tdlight/tdutils/td/utils/StringBuilder.cpp

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//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2018
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include "td/utils/StringBuilder.h"
#include "td/utils/misc.h"
#include "td/utils/port/thread_local.h"
#include <cstdio>
#include <limits>
#include <locale>
#include <sstream>
#include <utility>
namespace td {
template <class T>
static char *print_uint(char *current_ptr, T x) {
if (x < 100) {
if (x < 10) {
*current_ptr++ = static_cast<char>('0' + x);
} else {
*current_ptr++ = static_cast<char>('0' + x / 10);
*current_ptr++ = static_cast<char>('0' + x % 10);
}
return current_ptr;
}
auto begin_ptr = current_ptr;
do {
*current_ptr++ = static_cast<char>('0' + x % 10);
x /= 10;
} while (x > 0);
auto end_ptr = current_ptr - 1;
while (begin_ptr < end_ptr) {
std::swap(*begin_ptr++, *end_ptr--);
}
return current_ptr;
}
template <class T>
static char *print_int(char *current_ptr, T x) {
if (x < 0) {
if (x == std::numeric_limits<T>::min()) {
std::stringstream ss;
ss << x;
auto len = narrow_cast<int>(static_cast<std::streamoff>(ss.tellp()));
ss.read(current_ptr, len);
return current_ptr + len;
}
*current_ptr++ = '-';
x = -x;
}
return print_uint(current_ptr, x);
}
StringBuilder &StringBuilder::operator<<(int x) {
if (unlikely(end_ptr_ < current_ptr_)) {
return on_error();
}
current_ptr_ = print_int(current_ptr_, x);
return *this;
}
StringBuilder &StringBuilder::operator<<(unsigned int x) {
if (unlikely(end_ptr_ < current_ptr_)) {
return on_error();
}
current_ptr_ = print_uint(current_ptr_, x);
return *this;
}
StringBuilder &StringBuilder::operator<<(long int x) {
if (unlikely(end_ptr_ < current_ptr_)) {
return on_error();
}
current_ptr_ = print_int(current_ptr_, x);
return *this;
}
StringBuilder &StringBuilder::operator<<(long unsigned int x) {
if (unlikely(end_ptr_ < current_ptr_)) {
return on_error();
}
current_ptr_ = print_uint(current_ptr_, x);
return *this;
}
StringBuilder &StringBuilder::operator<<(long long int x) {
if (unlikely(end_ptr_ < current_ptr_)) {
return on_error();
}
current_ptr_ = print_int(current_ptr_, x);
return *this;
}
StringBuilder &StringBuilder::operator<<(long long unsigned int x) {
if (unlikely(end_ptr_ < current_ptr_)) {
return on_error();
}
current_ptr_ = print_uint(current_ptr_, x);
return *this;
}
StringBuilder &StringBuilder::operator<<(FixedDouble x) {
if (unlikely(end_ptr_ < current_ptr_)) {
return on_error();
}
static TD_THREAD_LOCAL std::stringstream *ss;
if (init_thread_local<std::stringstream>(ss)) {
ss->imbue(std::locale::classic());
ss->setf(std::ios_base::fixed, std::ios_base::floatfield);
} else {
ss->str(std::string());
ss->clear();
}
ss->precision(x.precision);
*ss << x.d;
int len = narrow_cast<int>(static_cast<std::streamoff>(ss->tellp()));
auto left = end_ptr_ + reserved_size - current_ptr_;
if (unlikely(len >= left)) {
error_flag_ = true;
len = left ? narrow_cast<int>(left - 1) : 0;
}
ss->read(current_ptr_, len);
current_ptr_ += len;
return *this;
}
StringBuilder &StringBuilder::operator<<(const void *ptr) {
if (unlikely(end_ptr_ < current_ptr_)) {
return on_error();
}
current_ptr_ += std::snprintf(current_ptr_, reserved_size, "%p", ptr);
return *this;
}
} // namespace td