redis-plus-plus

git clone https://github.com/redis/hiredis.git

cd hiredis

make

make install

make PREFIX=/non/default/path

make PREFIX=/non/default/path install

git clone https://github.com/sewenew/redis-plus-plus.git

cd redis-plus-plus

mkdir compile

cd compile

cmake -DCMAKE_BUILD_TYPE=Release ..

make

make install

cd ..

cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_PREFIX_PATH=/path/to/hiredis -DCMAKE_INSTALL_PREFIX=/path/to/install/redis-plus-plus ..

cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_PREFIX_PATH=/path/to/hiredis -DCMAKE_INSTALL_PREFIX=/path/to/install/redis-plus-plus -DREDIS_PLUS_PLUS_CXX_STANDARD=17 ..

cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_PREFIX_PATH=/path/to/hiredis -DCMAKE_INSTALL_PREFIX=/path/to/install/redis-plus-plus -DREDIS_PLUS_PLUS_BUILD_TEST=OFF ..

gcc version 4.8.5 20150623 (Red Hat 4.8.5-39) (GCC)
gcc version 5.5.0 20171010 (Ubuntu 5.5.0-12ubuntu1)
gcc version 6.5.0 20181026 (Ubuntu 6.5.0-2ubuntu1~18.04)
gcc version 7.4.0 (Ubuntu 7.4.0-1ubuntu1~18.04.1)
gcc version 8.3.0 (Ubuntu 8.3.0-6ubuntu1~18.04.1)
gcc version 9.2.1 20191008 (Ubuntu 9.2.1-9ubuntu2)
clang version 3.9.1-19ubuntu1 (tags/RELEASE_391/rc2)
clang version 4.0.1-10 (tags/RELEASE_401/final)
clang version 5.0.1-4 (tags/RELEASE_501/final)
clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
clang version 7.0.0-3~ubuntu0.18.04.1 (tags/RELEASE_700/final)
clang version 8.0.1-3build1 (tags/RELEASE_801/final)
Apple clang version 11.0.0 (clang-1100.0.33.12)

./compile/test/test_redis++ -h host -p port -a auth -n cluster_node -c cluster_port

./compile/test/test_redis++ -h host -p port -a auth

./compile/test/test_redis++ -a auth -n cluster_node -c cluster_port

sw::redis::test::ThreadsTest threads_test(opts, cluster_node_opts);
threads_test.run();

Pass all tests

./compile/test/test_redis++ -h host -p port -a auth -n cluster_node -c cluster_port -b -t thread_num -s connection_pool_size -r request_num -k key_len -v val_len

g++ -std=c++11 -o app app.cpp /path/to/libredis++.a /path/to/libhiredis.a -pthread

g++ -std=c++11 -I/non-default/install/include/path -o app app.cpp /path/to/libredis++.a /path/to/libhiredis.a -pthread

g++ -std=c++11 -o app app.cpp -lredis++ -lhiredis -pthread

g++ -std=c++11 -I/non-default/install/include/path -L/non-default/install/lib/path -o app app.cpp -lredis++ -lhiredis -pthread

error while loading shared libraries: xxx: cannot open shared object file: No such file or directory.

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib

# <------------ add hiredis dependency --------------->
find_path(HIREDIS_HEADER hiredis)
target_include_directories(target PUBLIC ${HIREDIS_HEADER})

find_library(HIREDIS_LIB hiredis)
target_link_libraries(target ${HIREDIS_LIB})

# <------------ add redis-plus-plus dependency -------------->
# NOTE: this should be *sw* NOT *redis++*
find_path(REDIS_PLUS_PLUS_HEADER sw)
target_include_directories(target PUBLIC ${REDIS_PLUS_PLUS_HEADER})

find_library(REDIS_PLUS_PLUS_LIB redis++)
target_link_libraries(target ${REDIS_PLUS_PLUS_LIB})

cmake -DCMAKE_PREFIX_PATH=/installation/path/to/the/two/libs ..

#include <sw/redis++/redis++.h>

using namespace sw::redis;

try {
    // Create an Redis object, which is movable but NOT copyable.
    auto redis = Redis("tcp://127.0.0.1:6379");

    // ***** STRING commands *****

    redis.set("key", "val");
    auto val = redis.get("key");    // val is of type OptionalString. See 'API Reference' section for details.
    if (val) {
        // Dereference val to get the returned value of std::string type.
        std::cout << *val << std::endl;
    }   // else key doesn't exist.

    // ***** LIST commands *****

    // std::vector<std::string> to Redis LIST.
    std::vector<std::string> vec = {"a", "b", "c"};
    redis.rpush("list", vec.begin(), vec.end());

    // std::initializer_list to Redis LIST.
    redis.rpush("list", {"a", "b", "c"});

    // Redis LIST to std::vector<std::string>.
    vec.clear();
    redis.lrange("list", 0, -1, std::back_inserter(vec));

    // ***** HASH commands *****

    redis.hset("hash", "field", "val");

    // Another way to do the same job.
    redis.hset("hash", std::make_pair("field", "val"));

    // std::unordered_map<std::string, std::string> to Redis HASH.
    std::unordered_map<std::string, std::string> m = {
        {"field1", "val1"},
        {"field2", "val2"}
    };
    redis.hmset("hash", m.begin(), m.end());

    // Redis HASH to std::unordered_map<std::string, std::string>.
    m.clear();
    redis.hgetall("hash", std::inserter(m, m.begin()));

    // Get value only.
    // NOTE: since field might NOT exist, so we need to parse it to OptionalString.
    std::vector<OptionalString> vals;
    redis.hmget("hash", {"field1", "field2"}, std::back_inserter(vals));

    // ***** SET commands *****

    redis.sadd("set", "m1");

    // std::unordered_set<std::string> to Redis SET.
    std::unordered_set<std::string> set = {"m2", "m3"};
    redis.sadd("set", set.begin(), set.end());

    // std::initializer_list to Redis SET.
    redis.sadd("set", {"m2", "m3"});

    // Redis SET to std::unordered_set<std::string>.
    set.clear();
    redis.smembers("set", std::inserter(set, set.begin()));

    if (redis.sismember("set", "m1")) {
        std::cout << "m1 exists" << std::endl;
    }   // else NOT exist.

    // ***** SORTED SET commands *****

    redis.zadd("sorted_set", "m1", 1.3);

    // std::unordered_map<std::string, double> to Redis SORTED SET.
    std::unordered_map<std::string, double> scores = {
        {"m2", 2.3},
        {"m3", 4.5}
    };
    redis.zadd("sorted_set", scores.begin(), scores.end());

    // Redis SORTED SET to std::unordered_map<std::string, double>.
    scores.clear();
    redis.zrangebyscore("sorted_set",
            UnboundedInterval<double>{},            // (-inf, +inf)
            std::inserter(scores, scores.begin()));

    // Only get member names:
    // pass an inserter of std::vector<std::string> type as output parameter.
    std::vector<std::string> without_score;
    redis.zrangebyscore("sorted_set",
            BoundedInterval<double>(1.5, 3.4, BoundType::CLOSED),   // [1.5, 3.4]
            std::back_inserter(without_score));

    // Get both member names and scores:
    // pass an inserter of std::unordered_map<std::string, double> as output parameter.
    std::unordered_map<std::string, double> with_score;
    redis.zrangebyscore("sorted_set",
            BoundedInterval<double>(1.5, 3.4, BoundType::LEFT_OPEN),    // (1.5, 3.4]
            std::inserter(with_score, with_score.end()));

    // ***** SCRIPTING commands *****

    // Script returns a single element.
    auto num = redis.eval<long long>("return 1", {}, {});

    // Script returns an array of elements.
    std::vector<long long> nums;
    redis.eval("return {ARGV[1], ARGV[2]}", {}, {"1", "2"}, std::back_inserter(nums));

    // ***** Pipeline *****

    // Create a pipeline.
    auto pipe = redis.pipeline();

    // Send mulitple commands and get all replies.
    auto pipe_replies = pipe.set("key", "value")
                            .get("key")
                            .rename("key", "new-key")
                            .rpush("list", {"a", "b", "c"})
                            .lrange("list", 0, -1)
                            .exec();

    // Parse reply with reply type and index.
    auto set_cmd_result = pipe_replies.get<bool>(0);

    auto get_cmd_result = pipe_replies.get<OptionalString>(1);

    // rename command result
    pipe_replies.get<void>(2);

    auto rpush_cmd_result = pipe_replies.get<long long>(3);

    std::vector<std::string> lrange_cmd_result;
    pipe_replies.get(4, back_inserter(lrange_cmd_result));

    // ***** Transaction *****

    // Create a transaction.
    auto tx = redis.transaction();

    // Run multiple commands in a transaction, and get all replies.
    auto tx_replies = tx.incr("num0")
                        .incr("num1")
                        .mget({"num0", "num1"})
                        .exec();

    // Parse reply with reply type and index.
    auto incr_result0 = tx_replies.get<long long>(0);

    auto incr_result1 = tx_replies.get<long long>(1);

    std::vector<OptionalString> mget_cmd_result;
    tx_replies.get(2, back_inserter(mget_cmd_result));

    // ***** Generic Command Interface *****

    // There's no *Redis::client_getname* interface.
    // But you can use *Redis::command* to get the client name.
    val = redis.command<OptionalString>("client", "getname");
    if (val) {
        std::cout << *val << std::endl;
    }

    // Same as above.
    auto getname_cmd_str = {"client", "getname"};
    val = redis.command<OptionalString>(getname_cmd_str.begin(), getname_cmd_str.end());

    // There's no *Redis::sort* interface.
    // But you can use *Redis::command* to send sort the list.
    std::vector<std::string> sorted_list;
    redis.command("sort", "list", "ALPHA", std::back_inserter(sorted_list));

    // Another *Redis::command* to do the same work.
    auto sort_cmd_str = {"sort", "list", "ALPHA"};
    redis.command(sort_cmd_str.begin(), sort_cmd_str.end(), std::back_inserter(sorted_list));

    // ***** Redis Cluster *****

    // Create a RedisCluster object, which is movable but NOT copyable.
    auto redis_cluster = RedisCluster("tcp://127.0.0.1:7000");

    // RedisCluster has similar interfaces as Redis.
    redis_cluster.set("key", "value");
    val = redis_cluster.get("key");
    if (val) {
        std::cout << *val << std::endl;
    }   // else key doesn't exist.

    // Keys with hash-tag.
    redis_cluster.set("key{tag}1", "val1");
    redis_cluster.set("key{tag}2", "val2");
    redis_cluster.set("key{tag}3", "val3");

    std::vector<OptionalString> hash_tag_res;
    redis_cluster.mget({"key{tag}1", "key{tag}2", "key{tag}3"},
            std::back_inserter(hash_tag_res));

} catch (const Error &e) {
    // Error handling.
}

ConnectionOptions connection_options;
connection_options.host = "127.0.0.1";  // Required.
connection_options.port = 6666; // Optional. The default port is 6379.
connection_options.password = "auth";   // Optional. No password by default.
connection_options.db = 1;  // Optional. Use the 0th database by default.

// Optional. Timeout before we successfully send request to or receive response from redis.
// By default, the timeout is 0ms, i.e. never timeout and block until we send or receive successfuly.
// NOTE: if any command is timed out, we throw a TimeoutError exception.
connection_options.socket_timeout = std::chrono::milliseconds(200);

// Connect to Redis server with a single connection.
Redis redis1(connection_options);

ConnectionPoolOptions pool_options;
pool_options.size = 3;  // Pool size, i.e. max number of connections.

// Connect to Redis server with a connection pool.
Redis redis2(connection_options, pool_options);

// auto redis3 = redis1;    // this won't compile.

// But it's movable.
auto redis3 = std::move(redis1);

ConnectionOptions options;
options.type = ConnectionType::UNIX;
options.path = "/path/to/socket";
Redis redis(options);

tcp://[[username:]password@]host[:port][/db]

unix://[[username:]password@]path-to-unix-domain-socket[/db]

// Single connection to the given host and port.
Redis redis1("tcp://127.0.0.1:6666");

// Use default port, i.e. 6379.
Redis redis2("tcp://127.0.0.1");

// Connect to Redis with password, and default port.
Redis redis3("tcp://pass@127.0.0.1");

// Connect to Redis and select the 2nd (db number starts from 0) database.
Redis redis4("tcp://127.0.0.1:6379/2");

// Set keep_alive option to true with query string.
Redis redis5("tcp://127.0.0.1:6379/2?keep_alive=true");

// Set socket_timeout to 50 milliseconds, and connect_timeout to 1 second with query string.
Redis redis6("tcp://127.0.0.1?socket_timeout=50ms&connect_timeout=1s");

// Connect to Unix Domain Socket.
Redis redis7("unix://path/to/socket");

// This is GOOD practice.
auto redis = Redis("tcp://127.0.0.1");
for (auto idx = 0; idx < 100; ++idx) {
    // Reuse the Redis object in the loop.
    redis.set("key", "val");
}

// This is VERY BAD! It's very inefficient.
// NEVER DO IT!!!
for (auto idx = 0; idx < 100; ++idx) {
    // Create a new Redis object for each iteration.
    auto redis = Redis("tcp://127.0.0.1");
    redis.set("key", "val");
}

// Delete a single key.
long long Redis::del(const StringView &key);

// Delete a batch of keys: [first, last).
template <typename Input>
long long Redis::del(Input first, Input last);

// Delete keys in the initializer_list.
template <typename T>
long long Redis::del(std::initializer_list<T> il);

// bool Redis::hset(const StringView &key, const StringView &field, const StringView &val)

// Pass c-style string to StringView.
redis.hset("key", "field", "value");

// Pass std::string to StringView.
std::string key = "key";
std::string field = "field";
std::string val = "val";
redis.hset(key, field, val);

// Mix std::string and c-style string.
redis.hset(key, field, "value");

// Or just: auto val = redis.get("key");
Optional<std::string> val = redis.get("key");

// Optional<T> has a conversion to bool.
// If it's NOT a null Optional<T> object, it's converted to true.
// Otherwise, it's converted to false.
if (val) {
    // Key exists. Dereference val to get the string result.
    std::cout << *val << std::endl;
} else {
    // Redis server returns a NULL Bulk String Reply.
    // It's invalid to dereference a null Optional<T> object.
    std::cout << "key doesn't exist." << std::endl;
}

std::vector<Optional<std::string>> values;
redis.mget({"key1", "key2", "key3"}, std::back_inserter(values));
for (const auto &val : values) {
    if (val) {
        // Key exist, process the value.
    }
}

using OptionalString = Optional<std::string>;

using OptionalLongLong = Optional<long long>;

using OptionalDouble = Optional<double>;

using OptionalStringPair = Optional<std::pair<std::string, std::string>>;

// ***** Parameters of StringView type *****

// Implicitly construct StringView with c-style string.
redis.set("key", "value");

// Implicitly construct StringView with std::string.
std::string key("key");
std::string val("value");
redis.set(key, val);

// Explicitly pass StringView as parameter.
std::vector<char> large_data;
// Avoid copying.
redis.set("key", StringView(large_data.data(), large_data.size()));

// ***** Parameters of long long type *****

// For index.
redis.bitcount(key, 1, 3);

// For number.
redis.incrby("num", 100);

// ***** Parameters of double type *****

// For score.
redis.zadd("zset", "m1", 2.5);
redis.zadd("zset", "m2", 3.5);
redis.zadd("zset", "m3", 5);

// For (longitude, latitude).
redis.geoadd("geo", std::make_tuple("member", 13.5, 15.6));

// ***** Time-related parameters *****

using namespace std::chrono;

redis.expire(key, seconds(1000));

auto tp = time_point_cast<seconds>(system_clock::now() + seconds(100));
redis.expireat(key, tp);

// ***** Some options for commands *****

if (redis.set(key, "value", milliseconds(100), UpdateType::NOT_EXIST)) {
    std::cout << "set OK" << std::endl;
}

redis.linsert("list", InsertPosition::BEFORE, "pivot", "val");

std::vector<std::string> res;

// (-inf, inf)
redis.zrangebyscore("zset", UnboundedInterval<double>{}, std::back_inserter(res));

// [3, 6]
redis.zrangebyscore("zset",
    BoundedInterval<double>(3, 6, BoundType::CLOSED),
    std::back_inserter(res));

// (3, 6]
redis.zrangebyscore("zset",
    BoundedInterval<double>(3, 6, BoundType::LEFT_OPEN),
    std::back_inserter(res));

// (3, 6)
redis.zrangebyscore("zset",
    BoundedInterval<double>(3, 6, BoundType::OPEN),
    std::back_inserter(res));

// [3, 6)
redis.zrangebyscore("zset",
    BoundedInterval<double>(3, 6, BoundType::RIGHT_OPEN),
    std::back_inserter(res));

// [3, +inf)
redis.zrangebyscore("zset",
    LeftBoundedInterval<double>(3, BoundType::RIGHT_OPEN),
    std::back_inserter(res));

// (3, +inf)
redis.zrangebyscore("zset",
    LeftBoundedInterval<double>(3, BoundType::OPEN),
    std::back_inserter(res));

// (-inf, 6]
redis.zrangebyscore("zset",
    RightBoundedInterval<double>(6, BoundType::LEFT_OPEN),
    std::back_inserter(res));

// (-inf, 6)
redis.zrangebyscore("zset",
    RightBoundedInterval<double>(6, BoundType::OPEN),
    std::back_inserter(res));

// ***** Pair of iterators *****

std::vector<std::pair<std::string, std::string>> kvs = {{"k1", "v1"}, {"k2", "v2"}, {"k3", "v3"}};
redis.mset(kvs.begin(), kvs.end());

std::unordered_map<std::string, std::string> kv_map = {{"k1", "v1"}, {"k2", "v2"}, {"k3", "v3"}};
redis.mset(kv_map.begin(), kv_map.end());

std::unordered_map<std::string, std::string> str_map = {{"f1", "v1"}, {"f2", "v2"}, {"f3", "v3"}};
redis.hmset("hash", str_map.begin(), str_map.end());

std::unordered_map<std::string, double> score_map = {{"m1", 20}, {"m2", 12.5}, {"m3", 3.14}};
redis.zadd("zset", score_map.begin(), score_map.end());

std::vector<std::string> keys = {"k1", "k2", "k3"};
redis.del(keys.begin(), keys.end());

// ***** Parameters of initializer_list type *****

redis.mset({
    std::make_pair("k1", "v1"),
    std::make_pair("k2", "v2"),
    std::make_pair("k3", "v3")
});

redis.hmset("hash",
    {
        std::make_pair("f1", "v1"),
        std::make_pair("f2", "v2"),
        std::make_pair("f3", "v3")
    });

redis.zadd("zset",
    {
        std::make_pair("m1", 20.0),
        std::make_pair("m2", 34.5),
        std::make_pair("m3", 23.4)
    });

redis.del({"k1", "k2", "k3"});

// ***** Return void *****

redis.save();

// ***** Return std::string *****

auto info = redis.info();

// ***** Return bool *****

if (!redis.expire("nonexistent", std::chrono::seconds(100))) {
    std::cerr << "key doesn't exist" << std::endl;
}

if (redis.setnx("key", "val")) {
    std::cout << "set OK" << std::endl;
}

// ***** Return long long *****

auto len = redis.strlen("key");
auto num = redis.del({"a", "b", "c"});
num = redis.incr("a");

// ***** Return double *****

auto real = redis.incrbyfloat("b", 23.4);
real = redis.hincrbyfloat("c", "f", 34.5);

// ***** Return Optional<std::string>, i.e. OptionalString *****

auto os = redis.get("kk");
if (os) {
    std::cout << *os << std::endl;
} else {
    std::cerr << "key doesn't exist" << std::endl;
}

os = redis.spop("set");
if (os) {
    std::cout << *os << std::endl;
} else {
    std::cerr << "set is empty" << std::endl;
}

// ***** Return Optional<long long>, i.e. OptionalLongLong *****

auto oll = redis.zrank("zset", "mem");
if (oll) {
    std::cout << "rank is " << *oll << std::endl;
} else {
    std::cerr << "member doesn't exist" << std::endl;
}

// ***** Return Optional<double>, i.e. OptionalDouble *****

auto ob = redis.zscore("zset", "m1");
if (ob) {
    std::cout << "score is " << *ob << std::endl;
} else {
    std::cerr << "member doesn't exist" << std::endl;
}

// ***** Return Optional<pair<string, string>> *****

auto op = redis.blpop({"list1", "list2"}, std::chrono::seconds(2));
if (op) {
    std::cout << "key is " << op->first << ", value is " << op->second << std::endl;
} else {
    std::cerr << "timeout" << std::endl;
}

// ***** Output iterators *****

std::vector<OptionalString> os_vec;
redis.mget({"k1", "k2", "k3"}, std::back_inserter(os_vec));

std::vector<std::string> s_vec;
redis.lrange("list", 0, -1, std::back_inserter(s_vec));

std::unordered_map<std::string, std::string> hash;
redis.hgetall("hash", std::inserter(hash, hash.end()));
// You can also save the result in a vecotr of string pair.
std::vector<std::pair<std::string, std::string>> hash_vec;
redis.hgetall("hash", std::back_inserter(hash_vec));

std::unordered_set<std::string> str_set;
redis.smembers("s1", std::inserter(str_set, str_set.end()));
// You can also save the result in a vecotr of string.
s_vec.clear();
redis.smembers("s1", std::back_inserter(s_vec));

auto cursor = 0LL;
auto pattern = "*pattern*";
auto count = 5;
std::unordered_set<std::string> keys;
while (true) {
    cursor = redis.scan(cursor, pattern, count, std::inserter(keys, keys.begin()));
    // Default pattern is "*", and default count is 10
    // cursor = redis.scan(cursor, std::inserter(keys, keys.begin()));

    if (cursor == 0) {
        break;
    }
}

// If the output iterator is an iterator of a container of string,
// we send *ZRANGE* command without the *WITHSCORES* option.
std::vector<std::string> members;
redis.zrange("list", 0, -1, std::back_inserter(members));

// If it's an iterator of a container of a <string, double> pair,
// we send *ZRANGE* command with *WITHSCORES* option.
std::unordered_map<std::string, double> res_with_score;
redis.zrange("list", 0, -1, std::inserter(res_with_score, res_with_score.end()));

// The above examples also apply to other command with the *WITHSCORES* options,
// e.g. *ZRANGEBYSCORE*, *ZREVRANGE*, *ZREVRANGEBYSCORE*.

// Another example is the *GEORADIUS* command.

// Only get members.
members.clear();
redis.georadius("geo",
            std::make_pair(10.1, 11.1),
            100,
            GeoUnit::KM,
            10,
            true,
            std::back_inserter(members));

// If the iterator is an iterator of a container of tuple<string, double>,
// we send the *GEORADIUS* command with *WITHDIST* option.
std::vector<std::tuple<std::string, double>> mem_with_dist;
redis.georadius("geo",
            std::make_pair(10.1, 11.1),
            100,
            GeoUnit::KM,
            10,
            true,
            std::back_inserter(mem_with_dist));

// If the iterator is an iterator of a container of tuple<string, double, string>,
// we send the *GEORADIUS* command with *WITHDIST* and *WITHHASH* options.
std::vector<std::tuple<std::string, double, std::string>> mem_with_dist_hash;
redis.georadius("geo",
            std::make_pair(10.1, 11.1),
            100,
            GeoUnit::KM,
            10,
            true,
            std::back_inserter(mem_with_dist_hash));

// If the iterator is an iterator of a container of
// tuple<string, string, pair<double, double>, double>,
// we send the *GEORADIUS* command with *WITHHASH*, *WITHCOORD* and *WITHDIST* options.
std::vector<std::tuple<std::string, double, std::string>> mem_with_hash_coord_dist;
redis.georadius("geo",
            std::make_pair(10.1, 11.1),
            100,
            GeoUnit::KM,
            10,
            true,
            std::back_inserter(mem_with_hash_coord_dist));

try {
    redis.set("key", "value");

    // Wrong type error
    redis.lpush("key", {"a", "b", "c"});
} catch (const ReplyError &err) {
    // WRONGTYPE Operation against a key holding the wrong kind of value
    cout << err.what() << endl;
} catch (const TimeoutError &err) {
    // reading or writing timeout
} catch (const ClosedError &err) {
    // the connection has been closed.
} catch (const IoError &err) {
    // there's an IO error on the connection.
} catch (const Error &err) {
   // other errors
}

auto redis = Redis("tcp://127.0.0.1");

// Redis class doesn't have built-in *CLIENT SETNAME* method.
// However, you can use Redis::command to send the command manually.
redis.command<void>("client", "setname", "name");
auto val = redis.command<OptionalString>("client", "getname");
if (val) {
    std::cout << *val << std::endl;
}

// NOTE: the following code is for example only. In fact, Redis has built-in
// methods for the following commands.

// Arguments of the command can be strings.
// NOTE: for SET command, the return value is NOT always void, I'll explain latter.
redis.command<void>("set", "key", "100");

// Arguments of the command can be a combination of strings and integers.
auto num = redis.command<long long>("incrby", "key", 1);

// Argument can also be double.
auto real = redis.command<double>("incrbyfloat", "key", 2.3);

// Even the key of the command can be of arithmetic type.
redis.command<void>("set", 100, "value");

val = redis.command<OptionalString>("get", 100);

// If the command returns an array of elements.
std::vector<OptionalString> result;
redis.command("mget", "k1", "k2", "k3", std::back_inserter(result));

// Or just parse it into a vector.
result = redis.command<std::vector<OptionalString>>("mget", "k1", "k2", "k3");

// Arguments of the command can be a range of strings.
auto set_cmd_strs = {"set", "key", "value"};
redis.command<void>(set_cmd_strs.begin(), set_cmd_strs.end());

auto get_cmd_strs = {"get", "key"};
val = redis.command<OptionalString>(get_cmd_strs.begin(), get_cmd_strs.end());

// If it returns an array of elements.
result.clear();
auto mget_cmd_strs = {"mget", "key1", "key2"};
redis.command(mget_cmd_strs.begin(), mget_cmd_strs.end(), std::back_inserter(result));

// This is GOOD.
redis.command<void>("client", "setname", "name");

// This is BAD, and will fail to send command to Redis server.
// redis.command<void>("client setname", "name");

auto redis = Redis("tcp://127.0.0.1");

redis.command("client", "setname", "name");
auto r = redis.command("client", "getname");
assert(r);

// If the command returns a single element,
// use `reply::parse<T>(redisReply&)` to parse it.
auto val = reply::parse<OptionalString>(*r);
if (val) {
    std::cout << *val << std::endl;
}

// Arguments of the command can be strings.
redis.command("set", "key", "100");

// Arguments of the command can be a combination of strings and integers.
r = redis.command("incrby", "key", 1);
auto num = reply::parse<long long>(*r);

// Argument can also be double.
r = redis.command("incrbyfloat", "key", 2.3);
auto real = reply::parse<double>(*r);

// Even the key of the command can be of arithmetic type.
redis.command("set", 100, "value");

r = redis.command("get", 100);
val = reply::parse<OptionalString>(*r);

// If the command returns an array of elements.
r = redis.command("mget", "k1", "k2", "k3");
// Use `reply::to_array(redisReply&, OutputIterator)` to parse the result into an STL container.
std::vector<OptionalString> result;
reply::to_array(*r, std::back_inserter(result));

// Or just call `reply::parse` to parse it into vector.
result = reply::parse<std::vector<OptionalString>>(*r);

// Arguments of the command can be a range of strings.
auto get_cmd_strs = {"get", "key"};
r = redis.command(get_cmd_strs.begin(), get_cmd_strs.end());
val = reply::parse<OptionalString>(*r);

// If it returns an array of elements.
result.clear();
auto mget_cmd_strs = {"mget", "key1", "key2"};
r = redis.command(mget_cmd_strs.begin(), mget_cmd_strs.end());
reply::to_array(*r, std::back_inserter(result));

template <typename Cmd, typename ...Args>
auto command(Cmd cmd, Args &&...args)
    -> typename std::enable_if<!std::is_convertible<Cmd, StringView>::value, ReplyUPtr>::type;

// Create a Subscriber.
auto sub = redis.subscriber();

// Set callback functions.
sub.on_message([](std::string channel, std::string msg) {
            // Process message of MESSAGE type.
        });

sub.on_pmessage([](std::string pattern, std::string channel, std::string msg) {
            // Process message of PMESSAGE type.
        });

sub.on_meta([](Subscriber::MsgType type, OptionalString channel, long long num) {
            // Process message of META type.
        });

// Subscribe to channels and patterns.
sub.subscribe("channel1");
sub.subscribe({"channel2", "channel3"});

sub.psubscribe("pattern1*");

// Consume messages in a loop.
while (true) {
    try {
        sub.consume();
    } catch (const Error &err) {
        // Handle exceptions.
    }
}

while (true) {
    try {
        sub.consume();
    } catch (const TimeoutError &e) {
        // Try again.
        continue;
    } catch (const Error &err) {
        // Handle other exceptions.
    }
}

ConnectionOptions connection_options;
ConnectionPoolOptions pool_options;

Redis redis(connection_options, pool_options);

auto pipe = redis.pipeline();

pipe.set("key", "val").incr("num").rpush("list", {0, 1, 2}).command("hset", "key", "field", "value");

pipe.set("key", "val").incr("num");
auto replies = pipe.exec();

// The same as:
replies = pipe.set("key", "val").incr("num).exec();

pipe.set("key", "val").incr("num");

pipe.discard();

auto replies = pipe.set("key", "val").incr("num").lrange("list", 0, -1).exec();

auto set_cmd_result = replies.get<bool>(0);

auto incr_cmd_result = replies.get<long long>(1);

std::vector<std::string> list_cmd_result;
replies.get(2, std::back_inserter(list_cmd_result));

ConnectionOptions connection_options;
ConnectionPoolOptions pool_options;

Redis redis(connection_options, pool_options);

auto tx = redis.transaction();

tx.set("key", "val").incr("num").lpush("list", {0, 1, 2}).command("hset", "key", "field", "val");

auto replies = tx.set("key", "val").incr("num").exec();

tx.set("key", "val").incr("num");

// Discard the transaction.
tx.discard();

// Create a piped transaction
auto tx = redis.transaction(true);

WATCH key           // watch a key
val = GET key       // get value of the key
new_val = val + 1   // incr the value
MULTI               // begin the transaction
SET key new_val     // set value only if the value is NOT modified by others
EXEC                // try to execute the transaction.
                    // if val has been modified, the transaction won't be executed.

auto redis = Redis("tcp://127.0.0.1");

// Create a transaction.
auto tx = redis.transaction();

// Create a Redis object from the Transaction object. Both objects share the same connection.
auto r = tx.redis();

// If the watched key has been modified by other clients, the transaction might fail.
// So we need to retry the transaction in a loop.
while (true) {
    try {
        // Watch a key.
        r.watch("key");

        // Get the old value.
        auto val = r.get("key");
        auto num = 0;
        if (val) {
            num = std::stoi(*val);
        } // else use default value, i.e. 0.

        // Incr value.
        ++num;

        // Execute the transaction.
        auto replies = tx.set("key", std::to_string(num)).exec();

        // Transaction has been executed successfully. Check the result and break.

        assert(replies.size() == 1 && replies.get<bool>(0) == true);

        break;
    } catch (const WatchError &err) {
        // Key has been modified by other clients, retry.
        continue;
    } catch (const Error &err) {
        // Something bad happens, and the Transaction object is no longer valid.
        throw;
    }
}

// Set a master node's host & port.
ConnectionOptions connection_options;
connection_options.host = "127.0.0.1";  // Required.
connection_options.port = 7000; // Optional. The default port is 6379.
connection_options.password = "auth"; // Optional. No password by default.

// Automatically get other nodes' info,
// and connect to every master node with a single connection.
RedisCluster cluster1(connection_options);

ConnectionPoolOptions pool_options;
pool_options.size = 3;

// For each master node, maintains a connection pool of size 3.
RedisCluster cluster2(connection_options, pool_options);

// Specify a master node's host & port.
RedisCluster cluster3("tcp://127.0.0.1:7000");

// Use default port, i.e. 6379.
RedisCluster cluster4("tcp://127.0.0.1");

Pipeline RedisCluster::pipeline(const StringView &hash_tag);

Transaction RedisCluster::transaction(const StringView &hash_tag, bool piped = false);

#include <sw/redis++/redis++.h>

using namespace sw::redis;

auto redis_cluster = RedisCluster("tcp://127.0.0.1:7000");

redis_cluster.set("key", "value");
auto val = redis_cluster.get("key");
if (val) {
    std::cout << *val << std::endl;
}

// With hash-tag.
redis_cluster.set("key{tag}1", "val1");
redis_cluster.set("key{tag}2", "val2");
redis_cluster.set("key{tag}3", "val3");
std::vector<OptionalString> hash_tag_res;
redis_cluster.mget({"key{tag}1", "key{tag}2", "key{tag}3"},
        std::back_inserter(hash_tag_res));

redis_cluster.lpush("list", {"1", "2", "3"});
std::vector<std::string> list;
redis_cluster.lrange("list", 0, -1, std::back_inserter(list));

// Pipeline.
auto pipe = redis_cluster.pipeline("counter");
auto replies = pipe.incr("{counter}:1").incr("{counter}:2").exec();

// Transaction.
auto tx = redis_cluster.transaction("key");
replies = tx.incr("key").get("key").exec();

// Create a Redis object with hash-tag.
// It connects to the Redis instance that holds the given key, i.e. hash-tag.
auto r = redis_cluster.redis("hash-tag");

// And send command without key parameter to the server.
r.command("client", "setname", "connection-name");

// This is BAD! It's very inefficient.
// NEVER DO IT!!!
// After sending PING command, the newly created Redis object will be destroied.
cluster.redis("key").ping();

// Then it creates a connection to Redis, and closes the connection after sending the command.
cluster.redis("key").command("client", "setname", "hello");

// Instead you should reuse the Redis object.
// This is GOOD!
auto redis = cluster.redis("key");

redis.ping();
redis.command("client", "setname", "hello");

SentinelOptions sentinel_opts;
sentinel_opts.nodes = {{"127.0.0.1", 9000},
                        {"127.0.0.1", 9001},
                        {"127.0.0.1", 9002}};   // Required. List of Redis Sentinel nodes.

// Optional. Timeout before we successfully connect to Redis Sentinel.
// By default, the timeout is 100ms.
sentinel_opts.connect_timeout = std::chrono::milliseconds(200);

// Optional. Timeout before we successfully send request to or receive response from Redis Sentinel.
// By default, the timeout is 100ms.
sentinel_opts.socket_timeout = std::chrono::milliseconds(200);

auto sentinel = std::make_shared<Sentinel>(sentinel_opts);

ConnectionOptions connection_opts;
connection_opts.password = "auth";  // Optional. No password by default.
connection_opts.connect_timeout = std::chrono::milliseconds(100);   // Required.
connection_opts.socket_timeout = std::chrono::milliseconds(100);    // Required.

ConnectionPoolOptions pool_opts;
pool_opts.size = 3; // Optional. The default size is 1.

auto redis = Redis(sentinel, "master_name", Role::MASTER, connection_opts, pool_opts);

auto sentinel = std::make_shared<Sentinel>(sentinel_opts);

auto master = Redis(sentinel, "master_name", Role::MASTER, connection_opts, pool_opts);

auto slave = Redis(sentinel, "master_name", Role::SLAVE, connection_opts, pool_opts);

// Write to master.
master.set("key", "value");

// Read from slave.
slave.get("key");

auto redis = Redis("tcp://127.0.0.1");

using Attrs = std::vector<std::pair<std::string, std::string>>;

// You can also use std::unordered_map, if you don't care the order of attributes:
// using Attrs = std::unordered_map<std::string, std::string>;

Attrs attrs = { {"f1", "v1"}, {"f2", "v2"} };

// Add an item into the stream. This method returns the auto generated id.
auto id = redis.xadd("key", "*", attrs.begin(), attrs.end());

// Each item is assigned with an id: pair<id, attributes>.
using Item = std::pair<std::string, Attrs>;
using ItemStream = std::vector<Item>;

// If you don't care the order of items in the stream, you can also use unordered_map:
// using ItemStream = std::unordered_map<std::string, Attrs>;

// Read items from a stream, and return at most 10 items.
// You need to specify a key and an id (timestamp + offset).
std::unordered_map<std::string, ItemStream> result;
redis.xread("key", id, 10, std::inserter(result, result.end()));

// Read from multiple streams. For each stream, you need to specify a key and an id.
std::unordered_map<std::string, std::string> keys = { {"key", id}, {"another-key", "0-0"} };
redis.xread(keys.begin(), keys.end(), 10, std::inserter(result, result.end()));

// Block for at most 1 second if currently there's no data in the stream.
redis.xread("key", id, std::chrono::seconds(1), 10, std::inserter(result, result.end()));

// Block for multiple streams.
redis.xread(keys.begin(), keys.end(), std::chrono::seconds(1), 10, std::inserter(result, result.end()));

// Read items in a range:
ItemStream item_stream;
redis.xrange("key", "-", "+", std::back_inserter(item_stream));

// Trim the stream to a given number of items. After the operation, the stream length is NOT exactly
// 10. Instead, it might be much larger than 10.
// `XTRIM key MAXLEN 10`
redis.xtrim("key", 10);

// In order to trim the stream to exactly 10 items, specify the third argument, i.e. approx, as false.
// `XTRIM key MAXLEN ~ 10`
redis.xtrim("key", 10, false);

// Delete an item from the stream.
redis.xdel("key", id);

// Create a consumer group.
redis.xgroup_create("key", "group", "$");

// If the stream doesn't exist, you can set the fourth argument, i.e. MKSTREAM, to be true.
// redis.xgroup_create("key", "group", "$", true);

id = redis.xadd("key", "*", attrs.begin(), attrs.end());

// Read item by a consumer of a consumer group.
redis.xreadgroup("group", "consumer", "key", ">", 1, std::inserter(result, result.end()));

using PendingItem = std::tuple<std::string, std::string, long long, long long>;
std::vector<PendingItem> pending_items;

// Get pending items of a speicified consumer.
redis.xpending("key", "group", "-", "+", 1, "consumer", std::back_inserter(pending_items));

redis.xack("key", "group", id);

redis.xgroup_delconsumer("key", "group", "consumer");
redis.xgroup_destroy("key", "group");