IMPORTANT: In July 2025, we stopped releasing new versions of KTX modules, and we removed the KTX libraries from the Firebase Android BoM (v34.0.0). If you use KTX APIs from the previously released KTX modules, we recommend that you migrate your app to use KTX APIs from the main modules instead. For details, see the FAQ about this initiative.

Trace

class Trace : Parcelable

Trace allows you to set beginning and end of a certain action in your app.

Summary

Constants
`const Parcelable.Creator<Trace!>!`	`@Keep CREATOR` A public static CREATOR field that implements `Parcelable.Creator` and generates instances of your Parcelable class from a Parcel.
`const Int`	`MAX_ATTRIBUTE_KEY_LENGTH = 40` Maximum allowed length of the Key of the `Trace` attribute
`const Int`	`MAX_ATTRIBUTE_VALUE_LENGTH = 100` Maximum allowed length of the Value of the `Trace` attribute
`const Int`	`MAX_TRACE_CUSTOM_ATTRIBUTES = 5` Maximum allowed number of attributes allowed in a trace.
`const Int`	`MAX_TRACE_NAME_LENGTH = 100` Maximum allowed length of the name of the `Trace`

Public functions
`Int`	`@Keep describeContents()` Describes the kinds of special objects contained in this Parcelable's marshalled representation.
`String?`	`@Keep getAttribute(attribute: String)` Returns the value of an attribute.
`(Mutable)Map<String!, String!>`	`@Keep getAttributes()` Returns the map of all the attributes added to this trace.
`Long`	`@Keep getLongMetric(metricName: String)` Gets the value of the metric with the given name in the current trace.
`Unit`	`@Keep incrementMetric(metricName: String, incrementBy: Long)` Atomically increments the metric with the given name in this trace by the incrementBy value.
`Unit`	`@Keep putAttribute(attribute: String, value: String)` Sets a String value for the specified attribute.
`Unit`	`@Keep putMetric(metricName: String, value: Long)` Sets the value of the metric with the given name in this trace to the value provided.
`Unit`	`@Keep removeAttribute(attribute: String)` Removes an already added attribute from the Traces.
`Unit`	`@Keep start()` Starts this trace.
`Unit`	`@Keep stop()` Stops this trace.
`Unit`	`@Keep writeToParcel(out: Parcel, flags: Int)` Flatten this object into a Parcel.

Public properties
`String!`	`name`

Extension functions
`inline T`	`<T : Any?> Trace.trace(block: Trace.() -> T)` Measures the time it takes to run the `block` wrapped by calls to start and stop using `Trace`.

Inherited Constants

From android.os.Parcelable

`const Int`	`CONTENTS_FILE_DESCRIPTOR = 1`
`const Int`	`PARCELABLE_WRITE_RETURN_VALUE = 1`

Constants

CREATOR

@Keep
const val CREATOR: Parcelable.Creator<Trace!>!

A public static CREATOR field that implements Parcelable.Creator and generates instances of your Parcelable class from a Parcel.

MAX_ATTRIBUTE_KEY_LENGTH

const val MAX_ATTRIBUTE_KEY_LENGTH = 40: Int

Maximum allowed length of the Key of the Trace attribute

MAX_ATTRIBUTE_VALUE_LENGTH

const val MAX_ATTRIBUTE_VALUE_LENGTH = 100: Int

Maximum allowed length of the Value of the Trace attribute

MAX_TRACE_CUSTOM_ATTRIBUTES

const val MAX_TRACE_CUSTOM_ATTRIBUTES = 5: Int

Maximum allowed number of attributes allowed in a trace.

MAX_TRACE_NAME_LENGTH

const val MAX_TRACE_NAME_LENGTH = 100: Int

Maximum allowed length of the name of the Trace

Public functions

describeContents

@Keep
fun describeContents(): Int

Describes the kinds of special objects contained in this Parcelable's marshalled representation.

Returns
`Int`	always returns 0.

See also
`Parcelable`

getAttribute

@Keep
fun getAttribute(attribute: String): String?

Returns the value of an attribute.

Parameters
`attribute: String`	name of the attribute to fetch the value for

Returns
`String?`	the value of the attribute if it exists or null otherwise.

getAttributes

@Keep
fun getAttributes(): (Mutable)Map<String!, String!>

Returns the map of all the attributes added to this trace.

Returns
`(Mutable)Map<String!, String!>`	map of attributes and its values currently added to this Trace

getLongMetric

@Keep
fun getLongMetric(metricName: String): Long

Gets the value of the metric with the given name in the current trace. If a metric with the given name doesn't exist, it is NOT created and a 0 is returned. This method is atomic.

Parameters
`metricName: String`	Name of the metric to get. Requires no leading or trailing whitespace, no leading underscore '_' character, max length is 100 characters.

Returns
`Long`	Value of the metric or 0 if it hasn't yet been set.

incrementMetric

@Keep
fun incrementMetric(metricName: String, incrementBy: Long): Unit

Atomically increments the metric with the given name in this trace by the incrementBy value. If the metric does not exist, a new one will be created. If the trace has not been started or has already been stopped, returns immediately without taking action.

Parameters
`metricName: String`	Name of the metric to be incremented. Requires no leading or trailing whitespace, no leading underscore [_] character, max length of 100 characters.
`incrementBy: Long`	Amount by which the metric has to be incremented.

putAttribute

@Keep
fun putAttribute(attribute: String, value: String): Unit

Sets a String value for the specified attribute. Updates the value of the attribute if the attribute already exists. If the trace has been stopped, this method returns without adding the attribute. The maximum number of attributes that can be added to a Trace are MAX_TRACE_CUSTOM_ATTRIBUTES.

Parameters
`attribute: String`	Name of the attribute
`value: String`	Value of the attribute

putMetric

@Keep
fun putMetric(metricName: String, value: Long): Unit

Sets the value of the metric with the given name in this trace to the value provided. If a metric with the given name doesn't exist, a new one will be created. If the trace has not been started or has already been stopped, returns immediately without taking action. This method is atomic.

Parameters
`metricName: String`	Name of the metric to set. Requires no leading or trailing whitespace, no leading underscore '_' character, max length is 100 characters.
`value: Long`	The value to which the metric should be set to.

removeAttribute

@Keep
fun removeAttribute(attribute: String): Unit

Removes an already added attribute from the Traces. If the trace has been stopped, this method returns without removing the attribute.

Parameters
`attribute: String`	Name of the attribute to be removed from the running Traces.

start

@Keep
fun start(): Unit

Starts this trace.

stop

@Keep
fun stop(): Unit

Stops this trace.

writeToParcel

@Keep
fun writeToParcel(out: Parcel, flags: Int): Unit

Flatten this object into a Parcel. Please refer to https://developer.android.com/reference/android/os/Parcelable.html

Parameters
`out: Parcel`	the Parcel in which the object should be written.
`flags: Int`	Additional flags about how the object should be written.

Public properties

name

val name: String!

Extension functions

trace

inline fun <T : Any?> Trace.trace(block: Trace.() -> T): T

Measures the time it takes to run the block wrapped by calls to start and stop using Trace.