mozaic/lib/read_database.hpp

#pragma once

#include <database.hpp>
#include <utilities.hpp>

#include <boost/archive/binary_iarchive.hpp>
#include <boost/archive/binary_oarchive.hpp>
#include <boost/filesystem.hpp>

#include <iostream>
#include <fstream>
#include <string>

template <typename T>
auto read_database(std::string const & database_directory, bool output_files = false){
	namespace fs = boost::filesystem;
	namespace ar = boost::archive;

	image_database<T> db;
	auto const database_file = database_directory + "-" + db.fingerprint_name() + ".db";

	if (!boost::filesystem::exists(database_file)){
		fs::path const directory(database_directory);
		fs::directory_iterator eod;
		for(fs::directory_iterator it(directory); it != eod; ++it){
			auto const path = it->path();
			auto const ext = to_lower(path.extension().string());
			if(ext != ".png" && ext != ".jpg" && ext != ".jpeg" && ext != ".gif") continue;
			if(output_files) std::cout << path << std::endl;
			db.add(path.string());
		}

		std::ofstream file(database_file);
		ar::binary_oarchive archive(file);
		archive << db;
	} else {
		std::ifstream file(database_file);
		ar::binary_iarchive archive(file);
		archive >> db;
	}

	return db;
}