TrackEvent class

Trace events emitted by client instrumentation library (TRACE_EVENT macros), which describe activity on a track, such as a thread or asynchronous event track. The track is specified using separate TrackDescriptor messages and referred to via the track's UUID.

A simple TrackEvent packet specifies a timestamp, category, name and type:

  trace_packet {
    timestamp: 1000
    track_event {
      categories: ["my_cat"]
      name: "my_event"
      type: TYPE_INSTANT
     }
   }

To associate an event with a custom track (e.g. a thread), the track is defined in a separate packet and referred to from the TrackEvent by its UUID:

  trace_packet {
    track_descriptor {
      track_uuid: 1234
      name: "my_track"

      // Optionally, associate the track with a thread.
      thread_descriptor {
        pid: 10
        tid: 10
        ..
      }
    }
  }

A pair of TYPE_SLICE_BEGIN and _END events form a slice on the track:

  trace_packet {
    timestamp: 1200
    track_event {
      track_uuid: 1234
      categories: ["my_cat"]
      name: "my_slice"
      type: TYPE_SLICE_BEGIN
    }
  }
  trace_packet {
    timestamp: 1400
    track_event {
      track_uuid: 1234
      type: TYPE_SLICE_END
    }
  }

TrackEvents also support optimizations to reduce data repetition and encoded data size, e.g. through data interning (names, categories, ...) and delta encoding of timestamps/counters. For details, see the InternedData message. Further, default values for attributes of events on the same sequence (e.g. their default track association) can be emitted as part of a TrackEventDefaults message.

Next reserved id: 13 (up to 15). Next id: 50.

Inheritance

Object
GeneratedMessage
TrackEvent

Available extensions

GeneratedMessageGenericExtensions

Constructors

TrackEvent.new({Iterable<Int64>? categoryIids, Iterable<DebugAnnotation>? debugAnnotations, TrackEvent_Type? type, Int64? nameIid, Int64? trackUuid, Iterable<String>? categories, String? name, Iterable<Int64>? flowIds, Iterable<Int64>? terminatingFlowIds}): factory
TrackEvent.fromBuffer(List<int> i, [ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]): factory
TrackEvent.fromJson(String i, [ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]): factory

Properties

categories → PbList<String>: non-interned variant.
no setter
categoryIids → PbList<Int64>: Names of categories of the event. In the client library, categories are a way to turn groups of individual events on or off. interned EventCategoryName.
no setter
debugAnnotations → PbList<DebugAnnotation>: Unstable key/value annotations shown in the trace viewer but not intended for metrics use.
no setter
flowIds → PbList<Int64>: IDs of flows originating, passing through, or ending at this event. Flow IDs are global within a trace.
no setter
hashCode → int: Calculates a hash code based on the contents of the protobuf.
no setterinherited
info_ → BuilderInfo: no setteroverride
isFrozen → bool: Returns true if this message is marked read-only. Otherwise false.
no setterinherited
name ↔ String: non-interned variant.
getter/setter pair
nameIid ↔ Int64: interned EventName.
getter/setter pair
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
terminatingFlowIds → PbList<Int64>: List of flow ids which should terminate on this event, otherwise same as |flow_ids|. Any one flow ID should be either listed as part of |flow_ids| OR |terminating_flow_ids|, not both.
no setter
trackUuid ↔ Int64: Identifies the track of the event. The default value may be overridden using TrackEventDefaults, e.g., to specify the track of the TraceWriter's sequence (in most cases sequence = one thread). If no value is specified here or in TrackEventDefaults, the TrackEvent will be associated with an implicit trace-global track (uuid 0). See TrackDescriptor::uuid.
getter/setter pair
type ↔ TrackEvent_Type: getter/setter pair
unknownFields → UnknownFieldSet: no setterinherited

Methods

addExtension(Extension extension, Object? value) → void: Adds an extension field value to a repeated field.
inherited
check() → void: Throws a StateError if the message has required fields without a value.
inherited
clear() → void: Clears all data that was set in this message.
inherited
clearExtension(Extension extension) → void: Clears an extension field and also removes the extension.
inherited
clearField(int tagNumber) → void: Clears the contents of a given field.
inherited
clearName() → void
clearNameField() → void
clearNameIid() → void
clearTrackUuid() → void
clearType() → void
clone() → TrackEvent: Creates a deep copy of the fields in this message. (The generated code uses mergeFromMessage.)
override
copyWith(void updates(TrackEvent)) → TrackEvent: Apply updates to a copy of this message.
override
createEmptyInstance() → TrackEvent: Creates an empty instance of the same message type as this.
override
deepCopy() → T: Available on T, provided by the GeneratedMessageGenericExtensions extension
Returns a writable deep copy of this message.
extensionsAreInitialized() → bool: inherited
freeze() → GeneratedMessage: Make this message read-only.
inherited
getDefaultForField(int tagNumber) → dynamic: Returns the default value for the given field.
inherited
getExtension(Extension extension) → dynamic: Returns the value of extension.
inherited
getField(int tagNumber) → dynamic: Returns the value of the field associated with tagNumber, or the default value if it is not set.
inherited
getFieldOrNull(int tagNumber) → dynamic: Returns the value of a field, ignoring any defaults.
inherited
getTagNumber(String fieldName) → int?: inherited
hasExtension(Extension extension) → bool: Returns true if a value of extension is present.
inherited
hasField(int tagNumber) → bool: Whether this message has a field associated with tagNumber.
inherited
hasName() → bool
hasNameIid() → bool
hasRequiredFields() → bool: Whether the message has required fields.
inherited
hasTrackUuid() → bool
hasType() → bool
isInitialized() → bool: Whether all required fields in the message and embedded messages are set.
inherited
mergeFromBuffer(List<int> input, [ExtensionRegistry extensionRegistry = ExtensionRegistry.EMPTY]) → void: Merges serialized protocol buffer data into this message.
inherited
mergeFromCodedBufferReader(CodedBufferReader input, [ExtensionRegistry extensionRegistry = ExtensionRegistry.EMPTY]) → void: Same as mergeFromBuffer, but takes a CodedBufferReader input.
inherited
mergeFromJson(String data, [ExtensionRegistry extensionRegistry = ExtensionRegistry.EMPTY]) → void: Merges field values from data, a JSON object, encoded as described by GeneratedMessage.writeToJson.
inherited
mergeFromJsonMap(Map<String, dynamic> json, [ExtensionRegistry extensionRegistry = ExtensionRegistry.EMPTY]) → void: Merges field values from a JSON object represented as a Dart map.
inherited
mergeFromMessage(GeneratedMessage other) → void: Merges the contents of the other into this message.
inherited
mergeFromProto3Json(Object? json, {TypeRegistry typeRegistry = const TypeRegistry.empty(), bool ignoreUnknownFields = false, bool supportNamesWithUnderscores = true, bool permissiveEnums = false}) → void: Merges field values from json, a JSON object using proto3 encoding.
inherited
mergeUnknownFields(UnknownFieldSet unknownFieldSet) → void: inherited
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
rebuild(void updates(T)) → T: Available on T, provided by the GeneratedMessageGenericExtensions extension
Apply updates to a copy of this message.
setExtension(Extension extension, Object value) → void: Sets the value of a non-repeated extension field to value.
inherited
setField(int tagNumber, Object value) → void: Sets the value of a field by its tagNumber.
inherited
toBuilder() → GeneratedMessage: Creates a writable, shallow copy of this message.
inherited
toDebugString() → String: Returns a String representation of this message.
inherited
toProto3Json({TypeRegistry typeRegistry = const TypeRegistry.empty()}) → Object?: Returns an Object representing Proto3 JSON serialization of this.
inherited
toString() → String: Returns a String representation of this message.
inherited
whichNameField() → TrackEvent_NameField
writeToBuffer() → Uint8List: Serialize the message as the protobuf binary format.
inherited
writeToCodedBufferWriter(CodedBufferWriter output) → void: Same as writeToBuffer, but serializes to the given CodedBufferWriter.
inherited
writeToJson() → String: Returns a JSON string that encodes this message.
inherited
writeToJsonMap() → Map<String, dynamic>: Returns the JSON encoding of this message as a Dart Map.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited

Static Methods

create() → TrackEvent
createRepeated() → PbList<TrackEvent>
getDefault() → TrackEvent