trace

package
v0.8.0 Latest Latest
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 Go to latest Published: Jun 22, 2026 License: MPL-2.0 Imports: 23 Imported by: 0

Documentation

Overview

Package trace provides a dependency-free tracing core for GOWDK Runtime and plain Go applications.

Index

Constants

View Source 
const (
	AttrGOWDKSurface           = "gowdk.surface"
	AttrGOWDKLane              = "gowdk.lane"
	AttrGOWDKSourceFile        = "gowdk.source.file"
	AttrGOWDKSourceLine        = "gowdk.source.line"
	AttrGOWDKSourceCol         = "gowdk.source.column"
	AttrHTTPRoute              = "http.route"
	AttrHTTPRequestMethod      = "http.request.method"
	AttrHTTPResponseStatusCode = "http.response.status_code"
	AttrURLPath                = "url.path"
	AttrServerAddress          = "server.address"
)
View Source 
const (
	SlogTraceIDKey = "trace_id"
	SlogSpanIDKey  = "span_id"
)
View Source 
const (
	// MaxTraceparentHeaderBytes is the maximum traceparent header size accepted
	// by Extract and ParseTraceparent.
	MaxTraceparentHeaderBytes = 256
	// MaxTracestateHeaderBytes is the W3C tracestate list-member byte budget.
	MaxTracestateHeaderBytes = 512
)

Variables

View Source 
var SinkLogger func(message string) = func(message string) {
	log.Print(message)
}

SinkLogger receives completed-span export failures. Set it to nil to silence sink failure logging. It defaults to the standard log package.

Functions

func ContextWithTraceContext 

func ContextWithTraceContext(ctx context.Context, traceContext TraceContext) context.Context

ContextWithTraceContext returns a context carrying trace identity.

func ContextWithTracer 

func ContextWithTracer(ctx context.Context, tracer *Tracer) context.Context

ContextWithTracer returns a context carrying tracer for child spans started by helper packages such as runtime/app and runtime/contracts.

func EntropyFailureCount added in v0.8.0 

func EntropyFailureCount() uint64

EntropyFailureCount reports how many crypto/rand failures the default ID generator has observed since process start. It is zero on healthy systems. A non-zero value means trace/span identity could not be generated from the system CSPRNG and the affected spans were dropped rather than assigned a predictable identifier.

func Extract 

func Extract(ctx context.Context, carrier Carrier) context.Context

Extract reads W3C traceparent/tracestate headers from carrier into ctx.

func Inject 

func Inject(ctx context.Context, carrier Carrier)

Inject writes the active span or trace context from ctx into carrier.

func MatchLane added in v0.8.0 

func MatchLane(lane Lane) func(SamplingContext) bool

MatchLane matches spans on the given GOWDK lane.

func MatchSpanName added in v0.8.0 

func MatchSpanName(name string) func(SamplingContext) bool

MatchSpanName matches spans whose name equals name.

func MatchSpanNamePrefix added in v0.8.0 

func MatchSpanNamePrefix(prefix string) func(SamplingContext) bool

MatchSpanNamePrefix matches spans whose name starts with prefix.

func MatchSurface added in v0.8.0 

func MatchSurface(surface Surface) func(SamplingContext) bool

MatchSurface matches spans on the given GOWDK surface.

func NormalizeSourceFile added in v0.8.0 

func NormalizeSourceFile(file string, policy SourcePolicy) string

NormalizeSourceFile applies policy to a single SourceRef.File value.

In the default relative mode it never returns an absolute path: Windows drive letters and UNC prefixes are stripped, the path is made relative to policy.ProjectRoot when it lies beneath it, leading separators are removed, and leading parent-directory ("..") segments are collapsed so the logical path cannot escape the project root. In absolute mode the path is returned cleaned but otherwise unchanged.

func SetEntropyFailureHandler added in v0.8.0 

func SetEntropyFailureHandler(handler func(error))

SetEntropyFailureHandler installs a callback invoked for each crypto/rand failure observed by the default ID generator. Pass nil to clear it.

The handler must not start spans or otherwise re-enter the tracer: doing so during an entropy failure can recurse. Use it to increment an external metric or emit a single rate-limited alert.

func SetSourcePolicy added in v0.8.0 

func SetSourcePolicy(policy SourcePolicy)

SetSourcePolicy installs the process-wide source-path normalization policy. It is applied to every span snapshot before it is exposed through the trace viewer, JSON/SSE, console, or OTLP surfaces. The zero SourcePolicy (relative mode, no project root) is the default and never exposes absolute paths.

func SlogArgs added in v0.8.0 

func SlogArgs(ctx context.Context) []any

SlogArgs returns trace/span attributes as alternating key/value args for slog.Logger methods.

func SlogAttrs added in v0.8.0 

func SlogAttrs(ctx context.Context) []slog.Attr

SlogAttrs returns stable slog attributes for the active trace context. It returns nil when ctx has no valid trace identity.

func Traceparent 

func Traceparent(traceContext TraceContext) string

Traceparent encodes traceContext as a W3C traceparent header.

Types

type Attribute 

type Attribute struct {
	Key   string `json:"key"`
	Value any    `json:"value,omitempty"`
}

Attribute is an OpenTelemetry-compatible key/value attribute. Supported values are string, bool, integer, float64, and homogeneous slices of those scalar forms. Trace boundaries copy supported values and drop unsupported pointer/map/object values so snapshots remain serialization-safe.

type Carrier 

type Carrier interface {
	Get(string) string
	Set(string, string)
}

Carrier is the minimal interface implemented by http.Header and compatible request metadata maps.

type Collector 

type Collector struct {
	// contains filtered or unexported fields
}

Collector combines an in-memory ring sink with a small HTTP JSON/SSE handler for local inspection.

func NewCollector 

func NewCollector(limit int, options ...CollectorOption) *Collector

NewCollector creates a collector backed by a RingSink.

func (*Collector) Dropped 

func (collector *Collector) Dropped() uint64

Dropped returns the ring overflow and slow-subscriber drop count.

func (*Collector) Handler 

func (collector *Collector) Handler() http.Handler

Handler serves recent spans as JSON. Requests to /events or requests with an Accept header containing text/event-stream receive an SSE stream of existing and future spans. POST requests accept one Snapshot or a JSON array of Snapshots so generated browser runtimes can join frontend spans to backend traces without another collector dependency.

func (*Collector) HealthSnapshot added in v0.8.0 

func (collector *Collector) HealthSnapshot() CollectorHealthSnapshot

HealthSnapshot returns local collector storage, rejection, and stream queue health.

func (*Collector) RecordSpan 

func (collector *Collector) RecordSpan(ctx context.Context, span Snapshot) error

RecordSpan implements Sink.

func (*Collector) Rejected added in v0.8.0 

func (collector *Collector) Rejected() uint64

Rejected returns the number of rejected ingest or stream requests.

func (*Collector) Spans 

func (collector *Collector) Spans() []Snapshot

Spans returns completed spans from oldest to newest.

func (*Collector) ViewerHandler 

func (collector *Collector) ViewerHandler() http.Handler

ViewerHandler serves a self-contained local trace viewer plus JSON and SSE endpoints. Generated apps mount it behind an access gate when enabling it outside dev; raw callers should do the same for internet-facing handlers.

type CollectorHealthSnapshot added in v0.8.0 

type CollectorHealthSnapshot struct {
	Spans                    int    `json:"spans"`
	Dropped                  uint64 `json:"dropped"`
	Rejected                 uint64 `json:"rejected"`
	Subscribers              int    `json:"subscribers"`
	SubscriberQueueDepth     int    `json:"subscriberQueueDepth"`
	SubscriberQueueCapacity  int    `json:"subscriberQueueCapacity"`
	SSELimit                 int    `json:"sseLimit"`
	IngestRateLimit          int    `json:"ingestRateLimit"`
	IngestRateWindowDuration string `json:"ingestRateWindowDuration"`
}

CollectorHealthSnapshot is a point-in-time view of local collector state.

type CollectorOption added in v0.8.0 

type CollectorOption func(*Collector)

CollectorOption configures a Collector.

func WithCollectorIngestRate added in v0.8.0 

func WithCollectorIngestRate(limit int, window time.Duration) CollectorOption

WithCollectorIngestRate sets a fixed-window POST ingest rate per remote address. A non-positive limit or window disables rate limiting.

func WithCollectorSSELimit added in v0.8.0 

func WithCollectorSSELimit(limit int) CollectorOption

WithCollectorSSELimit sets the maximum number of concurrent SSE subscribers. A non-positive limit disables the cap.

type ConsoleSink 

type ConsoleSink struct {
	// contains filtered or unexported fields
}

ConsoleSink writes one readable line per completed span.

ConsoleSink is intended for development and local diagnostics. Span names, status messages, source paths, and event messages can derive from request, route, or browser-supplied values, so every field is escaped (see escapeControl) before it is written: control characters cannot forge an additional log line or emit raw terminal control sequences. Use JSONLSink for production logging where downstream tooling parses structured records.

func NewConsoleSink 

func NewConsoleSink(writer io.Writer) *ConsoleSink

NewConsoleSink creates a console sink.

func (*ConsoleSink) RecordSpan 

func (sink *ConsoleSink) RecordSpan(ctx context.Context, span Snapshot) error

RecordSpan implements Sink.

type CountedSampler 

type CountedSampler struct {
	N uint64
	// contains filtered or unexported fields
}

CountedSampler is a deterministic test helper that samples every n-th span.

func (*CountedSampler) Sample 

func (sampler *CountedSampler) Sample(SamplingContext) bool

Sample implements Sampler.

type CryptoIDGenerator added in v0.8.0 

type CryptoIDGenerator struct{}

CryptoIDGenerator is the default IDGenerator. It reads identifiers from crypto/rand and never falls back to predictable values such as timestamps or sequence counters. On the (extraordinary) event of a crypto/rand failure it records the failure via EntropyFailureCount and the entropy failure handler, then returns an invalid ID so the caller can observe the loss instead of emitting a guessable identifier.

func (CryptoIDGenerator) NewSpanID added in v0.8.0 

func (CryptoIDGenerator) NewSpanID() SpanID

NewSpanID implements IDGenerator.

func (CryptoIDGenerator) NewTraceID added in v0.8.0 

func (CryptoIDGenerator) NewTraceID() TraceID

NewTraceID implements IDGenerator.

type Event 

type Event struct {
	Time       time.Time   `json:"time"`
	Level      string      `json:"level,omitempty"`
	Message    string      `json:"message"`
	Attributes []Attribute `json:"attributes,omitempty"`
}

Event records a timestamped span event.

type Exporter 

type Exporter interface {
	ExportSpans(context.Context, []OTLPSpan) error
}

Exporter receives completed spans in the dependency-free OTLP-like shape.

type IDGenerator added in v0.8.0 

type IDGenerator interface {
	// NewTraceID returns a valid W3C trace ID, or "" if one cannot be produced.
	NewTraceID() TraceID
	// NewSpanID returns a valid W3C span ID, or "" if one cannot be produced.
	NewSpanID() SpanID
}

IDGenerator produces trace and span identifiers for new spans.

The default generator (CryptoIDGenerator) draws identifiers from crypto/rand. Provide a custom generator with WithIDGenerator to make IDs deterministic in tests, or to source identity from another subsystem. A generator may report transient failure by returning an empty (invalid) ID; the tracer treats that as "cannot start a span" rather than substituting a predictable identifier.

type JSONLSink 

type JSONLSink struct {
	// contains filtered or unexported fields
}

JSONLSink writes one JSON object per completed span.

func NewJSONLSink 

func NewJSONLSink(writer io.Writer) *JSONLSink

NewJSONLSink creates a JSON Lines sink.

func (*JSONLSink) RecordSpan 

func (sink *JSONLSink) RecordSpan(ctx context.Context, span Snapshot) error

RecordSpan implements Sink.

type Lane 

type Lane string

Lane identifies the GOWDK execution lane represented by a span. 

const (
	LaneRoute    Lane = "route"
	LaneGuard    Lane = "guard"
	LaneHandler  Lane = "handler"
	LaneSSR      Lane = "ssr"
	LaneAction   Lane = "action"
	LaneAPI      Lane = "api"
	LaneFragment Lane = "fragment"
	LaneContract Lane = "contract"
	LaneJob      Lane = "job"
	LaneIsland   Lane = "island"
	LaneNav      Lane = "nav"
	LaneUser     Lane = "user"
)

type OTLPSpan 

type OTLPSpan struct {
	TraceID           TraceID     `json:"traceId"`
	SpanID            SpanID      `json:"spanId"`
	ParentSpanID      SpanID      `json:"parentSpanId,omitempty"`
	Name              string      `json:"name"`
	StartTimeUnixNano int64       `json:"startTimeUnixNano"`
	EndTimeUnixNano   int64       `json:"endTimeUnixNano"`
	Attributes        []Attribute `json:"attributes,omitempty"`
	Events            []Event     `json:"events,omitempty"`
	Status            Status      `json:"status,omitempty"`
}

OTLPSpan is intentionally shaped like the OTLP span model while remaining a dependency-free value type.

func OTLPSpanFromSnapshot 

func OTLPSpanFromSnapshot(span Snapshot) OTLPSpan

OTLPSpanFromSnapshot converts a completed span to the OTLP-like model.

type RingSink 

type RingSink struct {
	// contains filtered or unexported fields
}

RingSink stores the most recent completed spans in memory. On overflow it drops the oldest span and increments Dropped.

func NewRingSink 

func NewRingSink(limit int) *RingSink

NewRingSink creates a bounded in-memory sink.

func (*RingSink) Dropped 

func (sink *RingSink) Dropped() uint64

Dropped returns the number of spans dropped because the ring was full.

func (*RingSink) RecordSpan 

func (sink *RingSink) RecordSpan(ctx context.Context, span Snapshot) error

RecordSpan implements Sink. It never blocks on external I/O.

func (*RingSink) Spans 

func (sink *RingSink) Spans() []Snapshot

Spans returns completed spans from oldest to newest.

type Sampler 

type Sampler interface {
	Sample(SamplingContext) bool
}

Sampler decides whether a span should be recorded.

func AlwaysOff 

func AlwaysOff() Sampler

AlwaysOff samples no spans.

func AlwaysOn 

func AlwaysOn() Sampler

AlwaysOn samples every span.

func ParentBasedSampler added in v0.8.0 

func ParentBasedSampler(root Sampler) Sampler

ParentBasedSampler returns a sampler that keeps a trace whole: when a span has a propagated parent, it honors the parent's sampling decision; for a root span (no parent) it delegates to root. This is the production-safe default for distributed tracing — a downstream service does not re-roll the dice and split one logical trace into sampled and unsampled fragments. Pair it with RatioSampler as the root to sample a deterministic fraction of whole traces: 

trace.ParentBasedSampler(trace.RatioSampler(0.1))

func RatioSampler 

func RatioSampler(ratio float64) Sampler

RatioSampler returns a deterministic trace-id based sampler. Ratios <= 0 are always off; ratios >= 1 are always on.

func RuleSampler added in v0.8.0 

func RuleSampler(base Sampler, rules ...SamplerRule) Sampler

RuleSampler applies the first matching rule's decision and falls back to base when no rule matches. It is the GOWDK-owned override hook for app and generated route/endpoint policy: silence health checks and noisy endpoints (Keep:false), force high-value endpoints on (Keep:true), and sample everything else with base. 

trace.RuleSampler(
    trace.ParentBasedSampler(trace.RatioSampler(0.1)),
    trace.DropSpansNamed("GET /_gowdk/health"),
    trace.KeepSpansNamed("POST /checkout"),
)

type SamplerRule added in v0.8.0 

type SamplerRule struct {
	Match func(SamplingContext) bool
	// Keep is the decision applied when Match returns true.
	Keep bool
}

SamplerRule overrides the sampling decision for spans whose SamplingContext matches. The first matching rule in a RuleSampler wins.

func DropSpansNamed added in v0.8.0 

func DropSpansNamed(name string) SamplerRule

DropSpansNamed builds a rule that always drops spans with the exact name, for health checks and other always-off endpoints.

func KeepSpansNamed added in v0.8.0 

func KeepSpansNamed(name string) SamplerRule

KeepSpansNamed builds a rule that always keeps spans with the exact name, for high-value endpoints that must be traced regardless of the base ratio.

type SamplingContext 

type SamplingContext struct {
	TraceID       TraceID
	ParentSpanID  SpanID
	HasParent     bool
	ParentSampled bool
	Name          string
	Surface       Surface
	Lane          Lane
	Attributes    []Attribute
}

SamplingContext is passed to samplers before a span is allocated. HasParent and ParentSampled describe the propagated parent decision so a parent-based sampler can keep a trace whole: every span in a sampled trace is kept, and every span in an unsampled trace is dropped.

type Sink 

type Sink interface {
	RecordSpan(context.Context, Snapshot) error
}

Sink receives completed span snapshots.

func ExporterSink 

func ExporterSink(exporter Exporter) Sink

ExporterSink adapts an Exporter into a Sink.

func MultiSink 

func MultiSink(sinks ...Sink) Sink

MultiSink sends completed spans to each sink in order.

type Snapshot 

type Snapshot struct {
	TraceID      TraceID     `json:"traceId"`
	SpanID       SpanID      `json:"spanId"`
	ParentSpanID SpanID      `json:"parentSpanId,omitempty"`
	Name         string      `json:"name"`
	Surface      Surface     `json:"surface,omitempty"`
	Lane         Lane        `json:"lane,omitempty"`
	Source       SourceRef   `json:"source,omitempty"`
	Attributes   []Attribute `json:"attributes,omitempty"`
	Events       []Event     `json:"events,omitempty"`
	Status       Status      `json:"status,omitempty"`
	StartTime    time.Time   `json:"startTime"`
	EndTime      time.Time   `json:"endTime"`
	DurationNS   int64       `json:"durationNs"`
}

Snapshot is the immutable JSON/export shape of a completed span.

type SourcePathMode added in v0.8.0 

type SourcePathMode int

SourcePathMode controls how SourceRef.File paths are exposed outside the process (trace viewer, JSON/SSE, console, and OTLP export). 

const (
	// SourcePathRelative reduces absolute filesystem paths to project-relative
	// logical paths so local filesystem structure is not revealed to trace
	// consumers. It is the default and the only production-safe mode.
	SourcePathRelative SourcePathMode = iota
	// SourcePathAbsolute exposes source paths verbatim, including absolute local
	// filesystem paths. It is a debugging aid for local development and must not
	// be enabled when traces leave the machine.
	SourcePathAbsolute
)

type SourcePolicy added in v0.8.0 

type SourcePolicy struct {
	// Mode selects relative (default) or absolute path exposure.
	Mode SourcePathMode
	// ProjectRoot, when set, is the directory that absolute source paths under
	// it are made relative to in SourcePathRelative mode.
	ProjectRoot string
}

SourcePolicy controls source-path normalization applied to a span snapshot's SourceRef.File before the snapshot is exposed outside the process.

func CurrentSourcePolicy added in v0.8.0 

func CurrentSourcePolicy() SourcePolicy

CurrentSourcePolicy returns the active source-path normalization policy.

type SourceRef 

type SourceRef struct {
	File      string `json:"file,omitempty"`
	Line      int    `json:"line,omitempty"`
	Column    int    `json:"column,omitempty"`
	OwnerKind string `json:"ownerKind,omitempty"`
	OwnerID   string `json:"ownerId,omitempty"`
}

SourceRef points a span back to GOWDK source or generated runtime metadata.

type Span 

type Span struct {
	// contains filtered or unexported fields
}

Span records one sampled unit of work. Methods are nil-safe so callers can defer span.End() even when sampling is disabled.

func SpanFrom 

func SpanFrom(ctx context.Context) *Span

SpanFrom returns the active sampled span from ctx.

func Start 

func Start(ctx context.Context, name string, options ...StartOption) (context.Context, *Span)

Start starts a span using the default tracer unless WithTracer is supplied.

func (*Span) End 

func (span *Span) End()

End completes the span and sends an immutable snapshot to the configured sink. Calling End more than once is safe.

func (*Span) EndTime 

func (span *Span) EndTime(t time.Time)

EndTime completes the span at t. It is useful for deterministic tests.

func (*Span) Event 

func (span *Span) Event(level string, message string, attrs map[string]any)

Event records a timestamped event on the span.

func (*Span) Set 

func (span *Span) Set(key string, value any)

Set records or replaces one span attribute.

func (*Span) SetStatus 

func (span *Span) SetStatus(code StatusCode, message string)

SetStatus records the final span status.

func (*Span) Snapshot 

func (span *Span) Snapshot() Snapshot

Snapshot returns an immutable copy of the span's current state.

func (*Span) TraceContext 

func (span *Span) TraceContext() TraceContext

TraceContext returns the span's W3C trace identity.

type SpanID 

type SpanID string

SpanID is a W3C Trace Context parent-id/span-id: 8 bytes encoded as 16 lowercase hexadecimal characters.

func NewSpanID 

func NewSpanID() SpanID

NewSpanID returns a valid W3C span ID from the default ID generator (CryptoIDGenerator). It returns "" only when the system CSPRNG cannot provide entropy; see EntropyFailureCount. It never falls back to a predictable value.

func (SpanID) Valid 

func (id SpanID) Valid() bool

Valid reports whether id is a valid non-zero W3C span ID.

type StartOption 

type StartOption func(*startConfig)

StartOption configures one span.

func WithAttributes 

func WithAttributes(attrs map[string]any) StartOption

WithAttributes records initial span attributes.

func WithLane 

func WithLane(lane Lane) StartOption

WithLane records a span lane.

func WithSource 

func WithSource(source SourceRef) StartOption

WithSource records a source reference.

func WithStartTime 

func WithStartTime(start time.Time) StartOption

WithStartTime sets a deterministic start time.

func WithSurface 

func WithSurface(surface Surface) StartOption

WithSurface records a span surface.

func WithTracer 

func WithTracer(tracer *Tracer) StartOption

WithTracer starts a span with tracer instead of the default tracer.

type Status 

type Status struct {
	Code    StatusCode `json:"code,omitempty"`
	Message string     `json:"message,omitempty"`
}

Status records the final span status.

type StatusCode 

type StatusCode string

StatusCode follows the OpenTelemetry span status shape without importing the OpenTelemetry SDK. 

const (
	StatusUnset StatusCode = "unset"
	StatusOK    StatusCode = "ok"
	StatusError StatusCode = "error"
)

type Surface 

type Surface string

Surface identifies where a span was produced. 

const (
	SurfaceBackend  Surface = "backend"
	SurfaceFrontend Surface = "frontend"
	SurfaceWorker   Surface = "worker"
)

type TraceContext 

type TraceContext struct {
	TraceID    TraceID
	SpanID     SpanID
	Sampled    bool
	Remote     bool
	TraceState string
}

TraceContext is the trace identity stored in context.Context and encoded in W3C traceparent/tracestate headers.

func ParseTraceContext added in v0.8.0 

func ParseTraceContext(traceparent string, tracestate string) (TraceContext, error)

ParseTraceContext parses W3C traceparent and tracestate headers. Invalid traceparent input rejects the context. Invalid tracestate input is dropped so a usable trace identity is still preserved without propagating ambiguous vendor state.

func ParseTraceparent 

func ParseTraceparent(value string) (TraceContext, error)

ParseTraceparent parses a W3C traceparent header.

func TraceContextFromContext 

func TraceContextFromContext(ctx context.Context) (TraceContext, bool)

TraceContextFromContext returns trace identity from ctx when present.

type TraceID 

type TraceID string

TraceID is a W3C Trace Context trace-id: 16 bytes encoded as 32 lowercase hexadecimal characters.

func NewTraceID 

func NewTraceID() TraceID

NewTraceID returns a valid W3C trace ID from the default ID generator (CryptoIDGenerator). It returns "" only when the system CSPRNG cannot provide entropy; see EntropyFailureCount. It never falls back to a predictable value.

func (TraceID) Valid 

func (id TraceID) Valid() bool

Valid reports whether id is a valid non-zero W3C trace ID.

type Tracer 

type Tracer struct {
	// contains filtered or unexported fields
}

Tracer owns sampling, identity generation, and completed-span delivery.

func NewTracer 

func NewTracer(options ...TracerOption) *Tracer

NewTracer creates a Tracer.

func TracerFromContext 

func TracerFromContext(ctx context.Context) (*Tracer, bool)

TracerFromContext returns the tracer stored in ctx, or the tracer that owns the active sampled span.

func (*Tracer) HealthSnapshot added in v0.8.0 

func (tracer *Tracer) HealthSnapshot() TracerHealthSnapshot

HealthSnapshot returns local sampling and sink export health.

func (*Tracer) Start 

func (tracer *Tracer) Start(ctx context.Context, name string, options ...StartOption) (context.Context, *Span)

Start starts a span. If sampling rejects the span, the returned context is unchanged and the returned span is nil.

type TracerHealthSnapshot added in v0.8.0 

type TracerHealthSnapshot struct {
	Sampler             string `json:"sampler"`
	SamplingRatio       string `json:"samplingRatio,omitempty"`
	SampledSpans        uint64 `json:"sampledSpans"`
	ExportedSpans       uint64 `json:"exportedSpans"`
	ExportFailures      uint64 `json:"exportFailures"`
	LastExportLatencyNS int64  `json:"lastExportLatencyNs"`
	MaxExportLatencyNS  int64  `json:"maxExportLatencyNs"`
}

TracerHealthSnapshot is a dependency-free point-in-time view of local tracer sampling and sink export health.

type TracerOption 

type TracerOption func(*Tracer)

TracerOption configures a Tracer.

func WithIDGenerator added in v0.8.0 

func WithIDGenerator(generator IDGenerator) TracerOption

WithIDGenerator sets the trace/span ID generator. Nil keeps the default CryptoIDGenerator. Tests use this to inject deterministic identifiers without relying on entropy failure.

func WithSampler 

func WithSampler(sampler Sampler) TracerOption

WithSampler sets the sampler. Nil means AlwaysOn.

func WithSink 

func WithSink(sink Sink) TracerOption

WithSink sets the completed-span sink.

Source Files

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