minetest/src/mods.cpp

/*
Minetest-c55
Copyright (C) 2011 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 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; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "mods.h"
#include <queue>
#include <fstream>
#include <sstream>
#include <map>
#include "filesys.h"
#include "strfnd.h"
#include "log.h"

static void collectMods(const std::string &modspath,
		std::queue<ModSpec> &mods_satisfied,
		core::list<ModSpec> &mods_unsorted,
		std::map<std::string, std::string> &mod_names,
		std::string indentation)
{
	TRACESTREAM(<<indentation<<"collectMods(\""<<modspath<<"\")"<<std::endl);
	TRACEDO(indentation += "  ");
	std::vector<fs::DirListNode> dirlist = fs::GetDirListing(modspath);
	for(u32 j=0; j<dirlist.size(); j++){
		if(!dirlist[j].dir)
			continue;
		std::string modname = dirlist[j].name;
		std::string modpath = modspath + DIR_DELIM + modname;
		TRACESTREAM(<<indentation<<"collectMods: "<<modname<<" at \""<<modpath<<"\""<<std::endl);
		// Handle modpacks (defined by containing modpack.txt)
		{
			std::ifstream is((modpath+DIR_DELIM+"modpack.txt").c_str(),
					std::ios_base::binary);
			if(is.good()){
				// Is a modpack
				is.close(); // We don't actually need the file
				// Recurse into it
				collectMods(modpath, mods_satisfied, mods_unsorted, mod_names, indentation);
				continue;
			}
		}
		// Detect mod name conflicts
		{
			std::map<std::string, std::string>::const_iterator i;
			i = mod_names.find(modname);
			if(i != mod_names.end()){
				std::string s;
				infostream<<indentation<<"WARNING: Mod name conflict detected: "
						<<std::endl
						<<"Already loaded: "<<i->second<<std::endl
						<<"Will not load: "<<modpath<<std::endl;
				continue;
			}
		}
		std::set<std::string> depends;
		std::ifstream is((modpath+DIR_DELIM+"depends.txt").c_str(),
				std::ios_base::binary);
		while(is.good()){
			std::string dep;
			std::getline(is, dep);
			dep = trim(dep);
			if(dep != "")
				depends.insert(dep);
		}
		ModSpec spec(modname, modpath, depends);
		mods_unsorted.push_back(spec);
		if(depends.empty())
			mods_satisfied.push(spec);
		mod_names[modname] = modpath;
	}
}

// Get a dependency-sorted list of ModSpecs
core::list<ModSpec> getMods(core::list<std::string> &modspaths)
		throw(ModError)
{
	std::queue<ModSpec> mods_satisfied;
	core::list<ModSpec> mods_unsorted;
	core::list<ModSpec> mods_sorted;
	// name, path: For detecting name conflicts
	std::map<std::string, std::string> mod_names;
	for(core::list<std::string>::Iterator i = modspaths.begin();
			i != modspaths.end(); i++){
		std::string modspath = *i;
		collectMods(modspath, mods_satisfied, mods_unsorted, mod_names, "");
	}
	// Sort by depencencies
	while(!mods_satisfied.empty()){
		ModSpec mod = mods_satisfied.front();
		mods_satisfied.pop();
		mods_sorted.push_back(mod);
		for(core::list<ModSpec>::Iterator i = mods_unsorted.begin();
				i != mods_unsorted.end(); i++){
			ModSpec &mod2 = *i;
			if(mod2.unsatisfied_depends.empty())
				continue;
			mod2.unsatisfied_depends.erase(mod.name);
			if(!mod2.unsatisfied_depends.empty())
				continue;
			mods_satisfied.push(mod2);
		}
	}
	std::ostringstream errs(std::ios::binary);
	// Check unsatisfied dependencies
	for(core::list<ModSpec>::Iterator i = mods_unsorted.begin();
			i != mods_unsorted.end(); i++){
		ModSpec &mod = *i;
		if(mod.unsatisfied_depends.empty())
			continue;
		errs<<"mod \""<<mod.name
				<<"\" has unsatisfied dependencies:";
		for(std::set<std::string>::iterator
				i = mod.unsatisfied_depends.begin();
				i != mod.unsatisfied_depends.end(); i++){
			errs<<" \""<<(*i)<<"\"";
		}
		errs<<"."<<std::endl;
		mods_sorted.push_back(mod);
	}
	// If an error occurred, throw an exception
	if(errs.str().size() != 0){
		throw ModError(errs.str());
	}
	// Print out some debug info
	TRACESTREAM(<<"Detected mods in load order:"<<std::endl);
	for(core::list<ModSpec>::Iterator i = mods_sorted.begin();
			i != mods_sorted.end(); i++){
		ModSpec &mod = *i;
		TRACESTREAM(<<"name=\""<<mod.name<<"\" path=\""<<mod.path<<"\"");
		TRACESTREAM(<<" depends=[");
		for(std::set<std::string>::iterator i = mod.depends.begin();
				i != mod.depends.end(); i++)
			TRACESTREAM(<<" "<<(*i));
		TRACESTREAM(<<" ] unsatisfied_depends=[");
		for(std::set<std::string>::iterator i = mod.unsatisfied_depends.begin();
				i != mod.unsatisfied_depends.end(); i++)
			TRACESTREAM(<<" "<<(*i));
		TRACESTREAM(<<" ]"<<std::endl);
	}
	return mods_sorted;
}