Add python wrapper (#299)

.github/workflows/run-tests.yml

@@ -49,6 +49,33 @@ jobs:
           chmod +x examples.sh
           ./examples.sh
 
+  run-tests-python:
+    name: Run Python tests
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.10", "3.11", "3.12"]
+    steps:
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: ${{ matrix.python-version }}
+      - uses: actions/checkout@v3
+      - name: Install uv
+        run: pip install uv "maturin>=1.7"
+      - name: Make virtual environment
+        run: |
+          uv venv .venv
+          uv pip install pip pytest
+      - name: Install python package
+        run: |
+          source .venv/bin/activate
+          maturin develop
+      - name: Run Python tests
+        run: |
+          source .venv/bin/activate
+          python -m pytest python/test
+
   check-dependencies:
     name: Check dependencies
     runs-on: ubuntu-latest

.github/workflows/run-weekly-tests.yml

@@ -1,4 +1,4 @@
-name: 🧪
+name: 🧪📅
 
 on:
   schedule:

.gitignore

@@ -9,10 +9,8 @@ Cargo.lock
 # These are backup files generated by rustfmt
 **/*.rs.bk
 
-# nano swp files
-.*.swp
-
 *.pyc
+python/bempp/_bempprs
 
 examples.sh
 

Cargo.toml

@@ -27,7 +27,7 @@ lazy_static = "1.4"
 ndelement = { git = "https://github.com/bempp/ndelement.git" }
 ndgrid = { git = "https://github.com/bempp/ndgrid.git" }
 rayon = "1.9"
-rlst = "0.2"
+rlst = { version = "0.2.0", default-features = false }
 green-kernels = "0.2.0"
 
 [dev-dependencies]
@@ -37,6 +37,9 @@ cauchy = "0.4.*"
 criterion = { version = "0.5.*", features = ["html_reports"]}
 # kifmm = { version = "1.0" }
 
+[build-dependencies]
+cbindgen = "0.27.0"
+
 [[bench]]
 name = "assembly_benchmark"
 harness = false

build.rs

@@ -0,0 +1,31 @@
+use std::env;
+use std::fs;
+use std::path::{Path, PathBuf};
+
+fn main() {
+    let crate_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
+
+    // Determine the target directory within the workspace root
+    let target_dir = env::var("CARGO_TARGET_DIR")
+        .map(PathBuf::from)
+        .unwrap_or_else(|_| crate_dir.join("target"));
+
+    // Ensure the target directory exists
+    fs::create_dir_all(&target_dir).expect("Unable to create target directory");
+
+    // Create the header file path
+    let header_path = Path::new(&target_dir).join("include").join("_bempprs.h");
+
+    let config_path = Path::new(&crate_dir).join("cbindgen.toml");
+    let config = cbindgen::Config::from_file(config_path).expect("Unable to load cbindgen config");
+
+    // Generate the bindings
+    let bindings = cbindgen::Builder::new()
+        .with_crate(crate_dir)
+        .with_config(config)
+        .generate()
+        .expect("Unable to generate bindings");
+
+    // Write the bindings to the header file
+    bindings.write_to_file(header_path);
+}

cbindgen.toml

@@ -0,0 +1,7 @@
+language = "C"
+
+[export]
+exclude = []
+
+[enum]
+prefix_with_name = true

find_examples.py

@@ -15,9 +15,8 @@
 import os
 import argparse
 
-parser = argparse.ArgumentParser(description='Parse inputs.')
-parser.add_argument('--features', default=None,
-                    help='feature flags to pass to the examples')
+parser = argparse.ArgumentParser(description="Parse inputs.")
+parser.add_argument("--features", default=None, help="feature flags to pass to the examples")
 
 raw_features = parser.parse_args().features
 
@@ -61,7 +60,7 @@
         if options is None:
             options = ""
         if "--features" in options:
-            a, b = options.split("--features \"")
+            a, b = options.split('--features "')
             options = f"{a}--features \"{','.join(features)},{b}"
         else:
             options += f" --features \"{','.join(features)}\""

pyproject.toml

@@ -0,0 +1,50 @@
+[build-system]
+requires = ["maturin>=1,<2"]
+build-backend = "maturin"
+
+[project]
+name = "bempp-rs"
+version = "0.1.0-dev"
+description = "Boundary element method library"
+readme = "README.md"
+requires-python = ">=3.8"
+license = { file = "LICENSE" }
+authors = [
+    {name = "Timo Betcke", email = "[email protected]"},
+    {name = "Srinath Kailasa", email = "[email protected]"},
+    {name = "Matthew Scroggs", email = "[email protected]"}
+]
+classifiers = [
+    "Programming Language :: Rust",
+    "Programming Language :: Python :: Implementation :: CPython",
+]
+dependencies = [
+    "maturin>=1.7",
+    "numpy",
+    "cffi",
+    'patchelf; platform_system == "Linux"',
+    "ndelement",
+    "ndgrid"
+]
+packages = ["bempp"]
+
+[project.urls]
+homepage = "https://github.com/bempp/bempp-rs"
+repository = "https://github.com/bempp/bempp-rs"
+
+[tool.maturin]
+python-source = "python"
+module-name = "bempp._bempprs"
+
+[tool.ruff]
+line-length = 100
+indent-width = 4
+
+[tool.ruff.lint.per-file-ignores]
+"__init__.py" = ["F401"]
+
+[tool.ruff.lint.pydocstyle]
+convention = "google"
+
+[tool.mypy]
+ignore_missing_imports = true

python/bempp/__init__.py

@@ -0,0 +1,3 @@
+"""Bempp."""
+
+from bempp import function_space

python/bempp/function_space.py

@@ -0,0 +1,33 @@
+"""Function space."""
+
+from bempp._bempprs import lib as _lib, ffi as _ffi
+from ndgrid.grid import Grid
+from ndelement.ciarlet import ElementFamily
+
+
+class FunctionSpace(object):
+    """Function space."""
+
+    def __init__(self, rs_space):
+        """Initialise."""
+        self._rs_space = rs_space
+
+    def __del__(self):
+        """Delete."""
+        _lib.free_space(self._rs_space)
+
+    @property
+    def local_size(self) -> int:
+        """Number of DOFs on current process."""
+        return _lib.space_local_size(self._rs_space)
+
+    @property
+    def global_size(self) -> int:
+        """Number of DOFs on all processes."""
+        return _lib.space_global_size(self._rs_space)
+
+
+def function_space(grid: Grid, family: ElementFamily) -> FunctionSpace:
+    return FunctionSpace(
+        _lib.space_new(_ffi.cast("void*", grid._rs_grid), _ffi.cast("void*", family._rs_family))
+    )

python/test/test_function_space.py

@@ -0,0 +1,40 @@
+import pytest
+from bempp.function_space import function_space
+from ndgrid.shapes import regular_sphere
+from ndelement.ciarlet import create_family, Family, Continuity
+from ndelement.reference_cell import ReferenceCellType
+
+
+@pytest.mark.parametrize("level", range(4))
+def test_create_space_dp0(level):
+    grid = regular_sphere(level)
+    element = create_family(Family.Lagrange, 0, Continuity.Discontinuous)
+
+    space = function_space(grid, element)
+
+    assert space.local_size == grid.entity_count(ReferenceCellType.Triangle)
+    assert space.local_size == space.global_size
+
+
+@pytest.mark.parametrize("level", range(4))
+def test_create_space_p1(level):
+    grid = regular_sphere(level)
+    element = create_family(Family.Lagrange, 1)
+
+    space = function_space(grid, element)
+
+    assert space.local_size == grid.entity_count(ReferenceCellType.Point)
+    assert space.local_size == space.global_size
+
+
+@pytest.mark.parametrize("level", range(4))
+def test_create_space_p2(level):
+    grid = regular_sphere(level)
+    element = create_family(Family.Lagrange, 2)
+
+    space = function_space(grid, element)
+
+    assert space.local_size == grid.entity_count(ReferenceCellType.Point) + grid.entity_count(
+        ReferenceCellType.Interval
+    )
+    assert space.local_size == space.global_size