Tracing Domain
Methods
Tracing.start #
Start trace events collection.
Tracing.start fails if there is a tracing session already running in the current target. This matches Chrome's behavior.
Parameters
categoriesOptional
stringCategory/tag filter
optionsOptional
stringTracing options
bufferUsageReportingIntervalOptional
numberIf set, the agent will issue bufferUsage events at this interval, specified in milliseconds
transferModeOptional
stringWhether to report trace events as series of dataCollected events or to save trace to a
stream (defaults to ReportEvents).
Allowed values: ReportEvents, ReturnAsStream
streamFormatOptional
Trace data format to use. This only applies when using ReturnAsStream
transfer mode (defaults to json).
streamCompressionOptional
Compression format to use. This only applies when using ReturnAsStream
transfer mode (defaults to none)
traceConfigOptional
perfettoConfigOptional
stringBase64-encoded serialized perfetto.protos.TraceConfig protobuf message
When specified, the parameters categories, options, traceConfig
are ignored. (Encoded as a base64 string when passed over JSON)
tracingBackendOptional
Events
Tracing.tracingComplete #
Signals that tracing is stopped and there is no trace buffers pending flush, all data were delivered via dataCollected events.
Parameters
dataLossOccurred booleanIndicates whether some trace data is known to have been lost, e.g. because the trace ring buffer wrapped around.
streamOptional
A handle of the stream that holds resulting trace data.
traceFormatOptional
Trace data format of returned stream.
streamCompressionOptional
Compression format of returned stream.
Tracing.dataCollected Experimental#
Contains a bucket of collected trace events. When tracing is stopped collected events will be sent as a sequence of dataCollected events followed by tracingComplete event.
Parameters
value array[ object ]