<?php
/**
 * SeekQuarry/Yioop --
 * Open Source Pure PHP Search Engine, Crawler, and Indexer
 *
 * Copyright (C) 2009 - 2026  Chris Pollett chris@pollett.org
 *
 * LICENSE:
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * END LICENSE
 *
 * @author Chris Pollett chris@pollett.org
 * @license https://www.gnu.org/licenses/ GPL3
 * @link https://www.seekquarry.com/
 * @copyright 2009 - 2026
 * @filesource
 */
namespace seekquarry\yioop\library\compressors;

/** For Yioop global defines and packInt/unpackInt used by implementors*/
require_once __DIR__."/../../configs/Config.php";
/**
 * A Compressor is used to apply a filter to objects before they are stored
 * into a WebArchive. The filter is assumed to be invertible, and the typical
 * intention is the filter carries out some kind of string compression.
 *
 * @author Chris Pollett
 */
interface Compressor
{
    /**
     * Applies the Compressor compress filter to a string and returns the
     * resultsting string.
     *
     * @param string $str  string to apply filter to
     * @return string  the result of applying the filter
     */
    public function compress($str);
    /**
     * Applies the Compressor compress filter to a string $str and
     * then writes it to file $file_name
     *
     * @param string $file_name  to write string to
     * @param string $str  string to apply filter to
     * @return int  the number of bytes written
     */
    public function compressPutFile($file_name, $str);
    /**
     * Used to unapply the compress filter to data in a string $string
     *
     * @param string $str  data read from a string archive
     * @return string result of uncompressing
     */
    public function uncompress($str);
    /**
     * Applies the Compressor uncompress filter to the contents read
     * from $file_name and returns the result as a string
     *
     * @param string $file_name  to write string to
     * @return string the uncompressed contents of the $file_name
     */
    public function uncompressGetFile($file_name);
    /**
     * Used to compress an int as a fixed length string in the format of
     * the compression algorithm underlying the compressor.
     *
     * @param int $my_int the integer to compress as a fixed length string
     * @return string the fixed length string containing the packed int
     */
    public function compressInt($my_int);
    /**
     * Used to uncompress an int from a fixed length string in the format of
     * the compression algorithm underlying the compressor.
     *
     * @param string $my_compressed_int the fixed length string containing
     *     the packed int to extract
     * @return int the integer contained in that string
     */
    public function uncompressInt($my_compressed_int);
    /**
     * Computes the length of an int when packed using the underlying
     * compression algorithm as a fixed length string
     * @return int length of int as a fixed length compressed string
     */
    public function compressedIntLen();
    /**
     * File extension that should be associated with this compressor
     * @return string name of dos file extension
     */
    public static function fileExtension();
}
