Package io.perfmark.tracewriter

Class TraceEventWriter

java.lang.Object

io.perfmark.tracewriter.TraceEventWriter

public final class TraceEventWriter
extends Object

Writes the PerfMark results to a "Trace Event" JSON file usable by the Chromium Profiler "Catapult". The format is defined at ...

This code is NOT API stable, and may be removed in the future, or changed without notice.

Since:

0.16.0

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static final class	TraceEventWriter.TraceEventObject
private static final class	TraceEventWriter.TraceEventWalker

Field Summary

Fields

Modifier and Type	Field	Description
private static final String	HEX_TABLE
private static final Logger	logger

Constructor Summary

Constructors

Constructor	Description
TraceEventWriter()

Method Summary

Modifier and Type	Method	Description
private static long	getPid()
private static Path	guessDirectory()
private static boolean	maybeAddComment(Writer writer, boolean firstOf)
private static Path	pickNextDest(Path dir)
private static String	taskName(Mark mark)
private static void	writeString(Writer writer, String s)
private static void	writeTraceEventObject(Writer dest, List<TraceEvent> events)
static Path	writeTraceEvents()	Writes trace events the home directory.
static void	writeTraceEvents(Writer destination)	Writes all trace events in JSON format to the given destination.
static void	writeTraceEvents(Writer destination, List<? extends MarkList> markLists, long initNanoTime, long nowNanoTime, long pid)	Writes the trace events gathered from Storage.read().

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

logger

private static final Logger logger

HEX_TABLE

private static final String HEX_TABLE

See Also:

• Constant Field Values

Constructor Details

TraceEventWriter

public TraceEventWriter()

Method Details

writeTraceEvents

@CanIgnoreReturnValue
public static Path writeTraceEvents()
                             throws IOException

Writes trace events the home directory. By default, it prefers the location in $XDG_DATA_HOME/perfmark environment variable. If unset, it attempts to use $HOME/.local/share/perfmark.

Authors note: if you are on Windows, or the above defaults aren't right, I'm not really sure where else is a good place to put this data. Please file an issue at https://www.perfmark.io/ if you have a preference.

Updated in 0.17.0 to return the created path.

Returns:

the path used to create the trace file.

Throws:

IOException - if there is an error writing to the file.

writeTraceEvents

public static void writeTraceEvents(Writer destination)
                             throws IOException

Writes all trace events in JSON format to the given destination.

Parameters:

destination - the destination for the JSON data.

Throws:

IOException - if there are errors build the JSON, or can't write to the destination.

writeTraceEvents

public static void writeTraceEvents(Writer destination,
 List<? extends MarkList> markLists,
 long initNanoTime,
 long nowNanoTime,
 long pid)
                             throws IOException

Writes the trace events gathered from Storage.read(). This method is not API stable. It will be eventually.

Parameters:

destination - the destination for the JSON data.

markLists - the data to use to build the trace event JSON

initNanoTime - the time PerfMark classes were first loaded as specified by System.nanoTime()

nowNanoTime - the current time as specified by System.nanoTime().

pid - the PID of the current process.

Throws:

IOException - if there are errors build the JSON, or can't write to the destination.

writeTraceEventObject

private static void writeTraceEventObject(Writer dest,
 List<TraceEvent> events)
                                   throws IOException

Throws:

IOException

maybeAddComment

private static boolean maybeAddComment(Writer writer,
 boolean firstOf)
                                throws IOException

Throws:

IOException

pickNextDest

private static Path pickNextDest(Path dir)
                          throws IOException

Throws:

IOException

guessDirectory

private static Path guessDirectory()
                            throws IOException

Throws:

IOException

getPid

private static long getPid()

taskName

private static String taskName(Mark mark)

writeString

private static void writeString(Writer writer,
 String s)
                         throws IOException

Throws:

IOException