org.hypergraphdb

Interface HGRandomAccessResult<ValueType>

All Superinterfaces:

CloseMe, HGSearchResult<ValueType>, Iterator<ValueType>, TwoWayIterator<ValueType>

All Known Implementing Classes:

FilteredRAResultSet, InMemoryIntersectionResult, ZigZagIntersectionResult

public interface HGRandomAccessResult<ValueType>
extends HGSearchResult<ValueType>

A HGRandomAccessResult is a search result that is based on some kind of cursor that allows immediate positioning on some result value, if it exists. This is particularly useful for index-based search results where the whole result set is ordered and provides quick lookup to begin with. A query execution plan may take advantage of this capability.

Author:

Borislav Iordanov

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	HGRandomAccessResult.GotoResult Enumerates the possible results of a call to the goTo in a HGRandomAccessResult.

Field Summary

Fields inherited from interface org.hypergraphdb.HGSearchResult

EMPTY

Method Summary

Methods

Modifier and Type	Method and Description
void	goAfterLast() Move the cursor of this result set after the last result.
void	goBeforeFirst() Move the cursor of this result set before the first result.
HGRandomAccessResult.GotoResult	goTo(ValueType value, boolean exactMatch) Position the result set at a particular value if that value is indeed part of the result set.

Methods inherited from interface org.hypergraphdb.HGSearchResult

close, current, isOrdered

Methods inherited from interface org.hypergraphdb.TwoWayIterator

hasPrev, prev

Methods inherited from interface java.util.Iterator

hasNext, next, remove

Method Detail

goTo

HGRandomAccessResult.GotoResult goTo(ValueType value,
                                   boolean exactMatch)

Position the result set at a particular value if that value is indeed part of the result set.

Parameters:

value - The value where this result set should be positioned.

exactMatch - A flag indicating whether the passed in value should match exactly a value in the result set, or whether the cursor should be positioned to the closest value. Here "closest" means "smallest greater than the value parameter.

Returns:

A GotoResult.

goAfterLast

void goAfterLast()

Move the cursor of this result set after the last result. When positioned after the last result, there is no current element, hasNext will return false and hasPrev will return true if there's at least one element in this result set.

goBeforeFirst

void goBeforeFirst()

Move the cursor of this result set before the first result. This is equivalent to resetting the cursor to its initial state, right after the result set was created. When positioned before the first result, there is no current element, hasPrev will return false and hasNext will return true if there's at least one element in this result set.