Package com.tangosol.io.journal

Class FlashJournalRM.JournalFile

java.lang.Object
com.tangosol.io.journal.AbstractJournalRM.JournalFile
com.tangosol.io.journal.FlashJournalRM.JournalFile
All Implemented Interfaces:
Disposable, AutoCloseable
Enclosing class:
FlashJournalRM
protected class FlashJournalRM.JournalFile extends AbstractJournalRM.JournalFile
A JournalFile is created for each OS file used to store the journal contents. It is created in an initial "append" mode -- which may be interrupted from time to time by a "congested" mode if writes are falling too far behind, it then transitions to a "full" mode, and once enough of its storage has been released it transitions to an "evacuating" mode, which (once evacuated) becomes "garbage" and (upon deletion) is "discarded".

  • Field Details

    • m_file

      protected final File m_file
      The file. Immutable field.

    • m_channelRead

      protected FileChannel m_channelRead
      A random access FileChannel for read purposes.

    • m_channelWrite

      protected final FileChannel m_channelWrite
      A FileOutputStream FileChannel for append purposes.

    • m_abOv

      protected final byte[] m_abOv
      Random overlay data.

    • m_ofNextFlush

      protected long m_ofNextFlush
      The offset of the next Binary to clean out of the map (ie "flush" out of memory).

  • Constructor Details

    • JournalFile

      public JournalFile(int nFile)
      Construct a Journal File.
      Parameters:
      nFile - the file number in the range 0-511 (inclusive)

  • Method Details

    • enqueue

      public long enqueue(Binary bin)
      Enqueue a Binary value to be written to this file, returning a ticket, or return 0L if this file is full and the append has to occur to a new file.
      Specified by:
      enqueue in class AbstractJournalRM.JournalFile
      Parameters:
      bin - the value to append to the journal file
      Returns:
      a ticket if the Binary has successfully been enqueued, or 0L if the file is full

    • read

      public Binary read(long lTicket)
      Read the Binary associated with the specified ticket from the journal file.
      Specified by:
      read in class AbstractJournalRM.JournalFile
      Parameters:
      lTicket - a ticket previously returned from AbstractJournalRM.JournalFile.enqueue(com.tangosol.util.Binary)
      Returns:
      the Binary value that is associated with the ticket

    • release

      public void release(int cbValue)
      Release the specified number of bytes from this journal file.
      Overrides:
      release in class AbstractJournalRM.JournalFile
      Parameters:
      cbValue - the number of bytes that are being released

    • getNextJournalFile

      public FlashJournalRM.JournalFile getNextJournalFile()
      Determine the JournalFile for the file in the journal that follows the file represented by this JournalFile.
      Overrides:
      getNextJournalFile in class AbstractJournalRM.JournalFile
      Returns:
      the next file in the journal, or null if it has not yet been set

    • getFile

      public File getFile()
      Obtain the File that this JournalFile object represents.
      Returns:
      a File object representing the OS file that this JournalFile writes and reads to and from

    • getReadChannel

      public FileChannel getReadChannel()
      Obtain the FileChannel used for reading from the JournalFile.
      Returns:
      a random access FileChannel

    • getWriteChannel

      public FileChannel getWriteChannel()
      Obtain the FileChannel used for appending to the JournalFile.
      Returns:
      an appending FileChannel

    • touch

      public void touch()
      This method is called periodically by the collector daemon to indicate that the file is still being used.
      Overrides:
      touch in class AbstractJournalRM.JournalFile

    • getDescription

      protected String getDescription()
      Format the object attributes into a String for inclusion in the String returned from the AbstractJournalRM.JournalFile.toString() method.
      Overrides:
      getDescription in class AbstractJournalRM.JournalFile
      Returns:
      a comma-delimited String listing the attributes of this object in the form "attribute=value"

    • notifyWriteOccurred

      public void notifyWriteOccurred(int cbWritten)
      Called by the WriterDaemon to indicate that more data has been flushed from the write-behind queue to disk.
      Parameters:
      cbWritten - the number of additional bytes written

    • notifyWriteBehindCompleted

      public void notifyWriteBehindCompleted()
      Called by the WriterDaemon to indicate that all the data for the JournalFile has been flushed.

    • dispose

      public void dispose()
      Invoked when all resources owned by the implementer can safely be released.

      Once disposed of the object should no longer be considered to be usable.

      Note the Disposable interface is compatible with try-with-resources which will automatically invoke this method.

      Specified by:
      dispose in interface Disposable
      Specified by:
      dispose in class AbstractJournalRM.JournalFile

    • congestionCheck

      protected void congestionCheck(int cbDelta)
      Check if a change to the backlog causes a change to the congestion state.
      Parameters:
      cbDelta - number of bytes added to or removed from the backlog

    • allocateBuffer

      public FlashJournalRM.Buffer allocateBuffer()
      Allocate a Buffer to use with this JournalFile.
      Returns:
      a new (or pooled) Buffer