com.google.gerrit.server.index

Interface Index<K,V>

All Known Subinterfaces:

AccountIndex, ChangeIndex, GroupIndex

All Known Implementing Classes:

DummyChangeIndex

public interface Index<K,V>

Secondary index implementation for arbitrary documents.

Documents are inserted into the index and are queried by converting special Predicate instances into index-aware predicates that use the index search results as a source.

Implementations must be thread-safe and should batch inserts/updates where appropriate.

Method Summary

Modifier and Type	Method and Description
void	close() Close this index.
void	delete(K key) Delete a document from the index by key.
void	deleteAll() Delete all documents from the index.
default Optional<V>	get(K key, QueryOptions opts) Get a single document from the index.
Schema<V>	getSchema()
DataSource<V>	getSource(Predicate<V> p, QueryOptions opts) Convert the given operator predicate into a source searching the index and returning only the documents matching that predicate.
Predicate<V>	keyPredicate(K key) Get a predicate that looks up a single document by key.
void	markReady(boolean ready) Mark whether this index is up-to-date and ready to serve reads.
void	replace(V obj) Update a document in the index.
default void	stop() Stop and await termination of all executor threads

Method Detail

getSchema

Schema<V> getSchema()

Returns:

the schema version used by this index.

stop

default void stop()

Stop and await termination of all executor threads

close

void close()

Close this index.

replace

void replace(V obj)
      throws IOException

Update a document in the index.

Semantically equivalent to deleting the document and reinserting it with new field values. A document that does not already exist is created. Results may not be immediately visible to searchers, but should be visible within a reasonable amount of time.

Parameters:

obj - document object

Throws:

IOException

delete

void delete(K key)
     throws IOException

Delete a document from the index by key.

Parameters:

key - document key

Throws:

IOException

deleteAll

void deleteAll()
        throws IOException

Delete all documents from the index.

Throws:

IOException

getSource

DataSource<V> getSource(Predicate<V> p,
                        QueryOptions opts)
                 throws QueryParseException

Convert the given operator predicate into a source searching the index and returning only the documents matching that predicate.

This method may be called multiple times for variations on the same predicate or multiple predicate subtrees in the course of processing a single query, so it should not have any side effects (e.g. starting a search in the background).

Parameters:

p - the predicate to match. Must be a tree containing only AND, OR, or NOT predicates as internal nodes, and IndexPredicates as leaves.

opts - query options not implied by the predicate, such as start and limit.

Returns:

a source of documents matching the predicate, returned in a defined order depending on the type of documents.

Throws:

QueryParseException - if the predicate could not be converted to an indexed data source.

get

default Optional<V> get(K key,
                        QueryOptions opts)
                 throws IOException

Get a single document from the index.

Parameters:

key - document key.

opts - query options. Options that do not make sense in the context of a single document, such as start, will be ignored.

Returns:

a single document if present.

Throws:

IOException

keyPredicate

Predicate<V> keyPredicate(K key)

Get a predicate that looks up a single document by key.

Parameters:

key - document key.

Returns:

a single predicate.

markReady

void markReady(boolean ready)
        throws IOException

Mark whether this index is up-to-date and ready to serve reads.

Parameters:

ready - whether the index is ready

Throws:

IOException