Package com.apple.foundationdb.record.query.plan.temp.view

Class ViewExpressionComparisons

java.lang.Object

com.apple.foundationdb.record.query.plan.temp.view.ViewExpressionComparisons

public class ViewExpressionComparisons
extends Object

A data structure that represents a ViewExpression with a ComparisonRange on some of the Elements in its sort order.

A ViewExpressionComparisons is an analogue of a ScanComparisons that maintains information about which elements in the sort order of a ViewExpression correspond to each comparison. It maintains a list of ComparisonRanges for each of the elements. The matchWith(ElementPredicate) method can then take a ElementPredicate and try to add it to the existing comparisons.

The ViewExpressionComparisons encapsulates the core logic of marking parts of a complex key expression as satisfied by various types of Comparisons.Comparisons and attempting to match more comparisons to the remaining parts of the expression. This includes the "virtual" Comparisons.SortComparison which is used only to represent requested sort orders for index planning.

While this sounds a lot like a whole query planner, the scope of a ViewExpressionComparisons is intentionally very limited. In particular, it supports matching with an ElementPredicate rather than a more general QueryPredicate As a result, the logic for handling Boolean operations and other complexities does not belong in ViewExpressionComparisons.

Constructor Summary

Constructors

Constructor	Description
ViewExpressionComparisons(ViewExpression viewExpression)

Method Summary

Modifier and Type	Method	Description
int	getUnmatchedFieldCount()
boolean	hasComparison(Source source)
boolean	hasOrderBySourceWithoutComparison()
Optional<ViewExpressionComparisons>	matchWith(ElementPredicate component)
Optional<ViewExpressionComparisons>	matchWithSort(List<Element> sortOrder)
ScanComparisons	toScanComparisons()	Convert these comparisons to ScanComparisons for query execution.
ViewExpressionComparisons	withSourcesMappedInto(Source originalSource, Source duplicateSource)	Replace the given duplicate source with the given original source everywhere that it occurs in these view expression comparisons.

Methods inherited from class java.lang.Object

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

Constructor Detail

ViewExpressionComparisons

public ViewExpressionComparisons(@Nonnull
                                 ViewExpression viewExpression)

Method Detail

matchWith

@Nonnull
public Optional<ViewExpressionComparisons> matchWith(@Nonnull
                                                     ElementPredicate component)

matchWithSort

@Nonnull
public Optional<ViewExpressionComparisons> matchWithSort(@Nonnull
                                                         List<Element> sortOrder)

hasComparison

@Nonnull
public boolean hasComparison(@Nonnull
                             Source source)

getUnmatchedFieldCount

public int getUnmatchedFieldCount()

hasOrderBySourceWithoutComparison

public boolean hasOrderBySourceWithoutComparison()

withSourcesMappedInto

@Nonnull
public ViewExpressionComparisons withSourcesMappedInto(@Nonnull
                                                       Source originalSource,
                                                       @Nonnull
                                                       Source duplicateSource)

Replace the given duplicate source with the given original source everywhere that it occurs in these view expression comparisons.

Parameters:

originalSource - a source to replace all occurrences of the duplicate source with

duplicateSource - a source to replace with the original source

Returns:

a copy of these comparisons with all occurrences of the duplicate source replaced with the original source

toScanComparisons

@Nonnull
public ScanComparisons toScanComparisons()

Convert these comparisons to ScanComparisons for query execution.

Returns:

these comparisons as ScanComparisons