TraceDriver

Kotlin |Java

Cmn
```
class TraceDriver : AbstractTraceDriver
```

kotlin.Any
↳	androidx.tracing.AbstractTraceDriver
	↳	androidx.tracing.wire.TraceDriver

The entry point to tracing APIs.

Summary

Public companion functions
`TraceDriver`	`@<error> getStubTraceDriver()`	Cmn android

Public constructors
`TraceDriver( sink: AbstractTraceSink, isCategoryEnabled: (String) -> Boolean, attributes: (TraceAttributes.() -> Unit)? )` Constructs a `TraceDriver` instance on the JVM.	android
`TraceDriver( context: Context, sink: AbstractTraceSink, isCategoryEnabled: (category: String) -> Boolean, attributes: (TraceAttributes.() -> Unit)? )` Constructs a `TraceDriver` instance on Android based on the provided `Context` instance.	android

Public functions
`open Unit`	`close()` Flushes all outstanding packets to the `AbstractTraceSink` and then closes the `AbstractTraceSink`.	android
`open Unit`	`close()` Flushes all outstanding packets to the `AbstractTraceSink` and then closes the `AbstractTraceSink`.	android
`open Unit`	`flush()` Flushes the trace packets into the underlying `AbstractTraceSink`.	android
`open Unit`	`flush()` Flushes the trace packets into the underlying `AbstractTraceSink`.	android

Public properties
`open Tracer`	`tracer` Return an instance of a `Tracer` that can be used to emit trace events.	android
`open Tracer`	`tracer` Return an instance of a `Tracer` that can be used to emit trace events.	android

Inherited functions

From androidx.tracing.AbstractTraceDriver

`abstract Unit`	`close()` Flushes all outstanding packets to the `AbstractTraceSink` and then closes the `AbstractTraceSink`.	Cmn
`abstract Unit`	`flush()` Flushes the trace packets into the underlying `AbstractTraceSink`.	Cmn

Inherited properties

From androidx.tracing.AbstractTraceDriver

`AbstractTraceSink`	`sink` The `AbstractTraceSink` that asynchronously serializes trace events to a file or buffer, depending on implementation.	android
`AbstractTraceSink`	`sink` The `AbstractTraceSink` that asynchronously serializes trace events to a file or buffer, depending on implementation.	Cmn
`AbstractTraceSink`	`sink` The `AbstractTraceSink` that asynchronously serializes trace events to a file or buffer, depending on implementation.	android
`abstract Tracer`	`tracer` Return an instance of a `Tracer` that can be used to emit trace events.	Cmn

Public companion functions

getStubTraceDriver

Cmn android

Added in 2.0.0-alpha07

@<error>
fun getStubTraceDriver(): TraceDriver

Returns

Returns
`TraceDriver`	a `TraceDriver` instance that is a stub (does nothing). This is useful as a placeholder when you want to enable / disable tracing for the program. Effectively, this uses a `androidx.tracing.Tracer` that drops all trace packets. To get a stub tracer, you can also use the `androidx.tracing.Tracer.getStubTracer` API.

TraceDriver

a TraceDriver instance that is a stub (does nothing). This is useful as a placeholder when you want to enable / disable tracing for the program.

Effectively, this uses a androidx.tracing.Tracer that drops all trace packets. To get a stub tracer, you can also use the androidx.tracing.Tracer.getStubTracer API.

Public constructors

TraceDriver

android

TraceDriver(
    sink: AbstractTraceSink,
    isCategoryEnabled: (String) -> Boolean = { true },
    attributes: (TraceAttributes.() -> Unit)? = null
)

Constructs a TraceDriver instance on the JVM.

Parameters

Parameters
`sink: AbstractTraceSink`	The `TraceSink` instance.
`isCategoryEnabled: (String) -> Boolean = { true }`	returns `true` if the provided trace `category` should be enabled. If `false` then trace events corresponding to the `category` are dropped to reduce tracing overhead. This is particularly useful when you want to lower the overhead of trace events from uninteresting or noisy categories.
`attributes: (TraceAttributes.() -> Unit)? = null`	Collection of key value pairs to be attached to a trace to provide additional context about any facet of the trace. This can include what data it contains, and properties of the host / machine the trace was collected on, and other interesting information about a trace. Examples include: gradle_version = "9.0.10-alpha01" java_major_version = 24

sink: AbstractTraceSink

The TraceSink instance.

isCategoryEnabled: (String) -> Boolean = { true }

returns true if the provided trace category should be enabled. If false then trace events corresponding to the category are dropped to reduce tracing overhead. This is particularly useful when you want to lower the overhead of trace events from uninteresting or noisy categories.

attributes: (TraceAttributes.() -> Unit)? = null

Collection of key value pairs to be attached to a trace to provide additional context about any facet of the trace. This can include what data it contains, and properties of the host / machine the trace was collected on, and other interesting information about a trace.

Examples include:

gradle_version = "9.0.10-alpha01"
java_major_version = 24

TraceDriver

android

Added in 2.0.0-alpha07

TraceDriver(
    context: Context,
    sink: AbstractTraceSink,
    isCategoryEnabled: (category: String) -> Boolean = { Trace.isEnabled() },
    attributes: (TraceAttributes.() -> Unit)? = null
)

Constructs a TraceDriver instance on Android based on the provided Context instance.

Parameters
`context: Context`	The Android application `Context`.
`sink: AbstractTraceSink`	The `TraceSink` instance.
`isCategoryEnabled: (category: String) -> Boolean = { Trace.isEnabled() }`	returns `true` if the provided trace `category` should be enabled. If `false` then trace events corresponding to the `category` are dropped to reduce tracing overhead. This is particularly useful when you want to lower the overhead of trace events from uninteresting or noisy categories. The default implementation of this check allows all trace categories as long as a Perfetto tracing session is active (`Trace.isEnabled`). Note:This method should be extremely low overhead given it's called every time a `Tracer` can emit trace events.
`attributes: (TraceAttributes.() -> Unit)? = null`	Collection of key value pairs to be attached to a trace to provide additional context about any facet of the trace. This can include what data it contains, and properties of the host / machine the trace was collected on, and other interesting information about a trace. At the end of the `attributes` block, these key value pairs are dispatched to the designated `AbstractTraceSink` to be serialized. Examples include: gradle_version = "9.0.10-alpha01" java_major_version = 24