Encoder allows access to the contents of a Field (via a call to Field.Marshal).
Tracer implementations typically provide an implementation of Encoder; OpenTracing callers typically do not need to concern themselves with it.
type Encoder interface {
EmitString(key, value string)
EmitBool(key string, value bool)
EmitInt(key string, value int)
EmitInt32(key string, value int32)
EmitInt64(key string, value int64)
EmitUint32(key string, value uint32)
EmitUint64(key string, value uint64)
EmitFloat32(key string, value float32)
EmitFloat64(key string, value float64)
EmitObject(key string, value interface{})
EmitLazyLogger(value LazyLogger)
}
Field instances are constructed via LogBool, LogString, and so on. Tracing implementations may then handle them via the Field.Marshal method.
"heavily influenced by" (i.e., partially stolen from) https://github.com/uber-go/zap
type Field struct {
// contains filtered or unexported fields
}
func Bool(key string, val bool) Field
Bool adds a bool-valued key:value pair to a Span.LogFields() record
func Error(err error) Field
Error adds an error with the key "error.object" to a Span.LogFields() record
func Event(val string) Field
Event creates a string-valued Field for span logs with key="event" and value=val.
func Float32(key string, val float32) Field
Float32 adds a float32-valued key:value pair to a Span.LogFields() record
func Float64(key string, val float64) Field
Float64 adds a float64-valued key:value pair to a Span.LogFields() record
func Int(key string, val int) Field
Int adds an int-valued key:value pair to a Span.LogFields() record
func Int32(key string, val int32) Field
Int32 adds an int32-valued key:value pair to a Span.LogFields() record
func Int64(key string, val int64) Field
Int64 adds an int64-valued key:value pair to a Span.LogFields() record
func InterleavedKVToFields(keyValues ...interface{}) ([]Field, error)
InterleavedKVToFields converts keyValues a la Span.LogKV() to a Field slice a la Span.LogFields().
func Lazy(ll LazyLogger) Field
Lazy adds a LazyLogger to a Span.LogFields() record; the tracing implementation will call the LazyLogger function at an indefinite time in the future (after Lazy() returns).
func Message(val string) Field
Message creates a string-valued Field for span logs with key="message" and value=val.
func Noop() Field
Noop creates a no-op log field that should be ignored by the tracer. It can be used to capture optional fields, for example those that should only be logged in non-production environment:
func customerField(order *Order) log.Field {
if os.Getenv("ENVIRONMENT") == "dev" {
return log.String("customer", order.Customer.ID)
}
return log.Noop()
}
span.LogFields(log.String("event", "purchase"), customerField(order))
func Object(key string, obj interface{}) Field
Object adds an object-valued key:value pair to a Span.LogFields() record Please pass in an immutable object, otherwise there may be concurrency issues. Such as passing in the map, log.Object may result in "fatal error: concurrent map iteration and map write". Because span is sent asynchronously, it is possible that this map will also be modified.
func String(key, val string) Field
String adds a string-valued key:value pair to a Span.LogFields() record
func Uint32(key string, val uint32) Field
Uint32 adds a uint32-valued key:value pair to a Span.LogFields() record
func Uint64(key string, val uint64) Field
Uint64 adds a uint64-valued key:value pair to a Span.LogFields() record
func (lf Field) Key() string
Key returns the field's key.
func (lf Field) Marshal(visitor Encoder)
Marshal passes a Field instance through to the appropriate field-type-specific method of an Encoder.
func (lf Field) String() string
String returns a string representation of the key and value.
func (lf Field) Value() interface{}
Value returns the field's value as interface{}.
LazyLogger allows for user-defined, late-bound logging of arbitrary data
type LazyLogger func(fv Encoder)