Here is a quick overview of the most important code parts. They can be found in the telemetry folder.

  • TelemetryController: Main telemetry logic, e.g. assembling pings, local storage (when archiving is enabled), preference changes, testing

  • Telemetry.cpp contains most of the public interface, implements the IDL

  • The different data types for telemetry are handled in TelemetryHistogram, TelemetryScalar, TelemetryEvent.

  • TelemetryEnvironment: A helper for gathering environment data, like build version or graphics data

  • TelemetryScheduler: Starts regular jobs for collecting and sending data

  • TelemetrySend: Sending and caching of pings

  • TelemetryStorage: Handles writing pings to disk for TelemetrySend

  • TelemetrySession: Collects data for a browsing session, includes many of the most important probes (aka metrics)

  • Policy: A layer of indirection added to provide testability. A common pattern in many files

  • pings/: Contains definitions and handling for most ping types, like EventPing

More details on different topics can be found in these chapters: