Development Environment

If you are writing code, the first task to tackle is setting up the development environment.

You will need to check out the code, and at a minimum, build the Rust binaries.

Most developers will also install Python and/or R: If you are only interested in developing a feature in one of these languages, you will not need to set up the other.

Clone the OpenDP Repo

If you want to submit PRs, but don’t have write access to the OpenDP repository, you will either need to request to join the organization or make a fork. The GitHub documentation explains forking.

Clone the repo (or your fork) and change into the opendp directory that’s created.

git clone git@github.com:opendp/opendp.git
cd opendp

If you have not set up SSH, you can clone with https instead:

git clone https://github.com/opendp/opendp.git

Rust Build

If you have not already, install the Rust toolchain.

Make sure you are on the latest Rust version:

rustup update

Now run cargo build in the rust subdirectory of the repo:

cd rust
cargo build --all-features

This will compile a debug build of the OpenDP shared library, placing it in the directory opendp/rust/target/debug. (The specific name of the library file will vary depending on your platform.)

Substitute cargo build with cargo test to test, or cargo check to run a lightweight check that the code is valid.

In the above commands, the features untrusted and bindings are enabled.

Setting a feature changes how the crate compiles:

Feature List

Name	Description
untrusted	Enables untrusted features contrib and floating-point.
contrib	Enable to include constructors that have not passed the vetting process.
honest-but-curious	Enable to include constructors that are only private if the constructor arguments are honest.
floating-point	Enable to include transformations/measurements with floating-point vulnerabilities.
bindings	Enable to generate Python and R source code. Depends on the ffi and derive features.
partials	Enable to generate then_* functions from the corresponding make_* functions. Depends on the derive feature.
ffi	Enable to include C foreign function interfaces. Implicit in the bindings feature.
derive	Enable to support code generation and links to proofs in documentation. Implicit in the bindings and partials features.
use-openssl	Already enabled. Use OpenSSL for secure noise generation.

To make the crate compile faster, FFI functions in debug builds support a reduced set of primitive types. Release-mode builds support the full set of primitive types and undergo compiler optimizations, but take longer to compile. You can compile a release build by adding the --release flag. In contrast to debug builds, release builds are located in opendp/rust/target/release. To use a release-mode binary from the Python bindings, set the environment variable OPENDP_TEST_RELEASE=1 before importing OpenDP.

If you run into problems, please contact us!

Python Setup

If you have not already, install Python version 3.9 or higher.

You can install a local Python package that uses your new OpenDP binary.

Optional Virtual Environment

We recommend setting up a virtual environment first, but this is optional:

# recommended. conda is just as valid
cd opendp
python3 -m venv .venv
source .venv/bin/activate

Change to the python directory, install dependencies, and then install the Python OpenDP library itself.

cd python

pip install -r requirements-dev.txt
pip install -e '.[scikit-learn,polars]'

requirement-dev.txt is compiled from requirements-dev.in: To update dependencies, follow the directions in that file.

In the second line, the -e flag is significant! It stands for “editable”, meaning you only have to run this command once. That is, you do not need to reinstall the OpenDP Python package if changes are made in the /python/src folder or to the library binary, but you should restart the Python interpreter or kernel.

At this point, you should be able import OpenDP as a locally installed package:

import opendp

Note

If you encounter the following error on import:

OSError: dlopen ... (mach-o file, but is an incompatible architecture)

You should check that the architecture from rustc -vV matches your Python architecture. This can occur if you are on a Mac M1 and have an x86_64 Python install.

Python Tests

You can test that things are working by running OpenDP’s Python test suite, using pytest. Run the tests from the python directory.

pytest -v

If everything has gone well, you’ll see a bunch of output, then a line similar to this:

================== 57 passed in 1.02s ==================

If pytest is not found, don’t forget to activate your virtual environment!

This is just a quick overview of building OpenDP.

Python Documentation

This documentation website is built with Sphinx. The source code and developer documentation is here.

R Setup

If you have not already, install R.

Then, set an environment variable to the absolute path of the OpenDP Library binary directory:

export OPENDP_LIB_DIR=`realpath rust/target/debug`

The default R install for MacOS also includes GUI elements like Tcl/Tk, so for the smoothest development experience we suggest these additional installs:

brew install harfbuzz fribidi libgit2 xquartz

Then, install devtools in R:

install.packages(c("devtools", "RcppTOML", "lintr"))

After each edit to the R or Rust source, run the following command in R to (re)load the R package:

devtools::load_all("R/opendp/", recompile=TRUE)

To do a full package installation from local sources:

tools/r_stage.sh && Rscript -e 'devtools::install("R/opendp")'

To restore to a developer setup, run:

tools/r_stage.sh -c

R Tests

Run tests (tests are located in R/opendp/tests/):

devtools::test("R/opendp")

R also has a built-in check function that runs tests and checks for common errors:

devtools::check("R/opendp")

To run the same check manually, use:

R CMD build R/opendp
R CMD check opendp_*.tar.gz --as-cran

It is important R CMD check is run on the .tar.gz, not on R/opendp, because check depends on some of the changes build makes within the .tar.gz.

R Documentation

This script uses roxygen to generate R/opendp/man pages from #' code comments, and then uses pkgdown to render the documentation website.

tools/r_stage.sh -d

Developer Tooling

There are many development environments that work with Rust and LaTex. Here are a few:

• VS Code

• Intellij IDEA

• Sublime

Use whatever tooling you are comfortable with.

A few notes on VS Code:

• Be sure to install the rust-analyzer plugin, not the Rust plugin

• Open rust-analyzer’s extension settings, search “features” and add "untrusted", "bindings"

• Look for Problems in the bottom panel for live compilation errors as you work

• Other useful extensions are “Better Toml”, “crates” and “LaTex Workshop”

• To configure VS Code with suggested tasks and settings: cp -a .vscode-suggested .vscode

A few notes on Intellij IDEA:

• Both Intellij IDEA community edition and the CodeWithMe plugin are free

• Be sure to open the project at the root of the git repository

• Be sure to install the Python and Rust plugins for interactivity

• Be sure to “attach” the Cargo.toml in the red banner the first time you open a Rust source file

• Use run configurations to build the Rust library and run tests