AutocompleteEngine< T extends Indexable > Class Template Reference

Facade for indexing and searching Indexable elements. More...

Inheritance diagram for AutocompleteEngine< T extends Indexable >:

Collaboration diagram for AutocompleteEngine< T extends Indexable >:

Classes
class	Builder
	Builder for constructing AutocompleteEngine instances. More...

Public Member Functions
boolean	add (T element)
	Indexes a single element. More...
boolean	addAll (Collection< T > elements)
	Indexes a collection of elements. More...
boolean	remove (T element)
	Removes a single element. More...
boolean	removeAll (Collection< T > elements)
	Removes a collection of elements. More...
Collection< T >	getAll ()
	Gets all elements. More...
List< T >	search (String query)
	Returns a List of all elements that match a query, sorted according to the default comparator. More...
List< T >	search (String query, int limit)
	Returns a List of the top elements that match a query, sorted according to the default comparator. More...

Private Member Functions
	AutocompleteEngine (Builder< T > builder)

Private Attributes
final Analyzer	analyzer
final Comparator< ScoredObject< T > >	comparator
final IndexAdapter< T >	index
final Lock	read
final Lock	write

Detailed Description

Facade for indexing and searching Indexable elements.

Constructor & Destructor Documentation

AutocompleteEngine()

AutocompleteEngine ( Builder< T >  builder )

private

    {
        assert builder != null;
        this.analyzer = builder.analyzer;
        this.comparator = builder.comparator;
        this.index = builder.index;
        ReadWriteLock lock = new ReentrantReadWriteLock();
        this.read = lock.readLock();
        this.write = lock.writeLock();
    }

References AutocompleteEngine< T extends Indexable >.Builder< T extends Indexable >.analyzer, AutocompleteEngine< T extends Indexable >.Builder< T extends Indexable >.comparator, and AutocompleteEngine< T extends Indexable >.Builder< T extends Indexable >.index.

Member Function Documentation

add()

boolean add

(

T

element

)

Indexes a single element.

Exceptions

NullPointerException

if element is null;

    {
        return addAll(Arrays.asList(element));
    }

References AutocompleteEngine< T extends Indexable >.addAll().

addAll()

boolean addAll

(

Collection< T >

elements

)

Indexes a collection of elements.

Exceptions

NullPointerException

if elements is null or contains a null element;

    {
        checkPointer(elements != null);
        boolean result = false;
        for (T element : elements)
        {
            checkPointer(element != null);
            write.lock();
            try
            {
                for (String field : element.getFields())
                {
                    for (String token : analyzer.apply(field))
                    {
                        result |= index.put(token, element);
                    }
                }
            }
            finally
            {
                write.unlock();
            }
        }
        return result;
    }

References AutocompleteEngine< T extends Indexable >.analyzer, AutocompleteEngine< T extends Indexable >.index, and AutocompleteEngine< T extends Indexable >.write.

Referenced by AutocompleteEngine< T extends Indexable >.add().

getAll()

Collection<T> getAll

(

)

Gets all elements.

Exceptions

NullPointerException

if elements is null or contains a null element;

    {
        return new LinkedList<T>();
    }

remove()

boolean remove

(

T

element

)

Removes a single element.

Exceptions

NullPointerException

if element is null;

    {
        return removeAll(Arrays.asList(element));
    }

References AutocompleteEngine< T extends Indexable >.removeAll().

removeAll()

boolean removeAll

(

Collection< T >

elements

)

Removes a collection of elements.

Exceptions

NullPointerException

if elements is null or contains a null element;

    {
        checkPointer(elements != null);
        boolean result = false;
        for (T element : elements)
        {
            checkPointer(element != null);
            write.lock();
            try
            {
                result |= index.remove(element);
            }
            finally
            {
                write.unlock();
            }
        }
        return result;
    }

References AutocompleteEngine< T extends Indexable >.index, and AutocompleteEngine< T extends Indexable >.write.

Referenced by AutocompleteEngine< T extends Indexable >.remove().

search() [1/2]

List<T> search

(

String

query

)

Returns a List of all elements that match a query, sorted according to the default comparator.

Exceptions

NullPointerException

if query is null;

    {
        checkPointer(query != null);
        read.lock();
        try
        {
            Aggregator<T> aggregator = new Aggregator<>(comparator);
            Iterator<String> tokens = analyzer.apply(query).iterator();
            if (tokens.hasNext())
            {
                aggregator.addAll(index.get(tokens.next()));
            }
            while (tokens.hasNext())
            {
                if (aggregator.isEmpty())
                {
                    break;
                }
                aggregator.retainAll(index.get(tokens.next()));
            }
            return aggregator.values();
        }
        finally
        {
            read.unlock();
        }
    }

References AutocompleteEngine< T extends Indexable >.analyzer, AutocompleteEngine< T extends Indexable >.comparator, AutocompleteEngine< T extends Indexable >.index, and AutocompleteEngine< T extends Indexable >.read.

Referenced by AutocompleteEngine< T extends Indexable >.search().

search() [2/2]

List<T> search	(	String	query,
		int	limit
	)

Returns a List of the top elements that match a query, sorted according to the default comparator.

Exceptions

NullPointerException	if query is null;
IllegalArgumentException	if limit is negative;

    {
        checkArgument(limit >= 0);
        List<T> result = search(query);
        if (result.size() > limit)
        {
            return result.subList(0, limit);
        }
        return result;
    }

References AutocompleteEngine< T extends Indexable >.search().

Member Data Documentation

analyzer

final Analyzer analyzer

private

Referenced by AutocompleteEngine< T extends Indexable >.addAll(), and AutocompleteEngine< T extends Indexable >.search().

comparator

final Comparator<ScoredObject<T> > comparator

private

Referenced by AutocompleteEngine< T extends Indexable >.search().

index

final IndexAdapter<T> index

private

Referenced by AutocompleteEngine< T extends Indexable >.addAll(), AutocompleteEngine< T extends Indexable >.removeAll(), and AutocompleteEngine< T extends Indexable >.search().

read

final Lock read

private

Referenced by AutocompleteEngine< T extends Indexable >.search().

write

final Lock write

private

Referenced by AutocompleteEngine< T extends Indexable >.addAll(), and AutocompleteEngine< T extends Indexable >.removeAll().