Relevancy

The relevancy component tracks the user's interests locally, without sharing any data over the network. The component currently supports building an interest vector based on the URLs they visit.

Setting up the store

You need to import the following components to work with the RelevancyStore (these come from the generated relevancy.swift file, produced by uniffi):

import class MozillaAppServices.RelevancyStore
import struct MozillaAppServices.InterestVector

On startup of your application, you create a RelevancyStore. The store is initialized with a database path where the user’s interest vector will be stored:

let store = try RelevancyStore(dbPath: pathToDatabase)
  • dbPath: This is the path to the SQLite database where the relevancy data is stored. The initialization is non-blocking, and the database is opened lazily.

Ingesting relevancy data

Ingesting user data into the RelevancyStore builds the user's interest vector based on the top URLs they visit (measured by frequency). This should be called soon after startup but does not need to be scheduled periodically.

Example usage of ingest:

let topUrlsByFrequency: [String] = ["https://example.com", "https://another-example.com"]
try store.ingest(topUrlsByFrequency: topUrlsByFrequency)
  • topUrlsByFrequency: A list of URLs ranked by how often and recently the user has visited them. This data is used to build the user's interest vector.
  • The ingest function returns an InterestVector, which contains the user's interest levels for different tracked categories.

The ingestion process includes:

  • Downloading the interest data from remote settings (eventually cached/stored in the database).
  • Matching the user’s top URLs against the interest data.
  • Storing the interest vector in the database.

This method may execute for a long time and should only be called from a worker thread.

Getting the user's interest vector

After ingestion, you can retrieve the user's interest vector directly. This is useful for displaying the vector on an about: page or using it in other features.

Example usage of userInterestVector:

let interestVector = try store.userInterestVector()
  • This method returns an InterestVector, which is a record with a field that measures the interest for each category we track. The counts are not normalized.

Interrupting ongoing operations

If the application is shutting down or you need to stop ongoing database queries, you can call interrupt() to stop any work that the RelevancyStore is doing.

Example usage of interrupt:

store.interrupt()
  • This interrupts any in-progress work, like ingestion or querying operations.

Shutdown

Before shutting down the application, you should call close() to close the database and other open resources.

Example usage of close:

store.close()
  • This will close any open resources and interrupt any in-progress queries running on other threads.