com.healthmarketscience.jackcess.impl

Class IndexCursorImpl

java.lang.Object

com.healthmarketscience.jackcess.impl.CursorImpl

com.healthmarketscience.jackcess.impl.IndexCursorImpl

All Implemented Interfaces:

Cursor, IndexCursor, Iterable<Row>

public class IndexCursorImpl
extends CursorImpl
implements IndexCursor

Cursor backed by an index with extended traversal options.

Author:

James Ahlborn

Nested Class Summary

Nested classes/interfaces inherited from class com.healthmarketscience.jackcess.impl.CursorImpl

CursorImpl.BaseIterator, CursorImpl.DirHandler, CursorImpl.IdImpl, CursorImpl.PositionImpl, CursorImpl.SavepointImpl

Nested classes/interfaces inherited from interface com.healthmarketscience.jackcess.Cursor

Cursor.Id, Cursor.Position, Cursor.Savepoint

Field Summary

Fields inherited from class com.healthmarketscience.jackcess.impl.CursorImpl

_columnMatcher, _curPos, _prevPos, MOVE_FORWARD, MOVE_REVERSE

Method Summary

Modifier and Type	Method and Description
static IndexCursorImpl	createCursor(TableImpl table, IndexImpl index, Object[] startRow, boolean startInclusive, Object[] endRow, boolean endInclusive) Creates an indexed cursor for the given table, narrowed to the given range.
boolean	currentRowMatchesEntry(Object... entryValues) Returns true if the current row matches the given index entries.
Iterator<Row>	entryIterator(EntryIterableBuilder iterBuilder)
protected CursorImpl.PositionImpl	findAnotherPosition(TableImpl.RowState rowState, CursorImpl.PositionImpl curPos, boolean moveForward) Finds the next non-deleted row after the given row (as defined by this cursor) and returns the id of the row, where "next" may be backwards if moveForward is false.
protected boolean	findAnotherRowImpl(ColumnImpl columnPattern, Object valuePattern, boolean moveForward, ColumnMatcher columnMatcher, Object searchInfo) Moves to the next row (as defined by the cursor) where the given column has the given value.
protected boolean	findAnotherRowImpl(Map<String,?> rowPattern, boolean moveForward, ColumnMatcher columnMatcher, Object searchInfo) Moves to the next row (as defined by the cursor) where the given columns have the given values.
void	findClosestRowByEntry(Object... entryValues) Moves to the first row (as defined by the cursor) where the index entries are >= the given values.
boolean	findFirstRowByEntry(Object... entryValues) Moves to the first row (as defined by the cursor) where the index entries match the given values.
protected boolean	findFirstRowByEntryImpl(Object[] rowValues, boolean requireMatch, ColumnMatcher columnMatcher) Moves to the first row (as defined by the cursor) where the index entries match the given values.
Row	findRowByEntry(Object... entryValues) Finds the first row (as defined by the cursor) where the index entries match the given values.
protected ColumnMatcher	getDefaultColumnMatcher() Returns the default ColumnMatcher for this Cursor.
protected com.healthmarketscience.jackcess.impl.IndexCursorImpl.IndexDirHandler	getDirHandler(boolean moveForward) Returns the DirHandler for the given movement direction.
IndexImpl	getIndex()
protected CursorImpl.PositionImpl	getRowPosition(RowIdImpl rowId) Returns the appropriate position information for the given row (which is the current row and is valid).
protected boolean	isUpToDate() Returns true if this cursor is up-to-date with respect to the relevant table and related table objects, false otherwise.
protected boolean	keepSearching(ColumnMatcher columnMatcher, Object searchInfo) Called by findAnotherRowImpl to determine if the search should continue after finding a row which does not match the current pattern.
EntryIterableBuilder	newEntryIterable(Object... entryValues) Convenience method for constructing a new EntryIterableBuilder for this cursor.
protected Object	prepareSearchInfo(ColumnImpl columnPattern, Object valuePattern) Called before a search commences to allow for search specific data to be generated (which is cached for re-use by the iterators).
protected Object	prepareSearchInfo(Map<String,?> rowPattern) Called before a search commences to allow for search specific data to be generated (which is cached for re-use by the iterators).
protected void	reset(boolean moveForward) Resets this cursor for traversing the given direction.
protected void	restorePositionImpl(CursorImpl.PositionImpl curPos, CursorImpl.PositionImpl prevPos) Restores a current and previous position for the cursor.

Methods inherited from class com.healthmarketscience.jackcess.impl.CursorImpl

afterLast, beforeFirst, createCursor, currentRowMatches, currentRowMatches, currentRowMatches, currentRowMatchesImpl, currentRowMatchesImpl, deleteCurrentRow, findAnotherRow, findAnotherRow, findFirstRow, findFirstRow, findFirstRow, findNextRow, findNextRow, findNextRow, findRow, getColumnMatcher, getCurrentRow, getCurrentRow, getCurrentRowValue, getCurrentRowValue, getErrorHandler, getFirstPosition, getFormat, getId, getLastPosition, getNextRow, getNextRow, getPageChannel, getPreviousRow, getPreviousRow, getRowState, getSavepoint, getTable, isAfterLast, isAtBeginning, isBeforeFirst, isCurrentRowDeleted, isCurrentRowValid, iterator, iterator, moveNextRows, movePreviousRows, moveToAnotherRow, moveToNextRow, moveToPreviousRow, newIterable, reset, restorePosition, restorePosition, restoreSavepoint, restoreSavepoint, setColumnMatcher, setCurrentRowValue, setCurrentRowValue, setErrorHandler, toString, updateCurrentRow, updateCurrentRowFromMap

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.healthmarketscience.jackcess.Cursor

afterLast, beforeFirst, currentRowMatches, currentRowMatches, deleteCurrentRow, findFirstRow, findFirstRow, findNextRow, findNextRow, findRow, getColumnMatcher, getCurrentRow, getCurrentRow, getCurrentRowValue, getErrorHandler, getId, getNextRow, getNextRow, getPreviousRow, getPreviousRow, getSavepoint, getTable, isAfterLast, isBeforeFirst, isCurrentRowDeleted, iterator, moveNextRows, movePreviousRows, moveToNextRow, moveToPreviousRow, newIterable, reset, restoreSavepoint, setColumnMatcher, setCurrentRowValue, setErrorHandler, updateCurrentRow, updateCurrentRowFromMap

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Method Detail

createCursor

public static IndexCursorImpl createCursor(TableImpl table,
                                           IndexImpl index,
                                           Object[] startRow,
                                           boolean startInclusive,
                                           Object[] endRow,
                                           boolean endInclusive)
                                    throws IOException

Creates an indexed cursor for the given table, narrowed to the given range.

Note, index based table traversal may not include all rows, as certain types of indexes do not include all entries (namely, some indexes ignore null entries, see Index.shouldIgnoreNulls()).

Parameters:

table - the table over which this cursor will traverse

index - index for the table which will define traversal order as well as enhance certain lookups

startRow - the first row of data for the cursor, or null for the first entry

startInclusive - whether or not startRow is inclusive or exclusive

endRow - the last row of data for the cursor, or null for the last entry

endInclusive - whether or not endRow is inclusive or exclusive

Throws:

IOException

getIndex

public IndexImpl getIndex()

Specified by:

getIndex in interface IndexCursor

findRowByEntry

public Row findRowByEntry(Object... entryValues)
                   throws IOException

Description copied from interface: IndexCursor

Finds the first row (as defined by the cursor) where the index entries match the given values. If a match is not found (or an exception is thrown), the cursor is restored to its previous state.

Specified by:

findRowByEntry in interface IndexCursor

Parameters:

entryValues - the column values for the index's columns.

Returns:

the matching row or null if a match could not be found.

Throws:

IOException

findFirstRowByEntry

public boolean findFirstRowByEntry(Object... entryValues)
                            throws IOException

Description copied from interface: IndexCursor

Moves to the first row (as defined by the cursor) where the index entries match the given values. If a match is not found (or an exception is thrown), the cursor is restored to its previous state.

Warning, this method always starts searching from the beginning of the Table (you cannot use it to find successive matches).

Specified by:

findFirstRowByEntry in interface IndexCursor

Parameters:

entryValues - the column values for the index's columns.

Returns:

true if a valid row was found with the given values, false if no row was found

Throws:

IOException

findClosestRowByEntry

public void findClosestRowByEntry(Object... entryValues)
                           throws IOException

Description copied from interface: IndexCursor

Moves to the first row (as defined by the cursor) where the index entries are >= the given values. If a an exception is thrown, the cursor is restored to its previous state.

Specified by:

findClosestRowByEntry in interface IndexCursor

Parameters:

entryValues - the column values for the index's columns.

Throws:

IOException

currentRowMatchesEntry

public boolean currentRowMatchesEntry(Object... entryValues)
                               throws IOException

Description copied from interface: IndexCursor

Returns true if the current row matches the given index entries.

Specified by:

currentRowMatchesEntry in interface IndexCursor

Parameters:

entryValues - the column values for the index's columns.

Throws:

IOException

newEntryIterable

public EntryIterableBuilder newEntryIterable(Object... entryValues)

Description copied from interface: IndexCursor

Convenience method for constructing a new EntryIterableBuilder for this cursor. An EntryIterableBuilder provides a variety of options for more flexible iteration based on a specific index entry.

Specified by:

newEntryIterable in interface IndexCursor

Parameters:

entryValues - the column values for the index's columns.

entryIterator

public Iterator<Row> entryIterator(EntryIterableBuilder iterBuilder)

getDirHandler

protected com.healthmarketscience.jackcess.impl.IndexCursorImpl.IndexDirHandler getDirHandler(boolean moveForward)

Description copied from class: CursorImpl

Returns the DirHandler for the given movement direction.

Specified by:

getDirHandler in class CursorImpl

isUpToDate

protected boolean isUpToDate()

Description copied from class: CursorImpl

Returns true if this cursor is up-to-date with respect to the relevant table and related table objects, false otherwise.

Overrides:

isUpToDate in class CursorImpl

reset

protected void reset(boolean moveForward)

Description copied from class: CursorImpl

Resets this cursor for traversing the given direction.

Overrides:

reset in class CursorImpl

restorePositionImpl

protected void restorePositionImpl(CursorImpl.PositionImpl curPos,
                                   CursorImpl.PositionImpl prevPos)
                            throws IOException

Description copied from class: CursorImpl

Restores a current and previous position for the cursor.

Overrides:

restorePositionImpl in class CursorImpl

Throws:

IOException

getRowPosition

protected CursorImpl.PositionImpl getRowPosition(RowIdImpl rowId)
                                          throws IOException

Description copied from class: CursorImpl

Returns the appropriate position information for the given row (which is the current row and is valid).

Specified by:

getRowPosition in class CursorImpl

Throws:

IOException

findAnotherRowImpl

protected boolean findAnotherRowImpl(ColumnImpl columnPattern,
                                     Object valuePattern,
                                     boolean moveForward,
                                     ColumnMatcher columnMatcher,
                                     Object searchInfo)
                              throws IOException

Description copied from class: CursorImpl

Moves to the next row (as defined by the cursor) where the given column has the given value. Caller manages save/restore on failure.

Default implementation scans the table from beginning to end.

Overrides:

findAnotherRowImpl in class CursorImpl

Parameters:

columnPattern - column from the table for this cursor which is being matched by the valuePattern

valuePattern - value which is equal to the corresponding value in the matched row

Returns:

true if a valid row was found with the given value, false if no row was found

Throws:

IOException

findFirstRowByEntryImpl

protected boolean findFirstRowByEntryImpl(Object[] rowValues,
                                          boolean requireMatch,
                                          ColumnMatcher columnMatcher)
                                   throws IOException

Moves to the first row (as defined by the cursor) where the index entries match the given values. Caller manages save/restore on failure.

Parameters:

rowValues - the column values built from the index column values

requireMatch - whether or not an exact match is found

Returns:

true if a valid row was found with the given values, false if no row was found

Throws:

IOException

findAnotherRowImpl

protected boolean findAnotherRowImpl(Map<String,?> rowPattern,
                                     boolean moveForward,
                                     ColumnMatcher columnMatcher,
                                     Object searchInfo)
                              throws IOException

Description copied from class: CursorImpl

Moves to the next row (as defined by the cursor) where the given columns have the given values. Caller manages save/restore on failure.

Default implementation scans the table from beginning to end.

Overrides:

findAnotherRowImpl in class CursorImpl

Parameters:

rowPattern - column names and values which must be equal to the corresponding values in the matched row

Returns:

true if a valid row was found with the given values, false if no row was found

Throws:

IOException

prepareSearchInfo

protected Object prepareSearchInfo(ColumnImpl columnPattern,
                                   Object valuePattern)

Description copied from class: CursorImpl

Called before a search commences to allow for search specific data to be generated (which is cached for re-use by the iterators).

Overrides:

prepareSearchInfo in class CursorImpl

prepareSearchInfo

protected Object prepareSearchInfo(Map<String,?> rowPattern)

Description copied from class: CursorImpl

Called before a search commences to allow for search specific data to be generated (which is cached for re-use by the iterators).

Overrides:

prepareSearchInfo in class CursorImpl

keepSearching

protected boolean keepSearching(ColumnMatcher columnMatcher,
                                Object searchInfo)
                         throws IOException

Description copied from class: CursorImpl

Called by findAnotherRowImpl to determine if the search should continue after finding a row which does not match the current pattern.

Overrides:

keepSearching in class CursorImpl

Throws:

IOException

findAnotherPosition

protected CursorImpl.PositionImpl findAnotherPosition(TableImpl.RowState rowState,
                                                      CursorImpl.PositionImpl curPos,
                                                      boolean moveForward)
                                               throws IOException

Description copied from class: CursorImpl

Finds the next non-deleted row after the given row (as defined by this cursor) and returns the id of the row, where "next" may be backwards if moveForward is false. If there are no more rows, the returned rowId should equal the value returned by CursorImpl.getLastPosition() if moving forward and CursorImpl.getFirstPosition() if moving backward.

Specified by:

findAnotherPosition in class CursorImpl

Throws:

IOException

getDefaultColumnMatcher

protected ColumnMatcher getDefaultColumnMatcher()

Description copied from class: CursorImpl

Returns the default ColumnMatcher for this Cursor.

Overrides:

getDefaultColumnMatcher in class CursorImpl