lcn_scorer.h

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/* Copyright 2005 The Apache Software Foundation or its licensors, as
 * applicable.
 *
 * Licensed 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.
 */

/**
 * @file lcn_scorer.h
 * @brief Routines for working with scorers
 */

#ifndef _LCN_SCORER_H
#define _LCN_SCORER_H

#include "lcn_types.h"
#include "lcn_index.h"

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

/** The structure that stores data about a query that must be modified
 * during a search. This allows a given query to be reused for more than
 * one search.
 *
 * This is declared here rather than in lcn_query.h to avoid circular
 * dependencies.
 */
typedef struct lcn_weight_t lcn_weight_t;

/** Abstract scorer object. */
typedef struct lcn_scorer_t lcn_scorer_t;

/** Create a @a scorer that returns scores for each document matched
 * by @a weight in @a iter, allocated in @a pool.
 */
lcn_error_t *
lcn_term_scorer_create (lcn_scorer_t **scorer,
                        lcn_weight_t *weight,
                        lcn_doc_iter_t *iter,
                        apr_pool_t *pool);

/** Create a @a scorer that returns scores for documents matched by the
 * arrays of queries @a must, @a should, and @a must_not, searching in
 * @a index, allocated in @a pool.
 */
lcn_error_t *
lcn_boolean_scorer_create (lcn_scorer_t **scorer,
                           apr_array_header_t *must,
                           apr_array_header_t *should,
                           apr_array_header_t *must_not,
                           lcn_index_t *index,
                           apr_pool_t *pool);

/** Advance @a scorer to the next document.
 *
 * If there is another document in the sequence @a next is set to TRUE,
 * otherwise @a next is set to FALSE.
 */
lcn_error_t * lcn_scorer_next (lcn_boolean_t *next, lcn_scorer_t *scorer);

/** Return the current document for @a scorer. */
apr_uint32_t lcn_scorer_doc (lcn_scorer_t *scorer);

/** Return the score for the current document for @a scorer. */
float lcn_scorer_score (lcn_scorer_t *scorer);

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* _LCN_SCORER_H */

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