Our safety and alerting products work with geographic zones: a country, a region, a flood-warning area. A zone is a set of polygons, and those polygons decide, cell by cell, who gets alerted. That last part is what makes this a more interesting problem than it looks. This post is the write-up of a hackathon project that started as “these polygons are too big, let’s simplify them” and ended somewhere more subtle: you cannot simplify a coverage geometry the way you simplify a geometry you only want to draw.

This is Part 1 of a multi-part series on integrating Rust into a large C codebase.

• Part 1: Integrating Rust in a Waf-based C Build System
• Part 2: First Rust Component: Rewriting farchc (WIP)

Introduction

lib-common is a C library developed by Intersec . It provides core utilities (strings, containers, memory management), networking (HTTP, RPC, event loop), serialization through IOP (Intersec Object Packer, similar to Protocol Buffers), etc. It targets Linux environments and has been in active development for many years.

Introduction

Cython is a programming language that makes writing C extensions for Python as easy as Python itself. It lets us write Python code that calls back and forth from and to C/C++ code natively, and compiles to efficient C code usable as a Python extension module.

At Intersec , we use Cython in lib-common , our open-source C library. One of its key components is IOPy, the Python binding for our IOP serialization framework (similar to Protocol Buffers). IOPy dynamically creates Python classes from IOP type definitions at DSO load time, and each class needs to hold a pointer to its C type descriptor for fast serialization.