detail/impl/stack.ipp

0001 //
0002 // Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.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/json
0008 //
0009
0010 #ifndef BOOST_JSON_DETAIL_IMPL_STACK_IPP
0011 #define BOOST_JSON_DETAIL_IMPL_STACK_IPP
0012
0013 #include <boost/json/detail/stack.hpp>
0014
0015 namespace boost {
0016 namespace json {
0017 namespace detail {
0018
0019 stack::non_trivial<>*
0020 stack::non_trivial<>::destroy() noexcept
0021 {
0022     non_trivial* const result = next;
0023     rel(this, nullptr);
0024     return result;
0025 }
0026
0027 stack::non_trivial<>*
0028 stack::non_trivial<>::relocate(void* dst) noexcept
0029 {
0030     return rel(this, dst);
0031 }
0032
0033
0034 stack::
0035 ~stack()
0036 {
0037     clear();
0038     if(base_ != buf_)
0039         sp_->deallocate(
0040             base_, cap_);
0041 }
0042
0043 stack::
0044 stack(
0045     storage_ptr sp,
0046     unsigned char* buf,
0047     std::size_t buf_size) noexcept
0048     : sp_(std::move(sp))
0049     , cap_(buf_size)
0050     , base_(buf)
0051     , buf_(buf)
0052 {
0053 }
0054
0055 void
0056 stack::
0057 clear() noexcept
0058 {
0059     while(head_)
0060         head_ = head_->destroy();
0061     size_ = 0;
0062 }
0063
0064 void
0065 stack::
0066 reserve_impl(std::size_t n)
0067 {
0068     // caller checks this
0069     BOOST_ASSERT(n > cap_);
0070
0071     auto const base = static_cast<unsigned char*>( sp_->allocate(n) );
0072     if(base_)
0073     {
0074         // copy trivials
0075         std::memcpy(base, base_, size_);
0076
0077         // copy non-trivials
0078         non_trivial<>* src = head_;
0079         non_trivial<>** prev = &head_;
0080         while(src)
0081         {
0082             std::size_t const buf_offset =
0083                 reinterpret_cast<unsigned char*>(src) - base_;
0084             non_trivial<>* dest = src->relocate(base + buf_offset);
0085             *prev = dest;
0086             prev = &dest->next;
0087             src = dest->next;
0088         }
0089
0090         if(base_ != buf_)
0091             sp_->deallocate(base_, cap_);
0092     }
0093     base_ = base;
0094     cap_ = n;
0095 }
0096
0097 } // detail
0098 } // namespace json
0099 } // namespace boost
0100
0101 #endif