Contributor Guide on Lucille

Project Structure and Build

Mon, 09 Jun 2025 00:00:00 +0000

Overview

Lucille is a multi-module Maven project. The module hierarchy is:

lucille (root aggregator)
├── lucille-parent # parent POM: dependency versions, plugin config, build profiles
├── lucille-bom # Bill of Materials: version-aligned dependency declarations
├── lucille-core # the framework itself: Runner, Worker, Indexer, Pipeline, Document, Stages, Connectors
├── lucille-plugins/ # optional modules with heavy or specialized dependencies
│ # (tika, pinecone, weaviate, jlama, parquet, ocr, video, entity-extraction, api)
└── lucille-examples/ # runnable example projects demonstrating common ingestion patterns (not published to Maven Central)

The Modules

lucille-parent

The parent POM that all other modules inherit from. It defines:

Setup & Standards

Tue, 15 Oct 2024 00:00:00 +0000

Local Developer Setup

Prerequisite(s):

IntelliJ application installed on machine
Java project

Setting up Google Code Formatting Scheme

Make sure that Intellij is open
Go to the following link: styleguide/intellij-java-google-style.xml at gh-pages · google/styleguide
Download the .xml file
Open the file in an editor of your choice
Navigate to the <option …> tag with name ‘Right Margin’ and edit the value to be 132 (it should default as 100)
Save the file
In Intellij IDEA, navigate to Settings | Preferences → Code Style → Editor → Java
Click on the gear icon on the right panel and drill down to the option Import Scheme and then to Intellij IDEA Code Style XML
In the file explorer that opens, navigate to where you stored the aforementioned .xml file we downloaded
After selecting the file, you should see a pop-up allowing you to name the scheme; select a name and click ‘Okay’
Click ‘Apply’ in the Settings panel
Restart the IDE; You can use the ‘Reformat Code’ option to apply the plug-in on your code

Excluding Non-Java Files

Assuming that we don’t want to auto-format non-java files via a directory level ‘Reformat Code’ option, we need to exclude all other files from being reformatted

Coding Conventions

Mon, 09 Jun 2025 00:00:00 +0000

Lucille follows conventions broadly consistent with the Google Java Style Guide, with some deviations noted below. There is no enforced checkstyle or formatter plugin in the build — conventions are maintained through code review.

Formatting

Indentation: 2 spaces. All source files use 2-space indentation, consistent with Google style. No tabs.

Line length: No strict enforced limit, but lines are generally kept under 120 characters. Long lines (especially in constructors with many parameters or complex conditionals) are broken at natural points.