Tracing
The Tracing API offers a detailed overview of the operations performed by the Maps SDK. The tracing information includes style loading, tile parsing, and rendering events. Notably, the Tracing API is efficiently integrated with Xcode Instruments, ensuring a streamlined workflow for developers.
How to enable tracing
The tracing support in Maps v11 takes advantage of signpost events, which is an important instrument for analyzing performance and detecting bottlenecks. Here is how you can enable tracing:
Tracing.status = .enabled
Or, you can set the MAPBOX_MAPS_SIGNPOSTS_ENABLED environment variable to 1 in your application scheme.
Note that these options will enable all available Maps SDK components for tracing.
Configure tracing components
Signposts in the Maps SDK are currently separated into two components:
| Tracing component | Description |
|---|---|
core | Rendering engine (responsible for almost every rendering aspect in the MapView and Snapshotter). |
platform | Maps SDK functionality like gestures, animations, view annotations, etc. |
The tracing may generate a lot of events for each frame so that Instruments
might skip some of them in Immediate record mode. Enable Last N seconds
mode to preserve full signpost data (see
more).
You can limit signposts generation for a single component using the following API:
Tracing.status = .platform
You can also configure tracing components through the environment variable using a comma separated list of components:
MAPBOX_MAPS_SIGNPOSTS_ENABLED=core,platform
Pass 0 or disabled to disable tracing through environment variable.
Tracing.status API takes precedence over environment variable value. All values are case-insensitive.
Record traces and analyze the results
You can record traces using the Xcode Instruments application. The simplest way is to select Build and profile the current scheme in Xcode, and when the Instruments application starts, use the blank template and then add os_signpost instrument from the instrument library.
When the interesting part of the application is profiled, you can analyze the results. Here is an example of the MapView initialization and rendering of the Map content.