Ejemplo n.º 1
0
const int
getInt (JsonReader * reader, const gchar * member_name)
{
  json_reader_read_member (reader, member_name);
  int value = json_reader_get_int_value (reader);
  json_reader_end_member (reader);
  return value;
}
static guint64
reader_get_item_count (JsonReader *reader)
{
	gint64 count;

	json_reader_read_member (reader, "count");
	count = json_reader_get_int_value (reader);
	json_reader_end_member (reader);

	return (guint64) count;
}
static int websocket_callback(struct libwebsocket_context *context,struct libwebsocket *wsi,enum libwebsocket_callback_reasons reason, void *user,void *in, size_t len)
{
	//printf("Switch: %i\n",reason);


	switch (reason)
	{
		case LWS_CALLBACK_CLIENT_WRITEABLE:
		{
			//Connection has been established.
			//printf("Connection established\n");
			break;
		}
		case LWS_CALLBACK_CLOSED:
		{
			//Connection is closed, we need to remove all related sinks
			sinkManager->disconnectAll(wsi);
			/*g_io_
			GIOChannel *chan = g_io_channel_unix_new((int)(long)user);
			g_io_add_watch(chan,G_IO_IN,(GIOFunc)gioPollingFunc,0);
			g_io_add_watch(chan,G_IO_PRI,(GIOFunc)gioPollingFunc,0);
			pollfds[count_pollfds].fd = (int)(long)user;
			pollfds[count_pollfds].events = (int)len;
// 			pollfds[count_pollfds++].revents = 0;*/
			break;
		}
		case LWS_CALLBACK_CLIENT_RECEIVE:
		{
			//printf("Client writable\n");
			break;
		}
		case LWS_CALLBACK_SERVER_WRITEABLE:
		{
			//printf("Server writable\n");
			break;
		}

		case LWS_CALLBACK_RECEIVE:
		{
			//printf("Data Received: %s\n",(char*)in);
			//The lack of a break; here is intentional.
		}
		case LWS_CALLBACK_HTTP:
		{
			//TODO: Verify that ALL requests get sent via LWS_CALLBACK_HTTP, so we can use that instead of LWS_CALLBACK_RECIEVE
			//TODO: Do we want exceptions, or just to return an invalid json reply? Probably an invalid json reply.
			DebugOut() << __SMALLFILE__ << ":" << __LINE__ << " Requested: " << (char*)in << "\n";
			GError* error = nullptr;


			JsonParser* parser = json_parser_new();
			if (!json_parser_load_from_data(parser,(char*)in,len,&error))
			{
				DebugOut() << __SMALLFILE__ <<":"<< __LINE__ << "Error loading JSON\n";
				return 0;
			}

			JsonNode* node = json_parser_get_root(parser);
			if(node == nullptr)
			{
				DebugOut() << __SMALLFILE__ <<":"<< __LINE__ << "Error getting root node of json\n";
				//throw std::runtime_error("Unable to get JSON root object");
				return 0;
			}

			JsonReader* reader = json_reader_new(node);
			if(reader == nullptr)
			{
				DebugOut() << __SMALLFILE__ <<":"<< __LINE__ << "json_reader is null!\n";
				//throw std::runtime_error("Unable to create JSON reader");
				return 0;
			}





			string type;
			json_reader_read_member(reader,"type");
			type = json_reader_get_string_value(reader);
			json_reader_end_member(reader);

			string  name;
			json_reader_read_member(reader,"name");
			name = json_reader_get_string_value(reader);
			json_reader_end_member(reader);
			
			string id;
			json_reader_read_member(reader,"transactionid");
			if (strcmp("gchararray",g_type_name(json_node_get_value_type(json_reader_get_value(reader)))) == 0)
			{
				//Type is a string
				id = json_reader_get_string_value(reader);
			}
			else
			{
				//Type is an integer
				stringstream strstr;
				strstr << json_reader_get_int_value(reader);
				id = strstr.str();
			}
			json_reader_end_member(reader);

			
			if (type == "method" && name == "getRanged")
			{
				json_reader_read_member(reader,"data");
				if (json_reader_is_object(reader))
				{
					double timeBegin;
					double timeEnd;
					double sequenceBegin;
					double sequenceEnd;
					string property;
					if (json_reader_read_member(reader,"timeBegin"))
					{
						timeBegin = boost::lexical_cast<double,std::string>(json_reader_get_string_value(reader));
						json_reader_end_member(reader);
					}
					
					if (json_reader_read_member(reader,"timeEnd"))
					{
						timeEnd = boost::lexical_cast<double,std::string>(json_reader_get_string_value(reader));
						json_reader_end_member(reader);
					}
					if (json_reader_read_member(reader,"sequenceBegin"))
					{
						sequenceBegin = boost::lexical_cast<double,std::string>(json_reader_get_string_value(reader));
						json_reader_end_member(reader);
					}
					if (json_reader_read_member(reader,"sequenceEnd"))
					{
						sequenceEnd = boost::lexical_cast<double,std::string>(json_reader_get_string_value(reader));
						json_reader_end_member(reader);
					}
					if (json_reader_read_member(reader,"property"))
					{
						property = json_reader_get_string_value(reader);
						json_reader_end_member(reader);
					}
					if ((timeBegin < 0 && timeEnd > 0) || (timeBegin > 0 && timeEnd < 0))
					{
						//Invalid time begin/end pair
					}
					if ((sequenceBegin < 0 && sequenceEnd > 0) || (sequenceBegin > 0 && sequenceEnd < 0))
					{
						//Invalid sequence begin/end pair
					}
					sinkManager->addSingleShotRangedSink(wsi,property,timeBegin,timeEnd,sequenceBegin,sequenceEnd,id);
				}
				json_reader_end_member(reader);
			}
			else
			{

				vector<string> data;
				list<string> key;
				list<string> value;
				json_reader_read_member(reader,"data");
				if (json_reader_is_array(reader))
				{
					for(int i=0; i < json_reader_count_elements(reader); i++)
					{
						json_reader_read_element(reader,i);
						if (json_reader_is_value(reader))
						{
							//Raw string value
							string path = json_reader_get_string_value(reader);
							data.push_back(path);

						}
						else
						{
							//Not a raw string value, then it's "property/value" kvp, for "set" requests
							json_reader_read_member(reader,"property");
							string keystr = json_reader_get_string_value(reader);
							key.push_back(keystr);
							json_reader_end_member(reader);
							json_reader_read_member(reader,"value");
							string valuestr = json_reader_get_string_value(reader);
							value.push_back(valuestr);
							json_reader_end_member(reader);
						}
						json_reader_end_element(reader);
					}
				}
				else
				{
					string path = json_reader_get_string_value(reader);
					if (path != "")
					{
						data.push_back(path);
					}
				}
				json_reader_end_member(reader);
				if (type == "method")
				{
					if (name == "get")
					{
						if (data.size() > 0)
						{
							//GetProperty is going to be a singleshot sink.
							//string arg = arguments.front();
							sinkManager->addSingleShotSink(wsi,data.front(),id);
						}
						else
						{
							DebugOut() << __SMALLFILE__ << ":" << __LINE__ << " \"get\" method called with no data! Transaction ID:" << id << "\n";
						}
					}
					else if (name == "set")
					{
						if (data.size() > 0)
						{
						  //Should not happen
						}
						else if (value.size() > 0)
						{
							if (key.size() != value.size())
							{
								DebugOut() << __SMALLFILE__ << ":" << __LINE__ << "\"set\" method called with an invalid key value pair count\n";
							}
							else
							{
								list<string>::iterator d = value.begin();
								for (list<string>::iterator i=key.begin();i!=key.end();i++)
								{
									DebugOut() << __SMALLFILE__ << ":" << __LINE__ << "websocketsinkmanager setting" << (*i) << "to" << (*d) << "\n";
									//(*i);
									sinkManager->setValue((*i),(*d));
									//(*d);
									d++;
								}

							}
						}
					}
					else if (name == "subscribe")
					{
						//Websocket wants to subscribe to an event, data.front();
						for (auto i=data.begin();i!=data.end();i++)
						{
							sinkManager->addSink(wsi,(*i),id);
						}
					}
					else if (name == "unsubscribe")
					{
						//Websocket wants to unsubscribe to an event, data.front();
						for (auto i=data.begin();i!=data.end();i++)
						{
							sinkManager->removeSink(wsi,(*i),id);
						}
					}
					else if (name == "getSupportedEventTypes")
					{
						//If data.front() dosen't contain a property name, return a list of properties supported.
						//if it does, then return the event types that particular property supports.
						string typessupported = "";
						if (data.size() == 0)
						{
							//Send what properties we support
							typessupported = "\"running_status_speedometer\",\"running_status_engine_speed\",\"running_status_steering_wheel_angle\",\"running_status_transmission_gear_status\"";
							
							PropertyList foo = sinkManager->getSupportedProperties();
							PropertyList::const_iterator i=foo.cbegin();
							while (i != foo.cend())
							{
								typessupported.append(",\"").append((*i)).append("\"");
								i++;
							}
						}
						else
						{
							//Send what events a particular property supports
							if (data.front()== "running_status_speedometer")
							{
								typessupported = "\"get\",\"subscribe\",\"unsubscribe\",\"getSupportedEventTypes\"";
							}
							else if (data.front()== "running_status_engine_speed")
							{
								typessupported = "\"get\",\"subscribe\",\"unsubscribe\",\"getSupportedEventTypes\"";
							}
							else if (data.front() == "running_status_steering_wheel_angle")
							{
								typessupported = "\"get\",\"subscribe\",\"unsubscribe\",\"getSupportedEventTypes\"";
							}
							else if (data.front() == "running_status_transmission_gear_status")
							{
								typessupported = "\"get\",\"subscribe\",\"unsubscribe\",\"getSupportedEventTypes\"";
							}
							else
							{
								PropertyList foo = sinkManager->getSupportedProperties();
								if (ListPlusPlus<VehicleProperty::Property>(&foo).contains(data.front()))
								{
									//sinkManager->addSingleShotSink(wsi,data.front(),id);
									typessupported = "\"get\",\"subscribe\",\"unsubscribe\",\"getSupportedEventTypes\"";
								}
							}
						}
						stringstream s;
						string s2;
						s << "{\"type\":\"methodReply\",\"name\":\"getSupportedEventTypes\",\"data\":[" << typessupported << "],\"transactionid\":\"" << id << "\"}";
						string replystr = s.str();
						DebugOut() << __SMALLFILE__ << ":" << __LINE__ << " JSON Reply: " << replystr << "\n";
						//printf("Reply: %s\n",replystr.c_str());
						char *new_response = new char[LWS_SEND_BUFFER_PRE_PADDING + strlen(replystr.c_str()) + LWS_SEND_BUFFER_POST_PADDING];
						new_response+=LWS_SEND_BUFFER_PRE_PADDING;
						strcpy(new_response,replystr.c_str());
						libwebsocket_write(wsi, (unsigned char*)new_response, strlen(new_response), LWS_WRITE_TEXT);
						delete (char*)(new_response-LWS_SEND_BUFFER_PRE_PADDING);
					}
					else
					{
						DebugOut(0)<<"Unknown method called."<<endl;
					}
				}
			}

			
			///TODO: this will probably explode:
			//mlc: I agree with Kevron here, it does explode.
			//if(error) g_error_free(error);

			g_object_unref(reader);
			g_object_unref(parser);


			
			break;
		}
		case LWS_CALLBACK_ADD_POLL_FD:
		{
			//printf("Adding poll %i\n",sinkManager);
			//DebugOut() << __SMALLFILE__ <<":"<< __LINE__ << "Adding poll" << (int)sinkManager << "\n";
			if (sinkManager != 0)
			{
				sinkManager->addPoll((int)(long)user);
			}
			break;
		}
		case LWS_CALLBACK_DEL_POLL_FD:
		{
			sinkManager->removePoll((int)(long)user);
			break;
		}
		case LWS_CALLBACK_SET_MODE_POLL_FD:
		{
			//Set the poll mode
			break;
		}
		case LWS_CALLBACK_CLEAR_MODE_POLL_FD:
		{
			//Don't handle this yet.
			break;
		}
		default:
		{
			//printf("Unhandled callback: %i\n",reason);
			DebugOut() << __SMALLFILE__ <<":"<< __LINE__ << "Unhandled callback:" << reason << "\n";
			break;
		}
	}
	return 0; 
}
Ejemplo n.º 4
0
/* Save key/values on the table in the stack if the value is an
 * object or an array, it calls recursively the function again.
 *
 * @param L, pointer to the L with nil on top of it;
 * @param reader, pointed to the first element of main object;
 *
 * returns: the table in the stack with all json values
 */
static void
build_table_from_json_reader (lua_State *L,
                              JsonReader *reader)
{
  const GError *err = json_reader_get_error (reader);
  if (err != NULL) {
    GRL_WARNING ("Error when building json: %s", err->message);
    return;
  }

  if (lua_isnil (L, -1)) {
    /* In the first execution of this recursive call, the main json object
     * does not have a member name. The nil is in the top of the stack and
     * it shall be converted to the table with json content */
    lua_pop (L, 1);

  } else if (lua_istable (L, -1)) {
    const gchar *member_name = json_reader_get_member_name (reader);
    if (member_name)
      lua_pushstring (L, member_name);

  } else if (!lua_isnumber (L, -1)) {
    GRL_DEBUG ("getting value to either table or array");
    return;
  }

  if (json_reader_is_object (reader)) {
    guint index_member = 0;
    guint num_members = json_reader_count_members (reader);

    lua_createtable (L, num_members, 0);
    for (index_member = 0; index_member < num_members; index_member++) {
      json_reader_read_element (reader, index_member);
      build_table_from_json_reader (L, reader);
      json_reader_end_element (reader);
    }

  } else if (json_reader_is_array (reader)) {
    guint index_element = 0;
    guint num_elements = json_reader_count_elements (reader);

    lua_createtable (L, num_elements, 0);
    for (index_element = 0; index_element < num_elements; index_element++) {
      json_reader_read_element (reader, index_element);
      lua_pushinteger (L, index_element + 1);
      build_table_from_json_reader (L, reader);
      json_reader_end_element (reader);
    }

  } else if (json_reader_is_value (reader)) {
    if (json_reader_get_null_value (reader)) {
      lua_pushnil (L);
    } else {
      /* value of the element */
      JsonNode *value = json_reader_get_value (reader);
      switch (json_node_get_value_type (value)) {
      case G_TYPE_STRING:
        lua_pushstring (L, json_reader_get_string_value (reader));
        break;
      case G_TYPE_INT64:
        lua_pushinteger (L, json_reader_get_int_value (reader));
        break;
      case G_TYPE_DOUBLE:
        lua_pushnumber (L, json_reader_get_double_value (reader));
        break;
      case G_TYPE_BOOLEAN:
        lua_pushnumber (L, json_reader_get_boolean_value (reader));
        break;
      default:
        GRL_DEBUG ("'%d' (json-node-type) is not being handled",
                   (gint) json_node_get_value_type (value));
        lua_pushnil (L);
      }
    }
  }

  if (lua_gettop (L) > 3) {
    /* save this key/value on previous table */
    lua_settable (L, -3);
  }
}
Ejemplo n.º 5
0
static gboolean dt_noiseprofile_verify(JsonParser *parser)
{
  JsonReader *reader = NULL;
  gboolean valid = TRUE;

  dt_print(DT_DEBUG_CONTROL, "[noiseprofile] verifying noiseprofile file\n");

  JsonNode *root = json_parser_get_root(parser);
  if(!root) _ERROR("can't get the root node");

  reader = json_reader_new(root);

  if(!json_reader_read_member(reader, "version")) _ERROR("can't find file version.");

  // check the file version
  const int version = json_reader_get_int_value(reader);
  json_reader_end_member(reader);

  if(version != DT_NOISE_PROFILE_VERSION) _ERROR("file version is not what this code understands");

  if(!json_reader_read_member(reader, "noiseprofiles")) _ERROR("can't find `noiseprofiles' entry.");

  if(!json_reader_is_array(reader)) _ERROR("`noiseprofiles' is supposed to be an array");

  // go through all makers
  const int n_makers = json_reader_count_elements(reader);
  dt_print(DT_DEBUG_CONTROL, "[noiseprofile] found %d makers\n", n_makers);
  for(int i = 0; i < n_makers; i++)
  {
    if(!json_reader_read_element(reader, i)) _ERROR("can't access maker at position %d / %d", i+1, n_makers);

    if(!json_reader_read_member(reader, "maker")) _ERROR("missing `maker`");

    dt_print(DT_DEBUG_CONTROL, "[noiseprofile] found maker `%s'\n", json_reader_get_string_value(reader));
    // go through all models and check those
    json_reader_end_member(reader);

    if(!json_reader_read_member(reader, "models")) _ERROR("missing `models`");

    const int n_models = json_reader_count_elements(reader);
    dt_print(DT_DEBUG_CONTROL, "[noiseprofile] found %d models\n", n_models);
    for(int j = 0; j < n_models; j++)
    {
      if(!json_reader_read_element(reader, j)) _ERROR("can't access model at position %d / %d", j+1, n_models);

      if(!json_reader_read_member(reader, "model")) _ERROR("missing `model`");

      dt_print(DT_DEBUG_CONTROL, "[noiseprofile] found %s\n", json_reader_get_string_value(reader));
      json_reader_end_member(reader);

      if(!json_reader_read_member(reader, "profiles")) _ERROR("missing `profiles`");

      const int n_profiles = json_reader_count_elements(reader);
      dt_print(DT_DEBUG_CONTROL, "[noiseprofile] found %d profiles\n", n_profiles);
      for(int k = 0; k < n_profiles; k++)
      {
        if(!json_reader_read_element(reader, k)) _ERROR("can't access profile at position %d / %d", k+1, n_profiles);

        gchar** member_names = json_reader_list_members(reader);

        // name
        if(!is_member(member_names, "name"))
        {
          g_strfreev(member_names);
          _ERROR("missing `name`");
        }

        // iso
        if(!is_member(member_names, "iso"))
        {
          g_strfreev(member_names);
          _ERROR("missing `iso`");
        }

        // a
        if(!is_member(member_names, "a"))
        {
          g_strfreev(member_names);
          _ERROR("missing `a`");
        }
        json_reader_read_member(reader, "a");
        if(json_reader_count_elements(reader) != 3)
        {
          g_strfreev(member_names);
          _ERROR("`a` with size != 3");
        }
        json_reader_end_member(reader);

        // b
        if(!is_member(member_names, "b"))
        {
          g_strfreev(member_names);
          _ERROR("missing `b`");
        }
        json_reader_read_member(reader, "b");
        if(json_reader_count_elements(reader) != 3)
        {
          g_strfreev(member_names);
          _ERROR("`b` with size != 3");
        }
        json_reader_end_member(reader);

        json_reader_end_element(reader);

        g_strfreev(member_names);
      } // profiles

      json_reader_end_member(reader);
      json_reader_end_element(reader);
    } // models

    json_reader_end_member(reader);
    json_reader_end_element(reader);
  } // makers

  json_reader_end_member(reader);

  dt_print(DT_DEBUG_CONTROL, "[noiseprofile] verifying noiseprofile completed\n");

end:
  if(reader) g_object_unref(reader);
  return valid;
}
Ejemplo n.º 6
0
static gboolean
handler (GThreadedSocketService *service,
         GSocketConnection      *connection,
         GSocketListener        *listener,
         gpointer                user_data)
{
  GLibJsonRpcServerPrivate *jsonrpc_server = (GLibJsonRpcServerPrivate*)user_data;
  GError *error = NULL;
  
  // Check if it is a local connection. - This doesn't work!
  GSocketAddress *sockaddr
    = g_socket_connection_get_remote_address(connection,
                                             &error);
  GInetAddress *addr = g_inet_socket_address_get_address(G_INET_SOCKET_ADDRESS(sockaddr));

  if (!jsonrpc_server->allow_non_loopback_connections)
    {
#if 0
      // Why doesn't this work?
      if (!g_inet_address_get_is_loopback(addr))
        return TRUE; // just fail
#endif
      
      gchar *addr_string = g_inet_address_to_string(addr);
      gboolean is_local = g_strstr_len(addr_string, -1, "127.0.0.1") != NULL;
      g_free(addr_string);
      if (!is_local) 
        return TRUE; // silently fail
    }

  GOutputStream *out;
  GInputStream *in;
  char buffer[1024];
  gssize size;

  out = g_io_stream_get_output_stream (G_IO_STREAM (connection));
  in = g_io_stream_get_input_stream (G_IO_STREAM (connection));

  // Read the http header
  gboolean skip_header = TRUE;
  JsonParser *parser = json_parser_new();
  GString *json_string = g_string_new("");
  while (0 < (size = g_input_stream_read (in, buffer,
                                          sizeof buffer, NULL, NULL)))
    {
      int header_size = 0;
      
      if (skip_header)
        {
          gchar *head_end = g_strstr_len(buffer, size,
                                         "\r\n\r\n");
          if (head_end > 0)
            header_size = head_end - buffer;
          else
            continue;
        }
      
      g_string_append_len(json_string, buffer+header_size, size-header_size);
      if (json_parser_load_from_data(parser, json_string->str, -1, &error))
        break;
      else
        g_error_free(error);
    }

  // TBD:   raise error if there was a syntax error
  g_string_free(json_string, TRUE);

  // Get params object without the reader 
  JsonNode *root = json_parser_get_root(parser);
  JsonObject *root_object = json_node_get_object(root);
  JsonNode* params = json_object_get_member(root_object, "params");

  // Use reader for method and id
  JsonReader *reader = json_reader_new(json_parser_get_root(parser));
  json_reader_read_member (reader, "method");
  const gchar *method = json_reader_get_string_value (reader);
  json_reader_end_member (reader);
  
  json_reader_read_member (reader, "id");
  gint64 id = json_reader_get_int_value(reader);
  json_reader_end_member (reader);

  // Build the response which is either a response object or an error object
  JsonNode *response = NULL;
  
  /* Call the callback */
  command_hash_value_t *command_val = NULL;
  if (method)
    command_val = g_hash_table_lookup(jsonrpc_server->command_hash,
                                      method);
  if (!command_val)
    response = create_fault_msg_response(-2, "No such method!",id);
  else if (command_val->async_callback)
    {
      if (jsonrpc_server->async_busy)
        response = create_fault_msg_response(-2, "Busy!",id);
      else
        {
          // With the embedding of the mutex in the query we should
          // be able to handle more than one connection, so there
          // is no need to protect against a busy state.
          // jsonrpc_server->async_busy = TRUE;
          GLibJsonRpcAsyncQueryPrivate *query = glib_jsonrpc_server_query_new((GLibJsonRpcServer*)jsonrpc_server);
          
          // Create a secondary main loop
          (*command_val->async_callback)((GLibJsonRpcServer*)jsonrpc_server,
                                         (GLibJsonRpcAsyncQuery*)query,
                                         method,
                                         params,
                                         command_val->user_data);
          
          // Lock on a mutex
          g_mutex_lock(&query->mutex);
          g_cond_wait(&query->cond, &query->mutex);
          g_mutex_unlock(&query->mutex);

          if (query->error_num != 0)
            response = create_fault_value_response(query->error_num,query->reply,id);
          else
            response = create_response(query->reply, id);
          jsonrpc_server->async_busy = FALSE;

          // Erase the query
          glib_jsonrpc_async_query_free(query);
        }
    }
  else
    {
      JsonNode *reply;

      int ret = (*command_val->callback)((GLibJsonRpcServer*)jsonrpc_server,
                                         method,
                                         params,
                                         &reply,
                                         command_val->user_data);

      if (ret == 0)
        response = create_response(reply,id);
      else
        // For faults expect a string response containing the error
        response = create_fault_value_response(ret, reply,id);

      if (reply)
        json_node_free(reply);
    }

  if (response)
    {
      GString *response_string = g_string_new("");
  
      // Serialize response into content_string
      JsonGenerator *gen = json_generator_new ();
      gsize len;
      json_generator_set_root (gen, response);
      json_node_free(response);
      gchar *content_string = json_generator_to_data(gen, &len);
      g_object_unref (gen);

      g_string_append_printf(response_string,
                             "HTTP/1.1 200 OK\r\n"
                             "Connection: close\r\n"
                             "Content-Length: %d\r\n"
                             "Content-Type: text/xml\r\n"
                             "Date: Fri, 1 Jan 2000 00:00:00 GMT\r\n"
                             "Server: GlibJsonRPC server\r\n"
                             "\r\n"
                             "%s",
                             (int)len,
                             content_string
                             );
      g_free(content_string);
  
      g_output_stream_write (out,
                             response_string->str,
                             response_string->len,
                             NULL,NULL);
      g_string_free(response_string, TRUE);
    }

  g_object_unref(parser);

  return TRUE;
}
Ejemplo n.º 7
0
static void restore_state(session_callback_type type, gpointer data, gpointer user_data) {
    JsonParser* jp = NULL;
    JsonReader* jr = NULL;

    const gchar* sqs;
    saved_state* s = NULL;

    GError* err = NULL;

    /* Is it the callback we're interested in? */
    if (type != SPOP_SESSION_LOGGED_IN)
        return;

    /* First disable the callback so it's not called again */
    session_remove_callback(restore_state, NULL);

    g_debug("savestate: reading saved state...");
    s = g_new0(saved_state, 1);

    /* Read and parse state file */
    jp = json_parser_new();
    if (!json_parser_load_from_file(jp, g_state_file_path, &err)) {
        g_warning("savestate: error while reading state file: %s", err->message);
        goto restorestate_error;
    }

    jr = json_reader_new(json_parser_get_root(jp));

    /* Read basic state */
    if (!json_reader_read_member(jr, "status")) goto restorestate_jr_error;
    sqs = json_reader_get_string_value(jr);
    json_reader_end_member(jr);
    if      (strcmp(sqs, "stopped")) s->qs = STOPPED;
    else if (strcmp(sqs, "playing")) s->qs = PLAYING;
    else if (strcmp(sqs, "paused"))  s->qs = PAUSED;
    else {
        g_warning("savestate: bad value for queue status: %s", sqs);
        goto restorestate_error;
    }

    if (!json_reader_read_member(jr, "repeat")) goto restorestate_jr_error;
    s->repeat = json_reader_get_boolean_value(jr);
    json_reader_end_member(jr);

    if (!json_reader_read_member(jr, "shuffle")) goto restorestate_jr_error;
    s->shuffle = json_reader_get_boolean_value(jr);
    json_reader_end_member(jr);

    if (!json_reader_read_member(jr, "current_track")) goto restorestate_jr_error;
    s->cur_track = json_reader_get_int_value(jr);
    json_reader_end_member(jr);

    /* Now read tracks URIs */
    if (!json_reader_read_member(jr, "tracks")) goto restorestate_jr_error;
    if (!json_reader_is_array(jr)) {
        g_warning("savestate: error while parsing JSON: tracks is not an array");
        goto restorestate_error;
    }
    gint tracks = json_reader_count_elements(jr);
    if (s->cur_track >= tracks) {
        g_warning("savestate: incoherent state file: cur_track >= tracks");
        goto restorestate_error;
    }

    s->tracks = g_array_sized_new(FALSE, FALSE, sizeof(sp_track*), tracks);
    if (!s->tracks)
        g_error("Can't allocate array of %d tracks.", tracks);

    size_t i;
    gboolean can_restore_now = TRUE;
    for (i=0; i < tracks; i++) {
        json_reader_read_element(jr, i);
        const gchar* uri = json_reader_get_string_value(jr);
        json_reader_end_element(jr);

        sp_link* lnk = sp_link_create_from_string(uri);
        sp_linktype lt = sp_link_type(lnk);
        if (lt != SP_LINKTYPE_TRACK) {
            g_warning("savestate: invalid link type for track %zu: %d", i, lt);
            sp_link_release(lnk);
            goto restorestate_error;
        }
        sp_track* tr = sp_link_as_track(lnk);
        sp_track_add_ref(tr);
        sp_link_release(lnk);
        g_array_append_val(s->tracks, tr);
        if (!sp_track_is_loaded(tr))
            can_restore_now = FALSE;
    }

    /* If possible, restore now, else wait for all tracks to be loaded */
    if (can_restore_now)
        really_restore_state(s);
    else {
        g_timeout_add(100, (GSourceFunc) really_restore_state, s);
        g_debug("savestate: waiting for all tracks to be loaded before restoring saved state...");
    }

    /* Add a notification callback */
    if (!interface_notify_add_callback(savestate_notification_callback, NULL))
        g_error("Could not add savestate callback.");

    goto restorestate_clean;

 restorestate_jr_error:
    err = (GError*) json_reader_get_error(jr);
    g_warning("savestate: error while parsing JSON: %s", err->message);

 restorestate_error:
    if (s) {
        if (s->tracks)
            g_array_free(s->tracks, TRUE);
        g_free(s);
    }

 restorestate_clean:
    if (jp)
        g_object_unref(jp);
    if (jr)
        g_object_unref(jr);
}