lo_cpp.h

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#ifndef _LO_CPP_H_
#define _LO_CPP_H_

#include <lo/lo.h>
#include <lo/lo_throw.h>

#include <functional>
#include <memory>
#include <list>
#include <algorithm>
#include <unordered_map>
#include <string>
#if __cplusplus >= 201703L
#include <string_view>
#endif
#include <initializer_list>
#ifndef LO_USE_EXCEPTIONS
#include <cassert>
#endif

#define LO_ADD_METHOD_RT(ht, argtypes, args, rt, r, r1, r2)             \
    template <typename H>                                               \
    Method add_method(const string_type path, const string_type types,  \
                      H&& h, rt* _unused=0)                             \
    {                                                                   \
        std::string key(path.s() + "," + types.s());                    \
        _handlers[key].push_front(                                      \
            std::unique_ptr<handler>(new handler_type<r ht>(h)));       \
        lo_method m = _add_method(path, types,                          \
            [](const char *path, const char *types,                     \
               lo_arg **argv, int argc, lo_message msg,                 \
               void *data)->int                                         \
            {                                                           \
                r1 (*static_cast<handler_type<r ht>*>(data)) args;      \
                r2;                                                     \
            }, _handlers[key].front().get());                           \
        _handlers[key].front()->method = m;                             \
        return m;                                                       \
    }

#define RT_INT(argtypes) \
    typename std::enable_if<std::is_same<decltype(h argtypes), int>::value, void>::type
#define RT_VOID(argtypes) \
    typename std::enable_if<std::is_same<decltype(h argtypes), void>::value, void>::type

#define LO_ADD_METHOD(ht, argtypes, args)                         \
    LO_ADD_METHOD_RT(ht, argtypes, args,                          \
                     RT_INT(argtypes), int, return,);             \
    LO_ADD_METHOD_RT(ht, argtypes, args,                          \
                     RT_VOID(argtypes), void, , return 0)

namespace lo {

    // Helper classes to allow polymorphism on "const char *",
    // "std::string", and "int".
    class string_type {
      public:
        string_type(const string_type& s) { _s = s._s; }
        string_type(const char *s=0) { _s = s; }
        string_type(const std::string &s) { _s = s.c_str(); }
#if __cplusplus >= 201703L
        string_type(const std::string_view& s) {
            if (s[s.length()]==0) _s = s.data();
            else { _p.reset(new std::string(s)); _s = _p->c_str(); }
        }
#endif
        operator const char*() const { return _s; }
        std::string s() const { return _s?_s:""; }
        const char *_s;
        std::unique_ptr<std::string> _p;
    };

    class num_string_type : public string_type {
      public:
        num_string_type(const char *s) : string_type(s) {}
        num_string_type(const std::string &s) : string_type(s) {}
#if __cplusplus >= 201703L
        num_string_type(const std::string_view& s) : string_type(s) {}
#endif
        num_string_type(int n)
          {_p.reset(new std::string(std::to_string(n))); _s = _p->c_str(); }
    };

/*
 * Error handling:
 *
 * Define LO_USE_EXCEPTIONS to throw the following exceptions instead
 * of aborting on error.  The alternative (and default) is that
 * assert() will crash your program in debug mode, and you should
 * check is_valid() before operations that might break the assertion.
 *
 * Note that in the latter case, the program may return a C++ class
 * that will not contain a valid liblo object, this is why
 * LO_CHECK_AFTER does not do anything; it is up to user code to check
 * is_valid() after constructing Server() and ServerThread(). On the
 * contrary, when LO_USE_EXCEPTIONS is enabled, an Error exception
 * will be thrown if the object was not successfully created.
 *
 * Rules:
 *
 * - Constructors that create underlying liblo objects shall either
 *   fail silently, depending on calling code to check is_valid(), or
 *   throw lo::Error() in the case of LO_USE_EXCEPTIONS.
 *
 * - Constructors that receive an existing liblo object do not throw
 *   any exceptions if the passed in object is nullptr.
 *
 * - All other functions shall assert() or throw lo::Invalid() if the
 *   underlying liblo object is not valid.
 *
 */

#ifdef LO_USE_EXCEPTIONS
    struct Invalid {};
    struct Error {};
#define LO_CHECK_BEFORE if (!is_valid()) throw Invalid();
#define LO_CHECK_AFTER if (!is_valid()) throw Error();
#else
#define LO_CHECK_BEFORE assert(is_valid());
#define LO_CHECK_AFTER
#endif

    class ServerThread;

    class Method
    {
      public:
        Method(lo_method m) : method(m) {}
        operator lo_method() const
            { return method; }
      protected:
        lo_method method;
    };

    class Address
    {
      public:
        Address(const string_type &host, const num_string_type &port,
                int proto=LO_UDP)
          { address = lo_address_new_with_proto(proto, host, port); owned=true;
            LO_CHECK_AFTER; }

        Address(const string_type &url)
          { address = lo_address_new_from_url(url); owned=true; LO_CHECK_AFTER; }

        Address(lo_address a, bool _owned=true)
          { address = a; owned=_owned; LO_CHECK_AFTER; }

        ~Address()
          { if (address && owned) lo_address_free(address); }

        Address& operator=(Address b) { b.swap(*this); return *this; }
        void swap(Address& b) throw () { std::swap(this->address, b.address); }

        bool is_valid() const { return address!=nullptr; }

        int ttl() const
          { LO_CHECK_BEFORE; return lo_address_get_ttl(address); }

        void set_ttl(int ttl)
          { LO_CHECK_BEFORE; lo_address_set_ttl(address, ttl); }

        int send(const string_type &path) const
          { LO_CHECK_BEFORE; return lo_send(address, path, ""); }

        // In these functions we append "$$" to the type string, which
        // simply instructs lo_message_add_varargs() not to use
        // LO_MARKER checking at the end of the argument list.
        int send(const string_type &path, const string_type type, ...) const
        {
            LO_CHECK_BEFORE;
            va_list q;
            va_start(q, type);
            lo_message m = lo_message_new();
            std::string t = type.s() + "$$";
            lo_message_add_varargs(m, t.c_str(), q);
            int r = lo_send_message(address, path, m);
            lo_message_free(m);
            va_end(q);
            return r;
        }

        int send(lo_timetag ts, const string_type &path,
                 const string_type type, ...) const
        {
            LO_CHECK_BEFORE;
            va_list q;
            va_start(q, type);
            lo_message m = lo_message_new();
            std::string t = std::string(type) + "$$";
            lo_message_add_varargs(m, t.c_str(), q);
            lo_bundle b = lo_bundle_new(ts);
            lo_bundle_add_message(b, path, m);
            int r = lo_send_bundle(address, b);
            lo_bundle_free_messages(b);
            va_end(q);
            return r;
        }

        int send(const string_type &path, lo_message m) const
            { LO_CHECK_BEFORE; return lo_send_message(address, path, m); }

        int send(lo_bundle b)
            { LO_CHECK_BEFORE; return lo_send_bundle(address, b); }

        int send_from(lo::ServerThread &from, const string_type &path,
                      const string_type type, ...) const;

        int send_from(lo_server from, const string_type &path,
                      const string_type type, ...) const
        {
            LO_CHECK_BEFORE;
            va_list q;
            va_start(q, type);
            lo_message m = lo_message_new();
            std::string t = std::string(type) + "$$";
            lo_message_add_varargs(m, t.c_str(), q);
            int r = lo_send_message_from(address, from, path, m);
            lo_message_free(m);
            va_end(q);
            return r;
        }

        int send_from(lo_server from, lo_timetag ts, 
                      const string_type &path,
                      const string_type type, ...) const
        {
            LO_CHECK_BEFORE;
            va_list q;
            va_start(q, type);
            lo_message m = lo_message_new();
            std::string t = std::string(type) + "$$";
            lo_message_add_varargs(m, t.c_str(), q);
            lo_bundle b = lo_bundle_new(ts);
            lo_bundle_add_message(b, path, m);
            int r = lo_send_bundle_from(address, from, b);
            lo_bundle_free_messages(b);
            va_end(q);
            return r;
        }

        int send_from(lo_server from, const string_type &path, lo_message m) const
          { LO_CHECK_BEFORE; return lo_send_message_from(address, from, path, m); }

        int send_from(lo::ServerThread &from, lo_bundle b) const;

        int send_from(lo_server from, lo_bundle b) const
          { LO_CHECK_BEFORE; return lo_send_bundle_from(address, from, b); }

        int get_errno() const
          { LO_CHECK_BEFORE; return lo_address_errno(address); }

        std::string errstr() const
          { LO_CHECK_BEFORE; auto s(lo_address_errstr(address)); return std::string(s?s:""); }

        std::string hostname() const
          { LO_CHECK_BEFORE; auto s(lo_address_get_hostname(address)); return std::string(s?s:""); }

        std::string port() const
          { LO_CHECK_BEFORE; auto s(lo_address_get_port(address)); return std::string(s?s:""); }

        int protocol() const
          { LO_CHECK_BEFORE; return lo_address_get_protocol(address); }

        std::string url() const
        {
            LO_CHECK_BEFORE;
            char* s(lo_address_get_url(address));
            std::string result(s?s:"");
            free(s);
            return result;
        }

        std::string iface() const
          { LO_CHECK_BEFORE; auto s(lo_address_get_iface(address)); return std::string(s?s:""); }

        void set_iface(const string_type &iface, const string_type &ip)
          { LO_CHECK_BEFORE; lo_address_set_iface(address, iface, ip); }

        int set_tcp_nodelay(int enable)
          { LO_CHECK_BEFORE; return lo_address_set_tcp_nodelay(address, enable); }

        int set_stream_slip(lo_slip_encoding encoding)
          { LO_CHECK_BEFORE; return lo_address_set_stream_slip(address, encoding); }

        operator lo_address() const
            { return address; }

      protected:
        lo_address address;
        bool owned;
    };

    class Message
    {
      public:
        Message()
            : message(lo_message_new()) { if (message) lo_message_incref(message); LO_CHECK_AFTER; }

        Message(lo_message m)
            : message(m) { if (m) { lo_message_incref(m); } }

        Message(const Message &m)
            : message(m.message) { if (m.message)
                                       lo_message_incref(m.message); }

        Message(const string_type types, ...)
        {
            message = lo_message_new();
            if (message) {
                lo_message_incref(message);
                va_list q;
                va_start(q, types);
                std::string t(std::string(types)+"$$");
                add_varargs(t.c_str(), q);
                va_end(q);
            }
            LO_CHECK_AFTER;
        }

        ~Message()
            { if (message) lo_message_free(message); }

        Message& operator=(Message m) { m.swap(*this); return *this; }
        void swap(Message& m) throw () { std::swap(this->message, m.message); }

        bool is_valid() const { return message!=nullptr; }

        int add(const string_type types, ...)
        {
            LO_CHECK_BEFORE;
            va_list q;
            va_start(q, types);
            std::string t(std::string(types)+"$$");
            int ret = add_varargs(t.c_str(), q);
            va_end(q);
            return ret;
        }

        int add_varargs(const string_type &types, va_list ap)
            { LO_CHECK_BEFORE; return lo_message_add_varargs(message, types, ap); }

        int add_int32(int32_t a)
            { LO_CHECK_BEFORE; return lo_message_add_int32(message, a); }

        int add_float(float a)
            { LO_CHECK_BEFORE; return lo_message_add_float(message, a); }

        int add_string(const string_type &a)
            { LO_CHECK_BEFORE; return lo_message_add_string(message, a); }

        int add_blob(lo_blob a)
            { LO_CHECK_BEFORE; return lo_message_add_blob(message, a); }

        int add_int64(int64_t a)
            { LO_CHECK_BEFORE; return lo_message_add_int64(message, a); }

        int add_timetag(lo_timetag a)
            { LO_CHECK_BEFORE; return lo_message_add_timetag(message, a); }

        int add_double(double a)
            { LO_CHECK_BEFORE; return lo_message_add_double(message, a); }

        int add_symbol(const string_type &a)
            { LO_CHECK_BEFORE; return lo_message_add_symbol(message, a); }

        int add_char(char a)
            { LO_CHECK_BEFORE; return lo_message_add_char(message, a); }

        int add_midi(uint8_t a[4])
            { LO_CHECK_BEFORE; return lo_message_add_midi(message, a); }

        int add_bool(bool b)
            { LO_CHECK_BEFORE;
              if (b)
                return lo_message_add_true(message);
              else
                return lo_message_add_false(message); }

        int add_true()
            { LO_CHECK_BEFORE; return lo_message_add_true(message); }

        int add_false()
            { LO_CHECK_BEFORE; return lo_message_add_false(message); }

        int add_nil()
            { LO_CHECK_BEFORE; return lo_message_add_nil(message); }

        int add_infinitum()
            { LO_CHECK_BEFORE; return lo_message_add_infinitum(message); }

        // Note, for polymorphic versions of "add", below, we can't do
        // this for "string" or "symbol" types, since it is ambiguous
        // with "add(types, ...)" above.

        int add(int32_t a)
            { LO_CHECK_BEFORE; return lo_message_add_int32(message, a); }

        int add(float a)
            { LO_CHECK_BEFORE; return lo_message_add_float(message, a); }

        int add(lo_blob a)
            { LO_CHECK_BEFORE; return lo_message_add_blob(message, a); }

        int add(int64_t a)
            { LO_CHECK_BEFORE; return lo_message_add_int64(message, a); }

        int add(lo_timetag a)
            { LO_CHECK_BEFORE; return lo_message_add_timetag(message, a); }

        int add(double a)
            { LO_CHECK_BEFORE; return lo_message_add_double(message, a); }

        int add(char a)
            { LO_CHECK_BEFORE; return lo_message_add_char(message, a); }

        int add(uint8_t a[4])
            { LO_CHECK_BEFORE; return lo_message_add_midi(message, a); }

        int add(bool b)
            { LO_CHECK_BEFORE;
              if (b)
                return lo_message_add_true(message);
              else
                return lo_message_add_false(message); }

        Address source() const
            { LO_CHECK_BEFORE; return Address(lo_message_get_source(message), false); }

        lo_timetag timestamp() const
            { LO_CHECK_BEFORE; return lo_message_get_timestamp(message); }

        std::string types() const
            { LO_CHECK_BEFORE;
              auto s(lo_message_get_types(message)); return std::string(s?s:""); }

        int argc() const
            { LO_CHECK_BEFORE; return lo_message_get_argc(message); }

        lo_arg **argv() const
            { LO_CHECK_BEFORE; return lo_message_get_argv(message); }

        size_t length(const string_type &path) const
            { LO_CHECK_BEFORE; return lo_message_length(message, path); }

        void *serialise(const string_type &path, void *to, size_t *size) const
            { LO_CHECK_BEFORE; return lo_message_serialise(message, path, to, size); }

        typedef std::pair<int, Message> maybe;

        static
        maybe deserialise(void *data, size_t size)
            { int result = 0;
              lo_message m = lo_message_deserialise(data, size, &result);
              return maybe(result, m); }

        void print() const
            { LO_CHECK_BEFORE; lo_message_pp(message); }

        lo::Message clone() const
            { LO_CHECK_BEFORE; return lo::Message(lo_message_clone(message)); }

        Message& clear()
            { lo_message_clear(message); return *this; }

        operator lo_message() const
            { return message; }

      protected:
        lo_message message;
    };

    class Server
    {
      public:
        Server(lo_server s) : server(s) {}

        template <typename E>
        Server(const num_string_type &port, E&& e)
            : Server(lo_server_new(port,
              [](int num, const char *msg, const char *where){
                auto h = static_cast<handler_error*>(lo_error_get_context());
                if (h) (*h)(num, msg, where);
              }))
        {
            if (server) {
                lo_server_set_error_context(server,
                                            (_error_handler = std::unique_ptr<handler>(
                                                                                       new handler_error(e))).get());
            }
            LO_CHECK_AFTER;
        }

        template <typename E>
        Server(const num_string_type &port, int proto, E&& e=0)
            : Server(lo_server_new_with_proto(port, proto,
              [](int num, const char *msg, const char *where){
                auto h = static_cast<handler_error*>(lo_error_get_context());
                (*h)(num, msg, where);
              }))
        {
            if (server) {
                lo_server_set_error_context(server,
                                            (_error_handler = std::unique_ptr<handler>(
                                                                                       new handler_error(e))).get());
            }
            LO_CHECK_AFTER;
        }

        template <typename E>
        Server(const string_type &group, const num_string_type &port,
               const string_type &iface=0, const string_type &ip=0, E&& e=0)
            : Server((!iface._s || !ip._s)
                     ? lo_server_new_multicast_iface(group, port, iface, ip,
                           [](int num, const char *msg, const char *where){
                               auto h = static_cast<handler_error*>(lo_error_get_context());
                               (*h)(num, msg, where);
                           })
                     : lo_server_new_multicast(group, port,
                           [](int num, const char *msg, const char *where){
                               auto h = static_cast<handler_error*>(lo_error_get_context());
                               (*h)(num, msg, where);
                       }))
        {
            if (server) {
                lo_server_set_error_context(server,
                                            (_error_handler = std::unique_ptr<handler>(
                                                                                       new handler_error(e))).get());
            }
            LO_CHECK_AFTER;
        }

        Server(const num_string_type &port, lo_err_handler err_h=0)
            : Server(lo_server_new(port, err_h)) { LO_CHECK_AFTER; }

        Server(const num_string_type &port, int proto, lo_err_handler err_h=0)
            : Server(lo_server_new_with_proto(port, proto, err_h))
            { LO_CHECK_AFTER; }

        Server(const string_type &group, const num_string_type &port,
               const string_type &iface="", const string_type &ip="", lo_err_handler err_h=0)
            : Server((iface._s || ip._s)
                     ? lo_server_new_multicast_iface(group, port,
                                                     iface, ip, err_h)
                     : lo_server_new_multicast(group, port, err_h))
            { LO_CHECK_AFTER; }

        virtual ~Server()
            { if (server) lo_server_free(server); }

        bool is_valid() const { return server!=nullptr; }

        // Regular old liblo method handlers

        Method add_method(const string_type &path, const string_type &types,
                        lo_method_handler h, void *data) const
            { LO_CHECK_BEFORE; return _add_method(path, types, h, data); }

        // Alternative callback prototypes

        LO_ADD_METHOD( (const char*, const char*, lo_arg**, int),
                       ((char*)0, (char*)0, (lo_arg**)0, (int)0),
                       (path, types, argv, argc) );

        LO_ADD_METHOD( (const char*, lo_arg**, int),
                       ((char*)0, (lo_arg**)0, (int)0),
                       (types, argv, argc) );
        LO_ADD_METHOD( (const char*, lo_arg**, int, const Message&),
                       ((char*)0, (lo_arg**)0, (int)0, Message((lo_message)0)),
                       (types, argv, argc, Message(msg)) );
        LO_ADD_METHOD( (const char*, const Message&),
                       ((char*)0, Message((lo_message)0)),
                       (path, Message(msg)) );
        LO_ADD_METHOD( (lo_arg**, int), ((lo_arg**)0, (int)0), (argv, argc) )
        LO_ADD_METHOD( (lo_arg**, int, const Message& ),
                       ((lo_arg**)0, (int)0, Message((lo_message)0)),
                       (argv, argc, Message(msg)) );
        LO_ADD_METHOD( (const Message&),
                       (Message((lo_message)0)),
                       (Message(msg)) );
        LO_ADD_METHOD( (), (), () );

        int del_method(const string_type &path, const string_type &typespec)
        {
            LO_CHECK_BEFORE;
            _handlers.erase(path.s() + "," + typespec.s());
            lo_server_del_method(server, path, typespec);
            return 0;
        }

        int del_method(const lo_method& m)
        {
          LO_CHECK_BEFORE;
          for (auto &i : _handlers) {
            auto it = std::remove_if(i.second.begin(), i.second.end(),
                           [&](std::unique_ptr<handler>& h){return h->method == m;});
            i.second.erase(it, i.second.end());
          }
          return lo_server_del_lo_method(server, m);
        }

        int dispatch_data(void *data, size_t size)
            { LO_CHECK_BEFORE; return lo_server_dispatch_data(server, data, size); }

        int wait(int timeout)
            { LO_CHECK_BEFORE; return lo_server_wait(server, timeout); }

        int recv()
            { LO_CHECK_BEFORE; return lo_server_recv(server); }

        int recv(int timeout)
            { LO_CHECK_BEFORE; return lo_server_recv_noblock(server, timeout); }

        int add_bundle_handlers(lo_bundle_start_handler sh,
                                lo_bundle_end_handler eh,
                                void *user_data)
        {
            LO_CHECK_BEFORE;
            return lo_server_add_bundle_handlers(server, sh, eh, user_data);
        }

        template <typename S, typename E>
        int add_bundle_handlers(S&& s, E&& e)
        {
            _bundle_handlers.reset(new std::pair<handler_bundle_start,
                                                 handler_bundle_end>(
                                       handler_bundle_start(s),
                                       handler_bundle_end(e)));
            return lo_server_add_bundle_handlers(
                server,
                [](lo_timetag time, void *user_data)->int{
                    auto h = (std::pair<handler_bundle_start,
                                        handler_bundle_end>*) user_data;
                    h->first(time);
                    return 0;
                },
                [](void *user_data)->int{
                    auto h = (std::pair<handler_bundle_start,
                                        handler_bundle_end>*) user_data;
                    h->second();
                    return 0;
                },
                _bundle_handlers.get());
        }

        int socket_fd() const
            { LO_CHECK_BEFORE; return lo_server_get_socket_fd(server); }

        int port() const
            { LO_CHECK_BEFORE; return lo_server_get_port(server); }

        int protocol() const
            { LO_CHECK_BEFORE; return lo_server_get_protocol(server); }

        std::string url() const
        {
            LO_CHECK_BEFORE;
            char* s(lo_server_get_url(server));
            std::string result(s?s:"");
            free(s);
            return result;
        }

        int enable_queue(int queue_enabled,
                         int dispatch_remaining=1)
            { LO_CHECK_BEFORE;
              return lo_server_enable_queue(server,
                                            queue_enabled,
                                            dispatch_remaining); }

        int events_pending() const
            { LO_CHECK_BEFORE; return lo_server_events_pending(server); }

        double next_event_delay() const
            { LO_CHECK_BEFORE; return lo_server_next_event_delay(server); }

        operator lo_server() const
            { return server; }

      protected:
        lo_server server;

        friend class ServerThread;

        struct handler { Method method; handler(Method m):method(m){} };
        template <typename T>
        class handler_type : public handler, public std::function<T> {
          public: template<typename H>handler_type(H&& h, Method m=0)
            : handler(m), std::function<T>(h) {}
        };
        typedef handler_type<void(int, const char *, const char *)> handler_error;
        typedef handler_type<void(int, const std::string&, const std::string&)> handler_error_s;
        typedef handler_type<void(lo_timetag)> handler_bundle_start;
        typedef handler_type<void()> handler_bundle_end;

        // Keep std::functions here so they are freed correctly
        std::unordered_map<std::string,
            std::list<std::unique_ptr<handler>>> _handlers;
        std::unique_ptr<handler> _error_handler;
        std::unique_ptr<std::pair<handler_bundle_start,
                                  handler_bundle_end>> _bundle_handlers;

        virtual Method _add_method(const char *path, const char *types,
                                   lo_method_handler h, void *data) const
        {
            LO_CHECK_BEFORE;
            return lo_server_add_method(server, path, types, h, data);
        }
    };

    class ServerThread : public Server
    {
      public:
        ServerThread(const num_string_type &port, lo_err_handler err_h=0)
          : Server(0)
        { server_thread = lo_server_thread_new(port, err_h);
          if (server_thread)
            server = lo_server_thread_get_server(server_thread);
          LO_CHECK_AFTER; }

        template <typename E>
        ServerThread(const num_string_type &port, E&& e)
            : Server(0)
            {
                server_thread = lo_server_thread_new(port,
                    [](int num, const char *msg, const char *where){
                    auto h = static_cast<handler_error*>(lo_error_get_context());
                    // TODO: Can't call "e" yet since error context is not yet
                    // provided, port unavailable errors will not be reported!
                    if (h) (*h)(num, msg, where);});
                if (server_thread) {
                    server = lo_server_thread_get_server(server_thread);
                    auto h = new handler_error(e);
                    _error_handler.reset(h);
                    lo_server_thread_set_error_context(server_thread, h);
                    lo_server_set_error_context(server,
                                            (_error_handler = std::unique_ptr<handler>(
                            new handler_error(e))).get());
                }
                LO_CHECK_AFTER;
            }

        ServerThread(const num_string_type &port, int proto, lo_err_handler err_h)
          : Server(0)
        { server_thread = lo_server_thread_new_with_proto(port, proto, err_h);
          if (server_thread)
            server = lo_server_thread_get_server(server_thread);
          LO_CHECK_AFTER;
        }

        template <typename E>
        ServerThread(const num_string_type &port, int proto, E&& e)
            : Server(0)
            {
                server_thread = lo_server_thread_new_with_proto(port, proto,
                    [](int num, const char *msg, const char *where){
                    auto h = static_cast<handler_error*>(lo_error_get_context());
                    // TODO: Can't call "e" yet since error context is not yet
                    // provided, port unavailable errors will not be reported!
                    if (h) (*h)(num, msg, where);});
                if (server_thread) {
                    server = lo_server_thread_get_server(server_thread);
                    auto h = new handler_error(e);
                    _error_handler.reset(h);
                    lo_server_thread_set_error_context(server_thread, h);
                    lo_server_set_error_context(server,
                                            (_error_handler = std::unique_ptr<handler>(
                            new handler_error(e))).get());
                }
                LO_CHECK_AFTER;
            }

        ServerThread(const string_type &group, const num_string_type &port,
                     const string_type &iface, const string_type &ip,
                     lo_err_handler err_h=0) : Server(0)
        { if (iface._s || ip._s)
            server_thread = lo_server_thread_new_multicast_iface(group, port,
                                                                 iface, ip, err_h);
          else
            server_thread = lo_server_thread_new_multicast(group, port, err_h);
          if (server_thread)
            server = lo_server_thread_get_server(server_thread);
          LO_CHECK_AFTER;
        }

        virtual ~ServerThread()
            { server = 0;
              if (server_thread) lo_server_thread_free(server_thread); }

        template <typename I, typename C>
        auto set_callbacks(I&& init, C&& cleanup)
            -> typename std::enable_if<
                std::is_same<decltype(init()), int>::value, void>::type
            {
                LO_CHECK_BEFORE;
                if (server_thread) {
                    _cb_handlers.reset(new handler_cb_pair(init, cleanup));
                    lo_server_thread_set_callbacks(server_thread,
                        [](lo_server_thread s, void *c){
                           auto cb = (handler_cb_pair*)c;
                           return (cb->first)();
                        },
                        [](lo_server_thread s, void *c){
                           auto cb = (handler_cb_pair*)c;
                           (cb->second)();
                        }, _cb_handlers.get());
                }
            }

        template <typename I, typename C>
        auto set_callbacks(I&& init, C&& cleanup)
            -> typename std::enable_if<
                std::is_same<decltype(init()), void>::value, void>::type
            {
                if (server_thread) {
                    _cb_handlers.reset(
                        (handler_cb_pair*)new handler_cb_pair_void(init, cleanup));
                    lo_server_thread_set_callbacks(server_thread,
                        [](lo_server_thread s, void *c){
                           auto cb = (handler_cb_pair_void*)c;
                           (cb->first)(); return 0;
                        },
                        [](lo_server_thread s, void *c){
                           auto cb = (handler_cb_pair_void*)c;
                           (cb->second)();
                        }, _cb_handlers.get());
                }
            }

        void start() { LO_CHECK_BEFORE; lo_server_thread_start(server_thread); }
        void stop() { LO_CHECK_BEFORE; lo_server_thread_stop(server_thread); }

        operator lo_server_thread() const
            { return server_thread; }

      protected:
        lo_server_thread server_thread;

        typedef std::pair<handler_type<int()>,handler_type<void()>> handler_cb_pair;
        typedef std::pair<handler_type<void()>,handler_type<void()>> handler_cb_pair_void;
        std::unique_ptr<handler_cb_pair> _cb_handlers;

        // Regular old liblo method handlers
        virtual Method _add_method(const char *path, const char *types,
                                   lo_method_handler h, void *data) const
        {
            LO_CHECK_BEFORE;
            return lo_server_thread_add_method(server_thread, path, types, h, data);
        }
    };

        // This function needed since lo::ServerThread doesn't
        // properly auto-upcast to lo::Server -> lo_server.  (Because
        // both lo_server and lo_serverthread are typedef'd as void*)
        inline
        int Address::send_from(lo::ServerThread &from, const string_type &path,
                                                   const string_type type, ...) const
        {
    LO_CHECK_BEFORE;
                va_list q;
                va_start(q, type);
                lo_message m = lo_message_new();
                std::string t = std::string(type) + "$$";
                lo_message_add_varargs(m, t.c_str(), q);
                lo_server s = static_cast<lo::Server&>(from);
                int r = lo_send_message_from(address, s, path, m);
                lo_message_free(m);
                va_end(q);
                return r;
        }

        inline
        int Address::send_from(lo::ServerThread &from, lo_bundle b) const
        {
    LO_CHECK_BEFORE;
                lo_server s = static_cast<lo::Server&>(from);
                return lo_send_bundle_from(address, s, b);
        }

    class Blob
    {
      public:
        Blob(int32_t size, const void *data=0)
            : blob(lo_blob_new(size, data)) { LO_CHECK_AFTER; }

        template <typename T>
        Blob(const T &t)
            : blob(lo_blob_new(t.size()*sizeof(t[0]), &t[0])) { LO_CHECK_AFTER; }

        virtual ~Blob()
            { lo_blob_free(blob); }

        Blob& operator=(Blob b) { b.swap(*this); return *this; }
        void swap(Blob& b) throw () { std::swap(this->blob, b.blob); }

        bool is_valid() const { return blob!=nullptr; }

        uint32_t datasize() const
            { LO_CHECK_BEFORE; return lo_blob_datasize(blob); }

        void *dataptr() const
            { LO_CHECK_BEFORE; return lo_blob_dataptr(blob); }

        uint32_t size() const
            { LO_CHECK_BEFORE; return lo_blobsize(blob); }

        operator lo_blob() const
            { return blob; };

      protected:
        lo_blob blob;
    };

    struct PathMsg
    {
        PathMsg() {}
        PathMsg(const string_type _path, const Message& _msg)
          : path(_path), msg(_msg) {}
        std::string path;
        Message msg;
    };

    class Bundle
    {
      public:
        template <typename T>
        struct ElementT
        {
            ElementT()
            : type((lo_element_type)0), pm("", 0), bundle((lo_bundle)0) {}
            ElementT(const string_type _path, const Message& _msg)
              : type(LO_ELEMENT_MESSAGE),
                pm(PathMsg(_path, _msg)),
                bundle((lo_bundle)0) {}
            ElementT(const T& _bundle)
              : type(LO_ELEMENT_BUNDLE), pm("", 0), bundle(_bundle) {}
            lo_element_type type;
            PathMsg pm;
            T bundle;
        };
        typedef ElementT<Bundle> Element;

        Bundle() { bundle = lo_bundle_new(LO_TT_IMMEDIATE);
                   if (bundle) lo_bundle_incref(bundle);
                   LO_CHECK_AFTER; }

        Bundle(lo_timetag tt)
            : bundle(lo_bundle_new(tt)) { if (bundle) lo_bundle_incref(bundle);
                                          LO_CHECK_AFTER; }

        Bundle(lo_bundle b)
            : bundle(b) { if (b) { lo_bundle_incref(b); } }

        Bundle(const string_type &path, lo_message m,
               lo_timetag tt=LO_TT_IMMEDIATE)
            : bundle(lo_bundle_new(tt))
        {
            if (bundle) {
                lo_bundle_incref(bundle);
                lo_bundle_add_message(bundle, path, m);
            }
            LO_CHECK_AFTER;
        }

        Bundle(const std::initializer_list<Element> &elements,
               lo_timetag tt=LO_TT_IMMEDIATE)
            : bundle(lo_bundle_new(tt))
        {
            if (bundle) {
            lo_bundle_incref(bundle);
            for (auto const &e : elements) {
                if (e.type == LO_ELEMENT_MESSAGE) {
                    lo_bundle_add_message(bundle, e.pm.path.c_str(), e.pm.msg);
                }
                else if (e.type == LO_ELEMENT_BUNDLE) {
                    lo_bundle_add_bundle(bundle, e.bundle);
                }
            }
            }
            LO_CHECK_AFTER;
        }

        Bundle(const Bundle &b)
            : Bundle((lo_bundle)b) {}

        ~Bundle()
            { if (bundle) lo_bundle_free_recursive(bundle); }

        Bundle& operator=(Bundle b) { b.swap(*this); return *this; }
        void swap(Bundle& b) throw () { std::swap(this->bundle, b.bundle); }

        bool is_valid() const { return bundle!=nullptr; }

        int add(const string_type &path, lo_message m)
            { LO_CHECK_BEFORE; return lo_bundle_add_message(bundle, path, m); }

        int add(const lo_bundle b)
            { LO_CHECK_BEFORE; return lo_bundle_add_bundle(bundle, b); }

        size_t length() const
            { LO_CHECK_BEFORE; return lo_bundle_length(bundle); }

        unsigned int count() const
            { LO_CHECK_BEFORE; return lo_bundle_count(bundle); }

        lo_message get_message(int index, const char **path=0) const
            { LO_CHECK_BEFORE; return lo_bundle_get_message(bundle, index, path); }

        Message get_message(int index, std::string &path) const
            { LO_CHECK_BEFORE;
              const char *p;
              lo_message m=lo_bundle_get_message(bundle, index, &p);
              path = p?p:0;
              return Message(m); }

        PathMsg get_message(int index) const
            { LO_CHECK_BEFORE;
              const char *p;
              lo_message m = lo_bundle_get_message(bundle, index, &p);
              return PathMsg(p?p:0, m); }

        Bundle get_bundle(int index) const
            { LO_CHECK_BEFORE; return lo_bundle_get_bundle(bundle, index); }

        Element get_element(int index, const char **path=0) const
            {
                LO_CHECK_BEFORE;
                switch (lo_bundle_get_type(bundle, index)) {
                case LO_ELEMENT_MESSAGE: {
                    const char *p;
                    lo_message m = lo_bundle_get_message(bundle, index, &p);
                    return Element(p, m);
                }
                case LO_ELEMENT_BUNDLE:
                    return Element(lo_bundle_get_bundle(bundle, index));
                default:
                    return Element();
                }
            }

        lo_timetag timestamp()
            { LO_CHECK_BEFORE; return lo_bundle_get_timestamp(bundle); }

        Bundle& set_timestamp(lo_timetag t)
            { LO_CHECK_BEFORE; lo_bundle_set_timestamp(bundle, t); return *this; }

        void *serialise(void *to, size_t *size) const
            { LO_CHECK_BEFORE; return lo_bundle_serialise(bundle, to, size); }

        void print() const
            { LO_CHECK_BEFORE; lo_bundle_pp(bundle); }

        operator lo_bundle() const
            { return bundle; }

        Bundle& clear()
            { LO_CHECK_BEFORE; lo_bundle_clear(bundle); return *this; }

      protected:
        lo_bundle bundle;
    };

    inline std::string version() {
        char str[32];
        lo_version(str, 32, 0, 0, 0, 0, 0, 0, 0);
        return std::string(str);
    }

    inline lo_timetag now() { lo_timetag tt; lo_timetag_now(&tt); return tt; }

    inline lo_timetag immediate() { return LO_TT_IMMEDIATE; }
};

#endif // _LO_CPP_H_