core/Lucy/Store/CompoundFileWriter.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;

/**
 * Consolidate segment files.
 *
 * CompoundFileWriter combines all the data files in a directory into a single
 * "compound" file named "cf.dat".  Metadata describing filename and
 * filepointer information is stored in a "cfmeta.json" file.
 *
 * Nested subdirectories and files ending in ".json" are excluded from
 * consolidation.
 *
 * Any given directory may only be consolidated once.
 */

class Lucy::Store::CompoundFileWriter cnick CFWriter
    inherits Lucy::Object::Obj {

    Folder      *folder;

    inert int32_t current_file_format;

    inert incremented CompoundFileWriter*
    new(Folder *folder);

    inert CompoundFileWriter*
    init(CompoundFileWriter *self, Folder *folder);

    /** Perform the consolidation operation, building the cf.dat and
     * cfmeta.json files.
     *
     * The commit point is a rename op, where a temp file gets renamed to the
     * cfmeta file.  After the commit completes, the source files are deleted.
     */
    void
    Consolidate(CompoundFileWriter *self);

    public void
    Destroy(CompoundFileWriter *self);
}