Module openj9.dtfj
Package com.ibm.j9ddr.corereaders.tdump.zebedee.dumpreader

Class 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 Detail

      • DATABLOCKSIZE

        public static final int DATABLOCKSIZE
        Size of a block excluding header
        See Also:
        Constant Field Values

    • Method Detail

      • 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​(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.

      • 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.

      • getName

        public String getName()
        Return the pathname for this dump