Class BasicSortObserver

java.lang.Object
org.apache.derby.impl.sql.execute.BasicSortObserver
All Implemented Interfaces:
SortObserver
Direct Known Subclasses:
AggregateSortObserver, UniqueIndexSortObserver, UniqueWithDuplicateNullsIndexSortObserver
public class BasicSortObserver extends Object implements SortObserver
This is the most basic sort observer. It handles distinct sorts and non-distinct sorts.

  • Field Details

    • doClone

      protected boolean doClone

    • distinct

      protected boolean distinct

    • reuseWrappers

      private boolean reuseWrappers

    • execRow

      private ExecRow execRow

    • vector

      private Vector<DataValueDescriptor[]> vector

  • Constructor Details

    • BasicSortObserver

      public BasicSortObserver(boolean doClone, boolean distinct, ExecRow execRow, boolean reuseWrappers)
      Simple constructor
      Parameters:
      doClone - If true, then rows that are retained by the sorter will be cloned. This is needed if language is reusing row wrappers.
      distinct - If true, toss out duplicates. Otherwise, retain them.
      execRow - ExecRow to use as source of clone for store.
      reuseWrappers - Whether or not we can reuse the wrappers

  • Method Details

    • insertNonDuplicateKey

      public DataValueDescriptor[] insertNonDuplicateKey(DataValueDescriptor[] insertRow) throws StandardException
      Called prior to inserting a distinct sort key.
      Specified by:
      insertNonDuplicateKey in interface SortObserver
      Parameters:
      insertRow - the current row that the sorter is on the verge of retaining
      Returns:
      the row to be inserted by the sorter. If null, then nothing is inserted by the sorter. Distinct sorts will want to return null.
      Throws:
      StandardException - never thrown

    • insertDuplicateKey

      public DataValueDescriptor[] insertDuplicateKey(DataValueDescriptor[] insertRow, DataValueDescriptor[] existingRow) throws StandardException
      Called prior to inserting a duplicate sort key.
      Specified by:
      insertDuplicateKey in interface SortObserver
      Parameters:
      insertRow - the current row that the sorter is on the verge of retaining. It is a duplicate of existingRow.
      existingRow - the row that is already in the the sorter which is a duplicate of insertRow
      Returns:
      the row to be inserted by the sorter. If null, then nothing is inserted by the sorter. Distinct sorts will want to return null.
      Throws:
      StandardException - never thrown

    • addToFreeList

      public void addToFreeList(DataValueDescriptor[] objectArray, int maxFreeListSize)
      Specified by:
      addToFreeList in interface SortObserver

    • getArrayClone

      public DataValueDescriptor[] getArrayClone() throws StandardException
      Specified by:
      getArrayClone in interface SortObserver
      Throws:
      StandardException

    • getClone

      private DataValueDescriptor[] getClone(DataValueDescriptor[] origArray)

    • deferred

      public boolean deferred()
      Description copied from interface: SortObserver
      Overridden by subclasses that observe sorters with uniqueness checking.
      Specified by:
      deferred in interface SortObserver
      Returns:
      true if constraint mode of the index's constraint is effectively deferred. Any SortObserver implementations that implement uniqueness checking need to keep track of this information.

    • deferrable

      public boolean deferrable()
      Description copied from interface: SortObserver
      Overridden by subclasses that observe sorters with uniqueness checking.
      Specified by:
      deferrable in interface SortObserver
      Returns:
      true if the index's constraint is deferrable. Any SortObserver implementations that implement uniqueness checking need to keep track of this information.

    • rememberDuplicate

      public void rememberDuplicate(DataValueDescriptor[] row) throws StandardException
      Description copied from interface: SortObserver
      Overridden by subclasses that observe sorters with uniqueness checking. Will be called by sorters iff deferrable() and deferred() and uniqueness violation, so implementations that sometimes return true to these must implement this method to save duplicate information till commit time.
      Specified by:
      rememberDuplicate in interface SortObserver
      Parameters:
      row - data of offending key
      Throws:
      StandardException - standard error policy