* [core] Introduce FileSourceManager and use it for default platform impl
- Add `FileSourceManager` interface that provides access to `FileSource`
instances and means of registering / unregistering `FileSource` factories
- Split `DefaultFileSource` into smaller parts
- Add `DatabaseFileSource` interface and it's default implementation
- Remove inter-dependencies between concrete `FileSource` classes
* [build] Add files to next build system
* [core] Add generic property setters / getters
* [core] Remove setOnlineStatus from OnlineFileSource interface
* [core] Hide threading implementation details from DatabaseFileSource interface
* [core] Make DB file source methods virtual
* [core] Add documentation for DatabaseFileSource and rename one method
* [core] Use simple callback instead of ActorRef
* [core] Remove ActorRef from OnlineFileSource public header
* [core] Add callback to FileSource::forward async API
* [core] Pass OfflineRegionDefinition by value
* [core] Update tests to use modular file sources
* [core] Update unit tests
* [core] Update unit tests after rebase
* [core] Backport low prio fix for cached requests
* [core] Backport pack database
* [core] Return removed factory from unRegisterFileSourceFactory
* [core] Rename shadowed args in onlinefilesource
* [core] Remove simple std::function callback aliases
* [core] Expose online file source property keys in public header file
* [test-runner] Add proxy file source test runner
* [cache] Update mbgl-cache utility to use new file source
* [metrics] Rebaseline binary size metrics
* [offline] Update offline utility
* [core] Update changelog
Darwin
The code in the Darwin platform targets Apple platforms but is not specific to iOS or macOS. This code is not distributed as an SDK in itself, but is required by the Mapbox iOS SDK and Mapbox macOS SDK.
These files depend on the Foundation and Core Foundation frameworks but do not depend on iOS- or macOS–specific frameworks, such as UIKit or AppKit. Any non-cross-platform code is guarded by TargetConditionals.h macros.