#include #include #include #include #include #include #include #include #if 0 template struct Column { constexpr explicit Column(const std::string_view& name) : name{name} { } const std::string name; }; struct BindingNameGenerator { public: [[nodiscard]] static std::string generate(size_t index) { assert(index > 0); std::string result{}; result.resize(std::max(index >> 4U, 1UL)); for(auto it = result.begin(); index > 0; index >>= 4U) *(it++) = number_map[index & 0xFU]; return result; } private: constexpr static std::array number_map{ 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p' }; }; template struct InsertQueryGenerator { struct GenerateOptions { bool enable_ignore{false}; sql::SqlType target{sql::SqlType::TYPE_SQLITE}; }; explicit InsertQueryGenerator(std::string target_table, Column... columns) : table_name{std::move(target_table)}, columns{std::move(columns.name)...} { } [[nodiscard]] constexpr inline auto column_count() const { return sizeof...(ColTypes); }; [[nodiscard]] inline std::string generate_query(size_t entry_count, sql::SqlType target = sql::SqlType::TYPE_SQLITE, bool enable_ignore = false) const { if(entry_count == 0) return "-- No entries given"; std::string result{"INSERT "}; if(enable_ignore) { if(target == sql::TYPE_MYSQL) result += "IGNORE "; else result += "OR IGNORE "; } result += this->table_name + " ("; //"INSERT INTO " + this->table_name + " (" for(auto it = this->columns.begin();;) { result += "`" + *it + "`"; if(++it != this->columns.end()) { result += ", "; } else { break; } } result += ") VALUES ("; for(size_t index{1}; index <= this->column_count() * entry_count; index++) result += ":" + BindingNameGenerator::generate(index) + ", "; result = result.substr(0, result.length() - 2) + ");"; return result; } const std::string table_name{}; const std::array columns{}; }; template struct InsertQuery : public InsertQueryGenerator { struct ExecuteResult { std::vector> failed_entries{}; [[nodiscard]] inline auto has_succeeded() const { return this->failed_entries.empty(); } }; explicit InsertQuery(const std::string& target_table, Column... columns) : InsertQueryGenerator{target_table, std::move(columns)...} { } inline void reserve_entries(size_t amount) { this->entries.reserve(amount); } inline void add_entry(const ColTypes&... values) { this->entries.push_back(std::array{variable{"", values}...}); } inline ExecuteResult execute(sql::SqlManager* sql, bool ignore_fails = false) { if(this->entries.empty()) return ExecuteResult{}; ExecuteResult result{}; const auto chunk_size = std::min(2UL, this->entries.size()); sql::model chunk_base{sql, this->generate_query(chunk_size, sql->getType(), ignore_fails)}; sql::model entry_model{sql, this->generate_query(1, sql->getType(), ignore_fails)}; for(size_t chunk{0}; chunk < this->entries.size() / chunk_size; chunk++) { auto command = chunk_base.command(); size_t parameter_index{1}; for(size_t index{chunk * chunk_size}; index < (chunk + 1) * chunk_size; index++) { for(auto& var : this->entries[index]) { var.set_key(":" + BindingNameGenerator::generate(parameter_index++)); command.value(var); } } auto exec_result = command.execute(); if(!exec_result) { /* try every entry 'till we've found the error one */ for(size_t index{chunk * chunk_size}; index < (chunk + 1) * chunk_size; index++) { parameter_index = 1; auto entry_command = entry_model.command(); for(auto& var : this->entries[index]) { var.set_key(":" + BindingNameGenerator::generate(parameter_index++)); entry_command.value(var); } exec_result = entry_command.execute(); if(!exec_result) { result.failed_entries.emplace_back(index, std::move(exec_result)); if(!ignore_fails) return result; } } } } for(size_t index{(this->entries.size() / chunk_size) * chunk_size}; index < this->entries.size(); index++) { size_t parameter_index{1}; auto entry_command = entry_model.command(); for(auto& var : this->entries[index]) { var.set_key(":" + BindingNameGenerator::generate(parameter_index++)); entry_command.value(var); } auto exec_result = entry_command.execute(); if(!exec_result) { result.failed_entries.emplace_back(index, std::move(exec_result)); if(!ignore_fails) return result; } } return result; } std::vector> entries{}; }; int main() { InsertQuery insert{"hello", Column{"column_a"}, Column{"column_ab"}}; for(int i{0}; i < 100; i++) insert.add_entry(i, "X"); std::cout << "Result: " << insert.generate_query(2) << "\n"; std::string value{}; insert.add_entry(2, value); insert.execute(nullptr); } #endif struct A { A() {} ~A() = default; }; #include #include int main() { #if 0 std::set elements{}; if(!elements.empty()) { auto it = elements.begin(); const int* last_element{&*(it++)}; /* if elements would be empty this would be undefined behaviour */ while(it != elements.end()) { const auto now = *it++; const auto diff = last_element - now; } } #endif sockaddr_in addr{}; addr.sin_addr.s_addr = INADDR_ANY; addr.sin_family = AF_INET; addr.sin_port = htons(9987); std::cout << "Result: " << (int) net::address_available(*(sockaddr_storage*) &addr, net::binding_type::TCP) << "\n"; std::cout << strerror(errno) << "\n"; }