Add a stub Rust crate (#12595)

.dockerignore

@@ -4,8 +4,12 @@
 # things to include
 !docker
 !synapse
+!rust
 !README.rst
 !pyproject.toml
 !poetry.lock
+!build_rust.py
+
+rust/target
 
 **/__pycache__

.github/workflows/release-artifacts.yml

@@ -89,9 +89,67 @@ jobs:
           name: debs
           path: debs/*
 
+  build-wheels:
+    name: Build wheels on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-20.04, macos-10.15]
+        is_pr:
+          - ${{ startsWith(github.ref, 'refs/pull/') }}
+
+        exclude:
+          # Don't build macos wheels on PR CI.
+          - is_pr: true
+            os: "macos-10.15"
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - uses: actions/setup-python@v3
+
+      - name: Install cibuildwheel
+        run: python -m pip install cibuildwheel==2.9.0 poetry==1.2.0
+
+      # Only build a single wheel in CI.
+      - name: Set env vars.
+        run: |
+          echo "CIBW_BUILD="cp37-manylinux_x86_64"" >> $GITHUB_ENV
+        if: startsWith(github.ref, 'refs/pull/')
+
+      - name: Build wheels
+        run: python -m cibuildwheel --output-dir wheelhouse
+        env:
+          # Skip testing for platforms which various libraries don't have wheels
+          # for, and so need extra build deps.
+          CIBW_TEST_SKIP: pp39-* *i686* *musl* pp37-macosx*
+
+      - uses: actions/upload-artifact@v3
+        with:
+          name: Wheel
+          path: ./wheelhouse/*.whl
+
   build-sdist:
-    name: "Build pypi distribution files"
+    name: Build sdist
-    uses: "matrix-org/backend-meta/.github/workflows/packaging.yml@v1"
+    runs-on: ubuntu-latest
+    if: ${{ !startsWith(github.ref, 'refs/pull/') }}
+
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: '3.10'
+
+      - run: pip install build
+
+      - name: Build sdist
+        run: python -m build --sdist
+
+      - uses: actions/upload-artifact@v2
+        with:
+          name: Sdist
+          path: dist/*.tar.gz
+
 
   # if it's a tag, create a release and attach the artifacts to it
   attach-assets:
@@ -99,6 +157,7 @@ jobs:
     if: ${{ !failure() && !cancelled() && startsWith(github.ref, 'refs/tags/') }}
     needs:
       - build-debs
+      - build-wheels
       - build-sdist
     runs-on: ubuntu-latest
     steps:

.github/workflows/tests.yml

@@ -139,6 +139,12 @@ jobs:
     steps:
       - uses: actions/checkout@v2
 
+      - name: Install Rust
+        uses: actions-rs/toolchain@v1
+        with:
+            toolchain: 1.61.0
+            override: true
+
       # There aren't wheels for some of the older deps, so we need to install
       # their build dependencies
       - run: |
@@ -247,6 +253,11 @@ jobs:
       - uses: actions/checkout@v2
       - name: Prepare test blacklist
         run: cat sytest-blacklist .ci/worker-blacklist > synapse-blacklist-with-workers
+      - name: Install Rust
+        uses: actions-rs/toolchain@v1
+        with:
+            toolchain: 1.61.0
+            override: true
       - name: Run SyTest
         run: /bootstrap.sh synapse
         working-directory: /src
@@ -353,6 +364,12 @@ jobs:
         with:
           path: synapse
 
+      - name: Install Rust
+        uses: actions-rs/toolchain@v1
+        with:
+            toolchain: 1.61.0
+            override: true
+
       - name: Prepare Complement's Prerequisites
         run: synapse/.ci/scripts/setup_complement_prerequisites.sh
 

.gitignore

@@ -60,3 +60,10 @@ book/
 # complement
 /complement-*
 /master.tar.gz
+
+# rust
+/target/
+/synapse/*.so
+
+# Poetry will create a setup.py, which we don't want to include.
+/setup.py

Cargo.toml

@@ -0,0 +1,5 @@
+# We make the whole Synapse folder a workspace so that we can run `cargo`
+# commands from the root (rather than having to cd into rust/).
+
+[workspace]
+members = ["rust"]

build_rust.py

@@ -0,0 +1,20 @@
+# A build script for poetry that adds the rust extension.
+
+import os
+from typing import Any, Dict
+
+from setuptools_rust import Binding, RustExtension
+
+
+def build(setup_kwargs: Dict[str, Any]) -> None:
+    original_project_dir = os.path.dirname(os.path.realpath(__file__))
+    cargo_toml_path = os.path.join(original_project_dir, "rust", "Cargo.toml")
+
+    extension = RustExtension(
+        target="synapse.synapse_rust",
+        path=cargo_toml_path,
+        binding=Binding.PyO3,
+        py_limited_api=True,
+    )
+    setup_kwargs.setdefault("rust_extensions", []).append(extension)
+    setup_kwargs["zip_safe"] = False

changelog.d/12595.misc

@@ -0,0 +1 @@
+Add a stub Rust crate.

debian/build_virtualenv

@@ -61,7 +61,7 @@ dh_virtualenv \
     --extras="all,systemd,test" \
     --requirements="exported_requirements.txt"
 
-PACKAGE_BUILD_DIR="debian/matrix-synapse-py3"
+PACKAGE_BUILD_DIR="$(pwd)/debian/matrix-synapse-py3"
 VIRTUALENV_DIR="${PACKAGE_BUILD_DIR}${DH_VIRTUALENV_INSTALL_ROOT}/matrix-synapse"
 TARGET_PYTHON="${VIRTUALENV_DIR}/bin/python"
 
@@ -78,9 +78,14 @@ case "$DEB_BUILD_OPTIONS" in
 
         cp -r tests "$tmpdir"
 
+        # To avoid pulling in the unbuilt Synapse in the local directory
+        pushd /
+
         PYTHONPATH="$tmpdir" \
             "${TARGET_PYTHON}" -m twisted.trial --reporter=text -j2 tests
 
+        popd
+
         ;;
 esac
 

debian/changelog

@@ -12,11 +12,15 @@ matrix-synapse-py3 (1.66.0) stable; urgency=medium
 
 matrix-synapse-py3 (1.66.0~rc2+nmu1) UNRELEASED; urgency=medium
 
+  [ Jörg Behrmann ]
   * Update debhelper to compatibility level 12.
   * Drop the preinst script stopping synapse.
   * Allocate a group for the system user.
   * Change dpkg-statoverride to --force-statoverride-add.
 
+  [ Erik Johnston ]
+  * Disable `dh_auto_configure` as it broke during Rust build.
+
  -- Jörg Behrmann <behrmann@physik.fu-berlin.de>  Tue, 23 Aug 2022 17:17:00 +0100
 
 matrix-synapse-py3 (1.66.0~rc2) stable; urgency=medium

debian/rules

@@ -12,6 +12,8 @@ override_dh_installsystemd:
 # we don't really want to strip the symbols from our object files.
 override_dh_strip:
 
+override_dh_auto_configure:
+
 # many libraries pulled from PyPI have allocatable sections after
 # non-allocatable ones on which dwz errors out. For those without the issue the
 # gains are only marginal

docker/Dockerfile

@@ -92,11 +92,20 @@ RUN \
     libxml++2.6-dev \
     libxslt1-dev \
     openssl \
-    rustc \
     zlib1g-dev \
     git \
+    curl \
     && rm -rf /var/lib/apt/lists/*
 
+
+# Install rust and ensure its in the PATH
+ENV RUSTUP_HOME=/rust
+ENV CARGO_HOME=/cargo
+ENV PATH=/cargo/bin:/rust/bin:$PATH
+RUN mkdir /rust /cargo
+
+RUN curl -sSf https://sh.rustup.rs | sh -s -- -y --no-modify-path --default-toolchain stable
+
 # To speed up rebuilds, install all of the dependencies before we copy over
 # the whole synapse project, so that this layer in the Docker cache can be
 # used while you develop on the source
@@ -108,8 +117,9 @@ RUN --mount=type=cache,target=/root/.cache/pip \
 
 # Copy over the rest of the synapse source code.
 COPY synapse /synapse/synapse/
+COPY rust /synapse/rust/
 # ... and what we need to `pip install`.
-COPY pyproject.toml README.rst /synapse/
+COPY pyproject.toml README.rst build_rust.py /synapse/
 
 # Repeat of earlier build argument declaration, as this is a new build stage.
 ARG TEST_ONLY_IGNORE_POETRY_LOCKFILE

docker/Dockerfile-dhvirtualenv

@@ -72,6 +72,7 @@ RUN apt-get update -qq -o Acquire::Languages=none \
     && env DEBIAN_FRONTEND=noninteractive apt-get install \
         -yqq --no-install-recommends -o Dpkg::Options::=--force-unsafe-io \
         build-essential \
+        curl \
         debhelper \
         devscripts \
         libsystemd-dev \
@@ -85,6 +86,15 @@ RUN apt-get update -qq -o Acquire::Languages=none \
         libpq-dev \
         xmlsec1
 
+# Install rust and ensure it's in the PATH
+ENV RUSTUP_HOME=/rust
+ENV CARGO_HOME=/cargo
+ENV PATH=/cargo/bin:/rust/bin:$PATH
+RUN mkdir /rust /cargo
+
+RUN curl -sSf https://sh.rustup.rs | sh -s -- -y --no-modify-path --default-toolchain stable
+
+
 COPY --from=builder /dh-virtualenv_1.2.2-1_all.deb /
 
 # install dhvirtualenv. Update the apt cache again first, in case we got a

docs/deprecation_policy.md

@@ -18,6 +18,12 @@ documented at [https://endoflife.date/python](https://endoflife.date/python) and
 [https://endoflife.date/postgresql](https://endoflife.date/postgresql).
 
 
+A Rust compiler is required to build Synapse from source. For any given release
+the minimum required version may be bumped up to a recent Rust version, and so
+people building from source should ensure they can fetch recent versions of Rust
+(e.g. by using [rustup](https://rustup.rs/)).
+
+
 Context
 -------
 
@@ -31,3 +37,10 @@ long process.
 By following the upstream support life cycles Synapse can ensure that its
 dependencies continue to get security patches, while not requiring system admins
 to constantly update their platform dependencies to the latest versions.
+
+For Rust, the situation is a bit different given that a) the Rust foundation
+does not generally support older Rust versions, and b) the library ecosystem
+generally bump their minimum support Rust versions frequently. In general, the
+Synapse team will try to avoid updating the dependency on Rust to the absolute
+latest version, but introducing a formal policy is hard given the constraints of
+the ecosystem.

docs/development/contributing_guide.md

@@ -28,6 +28,9 @@ The source code of Synapse is hosted on GitHub. You will also need [a recent ver
 
 For some tests, you will need [a recent version of Docker](https://docs.docker.com/get-docker/).
 
+A recent version of the Rust compiler is needed to build the native modules. The
+easiest way of installing the latest version is to use [rustup](https://rustup.rs/).
+
 
 # 3. Get the source.
 
@@ -114,6 +117,11 @@ Some documentation also exists in [Synapse's GitHub
 Wiki](https://github.com/matrix-org/synapse/wiki), although this is primarily
 contributed to by community authors.
 
+When changes are made to any Rust code then you must call either `poetry install`
+or `maturin develop` (if installed) to rebuild the Rust code. Using [`maturin`](https://github.com/PyO3/maturin)
+is quicker than `poetry install`, so is recommended when making frequent
+changes to the Rust code.
+
 
 # 8. Test, test, test!
 <a name="test-test-test"></a>

docs/setup/installation.md

@@ -196,6 +196,10 @@ System requirements:
 - Python 3.7 or later, up to Python 3.10.
 - At least 1GB of free RAM if you want to join large public rooms like #matrix:matrix.org
 
+If building on an uncommon architecture for which pre-built wheels are
+unavailable, you will need to have a recent Rust compiler installed. The easiest
+way of installing the latest version is to use [rustup](https://rustup.rs/).
+
 To install the Synapse homeserver run:
 
 ```sh

mypy.ini

@@ -16,7 +16,8 @@ files =
   docker/,
   scripts-dev/,
   synapse/,
-  tests/
+  tests/,
+  build_rust.py
 
 # Note: Better exclusion syntax coming in mypy > 0.910
 # https://github.com/python/mypy/pull/11329
@@ -181,3 +182,6 @@ ignore_missing_imports = True
 
 [mypy-incremental.*]
 ignore_missing_imports = True
+
+[mypy-setuptools_rust.*]
+ignore_missing_imports = True

poetry.lock

@@ -1035,6 +1035,18 @@ python-versions = ">=3.6"
 cryptography = ">=2.0"
 jeepney = ">=0.6"
 
+[[package]]
+name = "semantic-version"
+version = "2.10.0"
+description = "A library implementing the 'SemVer' scheme."
+category = "main"
+optional = false
+python-versions = ">=2.7"
+
+[package.extras]
+dev = ["Django (>=1.11)", "check-manifest", "colorama (<=0.4.1)", "coverage", "flake8", "nose2", "readme-renderer (<25.0)", "tox", "wheel", "zest.releaser[recommended]"]
+doc = ["Sphinx", "sphinx-rtd-theme"]
+
 [[package]]
 name = "sentry-sdk"
 version = "1.5.11"
@@ -1099,6 +1111,19 @@ docs = ["furo", "jaraco.packaging (>=9)", "jaraco.tidelift (>=1.4)", "pygments-g
 testing = ["build[virtualenv]", "filelock (>=3.4.0)", "flake8 (<5)", "flake8-2020", "ini2toml[lite] (>=0.9)", "jaraco.envs (>=2.2)", "jaraco.path (>=3.2.0)", "mock", "pip (>=19.1)", "pip-run (>=8.8)", "pytest (>=6)", "pytest-black (>=0.3.7)", "pytest-checkdocs (>=2.4)", "pytest-cov", "pytest-enabler (>=1.3)", "pytest-flake8", "pytest-mypy (>=0.9.1)", "pytest-perf", "pytest-xdist", "tomli-w (>=1.0.0)", "virtualenv (>=13.0.0)", "wheel"]
 testing-integration = ["build[virtualenv]", "filelock (>=3.4.0)", "jaraco.envs (>=2.2)", "jaraco.path (>=3.2.0)", "pytest", "pytest-enabler", "pytest-xdist", "tomli", "virtualenv (>=13.0.0)", "wheel"]
 
+[[package]]
+name = "setuptools-rust"
+version = "1.5.1"
+description = "Setuptools Rust extension plugin"
+category = "main"
+optional = false
+python-versions = ">=3.7"
+
+[package.dependencies]
+semantic-version = ">=2.8.2,<3"
+setuptools = ">=62.4"
+typing-extensions = ">=3.7.4.3"
+
 [[package]]
 name = "signedjson"
 version = "1.1.4"
@@ -1600,7 +1625,7 @@ url_preview = ["lxml"]
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.7.1"
-content-hash = "0df36bf75561fef340a7af704ed379b235f07a7d4a231aaccec5e7afb87159ca"
+content-hash = "79cfa09d59f9f8b5ef24318fb860df1915f54328692aa56d04331ecbdd92a8cb"
 
 [metadata.files]
 attrs = [
@@ -2472,6 +2497,10 @@ secretstorage = [
     {file = "SecretStorage-3.3.1-py3-none-any.whl", hash = "sha256:422d82c36172d88d6a0ed5afdec956514b189ddbfb72fefab0c8a1cee4eaf71f"},
     {file = "SecretStorage-3.3.1.tar.gz", hash = "sha256:fd666c51a6bf200643495a04abb261f83229dcb6fd8472ec393df7ffc8b6f195"},
 ]
+semantic-version = [
+    {file = "semantic_version-2.10.0-py2.py3-none-any.whl", hash = "sha256:de78a3b8e0feda74cabc54aab2da702113e33ac9d9eb9d2389bcf1f58b7d9177"},
+    {file = "semantic_version-2.10.0.tar.gz", hash = "sha256:bdabb6d336998cbb378d4b9db3a4b56a1e3235701dc05ea2690d9a997ed5041c"},
+]
 sentry-sdk = [
     {file = "sentry-sdk-1.5.11.tar.gz", hash = "sha256:6c01d9d0b65935fd275adc120194737d1df317dce811e642cbf0394d0d37a007"},
     {file = "sentry_sdk-1.5.11-py2.py3-none-any.whl", hash = "sha256:c17179183cac614e900cbd048dab03f49a48e2820182ec686c25e7ce46f8548f"},
@@ -2484,6 +2513,10 @@ setuptools = [
     {file = "setuptools-65.3.0-py3-none-any.whl", hash = "sha256:2e24e0bec025f035a2e72cdd1961119f557d78ad331bb00ff82efb2ab8da8e82"},
     {file = "setuptools-65.3.0.tar.gz", hash = "sha256:7732871f4f7fa58fb6bdcaeadb0161b2bd046c85905dbaa066bdcbcc81953b57"},
 ]
+setuptools-rust = [
+    {file = "setuptools-rust-1.5.1.tar.gz", hash = "sha256:0e05e456645d59429cb1021370aede73c0760e9360bbfdaaefb5bced530eb9d7"},
+    {file = "setuptools_rust-1.5.1-py3-none-any.whl", hash = "sha256:306b236ff3aa5229180e58292610d0c2c51bb488191122d2fc559ae4caeb7d5e"},
+]
 signedjson = [
     {file = "signedjson-1.1.4-py3-none-any.whl", hash = "sha256:45569ec54241c65d2403fe3faf7169be5322547706a231e884ca2b427f23d228"},
     {file = "signedjson-1.1.4.tar.gz", hash = "sha256:cd91c56af53f169ef032c62e9c4a3292dc158866933318d0592e3462db3d6492"},

pyproject.toml

@@ -52,6 +52,9 @@ include_trailing_comma = true
 combine_as_imports = true
 skip_gitignore = true
 
+[tool.maturin]
+manifest-path = "rust/Cargo.toml"
+
 [tool.poetry]
 name = "matrix-synapse"
 version = "1.66.0"
@@ -82,7 +85,16 @@ include = [
     { path = "sytest-blacklist", format = "sdist" },
     { path = "tests", format = "sdist" },
     { path = "UPGRADE.rst", format = "sdist" },
+    { path = "Cargo.toml", format = "sdist" },
+    { path = "rust/Cargo.toml", format = "sdist" },
+    { path = "rust/Cargo.lock", format = "sdist" },
+    { path = "rust/src/**", format = "sdist" },
 ]
+exclude = [
+    { path = "synapse/*.so", format = "sdist"}
+]
+
+build = "build_rust.py"
 
 [tool.poetry.scripts]
 synapse_homeserver = "synapse.app.homeserver:main"
@@ -161,6 +173,15 @@ importlib_metadata = { version = ">=1.4", python = "<3.8" }
 # This is the most recent version of Pydantic with available on common distros.
 pydantic = ">=1.7.4"
 
+# This is for building the rust components during "poetry install", which
+# currently ignores the `build-system.requires` directive (c.f.
+# https://github.com/python-poetry/poetry/issues/6154). Both `pip install` and
+# `poetry build` do the right thing without this explicit dependency.
+#
+# This isn't really a dev-dependency, as `poetry install --no-dev` will fail,
+# but the alternative is to add it to the main list of deps where it isn't
+# needed.
+setuptools_rust = ">=1.3"
 
 
 # Optional Dependencies
@@ -285,5 +306,21 @@ twine = "*"
 towncrier = ">=18.6.0rc1"
 
 [build-system]
-requires = ["poetry-core>=1.0.0"]
+requires = ["poetry-core>=1.0.0", "setuptools_rust>=1.3"]
 build-backend = "poetry.core.masonry.api"
+
+
+[tool.cibuildwheel]
+# Skip unsupported platforms (by us or by Rust).
+skip = "cp36* *-musllinux_i686"
+
+# We need a rust compiler
+before-all =  "curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain stable -y"
+environment= { PATH = "$PATH:$HOME/.cargo/bin" }
+
+# For some reason if we don't manually clean the build directory we
+# can end up polluting the next build with a .so that is for the wrong
+# Python version.
+before-build = "rm -rf {project}/build"
+build-frontend = "build"
+test-command = "python -c 'from synapse.synapse_rust import sum_as_string; print(sum_as_string(1, 2))'"

rust/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+# We name the package `synapse` so that things like logging have the right
+# logging target.
+name = "synapse"
+
+# dummy version. See pyproject.toml for the Synapse's version number.
+version = "0.1.0"
+
+edition = "2021"
+rust-version = "1.61.0"
+
+[lib]
+name = "synapse"
+crate-type = ["cdylib"]
+
+[package.metadata.maturin]
+# This is where we tell maturin where to place the built library.
+name = "synapse.synapse_rust"
+
+[dependencies]
+pyo3 = { version = "0.16.5", features = ["extension-module", "macros", "abi3", "abi3-py37"] }

rust/src/lib.rs

@@ -0,0 +1,15 @@
+use pyo3::prelude::*;
+
+/// Formats the sum of two numbers as string.
+#[pyfunction]
+#[pyo3(text_signature = "(a, b, /)")]
+fn sum_as_string(a: usize, b: usize) -> PyResult<String> {
+    Ok((a + b).to_string())
+}
+
+/// The entry point for defining the Python module.
+#[pymodule]
+fn synapse_rust(_py: Python<'_>, m: &PyModule) -> PyResult<()> {
+    m.add_function(wrap_pyfunction!(sum_as_string, m)?)?;
+    Ok(())
+}

stubs/synapse/synapse_rust.pyi

@@ -0,0 +1 @@
+def sum_as_string(a: int, b: int) -> str: ...

tests/test_rust.py

@@ -0,0 +1,11 @@
+from synapse.synapse_rust import sum_as_string
+
+from tests import unittest
+
+
+class RustTestCase(unittest.TestCase):
+    """Basic tests to ensure that we can call into Rust code."""
+
+    def test_basic(self):
+        result = sum_as_string(1, 2)
+        self.assertEqual("3", result)