Module openj9.dtfj

Package com.ibm.j9ddr.corereaders.tdump.zebedee.dumpreader

Class Dump

java.lang.Object

javax.imageio.stream.ImageInputStreamImpl

com.ibm.j9ddr.corereaders.tdump.zebedee.dumpreader.Dump

All Implemented Interfaces:

Closeable, DataInput, AutoCloseable, ImageInputStream

public final class Dump
extends ImageInputStreamImpl

This class represents an svcdump. It is the main class in the dumpreader package and provides low-level access to the contents of an svcdump (eg the ability to read the contents of an address in a given address space).

Implementation note: currently implemented by linking to the old svcdump.jar code (so you need to include svcdump.jar when using) but this dependency will eventually be removed.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DATABLOCKSIZE	Size of a block excluding header

Fields declared in class javax.imageio.stream.ImageInputStreamImpl

bitOffset, byteOrder, flushedPos, streamPos

Constructor Summary

Constructors

Constructor	Description
Dump(BufferedInputStream inputStream, String filename)
Dump(InputStream stream, boolean initialize)	Creates a new instance of Dump from the given InputStream.
Dump(String filename)	Creates a new instance of Dump from the given filename.
Dump(String filename, boolean initialize)	Creates a new instance of Dump from the given filename.
Dump(String filename, ImageInputStream stream)	Creates a new instance of Dump from the given input stream (constructor used by J9 I think).
Dump(ImageInputStream in)
Dump(ImageInputStream in, boolean initialize)	Creates a new instance of Dump from the given filename.

Method Summary

Modifier and Type	Method	Description
void	close()	Close the file used to read the dump
AddressSpace	getAddressSpace(int id)	Returns the address space with the given id or null if it can't be found.
AddressSpace[]	getAddressSpaces()	Returns an array of all the address spaces in the dump.
Date	getCreationDate()	Returns the time when the dump was created.
String	getName()	Return the pathname for this dump
String	getProductModification()	Returns the z/OS product modification.
String	getProductName()	Returns the z/OS product name.
String	getProductRelease()	Returns the z/OS product release.
String	getProductVersion()	Returns the z/OS product version.
SystemTrace	getSystemTrace()	Returns an object representing the system trace table.
String	getTitle()	Returns the title of the dump.
void	initialize()	Scan the dump and build the array of AddressSpaces.
boolean	is64bit()	Returns true if this is a 64-bit dump.
static boolean	isValid(String filename)	Returns true if the given filename is a valid svcdump.
long	length()	Get the length of the dump file
void	localClose()	Close the file used to read the dump (MVS datasets only).
static Date	mvsClockToDate(long clock)	Convert an MVS style clock value to a Date object.
int	read()	Reads an unsigned byte from the file
int	read(byte[] buf)	Read from the dump file into the given buffer.
int	read(byte[] buf, int off, int len)	Read from the dump file into the given buffer.
void	seek(long offset)	Seek to the given offset in the dump file.

Methods declared in class javax.imageio.stream.ImageInputStreamImpl

checkClosed, finalize, flush, flushBefore, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, isCached, isCachedFile, isCachedMemory, mark, readBit, readBits, readBoolean, readByte, readBytes, readChar, readDouble, readFloat, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, setBitOffset, setByteOrder, skipBytes, skipBytes

Methods declared in class java.lang.Object

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

Field Details

DATABLOCKSIZE

public static final int DATABLOCKSIZE

Size of a block excluding header

See Also:

• Constant Field Values

Constructor Details

Dump

public Dump(String filename)
     throws FileNotFoundException,
FileFormatException

Creates a new instance of Dump from the given filename. The filename must represent either an absolute or relative pathname of the dump file, or if running on z/os it can be an MVS dataset name (eg DGRIFF.MYDUMP).

Parameters:

filename - the name of the dump to open

Throws:

FileNotFoundException

FileFormatException

Dump

public Dump(ImageInputStream in)
     throws FileNotFoundException,
FileFormatException

Throws:

FileNotFoundException

FileFormatException

Dump

public Dump(ImageInputStream in,
 boolean initialize)
     throws FileNotFoundException,
FileFormatException

Creates a new instance of Dump from the given filename. The filename must represent either an absolute or relative pathname of the dump file, or if running on z/os it can be an MVS dataset name (eg DGRIFF.MYDUMP).

Parameters:

initialize - whether to initialize the dump as well

filename - the name of the dump to open

Throws:

FileNotFoundException

FileFormatException

Dump

public Dump(String filename,
 boolean initialize)
     throws FileNotFoundException,
FileFormatException

Creates a new instance of Dump from the given filename. The filename must represent either an absolute or relative pathname of the dump file, or if running on z/os it can be an MVS dataset name (eg DGRIFF.MYDUMP).

Parameters:

filename - the name of the dump to open

initialize - whether to initialize the dump as well

Throws:

FileNotFoundException

FileFormatException

Dump

public Dump(InputStream stream,
 boolean initialize)
     throws FileNotFoundException,
FileFormatException

Creates a new instance of Dump from the given InputStream. The stream must represent either an absolute or relative pathname of the dump file, or if running on z/os it can be an MVS dataset name (eg DGRIFF.MYDUMP).

Parameters:

stream - the stream to read from

initialize - whether to initialize the dump as well

Throws:

FileNotFoundException

FileFormatException

Dump

public Dump(String filename,
 ImageInputStream stream)
     throws FileNotFoundException,
FileFormatException

Creates a new instance of Dump from the given input stream (constructor used by J9 I think).

Parameters:

filename - the name of the dump - also used to open the cache file

stream - an ImageInputStream for the dump or null - used in preference to opening the file

Throws:

FileNotFoundException

FileFormatException

Dump

public Dump(BufferedInputStream inputStream,
 String filename)
     throws FileNotFoundException,
FileFormatException

Throws:

FileNotFoundException

FileFormatException

Method Details

isValid

public static boolean isValid(String filename)

Returns true if the given filename is a valid svcdump.

initialize

public void initialize()
                throws FileNotFoundException,
FileFormatException

Scan the dump and build the array of AddressSpaces. Every block of the dump is read to build a mapping of block memory addresses to file offsets, for each address space in the dump Each block has a header containing the AddressSpace ID and the memory address the block maps to.

Throws:

FileNotFoundException

FileFormatException

seek

public void seek(long offset)
          throws IOException

Seek to the given offset in the dump file. This also handles MVS datasets in an efficient way (simply using fseek is too slow because the seek appears to read the file from the beginning every time!).

Specified by:

seek in interface ImageInputStream

Overrides:

seek in class ImageInputStreamImpl

Parameters:

offset - the offset to seek to

Throws:

IOException - if any other I/O error occurs.

read

public int read()
         throws IOException

Reads an unsigned byte from the file

Specified by:

read in interface ImageInputStream

Specified by:

read in class ImageInputStreamImpl

Returns:

Throws:

IOException

read

public int read(byte[] buf,
 int off,
 int len)
         throws IOException

Read from the dump file into the given buffer.

Specified by:

read in interface ImageInputStream

Specified by:

read in class ImageInputStreamImpl

Parameters:

buf - the buffer to read into

off - the offset into the buffer to start at

len - the maximum number of bytes to read

Returns:

the number of bytes actually read, or -1 to indicate EOF.

Throws:

IOException - if an I/O error occurs.

read

public int read(byte[] buf)
         throws IOException

Read from the dump file into the given buffer.

Specified by:

read in interface ImageInputStream

Overrides:

read in class ImageInputStreamImpl

Parameters:

buf - the buffer to read into

Returns:

the number of bytes actually read, or -1 to indicate EOF.

Throws:

IOException - if an I/O error occurs.

length

public long length()

Get the length of the dump file

Specified by:

length in interface ImageInputStream

Overrides:

length in class ImageInputStreamImpl

Returns:

-1L to indicate unknown length.

close

public void close()
           throws IOException

Close the file used to read the dump

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface ImageInputStream

Overrides:

close in class ImageInputStreamImpl

Throws:

IOException - if an I/O error occurs.

localClose

public void localClose()
                throws IOException

Close the file used to read the dump (MVS datasets only). Added this because need to let it know we have finished with the handle for MVS only. Need to clean this up.

Throws:

IOException

getAddressSpaces

public AddressSpace[] getAddressSpaces()

Returns an array of all the address spaces in the dump.

getAddressSpace

public AddressSpace getAddressSpace(int id)

Returns the address space with the given id or null if it can't be found.

is64bit

public boolean is64bit()

Returns true if this is a 64-bit dump. Always returns false at the moment 'cos I haven't yet got my paws on a 64-bit dump.

getTitle

public String getTitle()

Returns the title of the dump.

getProductName

public String getProductName()

Returns the z/OS product name.

getProductVersion

public String getProductVersion()

Returns the z/OS product version.

getProductRelease

public String getProductRelease()

Returns the z/OS product release.

getProductModification

public String getProductModification()

Returns the z/OS product modification.

mvsClockToDate

public static Date mvsClockToDate(long clock)

Convert an MVS style clock value to a Date object.

getCreationDate

public Date getCreationDate()

Returns the time when the dump was created.

getSystemTrace

public SystemTrace getSystemTrace()
                           throws IOException

Returns an object representing the system trace table.

Throws:

IOException

getName

public String getName()

Return the pathname for this dump