core/Lucy/Index/Posting/RawPosting.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;

/**
 * Sortable, serialized Posting.
 *
 * RawPosting is a specialized subclass of Posting for private use only.  It
 * is used at index-time for fast reading, writing, sorting and merging of
 * index posting data by PostingPool.
 *
 * RawPosting's Destroy method throws an error.  All RawPosting objects belong
 * to a particular MemoryPool, which takes responsibility for freeing them.
 *
 * The last struct member, [blob], is a "flexible array" member.  RawPosting
 * objects are assigned one continuous memory block of variable size,
 * depending on how much data needs to fit in blob.
 *
 * The first part of blob is the term's text content, the length of which is
 * indicated by [content_len].  At the end of the content, encoded auxilliary
 * posting information begins, ready to be blasted out verbatim to a postings
 * file once the after the doc id is written.
 */

class Lucy::Index::RawPosting cnick RawPost
    inherits Lucy::Index::Posting {

    uint32_t  freq;
    uint32_t  content_len;
    uint32_t  aux_len;
    char[1]   blob; /* flexible array */

    /** Constructor.  Uses pre-allocated memory.
     */
    inert incremented RawPosting*
    new(void *pre_allocated_memory, int32_t doc_id, uint32_t freq,
        char *term_text, size_t term_text_len);

    uint32_t
    Get_RefCount(RawPosting* self);

    incremented RawPosting*
    Inc_RefCount(RawPosting* self);

    uint32_t
    Dec_RefCount(RawPosting* self);

    /** Throws an error.
     */
    public void
    Destroy(RawPosting *self);
}

class Lucy::Index::Posting::RawPostingWriter cnick RawPostWriter
    inherits Lucy::Index::Posting::PostingWriter {

    OutStream *outstream;
    int32_t    last_doc_id;

    inert incremented RawPostingWriter*
    new(Schema *schema, Snapshot *snapshot, Segment *segment,
        PolyReader *polyreader, OutStream *outstream);

    inert RawPostingWriter*
    init(RawPostingWriter *self, Schema *schema, Snapshot *snapshot,
         Segment *segment, PolyReader *polyreader, OutStream *outstream);

    public void
    Destroy(RawPostingWriter *self);

    void
    Start_Term(RawPostingWriter *self, TermInfo *tinfo);

    void
    Update_Skip_Info(RawPostingWriter *self, TermInfo *tinfo);

    void
    Write_Posting(RawPostingWriter *self, RawPosting *posting);
}

__C__
extern lucy_RawPosting LUCY_RAWPOSTING_BLANK;

#ifdef LUCY_USE_SHORT_NAMES
  #define RAWPOSTING_BLANK         LUCY_RAWPOSTING_BLANK
#endif
__END_C__