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// Copyright 2013 Daniel Parker
// Distributed under the Boost license, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
// See https://github.com/danielaparker/jsoncons for latest version
#ifndef JSONCONS_DETAIL_STRING_WRAPPER_HPP
#define JSONCONS_DETAIL_STRING_WRAPPER_HPP
#include <stdexcept>
#include <string>
#include <exception>
#include <ostream>
#include <cstring> // std::memcpy
#include <memory> // std::allocator
#include <jsoncons/config/compiler_support.hpp>
namespace jsoncons {
namespace detail {
// From boost 1_71
template <class T, class U>
T launder_cast(U* u)
{
#if defined(__cpp_lib_launder) && __cpp_lib_launder >= 201606
return std::launder(reinterpret_cast<T>(u));
#elif defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__) > 800
return __builtin_launder(reinterpret_cast<T>(u));
#else
return reinterpret_cast<T>(u);
#endif
}
// string_wrapper
template <class CharT,class Allocator>
class string_wrapper
{
public:
using char_type = CharT;
private:
struct str_base_t
{
Allocator alloc_;
Allocator& get_allocator()
{
return alloc_;
}
const Allocator& get_allocator() const
{
return alloc_;
}
str_base_t(const Allocator& alloc)
: alloc_(alloc)
{
}
~str_base_t() noexcept = default;
};
struct str_t : public str_base_t
{
typedef typename std::allocator_traits<Allocator>::template rebind_alloc<CharT> allocator_type;
using allocator_traits_type = std::allocator_traits<allocator_type>;
using pointer = typename allocator_traits_type::pointer;
pointer p_;
std::size_t length_;
~str_t() noexcept = default;
const char_type* c_str() const { return type_traits::to_plain_pointer(p_); }
const char_type* data() const { return type_traits::to_plain_pointer(p_); }
std::size_t length() const { return length_; }
str_t(const Allocator& alloc)
: str_base_t(alloc), p_(nullptr), length_(0)
{
}
str_t(const str_t&) = delete;
str_t& operator=(const str_t&) = delete;
};
typedef typename std::allocator_traits<Allocator>::template rebind_alloc<char> byte_allocator_type;
using byte_pointer = typename std::allocator_traits<byte_allocator_type>::pointer;
typedef typename std::allocator_traits<Allocator>::template rebind_alloc<str_t> string_allocator_type;
using string_pointer = typename std::allocator_traits<string_allocator_type>::pointer;
struct storage_t
{
str_t data;
char_type c[1];
};
typedef typename std::aligned_storage<sizeof(storage_t), alignof(storage_t)>::type json_storage_kind;
string_pointer ptr_;
public:
string_wrapper() = default;
string_wrapper(string_pointer ptr)
: ptr_(ptr)
{
}
string_wrapper(const char_type* data, std::size_t length, const Allocator& a)
{
ptr_ = create(data,length,a);
}
string_wrapper(const string_wrapper& val)
{
ptr_ = create(val.data(),val.length(),val.get_allocator());
}
string_wrapper(const string_wrapper& val, const Allocator& a)
{
ptr_ = create(val.data(),val.length(),a);
}
~string_wrapper() noexcept
{
if (ptr_ != nullptr)
{
destroy(ptr_);
}
}
void swap(string_wrapper& other) noexcept
{
std::swap(ptr_,other.ptr_);
}
const char_type* data() const
{
return ptr_->data();
}
const char_type* c_str() const
{
return ptr_->c_str();
}
std::size_t length() const
{
return ptr_->length();
}
Allocator get_allocator() const
{
return ptr_->get_allocator();
}
private:
static size_t aligned_size(std::size_t n)
{
return sizeof(json_storage_kind) + n;
}
static string_pointer create(const char_type* s, std::size_t length, const Allocator& alloc)
{
std::size_t mem_size = aligned_size(length*sizeof(char_type));
byte_allocator_type byte_alloc(alloc);
byte_pointer ptr = byte_alloc.allocate(mem_size);
char* storage = type_traits::to_plain_pointer(ptr);
str_t* ps = new(storage)str_t(byte_alloc);
auto psa = launder_cast<storage_t*>(storage);
CharT* p = new(&psa->c)char_type[length + 1];
std::memcpy(p, s, length*sizeof(char_type));
p[length] = 0;
ps->p_ = std::pointer_traits<typename str_t::pointer>::pointer_to(*p);
ps->length_ = length;
return std::pointer_traits<string_pointer>::pointer_to(*ps);
}
static void destroy(string_pointer ptr)
{
str_t* rawp = type_traits::to_plain_pointer(ptr);
char* p = launder_cast<char*>(rawp);
std::size_t mem_size = aligned_size(ptr->length_*sizeof(char_type));
byte_allocator_type byte_alloc(ptr->get_allocator());
byte_alloc.deallocate(p,mem_size);
}
};
// tagged_string_wrapper
template <class CharT,class Allocator>
class tagged_string_wrapper
{
public:
using char_type = CharT;
private:
struct str_base_t
{
Allocator alloc_;
Allocator& get_allocator()
{
return alloc_;
}
const Allocator& get_allocator() const
{
return alloc_;
}
str_base_t(const Allocator& alloc)
: alloc_(alloc)
{
}
~str_base_t() noexcept = default;
};
struct str_t : public str_base_t
{
typedef typename std::allocator_traits<Allocator>::template rebind_alloc<CharT> allocator_type;
using allocator_traits_type = std::allocator_traits<allocator_type>;
using pointer = typename allocator_traits_type::pointer;
pointer p_;
std::size_t length_;
uint64_t tag_;
~str_t() noexcept = default;
const char_type* c_str() const { return type_traits::to_plain_pointer(p_); }
const char_type* data() const { return type_traits::to_plain_pointer(p_); }
std::size_t length() const { return length_; }
uint64_t tag() const { return tag_; }
str_t(uint64_t tag, const Allocator& alloc)
: str_base_t(alloc), p_(nullptr), length_(0), tag_(tag)
{
}
str_t(const str_t&) = delete;
str_t& operator=(const str_t&) = delete;
};
typedef typename std::allocator_traits<Allocator>::template rebind_alloc<char> byte_allocator_type;
using byte_pointer = typename std::allocator_traits<byte_allocator_type>::pointer;
typedef typename std::allocator_traits<Allocator>::template rebind_alloc<str_t> string_allocator_type;
using string_pointer = typename std::allocator_traits<string_allocator_type>::pointer;
struct storage_t
{
str_t data;
char_type c[1];
};
typedef typename std::aligned_storage<sizeof(storage_t), alignof(storage_t)>::type json_storage_kind;
string_pointer ptr_;
public:
tagged_string_wrapper() = default;
tagged_string_wrapper(string_pointer ptr)
: ptr_(ptr)
{
}
tagged_string_wrapper(const char_type* data, std::size_t length, uint64_t tag, const Allocator& alloc)
{
ptr_ = create(data, length, tag, alloc);
}
tagged_string_wrapper(const tagged_string_wrapper& val)
{
ptr_ = create(val.data(), val.length(), val.tag(), val.get_allocator());
}
tagged_string_wrapper(const tagged_string_wrapper& val, const Allocator& alloc)
{
ptr_ = create(val.data(), val.length(), val.tag(), alloc);
}
~tagged_string_wrapper() noexcept
{
if (ptr_ != nullptr)
{
destroy(ptr_);
}
}
void swap(tagged_string_wrapper& other) noexcept
{
std::swap(ptr_,other.ptr_);
}
const char_type* data() const
{
return ptr_->data();
}
const char_type* c_str() const
{
return ptr_->c_str();
}
std::size_t length() const
{
return ptr_->length();
}
uint64_t tag() const
{
return ptr_->tag();
}
Allocator get_allocator() const
{
return ptr_->get_allocator();
}
private:
static size_t aligned_size(std::size_t n)
{
return sizeof(json_storage_kind) + n;
}
static string_pointer create(const char_type* s, std::size_t length, uint64_t tag, const Allocator& alloc)
{
std::size_t mem_size = aligned_size(length*sizeof(char_type));
byte_allocator_type byte_alloc(alloc);
byte_pointer ptr = byte_alloc.allocate(mem_size);
char* storage = type_traits::to_plain_pointer(ptr);
str_t* ps = new(storage)str_t(tag, byte_alloc);
auto psa = launder_cast<storage_t*>(storage);
CharT* p = new(&psa->c)char_type[length + 1];
std::memcpy(p, s, length*sizeof(char_type));
p[length] = 0;
ps->p_ = std::pointer_traits<typename str_t::pointer>::pointer_to(*p);
ps->length_ = length;
return std::pointer_traits<string_pointer>::pointer_to(*ps);
}
static void destroy(string_pointer ptr)
{
str_t* rawp = type_traits::to_plain_pointer(ptr);
char* p = launder_cast<char*>(rawp);
std::size_t mem_size = aligned_size(ptr->length_*sizeof(char_type));
byte_allocator_type byte_alloc(ptr->get_allocator());
byte_alloc.deallocate(p,mem_size);
}
};
} // namespace detail
} // namespace jsoncons
#endif
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