core/Lucy/Search/HitQueue.cfh

/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

parcel Lucy;

/** Track highest sorting hits.
 *
 * HitQueue sorts MatchDoc objects according to a SortSpec.  Good matches
 * float to the top of the queue and poor matches fall out the bottom.
 */

class Lucy::Search::HitQueue cnick HitQ
    inherits Lucy::Util::PriorityQueue {

    FieldType     **field_types;
    uint8_t        *actions;
    uint32_t        num_actions;
    bool_t          need_values;

    inert incremented HitQueue*
    new(Schema *schema = NULL, SortSpec *sort_spec = NULL, uint32_t wanted);

    /**
     * @param schema A Schema.  Required if <code>sort_spec</code> supplied.
     * @param sort_spec A SortSpec.  If not supplied, the HitQueue will sort
     * by descending score first and ascending doc id second.
     * @param wanted Max elements the queue can hold.
     */
    inert HitQueue*
    init(HitQueue *self, Schema *schema = NULL, SortSpec *sort_spec = NULL,
         uint32_t wanted);

    public void
    Destroy(HitQueue *self);

    /** If sorting on fields, first verifies that the MatchDoc has a valid
     * values array, then invokes parent method.
     */
    incremented nullable Obj*
    Jostle(HitQueue *self, decremented Obj *element);

    bool_t
    Less_Than(HitQueue *self, Obj *a, Obj *b);
}