/**
* Returns the filter associated with listed filtering aliases.
*
* <p>The list of filtering aliases should be obtained by calling MetaData.filteringAliases.
* Returns <tt>null</tt> if no filtering is required.
*/
public Query aliasFilter(QueryShardContext context, String... aliasNames) {
if (aliasNames == null || aliasNames.length == 0) {
return null;
}
final ImmutableOpenMap<String, AliasMetaData> aliases =
indexSettings.getIndexMetaData().getAliases();
if (aliasNames.length == 1) {
AliasMetaData alias = aliases.get(aliasNames[0]);
if (alias == null) {
// This shouldn't happen unless alias disappeared after filteringAliases was called.
throw new InvalidAliasNameException(
index(), aliasNames[0], "Unknown alias name was passed to alias Filter");
}
return parse(alias, context);
} else {
// we need to bench here a bit, to see maybe it makes sense to use OrFilter
BooleanQuery.Builder combined = new BooleanQuery.Builder();
for (String aliasName : aliasNames) {
AliasMetaData alias = aliases.get(aliasName);
if (alias == null) {
// This shouldn't happen unless alias disappeared after filteringAliases was called.
throw new InvalidAliasNameException(
indexSettings.getIndex(),
aliasNames[0],
"Unknown alias name was passed to alias Filter");
}
Query parsedFilter = parse(alias, context);
if (parsedFilter != null) {
combined.add(parsedFilter, BooleanClause.Occur.SHOULD);
} else {
// The filter might be null only if filter was removed after filteringAliases was called
return null;
}
}
return combined.build();
}
}
/** Returns the index this module is associated with */
public Index getIndex() {
return indexSettings.getIndex();
}