log: Add EmitEvent and EnabledEvent

log/internal/global/log.go

@@ -102,6 +102,20 @@ func (l *logger) Enabled(ctx context.Context, param log.EnabledParameters) bool
 	return enabled
 }
 
+func (l *logger) EmitEvent(ctx context.Context, eventName string, e log.Event) {
+	if del, ok := l.delegate.Load().(log.Logger); ok {
+		del.EmitEvent(ctx, eventName, e)
+	}
+}
+
+func (l *logger) EnabledEvent(ctx context.Context, eventName string, param log.EnabledEventParameters) bool {
+	var enabled bool
+	if del, ok := l.delegate.Load().(log.Logger); ok {
+		enabled = del.EnabledEvent(ctx, eventName, param)
+	}
+	return enabled
+}
+
 func (l *logger) setDelegate(provider log.LoggerProvider) {
 	l.delegate.Store(provider.Logger(l.name, l.options...))
 }

log/internal/global/log_test.go

@@ -99,7 +99,7 @@ func (p *testLoggerProvider) Logger(name string, _ ...log.LoggerOption) log.Logg
 }
 
 type testLogger struct {
-	embedded.Logger
+	log.Logger
 
 	emitN, enabledN int
 }

log/logger.go

@@ -33,8 +33,8 @@ type Logger interface {
 	// Is should not be used for writing instrumentation.
 	Emit(ctx context.Context, record Record)
 
-	// Enabled returns whether the Logger emits for the given context and
-	// param.
+	// Enabled returns whether the Logger emits a log record for the given
+	// context and param.
 	//
 	// The passed param is likely to be a partial record with only the
 	// bridge-relevant information being provided (e.g a param with only the
@@ -57,6 +57,36 @@ type Logger interface {
 	// Notice: Enabled is intended to be used by log bridges.
 	// Is should not be used for writing instrumentation.
 	Enabled(ctx context.Context, param EnabledParameters) bool
+
+	// EmitEvent emits an event.
+	//
+	// The event may be held by the implementation. Callers should not mutate
+	// the event after passed.
+	//
+	// Implementations of this method need to be safe for a user to call
+	// concurrently.
+	//
+	// Notice: EmitEvent is intended to be used for writing instrumentation.
+	EmitEvent(ctx context.Context, eventName string, event Event)
+
+	// EnabledEvent returns whether the Logger emits an event for the given
+	// context, eventName, and param.
+	//
+	// The returned value will be true when the Logger will emit for the
+	// provided context and param, and will be false if the Logger will not
+	// emit. The returned value may be true or false in an indeterminate state.
+	// An implementation should default to returning true for an indeterminate
+	// state, but may return false if valid reasons in particular circumstances
+	// exist (e.g. performance, correctness).
+	//
+	// The param should not be held by the implementation. A copy should be
+	// made if the record needs to be held after the call returns.
+	//
+	// Implementations of this method need to be safe for a user to call
+	// concurrently.
+	//
+	// Notice: EnabledEvent is intended to be used for writing instrumentation.
+	EnabledEvent(ctx context.Context, eventName string, param EnabledEventParameters) bool
 }
 
 // LoggerOption applies configuration options to a [Logger].
@@ -140,3 +170,8 @@ func WithSchemaURL(schemaURL string) LoggerOption {
 type EnabledParameters struct {
 	Severity Severity
 }
+
+// EnabledEventParameters represents payload for [Logger]'s Enabled method.
+type EnabledEventParameters struct {
+	Severity Severity
+}

log/logtest/recorder.go

@@ -73,6 +73,10 @@ type ScopeRecords struct {
 	// Records are the log records, and their associated context this
 	// instrumentation scope recorded.
 	Records []EmittedRecord
+
+	// Events are the events, and their associated context this
+	// instrumentation scope recorded.
+	Events []EmittedEvent
 }
 
 // EmittedRecord holds a log record the instrumentation received, alongside its
@@ -88,6 +92,25 @@ func (rwc EmittedRecord) Context() context.Context {
 	return rwc.ctx
 }
 
+// EmittedEvent holds an event the instrumentation received, alongside its
+// context and event name.
+type EmittedEvent struct {
+	log.Event
+
+	ctx       context.Context
+	eventName string
+}
+
+// Context provides the context emitted with the event.
+func (rwc EmittedEvent) Context() context.Context {
+	return rwc.ctx
+}
+
+// EventName provides the context emitted with the event.
+func (rwc EmittedEvent) EventName() string {
+	return rwc.eventName
+}
+
 // Recorder is a recorder that stores all received log records
 // in-memory.
 type Recorder struct {
@@ -182,3 +205,17 @@ func (l *logger) Reset() {
 
 	l.scopeRecord.Records = nil
 }
+
+// Enabled indicates whether a specific event should be stored.
+func (l *logger) EnabledEvent(ctx context.Context, eventName string, opts log.EnabledEventParameters) bool {
+	// TODO:
+	return true
+}
+
+// EmitEvent stores the event.
+func (l *logger) EmitEvent(ctx context.Context, eventName string, event log.Event) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	l.scopeRecord.Events = append(l.scopeRecord.Events, EmittedEvent{event, ctx, eventName})
+}

log/noop/noop.go

@@ -48,3 +48,9 @@ func (Logger) Emit(context.Context, log.Record) {}
 
 // Enabled returns false. No log records are ever emitted.
 func (Logger) Enabled(context.Context, log.EnabledParameters) bool { return false }
+
+// EmitEvent does nothing.
+func (Logger) EmitEvent(context.Context, string, log.Event) {}
+
+// EnabledEvent returns false. No events are ever emitted.
+func (Logger) EnabledEvent(context.Context, string, log.EnabledEventParameters) bool { return false }

sdk/log/logger.go

@@ -58,6 +58,31 @@ func (l *logger) Enabled(ctx context.Context, param log.EnabledParameters) bool
 	return len(l.provider.processors) > len(fltrs) || anyEnabled(ctx, param, fltrs)
 }
 
+func (l *logger) EmitEvent(ctx context.Context, eventName string, r log.Event) {
+	newRecord := l.newEvent(ctx, eventName, r)
+	for _, p := range l.provider.processors {
+		if err := p.OnEmit(ctx, &newRecord); err != nil {
+			otel.Handle(err)
+		}
+	}
+}
+
+// EnabledEvent returns true if at least one Processor held by the LoggerProvider
+// that created the logger will process param for the provided context and param.
+//
+// If it is not possible to definitively determine the param will be
+// processed, true will be returned by default. A value of false will only be
+// returned if it can be positively verified that no Processor will process.
+func (l *logger) EnabledEvent(ctx context.Context, eventName string, param log.EnabledEventParameters) bool {
+	fltrs := l.provider.filterProcessors()
+	// If there are more Processors than FilterProcessors we cannot be sure
+	// that all Processors will drop the record. Therefore, return true.
+	//
+	// If all Processors are FilterProcessors, check if any is enabled.
+
+	return len(l.provider.processors) > len(fltrs) || anyEnabled(ctx, log.EnabledParameters(param), fltrs)
+}
+
 func anyEnabled(ctx context.Context, param log.EnabledParameters, fltrs []x.FilterProcessor) bool {
 	for _, f := range fltrs {
 		if f.Enabled(ctx, param) {
@@ -101,3 +126,38 @@ func (l *logger) newRecord(ctx context.Context, r log.Record) Record {
 
 	return newRecord
 }
+
+func (l *logger) newEvent(ctx context.Context, name string, e log.Event) Record {
+	sc := trace.SpanContextFromContext(ctx)
+
+	newRecord := Record{
+		eventName: name,
+
+		timestamp:         e.Timestamp(),
+		observedTimestamp: e.ObservedTimestamp(),
+		severity:          e.Severity(),
+		severityText:      e.SeverityText(),
+		body:              e.Body(),
+
+		traceID:    sc.TraceID(),
+		spanID:     sc.SpanID(),
+		traceFlags: sc.TraceFlags(),
+
+		resource:                  l.provider.resource,
+		scope:                     &l.instrumentationScope,
+		attributeValueLengthLimit: l.provider.attributeValueLengthLimit,
+		attributeCountLimit:       l.provider.attributeCountLimit,
+	}
+
+	// This field SHOULD be set once the event is observed by OpenTelemetry.
+	if newRecord.observedTimestamp.IsZero() {
+		newRecord.observedTimestamp = now()
+	}
+
+	e.WalkAttributes(func(kv log.KeyValue) bool {
+		newRecord.AddAttributes(kv)
+		return true
+	})
+
+	return newRecord
+}

sdk/log/record.go

@@ -50,6 +50,8 @@ type Record struct {
 	// Do not embed the log.Record. Attributes need to be overwrite-able and
 	// deep-copying needs to be possible.
 
+	eventName string
+
 	timestamp         time.Time
 	observedTimestamp time.Time
 	severity          log.Severity
@@ -104,6 +106,16 @@ func (r *Record) setDropped(n int) {
 	r.dropped = n
 }
 
+// EventName returns the event name.
+func (r *Record) EventName() string {
+	return r.eventName
+}
+
+// SetEventName sets the event name.
+func (r *Record) SetEventName(s string) {
+	r.eventName = s
+}
+
 // Timestamp returns the time when the log record occurred.
 func (r *Record) Timestamp() time.Time {
 	return r.timestamp