uhd: add cut-down rpclib source tree and import tool

1 files changed, 141 insertions, 0 deletions

diff --git a/host/lib/deps/rpclib/include/rpc/client.h b/host/lib/deps/rpclib/include/rpc/client.h
new file mode 100644
index 000000000..624607641
--- /dev/null
+++ b/host/lib/deps/rpclib/include/rpc/client.h
@@ -0,0 +1,141 @@
+#pragma once
+
+#include <future>
+#include <memory>
+
+#include "rpc/config.h"
+#include "rpc/detail/log.h"
+#include "rpc/detail/pimpl.h"
+#include "rpc/msgpack.hpp"
+
+namespace rpc {
+
+//! \brief Implements a client that connects to a msgpack-rpc server and is
+//! able to call functions synchronously or asynchronously. This is the main
+//! interfacing point for implementing client applications.
+//!
+//! Use this class to connect to msgpack-rpc servers and call their exposed
+//! functions. This class supports calling functions synchronously and
+//! asynchronously. When the client object is created, it initiates connecting
+//! to the given server asynchronically and disconnects when it is destroyed.
+class client {
+public:
+    //! \brief Constructs a client.
+    //!
+    //! When a client is constructed, it initiates a connection
+    //! asynchronically. This means that it will not block while the connection
+    //! is established. However, when the first call is performed, it *might*
+    //! block if the connection was not already established.
+    //!
+    //! \param addr The address of the server to connect to. This might be an
+    //! IP address or a host name, too.
+    //! \param port The port on the server to connect to.
+    client(std::string const &addr, uint16_t port);
+
+    //! \cond DOXYGEN_SKIP
+    client(client const &) = delete;
+    //! \endcond
+
+    //! \brief Destructor.
+    //!
+    //! During destruction, the connection to the server is gracefully closed.
+    //! This means that any outstanding reads and writes are completed first.
+    ~client();
+
+    //! \brief Calls a function with the given name and arguments (if any).
+    //!
+    //! \param func_name The name of the function to call on the server.
+    //! \param args A variable number of arguments to pass to the called
+    //! function.
+    //!
+    //! \tparam Args The types of the arguments. Each type in this parameter
+    //! pack have to be serializable by msgpack.
+    //!
+    //! \returns A RPCLIB_MSGPACK::object containing the result of the function (if
+    //! any). To obtain a typed value, use the msgpack API.
+    //!
+    //! \throws rpc::rpc_error if the server responds with an error.
+    template <typename... Args>
+    RPCLIB_MSGPACK::object_handle call(std::string const &func_name, Args... args);
+
+    //! \brief Calls a function asynchronously with the given name and
+    //! arguments.
+    //!
+    //! A call is performed asynchronously in the context of the client, i.e.
+    //! this is not to be confused with parallel execution on the server.
+    //! This function differs from `call` in that it does not wait for the
+    //! result of the function. Instead, it returns a std::future that
+    //! can be used to retrieve the result later.
+    //!
+    //! \param func_name The name of the function to call.
+    //! \param args The arguments to pass to the function.
+    //!
+    //! \tparam Args The types of the arguments.
+    //!
+    //! \returns A std::future, possibly holding a future result
+    //! (which is a RPCLIB_MSGPACK::object).
+    template <typename... Args>
+    std::future<RPCLIB_MSGPACK::object_handle> async_call(std::string const &func_name,
+                                                   Args... args);
+
+    //! \brief Sends a notification with the given name and arguments (if any).
+    //!
+    //! Notifications are a special kind of calls. They can be used to notify
+    //! the server, while not expecting a response. In `rpclib` terminology,
+    //! a notification is like an `async_call` without a return value.
+    //!
+    //! \param func_name The name of the notification to call.
+    //! \param args The arguments to pass to the function.
+    //! \tparam Args THe types of the arguments.
+    //!
+    //! \note This function returns immediately (possibly before the
+    //! notification is written to the socket).
+    template <typename... Args>
+    void send(std::string const &func_name, Args... args);
+
+    //! \brief Returns the timeout setting of this client in milliseconds.
+    //!
+    //! The timeout is applied to synchronous calls. If the timeout expires
+    //! without receiving a response from the server, rpc::timeout exceptio
+    //! will be thrown.
+    //!
+    //! \note The timeout has no effect on async calls. For those,
+    //! the preferred timeout mechanism remains using std::future.
+    //!
+    //! The default value for timeout is 5000ms (5 seconds).
+    uint64_t get_timeout() const;
+
+    //! \brief Sets the timeout for global calls. For more information,
+    //! see client::get_timeout().
+    void set_timeout(uint64_t value);
+
+    //! \brief Enum representing the connection states of the client.
+    enum class connection_state { initial, connected, disconnected, reset };
+
+    //! \brief Returns the current connection state.
+    connection_state get_connection_state() const;
+
+    //! \brief Waits for the completion of all ongoing calls.
+    void wait_all_responses();
+
+private:
+    //! \brief Type of a promise holding a future response.
+    using rsp_promise = std::promise<RPCLIB_MSGPACK::object_handle>;
+
+    enum class request_type { call = 0, notification = 2 };
+
+    void wait_conn();
+    void post(std::shared_ptr<RPCLIB_MSGPACK::sbuffer> buffer, int idx,
+              std::string const& func_name,
+              std::shared_ptr<rsp_promise> p);
+    void post(RPCLIB_MSGPACK::sbuffer *buffer);
+    int get_next_call_idx();
+    RPCLIB_NORETURN void throw_timeout(std::string const& func_name);
+
+private:
+    static constexpr double buffer_grow_factor = 1.8;
+    RPCLIB_DECLARE_PIMPL()
+};
+}
+
+#include "rpc/client.inl"