Package org.apache.jackrabbit.oak.plugins.index

Class Cursors

java.lang.Object

org.apache.jackrabbit.oak.plugins.index.Cursors

public class Cursors
extends Object

This utility class provides factory methods to create commonly used types of Cursors.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Cursors.AbstractCursor	A Cursor implementation where the remove method throws an UnsupportedOperationException.
static class	Cursors.PathCursor	PathCursor implements a simple Cursor that iterates over a String based path Iterable.

Method Summary

Modifier and Type	Method	Description
static void	checkMemoryLimit(long count, QueryLimits settings)
static void	checkReadLimit(long count, QueryLimits settings)
static Cursor	newAncestorCursor(Cursor c, int level, QueryLimits settings)	Returns a cursor wrapper, which returns the ancestor rows at the given level of the wrapped cursor c.
static Cursor	newConcatCursor(List<Cursor> cursors, QueryLimits settings)
static Cursor	newIntersectionCursor(Cursor a, Cursor b, QueryLimits settings)
static Cursor	newPathCursor(Iterable<String> paths, QueryLimits settings)	Creates a Cursor over paths.
static Cursor	newPathCursorDistinct(Iterable<String> paths, QueryLimits settings)	Creates a Cursor over paths, and make the result distinct.
static Cursor	newTraversingCursor(Filter filter, NodeState rootState)	Returns a traversing cursor based on the path restriction in the given Filter.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

checkMemoryLimit

public static void checkMemoryLimit(long count,
                                    QueryLimits settings)

checkReadLimit

public static void checkReadLimit(long count,
                                  QueryLimits settings)

newIntersectionCursor

public static Cursor newIntersectionCursor(Cursor a,
                                           Cursor b,
                                           QueryLimits settings)

newConcatCursor

public static Cursor newConcatCursor(List<Cursor> cursors,
                                     QueryLimits settings)

newPathCursor

public static Cursor newPathCursor(Iterable<String> paths,
                                   QueryLimits settings)

Creates a Cursor over paths.

Parameters:

paths - the paths to iterate over (must return distinct paths)

Returns:

the Cursor.

newPathCursorDistinct

public static Cursor newPathCursorDistinct(Iterable<String> paths,
                                           QueryLimits settings)

Creates a Cursor over paths, and make the result distinct. The iterator might return duplicate paths

Parameters:

paths - the paths to iterate over (might contain duplicate entries)

Returns:

the Cursor.

newTraversingCursor

public static Cursor newTraversingCursor(Filter filter,
                                         NodeState rootState)

Returns a traversing cursor based on the path restriction in the given Filter.

Parameters:

filter - the filter.

rootState - the root NodeState.

Returns:

the Cursor.

newAncestorCursor

public static Cursor newAncestorCursor(Cursor c,
                                       int level,
                                       QueryLimits settings)

Returns a cursor wrapper, which returns the ancestor rows at the given level of the wrapped cursor c. With level e.g. set to 1, the returned cursor iterates over the parent rows of the passed cursor c. The returned cursor guarantees distinct rows.

Parameters:

c - the cursor to wrap.

level - the ancestor level. Must be >= 1.

Returns:

cursor over the ancestors of c at level.