concrete/docs/dev/GETTING-STARTED.md

Getting Started

Preparation

Before you can start improving concretefhe you need to set up your development environment! This section will show how you can do that.

Installing Python v3.8

concretefhe is a Python library. So Python should be installed to develop concretefhe. v3.8 is recommended because our CI also uses v3.8.

You can follow this guide to install it (alternatively you can google how to install python 3.8).

Installing Poetry

Poetry is our package manager. It simplifies dependency and environment management by a lot.

You can follow this official guide to install it.

Installing make

The dev tools use make to launch the various commands.

On Linux you can install make from your distribution's preferred package manager.

On Mac OS you can install a more recent version of make via brew:

# check for gmake
which gmake
# If you don't have it, it will error out, install gmake
brew install make
# recheck, now you should have gmake
which gmake

It is possible to install gmake as make, check this StackOverflow post for more infos.

On Windows check this GitHub gist.

/!\ In the next sections, be sure to use the proper make tool for your system, make, gmake or other. /!\

Cloning repository

Now, it's time to get the source code of concretefhe. You can use the following command to do that.

git clone https://github.com/zama-ai/concretefhe-internal.git

Setting up environment

We are going to make use of virtual environments. This helps to keep the project isolated from other Python projects in the system. The following commands will create a new virtual environment under the project directory and install dependencies to it.

cd concrete
make setup_env

Activating the environment

Finally, all we need to do is to activate the newly created environment using the following command.

source .venv/bin/activate

Leaving the environment

After your work is done you can simply run the following command to leave the environment.

deactivate

Syncing environment with the latest changes

From time to time, new dependencies will be added to project or the old ones will be removed. The command below will make sure the project have proper environment. So run it regularly!

make sync_env

Terminology

In this section we will go over some terms that we use throughout the project.

• intermediate representation
  • a data structure to represent a calculation
  • basically a computation graph where nodes are either inputs or operations on other nodes
• tracing
  • it is our technique to take directly a plain numpy function from a user and deduce its intermediate representation in a painless way for the user
• bounds
  • before intermediate representation is sent to the compiler, we need to know which node will output which type (e.g., uint3 vs uint5)
  • there are several ways to do this but the simplest one is to evaluate the intermediate representation with all combinations of inputs and remember the maximum and the minimum values for each node, which is what we call bounds, and bounds can be used to determine the appropriate type for each node

Module Structure

In this section, we will discuss the module structure of concretefhe briefly. You are encouraged to check individual .py files to learn more!

• concrete
  • common: types and utilities that can be used by multiple frontends (e.g., numpy, torch)
    • bounds_measurement: utilities for determining bounds of intermediate representation
    • compilation: type definitions related to compilation (e.g., compilation config, compilation artifacts)
    • data_types: type definitions of typing information of intermediate representation
    • debugging: utilities for printing/displaying intermediate representation
    • extensions: utilities that provide special functionality to our users
    • representation: type definitions of intermediate representation
    • tracing: utilities for generic function tracing used during intermediate representation creation
  • numpy: numpy frontend of concrete

Working in Docker

Setting up docker and X forwarding

Before you start this section, go ahead and install docker. You can follow this official guide for that.

Linux

xhost +localhost

Mac OS

To be able to use X forwarding on Mac OS: first, you need to install xquartz. Secondly, open XQuartz.app application, and open a new terminal within XQuartz.app. Make sure in the application parameters to authorize network connections are set (currently in the Security settings); finally, in the XQuartz.app terminal, type

xhost +127.0.0.1

and now, the X server should be all set in docker (in the regular terminal).

Windows

Install Xming and use Xlaunch:

• Multiple Windows, Display number: 0
• Start no client
• IMPORTANT: Check No Access Control
• You can save this configuration to re-launch easily, then click finish.

Logging in and building the image

Docker image of concretefhe is based on another docker image provided by the compiler team. Once you have access to this repository you should be able to launch the commands to build the dev docker image with make docker_build.

Upon joining to the team, you need to log in using the following command:

docker login ghcr.io

This command will ask for a username and a password. For username, just enter your GitHub username. For password, you should create a personal access token from here selecting read:packages permission. Just paste the generated access token as your password, and you are good to go.

Once you do that you can get inside the docker environment using the following command:

make docker_build_and_start

After you finish your work, you can leave the docker by using the exit command or by pressing CTRL + D.

Contributing

Now, you have a working environment, and you know what is where in the project.

There are two ways to contribute to concretefhe:

• you can open issues to report bugs, typos and suggest ideas
• you can ask to become an official contributor by emailing hello@zama.ai. Only approved contributors can send pull requests, so please make sure to get in touch before you do!

Let's go over some other important things that you need to be careful about.

Creating a new branch

We are using a consistent branch naming scheme, and you are expected to follow it as well. Here is the format and some examples.

git checkout -b {feat|fix|refactor|test|benchmark|doc|style|chore}/short-description_$issue_id

e.g.

git checkout -b feat/explicit-tlu_11
git checkout -b fix/tracing_indexing_42

Before committing

Each commit to concretefhe should be comformant to the standards decided by the team. Conformance can be checked using the following commands.

make -k pcc
make pytest

Commiting

We are using a consistent commit naming scheme, and you are expected to follow it as well. Here is the format and some examples.

git commit -m "{feat|fix|refactor|test|benchmark|doc|style|chore}{($location)}?: description of the change"

e.g.

git commit -m "feat: implement bounds checking"
git commit -m "feat(debugging): add an helper function to draw intermediate representation"
git commit -m "fix(tracing): fix a bug that crashed pytorch tracer"

To learn more about conventional commits, check this page.

Before creating pull request

We remind that only official contributors can send pull requests. To become such an official contributor, please email hello@zama.ai.

You should rebase on top of main branch before you create your pull request. This is to avoid merge commits and have a clean git log. After you commit your changes to your new branch, you can use the following commands to rebase.

# fetch the list of active remote branches
git fetch --all --prune

# checkout to main
git checkout main

# pull the latest changes to main (--ff-only is there to prevent accidental commits to main)
git pull --ff-only

# checkout back to your branch
git checkout $YOUR_BRANCH

# rebase on top of main branch
git rebase main

# push the latest version of the local branch to remote 
git push --force

You can learn more about rebasing in here.

The last requirement before creating your PR is to make sure you get a hundred percent code coverage. You can verify this using the following command.

make pytest
make coverage

Note that this will compare the coverage with origin/main. If you want to set a custom base branch, you can specify BB environment variable like so BB=$YOUR_BASE_BRANCH make coverage.

If your coverage is below hundred percent, you should write more tests and then create the pull request. If you ignore this warning and create the PR, GitHub actions will fail and your PR will not be merged anyway.

Making docs with Sphinx

One can simply create docs with Sphinx and open them, by doing:

make build_and_open_docs

The documentation contains both files written by hand by developpers and files automatically created by parsing the source files.