Class OpenBTree

  • Direct Known Subclasses:
    BTreeController, BTreeCostController, BTreeScan

    public class OpenBTree
    extends java.lang.Object
    An open b-tree contains fields and methods common to scans and controllers.

    Concurrency Notes

    An instance of an open b-tree is owned by a single context. The b-tree code assumes that the context ensures that only one thread at a time is using the open b-tree. The open b-tree itself does not enforce or check this.

    • Field Detail

      • init_conglomerate

        private BTree init_conglomerate
        The following group of fields are all basic input parameters which are provided by the calling code when doing any sort of operation requiring an open conglomerate (openScan(), open(), openCostController(), ...). These are just saved values from what was initially input.
      • init_xact_manager

        private TransactionManager init_xact_manager
        The TransactionManager that open'd this btree. In the case of Internal transactions used by split this will be the internal transaction, and init_open_user_scans will be the user transaction that began the internal transaction.
      • init_openmode

        private int init_openmode
        The ContainerHandle mode the container is opened with. Remember this so that if the BTree needs to do SMO with another transaction, it would open the container with the same mode.
      • init_lock_level

        protected int init_lock_level
        Table or page locking?
      • init_hold

        private boolean init_hold
      • init_btree_locking_policy

        private BTreeLockingPolicy init_btree_locking_policy
        The Locking Policy to use for for access to this btree.
      • container

        protected ContainerHandle container
        The (open) container which contains the b-tree.
      • err_containerid

        protected long err_containerid
        The conglomerate containerid for error reporting.
      • init_open_user_scans

        protected TransactionManager init_open_user_scans
        The user transaction that opened this B-tree.
    • Constructor Detail

      • OpenBTree

        public OpenBTree()
    • Method Detail

      • getXactMgr

        public final TransactionManager getXactMgr()
        Public Accessors of This class:
      • getLockLevel

        public final int getLockLevel()
      • getOpenMode

        public final int getOpenMode()
      • getConglomerate

        public final BTree getConglomerate()
      • getHold

        public final boolean getHold()
      • isClosed

        public final boolean isClosed()
      • getEstimatedRowCount

        public long getEstimatedRowCount()
                                  throws StandardException
        Get the total estimated number of rows in the container.

        The number is a rough estimate and may be grossly off. In general the server will cache the row count and then occasionally write the count unlogged to a backing store. If the system happens to shutdown before the store gets a chance to update the row count it may wander from reality.

        This call is currently only supported on Heap conglomerates, it will throw an exception if called on btree conglomerates.

        Returns:
        The total estimated number of rows in the conglomerate.
        Throws:
        StandardException - Standard exception policy.
      • setEstimatedRowCount

        public void setEstimatedRowCount​(long count)
                                  throws StandardException
        Set the total estimated number of rows in the container.

        Often, after a scan, the client of RawStore has a much better estimate of the number of rows in the container than what store has. For instance if we implement some sort of update statistics command, or just after a create index a complete scan will have been done of the table. In this case this interface allows the client to set the estimated row count for the container, and store will use that number for all future references.

        This call is currently only supported on Heap conglomerates, it will throw an exception if called on btree conglomerates.

        Parameters:
        count - the estimated number of rows in the container.
        Throws:
        StandardException - Standard exception policy.
      • checkConsistency

        public void checkConsistency()
                              throws StandardException
        Check consistency of a btree.

        Read in root and check consistency of entire tree. Currently raises sanity check errors.

        RESOLVE (mikem) if this is to be supported in non-sanity servers what should it do?

        Throws:
        StandardException - Standard exception policy.
      • isTableLocked

        public boolean isTableLocked()
        is the open btree table locked?
      • init

        public void init​(TransactionManager open_user_scans,
                         TransactionManager xact_manager,
                         ContainerHandle input_container,
                         Transaction rawtran,
                         boolean hold,
                         int open_mode,
                         int lock_level,
                         BTreeLockingPolicy btree_locking_policy,
                         BTree conglomerate,
                         LogicalUndo undo,
                         DynamicCompiledOpenConglomInfo dynamic_info)
                  throws StandardException
        Initialize the open conglomerate.

        If container is null, open the container, otherwise use the container passed in. The container is always opened with no locking, it is up to the caller to make the appropriate container locking call.

        Parameters:
        open_user_scans - The user transaction which opened this btree.
        xact_manager - The current transaction, usually the same as "open_user_scans", but in the case of split it is the internal xact nested below the user xact.
        input_container - The open container holding the index, if it is already open, else null which will mean this routine will open it.
        rawtran - The current raw store transaction.
        open_mode - The opening mode for the ContainerHandle.
        conglomerate - Readonly description of the conglomerate.
        undo - Logical undo object to associate with all updates done on this open btree.
        Throws:
        StandardException - Standard exception policy.
      • reopen

        public ContainerHandle reopen()
                               throws StandardException
        Open the container after it has been closed previously.

        Open the container, obtaining necessary locks. Most work is actually done by RawStore.openContainer(). Will only reopen() if the container is not already open.

        Throws:
        StandardException - Standard exception policy.
      • isIndexableRowConsistent

        void isIndexableRowConsistent​(DataValueDescriptor[] row)
                               throws StandardException
        Check if all the columns are Indexable and Storable. Eventually this routine could check whether all the types were right also.
        Throws:
        StandardException - Standard Exception Policy.
      • getContainerHandle

        public ContainerHandle getContainerHandle()
        Return the container handle.

        Returns:
        The open container handle of the btree.
      • getHeight

        public int getHeight()
                      throws StandardException
        get height of the tree.

        Read in root and return the height (number of levels) of the tree. The level of a tree is 0 in the leaf and increases by 1 for each level of the tree as you go up the tree.

        Throws:
        StandardException - Standard exception policy.
      • debugConglomerate

        public void debugConglomerate()
                               throws StandardException
        Dump information about tree into the log.

        Traverse the tree dumping info about tree into the log.

        Throws:
        StandardException - Standard exception policy.
      • test_errors

        public static boolean test_errors​(OpenBTree open_btree,
                                          java.lang.String debug_string,
                                          BTreeRowPosition pos,
                                          BTreeLockingPolicy btree_locking_policy,
                                          LeafControlRow leaf,
                                          boolean input_latch_released)
                                   throws StandardException
        Testing infrastructure to cause unusual paths through the code.

        Through the use of debug flags allow test code to cause otherwise hard to cause paths through the code.

        Parameters:
        pos - the current scan position if the condition simulated by this call would have resulted in the position being saved
        Returns:
        whether the latch has been released by this routine.
        Throws:
        StandardException - Standard exception policy.