allow to write multiple configs in a network package.

It is now possible to write multiple config objects in a single package,
the server reads them then as one big config. Prevoulsy if people wanted
to do that they had to copy both configs into a new config which is
slow, specially if those configs are very big becasue they contain a
whole scenario or an era.

src/configr_assign.hpp

@@ -0,0 +1,47 @@
+/*
+   Copyright (C) 2014 - 2016 by David White <dave@whitevine.net>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+#pragma once
+
+#include <string>
+#include "config.hpp"
+#include <boost/variant.hpp>
+
+//Similar to config_of but it stores references to configs (instead of cyoping them).
+struct configr_of
+{
+	template <typename AT>
+	configr_of(const std::string& attrname, AT value)
+	{
+		this->operator()(attrname, value);
+	}
+
+	configr_of(const config& cfg)
+	{
+		this->operator()(cfg);
+	}
+
+	configr_of& operator()(const config& cfg)
+	{
+		data_ = &cfg;
+		return *this;
+	}
+
+	configr_of& operator()(const std::string& tagname, const configr_of& child)
+	{
+		subtags_.push_back(std::make_pair(&tagname, &child));
+		return *this;
+	}
+	std::vector<std::pair<const std::string*, const configr_of*>> subtags_;
+	const config* data_;
+};

src/serialization/parser.cpp

@@ -597,14 +597,35 @@ static void write_internal(config const &cfg, std::ostream &out, std::string& te
 	}
 }
 
-void write(std::ostream &out, config const &cfg, unsigned int level)
+static void write_internal(configr_of const &cfg, std::ostream &out, std::string& textdomain, size_t tab = 0)
+{
+	if (tab > max_recursion_levels)
+		throw config::error("Too many recursion levels in config write");
+	if (cfg.data_) {
+		write_internal(*cfg.data_, out, textdomain, tab);
+	}
+
+	for (const auto &pair: cfg.subtags_)
+	{
+		assert(pair.first && pair.second);
+		if (!config::valid_id(*pair.first)) {
+			ERR_CF << "Config contains invalid tag name '" << *pair.first << "', skipping...\n";
+			continue;
+		}
+		write_open_child(out, *pair.first, tab);
+		write_internal(*pair.second, out, textdomain, tab + 1);
+		write_close_child(out, *pair.first, tab);
+	}
+}
+
+void write(std::ostream &out, configr_of const &cfg, unsigned int level)
 {
 	std::string textdomain = PACKAGE;
 	write_internal(cfg, out, textdomain, level);
 }
 
 template <typename compressor>
-void write_compressed(std::ostream &out, config const &cfg)
+void write_compressed(std::ostream &out, configr_of const &cfg)
 {
 	boost::iostreams::filtering_stream<boost::iostreams::output> filter;
 	filter.push(compressor());
@@ -615,12 +636,12 @@ void write_compressed(std::ostream &out, config const &cfg)
 	filter << "\n";
 }
 
-void write_gz(std::ostream &out, config const &cfg)
+void write_gz(std::ostream &out, configr_of const &cfg)
 {
 	write_compressed<boost::iostreams::gzip_compressor>(out, cfg);
 }
 
-void write_bz2(std::ostream &out, config const &cfg)
+void write_bz2(std::ostream &out, configr_of const &cfg)
 {
 	write_compressed<boost::iostreams::bzip2_compressor>(out, cfg);
 }

src/serialization/parser.hpp

@@ -20,7 +20,7 @@
 
 #include "global.hpp"
 #include "config.hpp"
-
+#include "configr_assign.hpp"
 
 class abstract_validator;
 // Read data in, clobbering existing data.
@@ -33,9 +33,9 @@ void read_gz(config &cfg, std::istream &in,
 void read_bz2(config &cfg, std::istream &in,
 			 abstract_validator * validator = nullptr);
 
-void write(std::ostream &out, config const &cfg, unsigned int level=0);
-void write_gz(std::ostream &out, config const &cfg);
-void write_bz2(std::ostream &out, config const &cfg);
+void write(std::ostream &out, configr_of const &cfg, unsigned int level=0);
+void write_gz(std::ostream &out, configr_of const &cfg);
+void write_bz2(std::ostream &out, configr_of const &cfg);
 void write_key_val(std::ostream &out, const std::string &key, const config::attribute_value &value, unsigned level, std::string &textdomain);
 void write_open_child(std::ostream &out, const std::string &child, unsigned int level);
 void write_close_child(std::ostream &out, const std::string &child, unsigned int level);

src/wesnothd_connection.cpp

@@ -111,7 +111,7 @@ void twesnothd_connection::handle_handshake(const error_code& ec)
 	recv();
 }
 
-void twesnothd_connection::send_data(const config& request)
+void twesnothd_connection::send_data(const configr_of& request)
 {
 	poll();
 	send_queue_.emplace_back();

src/wesnothd_connection.hpp

@@ -33,7 +33,7 @@
 #include <list>
 #include "exceptions.hpp"
 #include "wesnothd_connection_error.hpp"
-
+#include "configr_assign.hpp"
 class config;
 
 /** A class that represents a TCP/IP connection to the wesnothd server. */
@@ -50,7 +50,7 @@ class twesnothd_connection : boost::noncopyable
 	 */
 	twesnothd_connection(const std::string& host, const std::string& service);
 
-	void send_data(const config& request);
+	void send_data(const configr_of& request);
 
 	bool receive_data(config& result);