com.facebook.buck.util.trace

Class ChromeTraceParser

java.lang.Object

com.facebook.buck.util.trace.ChromeTraceParser

public class ChromeTraceParser
extends Object

Event-driven parser for Chrome traces.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	ChromeTraceParser.ChromeTraceEventMatcher<T> Extracts data of interest if it finds a Chrome trace event of the type it is looking for.

Field Summary

Fields

Modifier and Type	Field and Description
static ChromeTraceParser.ChromeTraceEventMatcher<String>	COMMAND Tries to extract the command that was used to trigger the invocation of Buck that generated the trace.

Constructor Summary

Constructors

Constructor and Description
ChromeTraceParser(ProjectFilesystem projectFilesystem)

Method Summary

Modifier and Type	Method and Description
static <T> Optional<T>	getResultForMatcher(ChromeTraceParser.ChromeTraceEventMatcher<T> matcher, Map<ChromeTraceParser.ChromeTraceEventMatcher<?>,Object> results) Designed for use with the result of parse(Path, Set).
Map<ChromeTraceParser.ChromeTraceEventMatcher<?>,Object>	parse(Path pathToTrace, Set<ChromeTraceParser.ChromeTraceEventMatcher<?>> chromeTraceEventMatchers) Parses a Chrome trace and stops parsing once all of the specified matchers have been satisfied.

Methods inherited from class java.lang.Object

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

Field Detail

COMMAND

public static final ChromeTraceParser.ChromeTraceEventMatcher<String> COMMAND

Tries to extract the command that was used to trigger the invocation of Buck that generated the trace. If found, it returns the command as an opaque string.

Constructor Detail

ChromeTraceParser

public ChromeTraceParser(ProjectFilesystem projectFilesystem)

Method Detail

parse

public Map<ChromeTraceParser.ChromeTraceEventMatcher<?>,Object> parse(Path pathToTrace,
                                                                      Set<ChromeTraceParser.ChromeTraceEventMatcher<?>> chromeTraceEventMatchers)
                                                               throws IOException

Parses a Chrome trace and stops parsing once all of the specified matchers have been satisfied. This method parses only one Chrome trace event at a time, which avoids loading the entire trace into memory.

Parameters:

pathToTrace - is a relative path [to the ProjectFilesystem] to a Chrome trace in the "JSON Array Format."

chromeTraceEventMatchers - set of matchers this invocation of parse() is trying to satisfy. Once a matcher finds a match, it will not consider any other events in the trace.

Returns:

a Map where every matcher that found a match will have an entry whose key is the matcher and whose value is the one returned by ChromeTraceParser.ChromeTraceEventMatcher.test(Map, String) without the Optional wrapper.

Throws:

IOException

getResultForMatcher

public static <T> Optional<T> getResultForMatcher(ChromeTraceParser.ChromeTraceEventMatcher<T> matcher,
                                                  Map<ChromeTraceParser.ChromeTraceEventMatcher<?>,Object> results)

Designed for use with the result of parse(Path, Set). Helper function to avoid some distasteful casting logic.