@portsip folly::Future doesn't support folly::Future<void>, instead it has a folly::Future<folly::Unit>. So you have to do some tricky thing, i.e. make a proxy forfolly::Future. You can replace src/sw/redis++/async_utils.h with the following code:

#ifndef SEWENEW_REDISPLUSPLUS_ASYNC_UTILS_H
#define SEWENEW_REDISPLUSPLUS_ASYNC_UTILS_H

#include <folly/futures/Future.h>

namespace sw {

namespace redis {
template <typename T>
struct Future {
	explicit Future(folly::Future<T> fut) : future(std::move(fut)) {}
	folly::Future<T> future;
};

template <>
struct Future<void> {
	explicit Future(folly::Future<folly::Unit> fut) : future(std::move(fut)) {}

	folly::Future<folly::Unit> future;
};

template <typename T>
struct Promise {
	Future<T> get_future() {
		return Future<T>(promise.getFuture());
	}

	void set_value(T &&val) {
		promise.setValue(std::move(val));
	}

	void set_exception(std::exception_ptr err) {
		promise.setException(folly::exception_wrapper::from_exception_ptr(err));
	}

	folly::Promise<T> promise;
};

template <>
struct Promise<void> {
	Future<void> get_future() {
		return Future<void>(promise.getFuture());
	}

	void set_value() {
		promise.setValue();
	}

	void set_exception(std::exception_ptr err) {
		promise.setException(folly::exception_wrapper::from_exception_ptr(err));
	}

	folly::Promise<folly::Unit> promise;
};

}

}

#endif // end SEWENEW_REDISPLUSPLUS_ASYNC_UTILS_H

NOTE: you need to build the redis-plus-plus with -DREDIS_PLUS_PLUS_CXX_STANDARD=17, i.e. build the code with c++17 standard.

folly depends on lots of other libs, so you need to link your application with those libs. For example:

c++ -std=c++17 -o app app.cpp -lredis++ -lhiredis -pthread -lfolly -lglog -lgflags -pthread -ldl -levent -ldouble-conversion -lboost_context -liberty -lfmt -luv

Regards

Git it, thanks a lot.

@portsip folly::Future doesn't support folly::Future<void>, instead it has a folly::Future<folly::Unit>. So you have to do some tricky thing, i.e. make a proxy forfolly::Future. You can replace src/sw/redis++/async_utils.h with the following code:

#ifndef SEWENEW_REDISPLUSPLUS_ASYNC_UTILS_H
#define SEWENEW_REDISPLUSPLUS_ASYNC_UTILS_H

#include <folly/futures/Future.h>

namespace sw {

namespace redis {
template <typename T>
struct Future {
	explicit Future(folly::Future<T> fut) : future(std::move(fut)) {}
	folly::Future<T> future;
};

template <>
struct Future<void> {
	explicit Future(folly::Future<folly::Unit> fut) : future(std::move(fut)) {}

	folly::Future<folly::Unit> future;
};

template <typename T>
struct Promise {
	Future<T> get_future() {
		return Future<T>(promise.getFuture());
	}

	void set_value(T &&val) {
		promise.setValue(std::move(val));
	}

	void set_exception(std::exception_ptr err) {
		promise.setException(folly::exception_wrapper::from_exception_ptr(err));
	}

	folly::Promise<T> promise;
};

template <>
struct Promise<void> {
	Future<void> get_future() {
		return Future<void>(promise.getFuture());
	}

	void set_value() {
		promise.setValue();
	}

	void set_exception(std::exception_ptr err) {
		promise.setException(folly::exception_wrapper::from_exception_ptr(err));
	}

	folly::Promise<folly::Unit> promise;
};

}

}

#endif // end SEWENEW_REDISPLUSPLUS_ASYNC_UTILS_H

NOTE: you need to build the redis-plus-plus with -DREDIS_PLUS_PLUS_CXX_STANDARD=17, i.e. build the code with c++17 standard.

folly depends on lots of other libs, so you need to link your application with those libs. For example:

c++ -std=c++17 -o app app.cpp -lredis++ -lhiredis -pthread -lfolly -lglog -lgflags -pthread -ldl -levent -ldouble-conversion -lboost_context -liberty -lfmt -luv

Regards

In fact, an elegant implementation of future should give an option to run the callback in thread pool. Take boost for example, you can set a thread pool when you call the then method.

If you can use boost, you can try the following:

1. replace src/sw/redis++/async_utils.h with the following code:

#ifndef SEWENEW_REDISPLUSPLUS_ASYNC_UTILS_H
#define SEWENEW_REDISPLUSPLUS_ASYNC_UTILS_H

//#include <future>

#define BOOST_THREAD_PROVIDES_FUTURE
#define BOOST_THREAD_PROVIDES_FUTURE_CONTINUATION
#define BOOST_THREAD_PROVIDES_EXECUTORS
#include <boost/thread/future.hpp>

namespace sw {

namespace redis {

template <typename T>
using Future = boost::future<T>;
//using Future = std::future<T>;

template <typename T>
using Promise = boost::promise<T>;
//using Promise = std::promise<T>;

}

}

#endif

1. build and install redis-plus-plus.
2. use it as the following example:

#include <sw/redis++/async_redis++.h>
#include <boost/thread/executors/basic_thread_pool.hpp>

boost::executors::basic_thread_pool pool(3);

ConnectionOptions opts;
opts.host = "127.0.01";
opts.port = 6379;

auto async_redis = AsyncRedis(opts);
async_redis.get("key").then(pool, [](Future<OptionalString> f) {
    auto val = f.get();
    if (val) cout << *val << endl;
});

There's a plan to support boost and other popular future libs, and will have a cmake option to let user choose between these libs.

Regards

Please consider supporting Facebook folly future. Thanks

okay. thanks for the reply.

@vishnucool220 Sorry, but so far, it doesn't support FetchContent. I did some research before, it seems that FetchContent do the dependency check at configuration step. However, redis-plus-plus depends on the installation of hiredis. That's why it complains that it cannot find HIREDIS_LIB.

Regards

Of course, you can assign a DNS to ConnectionOptions::host. It will be resolved to IP address automatically.

Regards

@sewenew i tried using fetchContent but got the errore

Detected version: 1.0.0 1> [CMake] -- redis-plus-plus version: 1.2.1 1> [CMake] -- The CXX standard is c++11 1> [CMake] CMake Error: The following variables are used in this project, but they are set to NOTFOUND. 1> [CMake] Please set them or make sure they are set and tested correctly in the CMake files: 1> [CMake] HIREDIS_LIB 1> [CMake] linked by target "redis-plus-plus-shared" in directory /mnt/c/Users/marthala/Documents/workspace/KEBPLCComService/out/build/WSL-GCC-Debug/_deps/redis-plus-plus-src 1> [CMake] HIREDIS_STATIC_LIB 1> [CMake] linked by target "test_redis++" in directory /mnt/c/Users/marthala/Documents/workspace/KEBPLCComService/out/build/WSL-GCC-Debug/_deps/redis-plus-plus-src/test 1> [CMake]

include(FetchContent) FetchContent_Declare( hiredis GIT_REPOSITORY https://github.com/redis/hiredis.git GIT_TAG v1.0.0 ) FetchContent_MakeAvailable(hiredis) target_link_libraries(your-project PRIVATE hiredis::hiredis)

FetchContent_Declare( redis-plus-plus GIT_REPOSITORY https://github.com/sewenew/redis-plus-plus.git GIT_TAG 1.2.2 ) FetchContent_MakeAvailable(redis-plus-plus) target_link_libraries(your-project PRIVATE redis-plus-plus::redis-plus-plus)

I'd like to connect to elasticache. However, aws strongly recommends connecting using dns. Is this possible using redis-plus-plus? Apologies as I might have totally missed something.

For example:

sw::redis::ConnectionOptions connection_options; connection_options.host = "test-elasticache.2wnzk3.0002.use2.cache.amazonaws.com"; connection_options.port = 6379; sw::redis::RedisCluster(connection_options);

@sewenew is this issue fixed with using cmake fetchcontect?

@wingunder The async interface is partially done. It doesn't support Redis Sentinel and Redis Cluster. Recently I don't have enough time to finish it. The Bloom filter support was plan to support Bloom filter data structure with or without the Bloom filter module, and it was planed before the creation of redis-plus-plus-modules. Now, since we have redis-plus-plus-modules to work with Redis Modules, I'll remove this TODO from the list.

Regards