Package com.tangosol.util

Class MultiBinaryLongMap.MaskedLongMapHolder

java.lang.Object
com.tangosol.util.MultiBinaryLongMap.MaskedLongMapHolder
Direct Known Subclasses:
MultiBinaryLongMap.LeftoverLongMapHolder
Enclosing class:
MultiBinaryLongMap
protected static class MultiBinaryLongMap.MaskedLongMapHolder extends Object
MaskedLongMapHolder is used to produce MultiBinaryLongMap.MaskedBinaryLongMap instances backed by a shared BinaryLongMap. MaskedBinaryLongMap instances created by this holder are thread-safe and are all protected by the same shared and exclusive locks.

  • Field Details

    • m_listBLMs

      protected List<MultiBinaryLongMap.MaskedBinaryLongMap> m_listBLMs
      The list of reserved masked BLMs, ordered by increasing shift-position.

    • f_lMaskReserved

      protected final long f_lMaskReserved
      The bit-mask describing which bits in the underlying BLM representation are reserved (and may not be allocated by this holder).

    • m_lMaskFree

      protected long m_lMaskFree
      The bit-mask describing which bits in the underlying BLM representation are free.

    • f_lockS

      protected final Lock f_lockS
      The shared lock used to protected the logical contents of the maps exposed by this MaskedLongMapHolder.

    • f_lockX

      protected final Lock f_lockX
      The exclusive lock used to protected the logical contents of the maps exposed by this MaskedLongMapHolder.

    • f_blm

      protected final BinaryLongMap f_blm
      The BinaryLongMap shared by the component masked BLMs.

  • Constructor Details

    • MaskedLongMapHolder

      public MaskedLongMapHolder(BinaryLongMap blm, Lock lockSMaster)
      Construct a MaskedLongMapHolder backed by the specified blm.
      Parameters:
      blm - the BinaryLongMap that the component masked maps are backed by
      lockSMaster - the shared master-lock for the MultiBinaryLongMap

    • MaskedLongMapHolder

      public MaskedLongMapHolder(BinaryLongMap blm, Lock lockSMaster, long lMaskReserved)
      Construct a MaskedLongMapHolder backed by the specified blm with the specified reserved bit-mask.
      Parameters:
      blm - the BinaryLongMap that the component masked maps are backed by
      lockSMaster - the shared master-lock for the MultiBinaryLongMap
      lMaskReserved - the bit-mask representing the reserved bits

  • Method Details

    • getDelegateMap

      public BinaryLongMap getDelegateMap()
      Return the BinaryLongMap that provides the underlying storage for this MaskedLongMapHolder.
      Returns:
      the underlying BinaryLongMap

    • reserveMap

      public BinaryLongMap reserveMap(int cBits)
      Reserve and return a masked BLM from this MaskedLongMapHolder if available, or null otherwise. Reserved maps must be released when no longer needed.
      Parameters:
      cBits - the number of bits to use to store each value
      Returns:
      a masked BLM, or null

    • releaseMap

      public boolean releaseMap(MultiBinaryLongMap.MaskedBinaryLongMap blm)
      Release a masked BLM that was reserved from this MaskedLongMapHolder.
      Parameters:
      blm - the masked BLM to release
      Returns:
      true iff the MaskedLongMapHolder becomes empty as a result

    • isEmpty

      public boolean isEmpty()
      Return true iff all non-reserved bits are free (not in-use).
      Returns:
      true iff all non-reserved bits are free (not in use)

    • instantiateMaskedBinaryLongMap

      protected MultiBinaryLongMap.MaskedBinaryLongMap instantiateMaskedBinaryLongMap(int cShift, int cBits)
      Factory method for instantiating MaskedBinaryLongMap instances associated with this MaskedLongMapHolder.
      Parameters:
      cShift - the shift position of the masked BLM
      cBits - the bit-width of values represented by the BLM
      Returns:
      a MaskedBinaryLongMap with the specified shift and mask associated with this LongMapHolder (and backed by the underlying BLM)

    • shiftMaskedMap

      protected void shiftMaskedMap(MultiBinaryLongMap.MaskedBinaryLongMap blm, int cShiftRight)
      Shift the representation of the specified MaskedBinaryLongMap by the specified number of bits to the right.

      Note: the caller must hold exclusive access to the underlying BLM (and by extension, exclusive access to all derived masked maps).

      Parameters:
      blm - the MaskedBinaryLongMap to shift
      cShiftRight - the number of bits to shift to the right

    • checkRep

      protected void checkRep()
      Debugging function to check the representational invariant.