Current File : //backups/router/usr/local/include/boost/redis/request.hpp
/* Copyright (c) 2018-2023 Marcelo Zimbres Silva (mzimbres@gmail.com)
*
* Distributed under the Boost Software License, Version 1.0. (See
* accompanying file LICENSE.txt)
*/
#ifndef BOOST_REDIS_REQUEST_HPP
#define BOOST_REDIS_REQUEST_HPP
#include <boost/redis/resp3/type.hpp>
#include <boost/redis/resp3/serialization.hpp>
#include <string>
#include <tuple>
#include <algorithm>
// NOTE: For some commands like hset it would be a good idea to assert
// the value type is a pair.
namespace boost::redis {
namespace detail{
auto has_response(std::string_view cmd) -> bool;
}
/** \brief Creates Redis requests.
* \ingroup high-level-api
*
* A request is composed of one or more Redis commands and is
* referred to in the redis documentation as a pipeline, see
* https://redis.io/topics/pipelining. For example
*
* @code
* request r;
* r.push("HELLO", 3);
* r.push("FLUSHALL");
* r.push("PING");
* r.push("PING", "key");
* r.push("QUIT");
* @endcode
*
* \remarks
*
* Uses a std::string for internal storage.
*/
class request {
public:
/// Request configuration options.
struct config {
/** \brief If `true` calls to `connection::async_exec` will
* complete with error if the connection is lost while the
* request hasn't been sent yet.
*/
bool cancel_on_connection_lost = true;
/** \brief If `true` `connection::async_exec` will complete with
* `boost::redis::error::not_connected` if the call happens
* before the connection with Redis was established.
*/
bool cancel_if_not_connected = false;
/** \brief If `false` `connection::async_exec` will not
* automatically cancel this request if the connection is lost.
* Affects only requests that have been written to the socket
* but remained unresponded when
* `boost::redis::connection::async_run` completed.
*/
bool cancel_if_unresponded = true;
/** \brief If this request has a `HELLO` command and this flag
* is `true`, the `boost::redis::connection` will move it to the
* front of the queue of awaiting requests. This makes it
* possible to send `HELLO` and authenticate before other
* commands are sent.
*/
bool hello_with_priority = true;
};
/** \brief Constructor
*
* \param cfg Configuration options.
*/
explicit
request(config cfg = config{true, false, true, true})
: cfg_{cfg} {}
//// Returns the number of responses expected for this request.
[[nodiscard]] auto get_expected_responses() const noexcept -> std::size_t
{ return expected_responses_;};
//// Returns the number of commands contained in this request.
[[nodiscard]] auto get_commands() const noexcept -> std::size_t
{ return commands_;};
[[nodiscard]] auto payload() const noexcept -> std::string_view
{ return payload_;}
[[nodiscard]] auto has_hello_priority() const noexcept -> auto const&
{ return has_hello_priority_;}
/// Clears the request preserving allocated memory.
void clear()
{
payload_.clear();
commands_ = 0;
expected_responses_ = 0;
has_hello_priority_ = false;
}
/// Calls std::string::reserve on the internal storage.
void reserve(std::size_t new_cap = 0)
{ payload_.reserve(new_cap); }
/// Returns a const reference to the config object.
[[nodiscard]] auto get_config() const noexcept -> auto const& {return cfg_; }
/// Returns a reference to the config object.
[[nodiscard]] auto get_config() noexcept -> auto& {return cfg_; }
/** @brief Appends a new command to the end of the request.
*
* For example
*
* \code
* request req;
* req.push("SET", "key", "some string", "EX", "2");
* \endcode
*
* will add the `set` command with value "some string" and an
* expiration of 2 seconds.
*
* \param cmd The command e.g redis or sentinel command.
* \param args Command arguments.
* \tparam Ts Non-string types will be converted to string by calling `boost_redis_to_bulk` on each argument. This function must be made available over ADL and must have the following signature
*
* @code
* void boost_redis_to_bulk(std::string& to, T const& t);
* {
* boost::redis::resp3::boost_redis_to_bulk(to, serialize(t));
* }
* @endcode
*
* See cpp20_serialization.cpp
*/
template <class... Ts>
void push(std::string_view cmd, Ts const&... args)
{
auto constexpr pack_size = sizeof...(Ts);
resp3::add_header(payload_, resp3::type::array, 1 + pack_size);
resp3::add_bulk(payload_, cmd);
resp3::add_bulk(payload_, std::tie(std::forward<Ts const&>(args)...));
check_cmd(cmd);
}
/** @brief Appends a new command to the end of the request.
*
* This overload is useful for commands that have a key and have a
* dynamic range of arguments. For example
*
* @code
* std::map<std::string, std::string> map
* { {"key1", "value1"}
* , {"key2", "value2"}
* , {"key3", "value3"}
* };
*
* request req;
* req.push_range("HSET", "key", std::cbegin(map), std::cend(map));
* @endcode
*
* \param cmd The command e.g. Redis or Sentinel command.
* \param key The command key.
* \param begin Iterator to the begin of the range.
* \param end Iterator to the end of the range.
* \tparam Ts Non-string types will be converted to string by calling `boost_redis_to_bulk` on each argument. This function must be made available over ADL and must have the following signature
*
* @code
* void boost_redis_to_bulk(std::string& to, T const& t);
* {
* boost::redis::resp3::boost_redis_to_bulk(to, serialize(t));
* }
* @endcode
*
* See cpp20_serialization.cpp
*/
template <class ForwardIterator>
void
push_range(
std::string_view const& cmd,
std::string_view const& key,
ForwardIterator begin,
ForwardIterator end,
typename std::iterator_traits<ForwardIterator>::value_type * = nullptr)
{
using value_type = typename std::iterator_traits<ForwardIterator>::value_type;
if (begin == end)
return;
auto constexpr size = resp3::bulk_counter<value_type>::size;
auto const distance = std::distance(begin, end);
resp3::add_header(payload_, resp3::type::array, 2 + size * distance);
resp3::add_bulk(payload_, cmd);
resp3::add_bulk(payload_, key);
for (; begin != end; ++begin)
resp3::add_bulk(payload_, *begin);
check_cmd(cmd);
}
/** @brief Appends a new command to the end of the request.
*
* This overload is useful for commands that have a dynamic number
* of arguments and don't have a key. For example
*
* \code
* std::set<std::string> channels
* { "channel1" , "channel2" , "channel3" }
*
* request req;
* req.push("SUBSCRIBE", std::cbegin(channels), std::cend(channels));
* \endcode
*
* \param cmd The Redis command
* \param begin Iterator to the begin of the range.
* \param end Iterator to the end of the range.
* \tparam ForwardIterator If the value type is not a std::string it will be converted to a string by calling `boost_redis_to_bulk`. This function must be made available over ADL and must have the following signature
*
* @code
* void boost_redis_to_bulk(std::string& to, T const& t);
* {
* boost::redis::resp3::boost_redis_to_bulk(to, serialize(t));
* }
* @endcode
*
* See cpp20_serialization.cpp
*/
template <class ForwardIterator>
void
push_range(
std::string_view const& cmd,
ForwardIterator begin,
ForwardIterator end,
typename std::iterator_traits<ForwardIterator>::value_type * = nullptr)
{
using value_type = typename std::iterator_traits<ForwardIterator>::value_type;
if (begin == end)
return;
auto constexpr size = resp3::bulk_counter<value_type>::size;
auto const distance = std::distance(begin, end);
resp3::add_header(payload_, resp3::type::array, 1 + size * distance);
resp3::add_bulk(payload_, cmd);
for (; begin != end; ++begin)
resp3::add_bulk(payload_, *begin);
check_cmd(cmd);
}
/** @brief Appends a new command to the end of the request.
*
* Equivalent to the overload taking a range of begin and end
* iterators.
*
* \param cmd Redis command.
* \param key Redis key.
* \param range Range to send e.g. `std::map`.
* \tparam A type that can be passed to `std::cbegin()` and `std::cend()`.
*/
template <class Range>
void
push_range(
std::string_view const& cmd,
std::string_view const& key,
Range const& range,
decltype(std::begin(range)) * = nullptr)
{
using std::begin;
using std::end;
push_range(cmd, key, begin(range), end(range));
}
/** @brief Appends a new command to the end of the request.
*
* Equivalent to the overload taking a range of begin and end
* iterators.
*
* \param cmd Redis command.
* \param range Range to send e.g. `std::map`.
* \tparam A type that can be passed to `std::cbegin()` and `std::cend()`.
*/
template <class Range>
void
push_range(
std::string_view cmd,
Range const& range,
decltype(std::cbegin(range)) * = nullptr)
{
using std::cbegin;
using std::cend;
push_range(cmd, cbegin(range), cend(range));
}
private:
void check_cmd(std::string_view cmd)
{
++commands_;
if (!detail::has_response(cmd))
++expected_responses_;
if (cmd == "HELLO")
has_hello_priority_ = cfg_.hello_with_priority;
}
config cfg_;
std::string payload_;
std::size_t commands_ = 0;
std::size_t expected_responses_ = 0;
bool has_hello_priority_ = false;
};
} // boost::redis::resp3
#endif // BOOST_REDIS_REQUEST_HPP
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