lcn_index.h

Go to the documentation of this file.

/* 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_index.h
 * @brief Routines for manipulating a lucene index
 */

#ifndef _LCN_INDEX_H
#define _LCN_INDEX_H

#include "lcn_types.h"
#include "lcn_term.h"
#include "lcn_document.h"

#include <apr_file_io.h>

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

/** Opaque structure representing a lucene index. */
typedef struct lcn_index_t lcn_index_t;

/** Return the index contained in directory @a d in @a idx, allocated in
 * @a pool.
 */
lcn_error_t *
lcn_index_open (lcn_index_t **idx,
                const char *d,
                apr_pool_t *pool);

/** Return the maximum document number contained in index @a idx. */
apr_uint32_t
lcn_index_max_docs (lcn_index_t *idx);

/** Opaque iterator for iterating over a list of documents. */
typedef struct lcn_doc_iter_t lcn_doc_iter_t;

/** Return the current document number from @a itr. */
apr_uint32_t lcn_doc_iter_doc (lcn_doc_iter_t *itr);

/** Return the maximum document number that can be returned from @a itr. */
apr_uint32_t lcn_doc_iter_max_docs (lcn_doc_iter_t *itr);

/** Return the current document's frequency from @a itr. */
apr_uint32_t lcn_doc_iter_freq (lcn_doc_iter_t *itr);

/** Return the total number of hits for the term in the current segment. */
apr_uint32_t lcn_doc_iter_term_freq (lcn_doc_iter_t *itr);

/** Move @a itr to the next document.
 *
 * If the increment was successful, @a next is TRUE, if it moved us past
 * the end of the sequence @a next is FALSE.
 */
lcn_error_t * lcn_doc_iter_next (lcn_boolean_t *next, lcn_doc_iter_t *itr);

/* XXX need an interface to read multiple doc/freq pairs at once. */

/* XXX need an interface to skip to a certain document. */

/** Close @a itr. */
lcn_error_t * lcn_doc_iter_close (lcn_doc_iter_t *itr);

/** Return an iterator @a itr for iterating over all documents that contain
 * @a term within @a idx, allocated from within @a pool.
 */
lcn_error_t *
lcn_index_term_docs (lcn_doc_iter_t **itr,
                     lcn_index_t *idx,
                     lcn_term_t *term,
                     apr_pool_t *pool);

/** Return the document @a doc from @a idx that has the number @a docnum,
 * allocated from @a pool.
 */
lcn_error_t *
lcn_index_get_document (lcn_document_t **doc,
                        lcn_index_t *idx,
                        apr_uint32_t docnum,
                        apr_pool_t *pool);

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif

---