zlib/detail/ranges.hpp

0001 //
0002 // Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
0003 //
0004 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0005 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 //
0007 // Official repository: https://github.com/boostorg/beast
0008 //
0009 // This is a derivative work based on Zlib, copyright below:
0010 /*
0011     Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
0012
0013     This software is provided 'as-is', without any express or implied
0014     warranty.  In no event will the authors be held liable for any damages
0015     arising from the use of this software.
0016
0017     Permission is granted to anyone to use this software for any purpose,
0018     including commercial applications, and to alter it and redistribute it
0019     freely, subject to the following restrictions:
0020
0021     1. The origin of this software must not be misrepresented; you must not
0022        claim that you wrote the original software. If you use this software
0023        in a product, an acknowledgment in the product documentation would be
0024        appreciated but is not required.
0025     2. Altered source versions must be plainly marked as such, and must not be
0026        misrepresented as being the original software.
0027     3. This notice may not be removed or altered from any source distribution.
0028
0029     Jean-loup Gailly        Mark Adler
0030     jloup@gzip.org          madler@alumni.caltech.edu
0031
0032     The data format used by the zlib library is described by RFCs (Request for
0033     Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
0034     (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
0035 */
0036
0037 #ifndef BOOST_BEAST_ZLIB_DETAIL_RANGES_HPP
0038 #define BOOST_BEAST_ZLIB_DETAIL_RANGES_HPP
0039
0040 #include <cstdint>
0041 #include <type_traits>
0042
0043 namespace boost {
0044 namespace beast {
0045 namespace zlib {
0046 namespace detail {
0047
0048 struct ranges
0049 {
0050     template<bool isConst>
0051     struct range
0052     {
0053         using iter_t =
0054             typename std::conditional<isConst,
0055                 std::uint8_t const*,
0056                 std::uint8_t*>::type;
0057
0058         iter_t first;
0059         iter_t last;
0060         iter_t next;
0061
0062         // total bytes in range
0063         std::size_t
0064         size() const
0065         {
0066             return last - first;
0067         }
0068
0069         // bytes consumed
0070         std::size_t
0071         used() const
0072         {
0073             return next - first;
0074         }
0075
0076         // bytes remaining
0077         std::size_t
0078         avail() const
0079         {
0080             return last - next;
0081         }
0082     };
0083
0084     range<true> in;
0085     range<false> out;
0086 };
0087
0088 // Clamp u to v where u and v are different types
0089 template<class U, class V>
0090 U clamp(U u, V v)
0091 {
0092     if(u > v)
0093         u = static_cast<U>(v);
0094     return u;
0095 }
0096
0097 } // detail
0098 } // zlib
0099 } // beast
0100 } // boost
0101
0102 #endif