core/Lucy/Util/IndexFileNames.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;

/** Utilities for parsing, interpreting and generating index file names.
 */
inert class Lucy::Util::IndexFileNames nickname IxFileNames {

    /** Skip past the first instance of an underscore in the String, then
     * attempt to decode a base 36 number.  For example, "snapshot_5.json"
     * yields 5, and "seg_a1" yields 27.
     *
     * @return a generation number, or 0 if no number can be extracted.
     */
    inert uint64_t
    extract_gen(String *name);

    /** Return the name of the latest generation snapshot file in the Folder,
     * or NULL if no such file exists.
     */
    inert incremented nullable String*
    latest_snapshot(Folder *folder);

    /** Return the name of a new temporary snapshot file, which shall contain
     * a base-36 "generation" embedded inside it.
     */
    inert incremented String*
    make_temp_snapshot(uint64_t gen);

    /** Split the `path` on '/' and return the last component.
     * Trailing slashes will be stripped.
     */
    inert incremented String*
    local_part(String *path);
}