data

data

Generic, concurrency-safe data structures and OpenTelemetry baggage helpers for Go.

Map

A type-safe concurrent map with first-class support for the maps, slices, and iter packages.

m := data.NewMap[string, int]()
m.Set("alpha", 1)
m.Set("beta", 2)
m.Set("gamma", 3)

v, ok := m.Get("alpha") // 1, true

// range over all key-value pairs
for k, v := range m.All() {
    fmt.Println(k, v)
}

// collect into a plain map
snapshot := maps.Collect(m.All())

// collect sorted keys
keys := slices.Sorted(m.Keys())

// collect values
values := slices.Collect(m.Values())

Ref

A self-refreshing reference that periodically calls a function to keep its value current.

ref := data.NewRef[Config](ctx, fetchConfig,
    data.WithInterval[Config](30*time.Second),
    data.WithInitialValue[Config](defaultCfg),
    data.WithOnError[Config](func(err error) {
        slog.Error("config refresh failed", "err", err)
    }),
)

cfg := ref.Value() // always up-to-date

Baggage

Helpers for writing typed values into OpenTelemetry baggage.

ctx = data.SetBaggage(ctx, "user_id", 12345, "tenant", "acme", "region", "us-east-1")

To propagate baggage into logs, wrap your slog.Handler with logger.NewBaggageHandler, which copies baggage members from the context onto each log record. For traces, use the baggagecopy processors from the OTel contrib library.

Usage

go get github.com/jesse0michael/pkg/data