examples => example

example/cpp20_containers.cpp

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+/* Copyright (c) 2018-2022 Marcelo Zimbres Silva (mzimbres@gmail.com)
+ *
+ * Distributed under the Boost Software License, Version 1.0. (See
+ * accompanying file LICENSE.txt)
+ */
+
+#include <boost/redis/connection.hpp>
+#include <boost/asio/deferred.hpp>
+#include <boost/asio/detached.hpp>
+#include <boost/asio/co_spawn.hpp>
+#include <map>
+#include <vector>
+#include <iostream>
+
+#if defined(BOOST_ASIO_HAS_CO_AWAIT)
+
+namespace asio = boost::asio;
+using boost::redis::request;
+using boost::redis::response;
+using boost::redis::ignore_t;
+using boost::redis::ignore;
+using boost::redis::config;
+using boost::redis::connection;
+using boost::asio::awaitable;
+using boost::asio::deferred;
+using boost::asio::detached;
+using boost::asio::consign;
+
+void print(std::map<std::string, std::string> const& cont)
+{
+   for (auto const& e: cont)
+      std::cout << e.first << ": " << e.second << "\n";
+}
+
+void print(std::vector<int> const& cont)
+{
+   for (auto const& e: cont) std::cout << e << " ";
+   std::cout << "\n";
+}
+
+// Stores the content of some STL containers in Redis.
+auto store(std::shared_ptr<connection> conn) -> awaitable<void>
+{
+   std::vector<int> vec
+      {1, 2, 3, 4, 5, 6};
+
+   std::map<std::string, std::string> map
+      {{"key1", "value1"}, {"key2", "value2"}, {"key3", "value3"}};
+
+   request req;
+   req.push_range("RPUSH", "rpush-key", vec);
+   req.push_range("HSET", "hset-key", map);
+
+   co_await conn->async_exec(req, ignore, deferred);
+}
+
+auto hgetall(std::shared_ptr<connection> conn) -> awaitable<void>
+{
+   // A request contains multiple commands.
+   request req;
+   req.push("HGETALL", "hset-key");
+
+   // Responses as tuple elements.
+   response<std::map<std::string, std::string>> resp;
+
+   // Executes the request and reads the response.
+   co_await conn->async_exec(req, resp, deferred);
+
+   print(std::get<0>(resp).value());
+}
+
+// Retrieves in a transaction.
+auto transaction(std::shared_ptr<connection> conn) -> awaitable<void>
+{
+   request req;
+   req.push("MULTI");
+   req.push("LRANGE", "rpush-key", 0, -1); // Retrieves
+   req.push("HGETALL", "hset-key"); // Retrieves
+   req.push("EXEC");
+
+   response<
+      ignore_t, // multi
+      ignore_t, // lrange
+      ignore_t, // hgetall
+      response<std::optional<std::vector<int>>, std::optional<std::map<std::string, std::string>>> // exec
+   > resp;
+
+   co_await conn->async_exec(req, resp, deferred);
+
+   print(std::get<0>(std::get<3>(resp).value()).value().value());
+   print(std::get<1>(std::get<3>(resp).value()).value().value());
+}
+
+// Called from the main function (see main.cpp)
+awaitable<void> co_main(config cfg)
+{
+   auto conn = std::make_shared<connection>(co_await asio::this_coro::executor);
+   conn->async_run(cfg, {}, consign(detached, conn));
+
+   co_await store(conn);
+   co_await transaction(conn);
+   co_await hgetall(conn);
+   conn->cancel();
+}
+
+#endif // defined(BOOST_ASIO_HAS_CO_AWAIT)