mirror of
https://github.com/matrix-construct/construct
synced 2024-11-26 16:52:44 +01:00
123 lines
3 KiB
C++
123 lines
3 KiB
C++
// Matrix Construct
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//
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// Copyright (C) Matrix Construct Developers, Authors & Contributors
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// Copyright (C) 2016-2019 Jason Volk <jason@zemos.net>
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//
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// Permission to use, copy, modify, and/or distribute this software for any
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// purpose with or without fee is hereby granted, provided that the above
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// copyright notice and this permission notice is present in all copies. The
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// full license for this software is available in the LICENSE file.
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#pragma once
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#define HAVE_IRCD_BUFFER_PARSE_BUFFER_H
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/// The parse_buffer is the const version of a window_buffer. It is basically
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/// the same idea with the underlying data is being read rather than written.
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///
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struct ircd::buffer::parse_buffer
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:const_buffer
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{
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using closure = std::function<size_t (const const_buffer &)>;
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using closure_cbuf = std::function<const_buffer (const const_buffer &)>;
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using closure_spirit = std::function<bool (const char *&, const char *const &)>;
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const_buffer base;
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size_t remaining() const;
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size_t consumed() const;
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const_buffer completed() const;
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const_buffer operator()(const closure &);
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const_buffer operator()(const closure_cbuf &);
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const_buffer operator()(const closure_spirit &);
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const_buffer rewind(const size_t &n = 1);
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parse_buffer(const const_buffer &base);
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parse_buffer(const window_buffer &base);
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parse_buffer() = default;
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};
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inline
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ircd::buffer::parse_buffer::parse_buffer(const const_buffer &buf)
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:const_buffer{buf}
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,base{buf}
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{}
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inline ircd::buffer::const_buffer
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ircd::buffer::parse_buffer::rewind(const size_t &n)
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{
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const size_t nmax
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{
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std::min(n, consumed())
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};
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static_cast<const_buffer &>(*this).begin() -= nmax;
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assert(base.begin() <= begin());
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assert(begin() <= base.end());
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return completed();
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}
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inline ircd::buffer::const_buffer
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ircd::buffer::parse_buffer::operator()(const closure_spirit &closure)
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{
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return operator()([&closure]
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(const const_buffer &buf) -> size_t
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{
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const char *start(data(buf));
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const char *const stop(start + size(buf));
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if(!closure(start, stop))
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return 0;
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assert(start <= stop);
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assert(start >= data(buf));
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return start - data(buf);
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});
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}
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inline ircd::buffer::const_buffer
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ircd::buffer::parse_buffer::operator()(const closure_cbuf &closure)
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{
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return operator()([&closure]
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(const const_buffer &buf)
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{
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return size(closure(buf));
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});
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}
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inline ircd::buffer::const_buffer
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ircd::buffer::parse_buffer::operator()(const closure &closure)
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{
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consume(*this, closure(*this));
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return completed();
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}
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inline ircd::buffer::const_buffer
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ircd::buffer::parse_buffer::completed()
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const
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{
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assert(base.begin() <= begin());
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assert(base.begin() + consumed() <= base.end());
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return
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{
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base.begin(), base.begin() + consumed()
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};
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}
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inline size_t
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ircd::buffer::parse_buffer::consumed()
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const
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{
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assert(begin() >= base.begin());
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assert(begin() <= base.end());
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return std::distance(base.begin(), begin());
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}
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inline size_t
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ircd::buffer::parse_buffer::remaining()
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const
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{
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assert(begin() <= base.end());
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const size_t ret(std::distance(begin(), base.end()));
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assert(ret == size(*this));
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return ret;
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}
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