Package org.openjdk.jmc.flightrecorder.util

Class ChunkReader

java.lang.Object

org.openjdk.jmc.flightrecorder.util.ChunkReader

public final class ChunkReader
extends Object

Provides an efficient means to read JFR data, chunk by chunk. The actual method employed will depend on whether the JFR file is available as a stream or as a file, and whether or not the data is compressed or not.

Each chunk will be self-contained and parsable, for example by wrapping it in a ByteArrayInputStream and using the JfrLoaderToolkit.

Method Summary

Modifier and Type	Method	Description
static void	main(String[] args)	Program for listing the number of chunks in a recording.
static Iterator<byte[]>	readChunks(File jfrFile)	Reads a JFR file, chunk by chunk.
static Iterator<byte[]>	readChunks(InputStream jfrStream)	Reads a JFR file, chunk by chunk, from a stream.

Methods inherited from class java.lang.Object

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

Method Detail

readChunks

public static Iterator<byte[]> readChunks(File jfrFile)
                                   throws IOException

Reads a JFR file, chunk by chunk.

Each chunk will be self contained and parsable, for example by wrapping it in a ByteArrayInputStream. Note that Iterator.next() can throw IllegalArgumentException if it encounters a corrupted chunk.

Parameters:

jfrFile - the file to read binary data from

Returns:

returns an iterator over byte arrays, where each byte array is a self containing jfr chunk

Throws:

IOException

readChunks

public static Iterator<byte[]> readChunks(InputStream jfrStream)
                                   throws IOException

Reads a JFR file, chunk by chunk, from a stream.

Each chunk will be self contained and parsable, for example by wrapping it in a ByteArrayInputStream. Note that Iterator.next() can throw IllegalArgumentException if it encounters a corrupted chunk.

Parameters:

jfrStream - the stream to read binary data from

Returns:

returns an iterator over byte arrays, where each byte array is a self containing JFR chunk

Throws:

IOException

main

public static void main(String[] args)
                 throws IOException

Program for listing the number of chunks in a recording.

Parameters:

args - takes one argument, which must be the path to a recording

Throws:

IOException - if there was a problem reading the file