length.h

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/* Copyright (C) 2006,2007,2008,2009,2012,2015 Olly Betts
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */

#ifndef XAPIAN_INCLUDED_LENGTH_H
#define XAPIAN_INCLUDED_LENGTH_H

#include <string>

template<class T>
std::string
encode_length(T len)
{
    std::string result;
    if (len < 255) {
        result += static_cast<unsigned char>(len);
    } else {
        result += '\xff';
        len -= 255;
        while (true) {
            unsigned char b = static_cast<unsigned char>(len & 0x7f);
            len >>= 7;
            if (!len) {
                result += char(b | static_cast<unsigned char>(0x80));
                break;
            }
            result += b;
        }
    }
    return result;
}

void decode_length(const char ** p, const char *end, unsigned & out);

void decode_length(const char ** p, const char *end, unsigned long & out);

void decode_length(const char ** p, const char *end, unsigned long long & out);

void decode_length_and_check(const char ** p, const char *end, unsigned & out);

void decode_length_and_check(const char ** p, const char *end,
                             unsigned long & out);

void decode_length_and_check(const char ** p, const char *end,
                             unsigned long long & out);

#endif // XAPIAN_INCLUDED_LENGTH_H