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ea5a1caf28
- tables as std::array; the frames of the first 64 levels stay a C array (not initialized on purpose, NOLINT) - \u escapes are decoded with the library's hex_codepoint() instead of a second table - the parse failure is private, with an accessor; the special member functions of the builder are all declared - no nested conditional operators; explicit parentheses; a repeated branch body merged; auto for casts - the test's C arrays, fixed seed, and escaped literals are marked, as in the other tests Signed-off-by: Niels Lohmann <mail@nlohmann.me>
131 lines
4.1 KiB
C++
131 lines
4.1 KiB
C++
// __ _____ _____ _____
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// __| | __| | | | JSON for Modern C++
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// | | |__ | | | | | | version 3.12.0
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// |_____|_____|_____|_|___| https://github.com/nlohmann/json
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//
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// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
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// SPDX-License-Identifier: MIT
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#pragma once
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#include <array> // array
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#include <cstddef> // size_t
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#include <cstring> // memcpy
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#include <new> // operator new, placement new
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#include <string> // string
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#include <nlohmann/json.hpp>
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#include <nlohmann/detail/view/macro_scope.hpp>
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#include <nlohmann/detail/view/node.hpp>
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NLOHMANN_JSON_NAMESPACE_BEGIN
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namespace detail
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{
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namespace view
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{
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/// storage of a parsed document; heap-allocated (header and an initial node
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/// array in one block) so that views survive moves of the owning document
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struct document_data
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{
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const char* src = nullptr;
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std::size_t size = 0;
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node* tape = nullptr;
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std::size_t tape_size = 0;
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std::size_t tape_cap = 0;
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node* inline_tape = nullptr; ///< node array allocated together with this header
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std::size_t inline_cap = 0;
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std::string arena{}; ///< decoded strings that contained escapes // NOLINT(readability-redundant-member-init)
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std::string owned{}; ///< owned copy of the input, if any // NOLINT(readability-redundant-member-init)
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std::array<const char*, 4> base = {{nullptr, nullptr, nullptr, nullptr}}; ///< string bases: source, arena (indexed by flags & node_flags::storage)
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bool discarded = true;
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/// one allocation for the header and room for `nodes` nodes; large
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/// documents get a separate node array instead (so it can be trimmed)
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static document_data* create(std::size_t nodes)
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{
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nodes = nodes <= 256 ? nodes : 0;
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void* mem = ::operator new (sizeof(document_data) + (nodes * sizeof(node)));
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auto* d = new (mem) document_data(); // NOLINT(cppcoreguidelines-owning-memory): owned by the returned pointer, freed by deleter
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// (aligned: sizeof is a multiple of the alignment; through void*, as GCC's -Wcast-align wants)
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d->inline_tape = static_cast<node*>(static_cast<void*>(static_cast<char*>(mem) + sizeof(document_data))); // NOLINT(bugprone-casting-through-void)
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d->inline_cap = nodes;
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d->tape = d->inline_tape;
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d->tape_cap = nodes;
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return d;
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}
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struct deleter
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{
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void operator()(document_data* d) const noexcept
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{
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d->~document_data();
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::operator delete (d);
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}
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};
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document_data() noexcept = default;
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document_data(const document_data&) = delete;
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document_data(document_data&&) = delete;
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document_data& operator=(const document_data&) = delete;
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document_data& operator=(document_data&&) = delete;
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~document_data()
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{
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release();
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}
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void release() noexcept
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{
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if (tape != inline_tape)
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{
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::operator delete (tape);
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}
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tape = inline_tape;
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tape_cap = inline_cap;
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}
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/// make room for n nodes; keeps the first tape_size nodes
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void reserve(std::size_t n)
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{
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if (n <= tape_cap)
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{
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return;
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}
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node* fresh = static_cast<node*>(::operator new (n * sizeof(node)));
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if (tape_size != 0)
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{
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std::memcpy(fresh, tape, tape_size * sizeof(node));
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}
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release();
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tape = fresh;
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tape_cap = n;
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}
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const char* str(const node& n) const noexcept
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{
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return base[n.flags & node_flags::storage] + n.off;
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}
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/// the node after n's subtree (containers span `next` nodes, scalars one)
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static NLOHMANN_VIEW_ALWAYS_INLINE const node* after(const node* n) noexcept
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{
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return n + (is_container(*n) ? n->next : 1u);
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}
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/// first element (array) or first key (object) of a container
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static NLOHMANN_VIEW_ALWAYS_INLINE const node* first_child(const node* n) noexcept
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{
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return n + 1;
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}
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/// end of the elements of a container
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static NLOHMANN_VIEW_ALWAYS_INLINE const node* child_end(const node* n) noexcept
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{
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return n + n->next;
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}
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};
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} // namespace view
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} // namespace detail
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NLOHMANN_JSON_NAMESPACE_END
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