameter in the relevant methods that need one.
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
57 ///
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
58 /// Another possibility would be to introduce an abstract lock handle into
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
59 /// the core API, that would be tied to `GILGuard` / `Python<'p>`
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
60 /// in the case of the `cpython` crate bindings yet could leave room for other
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
61 /// mechanisms in other contexts.
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
62 pub struct Index {
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
63 index: PyObject,
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
64 parents: IndexParentsFn,
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
65 }
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
66
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
67 impl Index {
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
68 pub fn new(py: Python, index: PyObject) -> PyResult<Self> {
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
69 Ok(Index {
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
70 index: index,
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
71 parents: decapsule_parents_fn(py)?,
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
72 })
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
73 }
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
74 }
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
75
41054
ef54bd33b476 rust: core implementation for lazyancestors
Georges Racinet <gracinet@anybox.fr>
parents: 41052
diff changeset
76 impl Clone for Index {
ef54bd33b476 rust: core implementation for lazyancestors
Georges Racinet <gracinet@anybox.fr>
parents: 41052
diff changeset
77 fn clone(&self) -> Self {
ef54bd33b476 rust: core implementation for lazyancestors
Georges Racinet <gracinet@anybox.fr>
parents: 41052
diff changeset
78 let guard = Python::acquire_gil();
ef54bd33b476 rust: core implementation for lazyancestors
Georges Racinet <gracinet@anybox.fr>
parents: 41052
diff changeset
79 Index {
ef54bd33b476 rust: core implementation for lazyancestors
Georges Racinet <gracinet@anybox.fr>
parents: 41052
diff changeset
80 index: self.index.clone_ref(guard.python()),
ef54bd33b476 rust: core implementation for lazyancestors
Georges Racinet <gracinet@anybox.fr>
parents: 41052
diff changeset
81 parents: self.parents.clone(),
ef54bd33b476 rust: core implementation for lazyancestors
Georges Racinet <gracinet@anybox.fr>
parents: 41052
diff changeset
82 }
ef54bd33b476 rust: core implementation for lazyancestors
Georges Racinet <gracinet@anybox.fr>
parents: 41052
diff changeset
83 }
ef54bd33b476 rust: core implementation for lazyancestors
Georges Racinet <gracinet@anybox.fr>
parents: 41052
diff changeset
84 }
ef54bd33b476 rust: core implementation for lazyancestors
Georges Racinet <gracinet@anybox.fr>
parents: 41052
diff changeset
85
41052
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
86 impl Graph for Index {
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
87 /// wrap a call to the C extern parents function
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
88 fn parents(&self, rev: Revision) -> Result<[Revision; 2], GraphError> {
41350
ab0d762d89ef rust-cpython: raising error.WdirUnsupported
Georges Racinet <georges.racinet@octobus.net>
parents: 41054
diff changeset
89 if rev == WORKING_DIRECTORY_REVISION {
ab0d762d89ef rust-cpython: raising error.WdirUnsupported
Georges Racinet <georges.racinet@octobus.net>
parents: 41054
diff changeset
90 return Err(GraphError::WorkingDirectoryUnsupported);
ab0d762d89ef rust-cpython: raising error.WdirUnsupported
Georges Racinet <georges.racinet@octobus.net>
parents: 41054
diff changeset
91 }
41052
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
92 let mut res: [c_int; 2] = [0; 2];
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
93 let code = unsafe {
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
94 (self.parents)(
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
95 self.index.as_ptr(),
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
96 rev as c_int,
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
97 &mut res as *mut [c_int; 2],
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
98 )
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
99 };
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
100 match code {
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
101 0 => Ok(res),
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
102 _ => Err(GraphError::ParentOutOfRange(rev)),
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
103 }
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
104 }
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
105 }
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
106
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
107 /// Return the `index_get_parents` function of the parsers C Extension module.
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
108 ///
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
109 /// A pointer to the function is stored in the `parsers` module as a
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
110 /// standard [Python capsule](https://docs.python.org/2/c-api/capsule.html).
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
111 ///
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
112 /// This function retrieves the capsule and casts the function pointer
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
113 ///
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
114 /// Casting function pointers is one of the rare cases of
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
115 /// legitimate use cases of `mem::transmute()` (see
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
116 /// https://doc.rust-lang.org/std/mem/fn.transmute.html of
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
117 /// `mem::transmute()`.
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
118 /// It is inappropriate for architectures where
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
119 /// function and data pointer sizes differ (so-called "Harvard
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
120 /// architectures"), but these are nowadays mostly DSPs
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
121 /// and microcontrollers, hence out of our scope.
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
122 fn decapsule_parents_fn(py: Python) -> PyResult<IndexParentsFn> {
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
123 unsafe {
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
124 let caps_name = CStr::from_bytes_with_nul_unchecked(
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
125 b"mercurial.cext.parsers.index_get_parents_CAPI\0",
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
126 );
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
127 let from_caps = PyCapsule_Import(caps_name.as_ptr(), 0);
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
128 if from_caps.is_null() {
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
129 return Err(PyErr::fetch(py));
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
130 }
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
131 Ok(transmute(from_caps))
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
132 }
4c25038c112c rust-cpython: implement Graph using C parents function
Georges Racinet <gracinet@anybox.fr>
parents:
diff changeset
133 }