TraceEvent

Kotlin |Java

@DelicateTracingApi
public final class TraceEvent

Mutable in-memory only representation a trace event, such as a slice start, slice end, or counter update.

This structure is optimized for performance, with the expectation that these are created by a trace event, and passed to a background thread to be serialized. Mutability (and thus reuse) is an important component of this.

Code outside of tracing-driver implementation should only ever consume these objects, not produce them.

Summary

Public fields
`final @NonNull List<@NonNull AttributeEntry>`	`attributes` The list of trace attributes associated with the trace.
`final @NonNull List<@NonNull String>`	`categories` The categories that this Trace Event belongs to.
`final Long`	`correlationId` The optional correlation id associated with the event.
`final String`	`correlationIdString` The optional correlation id as `String` that is associated with the event.
`final Double`	`counterDoubleValue` Value of the trace event if the event `type` is `TRACE_EVENT_TYPE_COUNTER`.
`final Long`	`counterLongValue` Value of the trace event if the event `type` is `TRACE_EVENT_TYPE_COUNTER`.
`final @NonNull List<@NonNull Long>`	`flowIds` List of trace flows associated with this event.
`final @NonNull List<@NonNull Frame>`	`frames` A list of call stack frames that can be associated to the `androidx.tracing.TraceEvent`.
`final int`	`lastAttributeIndex` Keeping track of the index separately for `attributes`, because the `MutableList` is pre-allocated with sentinel objects for performance reasons.
`final int`	`lastCategoryIndex` Keeping track of the index separately for `categories`, because the `MutableList` is pre-allocated with sentinel objects for performance reasons.
`final int`	`lastFrameIndex` Keeping track of the index separately for `frames`, because the `MutableList` is pre-allocated with sentinel objects for performance reasons.
`final int`	`lastMetadataEntryIndex` Keeping track of the index separately, because the MutableList is pre-allocated with sentinel objects for performance reasons.
`final @NonNull List<@NonNull MetadataEntry>`	`metadataEntries` The list of debug annotations associated with a slice
`final String`	`name` Name of the trace event - null if the event `type` is `TRACE_EVENT_TYPE_COUNTER`.
`final @NonNull String`	`primaryCategory` The primary category that this trace event belongs to.
`final long`	`timestamp` Timestamp in nanoseconds of the trace event.
`final TrackDescriptor`	`trackDescriptor` If not null, this TraceEvent initializes a track, and the `TrackDescriptor` defines its properties.
`final long`	`trackUuid` Set to the value of the containing `Track`'s `Track.uuid`.
`final int`	`type` Must be one of `TRACE_EVENT_TYPE_UNDEFINED`, `TRACE_EVENT_TYPE_INSTANT`, `TRACE_EVENT_TYPE_BEGIN`, `TRACE_EVENT_TYPE_END`, `TRACE_EVENT_TYPE_COUNTER`

Public constructors
`TraceEvent()`

Public methods
`final void`	`copyFrom(@NonNull TraceEvent src)`
`final void`	`reset()`

Public fields

attributes

Added in 2.0.0-rc01

public final @NonNull List<@NonNull AttributeEntry> attributes

The list of trace attributes associated with the trace.

correlationId

Added in 2.0.0-rc01

public final Long correlationId

The optional correlation id associated with the event.

correlationIdString

Added in 2.0.0-rc01

public final String correlationIdString

The optional correlation id as String that is associated with the event.

counterDoubleValue

Added in 2.0.0-rc01

public final Double counterDoubleValue

Value of the trace event if the event type is TRACE_EVENT_TYPE_COUNTER.

Note that only one of counterDoubleValue and counterLongValue may be set.

counterLongValue

Added in 2.0.0-rc01

public final Long counterLongValue

Value of the trace event if the event type is TRACE_EVENT_TYPE_COUNTER.

Note that only one of counterDoubleValue and counterLongValue may be set.

flowIds

Added in 2.0.0-rc01

public final @NonNull List<@NonNull Long> flowIds

List of trace flows associated with this event.

frames

Added in 2.0.0-rc01

public final @NonNull List<@NonNull Frame> frames

A list of call stack frames that can be associated to the androidx.tracing.TraceEvent.

lastAttributeIndex

Added in 2.0.0-rc01

public final int lastAttributeIndex

Keeping track of the index separately for attributes, because the MutableList is pre-allocated with sentinel objects for performance reasons. This index can be used to determine the true size of the attributes MutableList.

lastCategoryIndex

Added in 2.0.0-rc01

public final int lastCategoryIndex

Keeping track of the index separately for categories, because the MutableList is pre-allocated with sentinel objects for performance reasons. This index can be used to determine the true size of the categories MutableList.

lastFrameIndex

Added in 2.0.0-rc01

public final int lastFrameIndex

Keeping track of the index separately for frames, because the MutableList is pre-allocated with sentinel objects for performance reasons. This index can be used to determine the true size of the frames MutableList.

lastMetadataEntryIndex

Added in 2.0.0-rc01

public final int lastMetadataEntryIndex

Keeping track of the index separately, because the MutableList is pre-allocated with sentinel objects for performance reasons. This index can be used to determine the true size of the metadataEntries MutableList.

metadataEntries

Added in 2.0.0-rc01

public final @NonNull List<@NonNull MetadataEntry> metadataEntries

The list of debug annotations associated with a slice

name

Added in 2.0.0-rc01

public final String name

Name of the trace event - null if the event type is TRACE_EVENT_TYPE_COUNTER.

primaryCategory

Added in 2.0.0-rc01

public final @NonNull String primaryCategory

The primary category that this trace event belongs to.

timestamp

Added in 2.0.0-rc01

public final long timestamp

Timestamp in nanoseconds of the trace event.

trackDescriptor

Added in 2.0.0-rc01

public final TrackDescriptor trackDescriptor

If not null, this TraceEvent initializes a track, and the TrackDescriptor defines its properties.

trackUuid

Added in 2.0.0-rc01

public final long trackUuid

Set to the value of the containing Track's Track.uuid.

type

Added in 2.0.0-rc01

public final int type

Must be one of TRACE_EVENT_TYPE_UNDEFINED, TRACE_EVENT_TYPE_INSTANT, TRACE_EVENT_TYPE_BEGIN, TRACE_EVENT_TYPE_END, TRACE_EVENT_TYPE_COUNTER

Public constructors

TraceEvent

Added in 2.0.0-rc01

public TraceEvent()

Public methods

copyFrom

Added in 2.0.0-rc01

public final void copyFrom(@NonNull TraceEvent src)

reset

Added in 2.0.0-rc01

public final void reset()