1.0.0-beta.1

First Beta release

Hi everyone, this is the first beta release of the tracing API.

We changed many things but believe we have arrived at the final API shapes of the library.

Most notably, it is possible to stick to concrete types if necessary, abstract away the notion of time, as well as mutate span names in-flight before they are ended.

No-op tracing also gained significant performance improvements, with NoopSpan becoming a struct and therefore not incurring reference counting traffic. And time is not going to be read unless the tracer decides to do so (allowing for no-op and inactive spans to avoid reading the system clock).

Call to action: please try out the APIs in your tracers or adoption

Please try out the APIs before we freeze them in a 1.0 release in the coming weeks.

During the beta period, we are still able to perform any breaking or important changes before this API will become frozen for the foreseeable future. Please raise your issues on the github issue tracker.

Updating from 0.3.x

There have been a number of source breaking changes in order to achieve the ideal 1.0 shape of APIs since the 0.3.x series of this library.

• protocol Tracer became protocol TracerProtocol
  • this was in order to introduce the Tracer namespace so that we can offer Tracer.withSpan(...) { ... } rather than the too long InstrumentationSystem.tracer.withSpan(...) {
• the startSpan protocol requirement now accepts a function and clock parameters
  • please use the clock to obtain the timestamp of the events emitted by the tracer, rather than other time sources
  • by default the DefaultTracerClock will be used
• a new LegacyTracerProtocol is introduced which is designed specifically to support Swift 5.6 clients
  • this protocol cannot make use of returning generic Span types, and has to erase them to any Span, which is why all APIs are phrased as startAnySpan
  • this protocol will be deprecated as soon as the library is able to require Swift 5.7, however it will not be removed in order to retain source compatibility with adopters who may have been using this API for a migration period.
  • if your library adopting (or implementing) distributed tracing CAN use Swift 5.7+, please implement the TracerProtocol directly; Implementations for the Any versions of APIs will be provided for you automatically, delegating to your startSpan implementation, so you do not need to implement any of the Legacy APIs.
• documentation updates are incoming, including full guides for implementing and using tracers here: #69

Swift versions

We are going to stick to the AsyncHTTP, gRPC and other core server library's Swift support strategy.

This means that this package currently will support Swift: 5.6, 5.7, 5.8, and when 5.9 is released, we will drop support for 5.6.
Supporting Swift 5.6 comes with a significant burden for this project, and we want to drop it as soon as our adopters allow us to (i.e. AsyncHTTPClient and friends).

We envision this library to be depended on by these projects and therefore must adhere to their minimum supported Swift policies.

What's Changed

• startSpan should take tracepoint location by @ktoso in #68
• Add .spi.yml for Swift Package Index DocC support by @yim-lee in #72
• Change 'landing' target to Tracing by @yim-lee in #74
• notes about LoggingContext by @ktoso in #75
• Add CI for Swift 5.8 and update nightly to Ubuntu 22.04 by @yim-lee in #76
• Mark types Sendable by @ktoso in #83
• Update CoC and add CONTRIBUTING file by @ktoso in #87
• Allow for reading and mutating a span name by @ktoso in #88
• Recording an error may carry attributes by @ktoso in #90
• associated type Span, Tracer as short-hand, and *Protocol types by @ktoso in #93
• Enable struct Spans with reference semantics; optimal NoopSpan by @ktoso in #94
• remove not used docker configurations by @ktoso in #96
• remove linux test shims by @ktoso in #97
• Provide explicit set/get to avoid SpanAttributeConvertible wrapping by @ktoso in #95
• Implement TracerClock and abstract away "now" by @ktoso in #98

Full Changelog: 0.3.1...1.0.0-beta.1