💿🐜 Antkeeper source code https://antkeeper.com
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/*
* Copyright (C) 2020 Christopher J. Howard
*
* This file is part of Antkeeper source code.
*
* Antkeeper source code 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 3 of the License, or
* (at your option) any later version.
*
* Antkeeper source code 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Antkeeper source code. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef ANTKEEPER_RESOURCE_MANAGER_HPP
#define ANTKEEPER_RESOURCE_MANAGER_HPP
#include "resource-handle.hpp"
#include "resource-loader.hpp"
#include "debug/logger.hpp"
#include <fstream>
#include <list>
#include <map>
#include <stdexcept>
#include <string>
#include <entt/entt.hpp>
/**
* Loads resources.
*/
class resource_manager
{
public:
/**
* Creates a resource manager.
*/
resource_manager();
/**
* Destroys a resource manager and frees all of its resources.
*/
~resource_manager();
/**
* Adds a path to be searched when a resource is requested.
*
* @param path Search path.
*/
void include(const std::string& path);
/**
* Loads the requested resource. If the resource has already been loaded it will be retrieved from the resource cache and its reference count incremented.
*
* @tparam T Resource type.
* @param path Path to the resource, relative to the search paths.
* @return Pointer to the requested resource, or nullptr if the resource could not be found nor loaded.
*/
template <typename T>
T* load(const std::string& path);
/**
* Decrements a resource's reference count and unloads the resource if it's unreferenced.
*
* @param path Path to the resource, relative to the search paths.
*/
void unload(const std::string& path);
/**
* Saves the specified resource.
*
* @tparam T Resource type.
* @param resource Pointer to the resource.
* @param path Path to the resource.
*/
template <typename T>
void save(const T* resource, const std::string& path);
entt::registry& get_archetype_registry();
void set_logger(::logger* logger);
private:
std::map<std::string, resource_handle_base*> resource_cache;
std::list<std::string> paths;
entt::registry archetype_registry;
::logger* logger;
};
template <typename T>
T* resource_manager::load(const std::string& path)
{
// Check if resource is in the cache
auto it = resource_cache.find(path);
if (it != resource_cache.end())
{
// Resource found
resource_handle<T>* resource = static_cast<resource_handle<T>*>(it->second);
// Increment resource handle reference count
++resource->reference_count;
// Return resource data
return resource->data;
}
if (logger)
{
logger->push_task("Loading resource \"" + path + "\"");
}
// Resource not found, load resource data
T* data = nullptr;
try
{
// For each directory in search paths
bool opened = false;
for (const std::string& directory: paths)
{
// Attempt to open file
std::string full_path = directory + path;
std::ifstream fs;
fs.open(full_path.c_str(), std::ios::in | std::ios::binary);
// If unable to open file
if (!fs.is_open() || !fs.good())
{
if (fs.is_open())
{
fs.close();
}
// Try again in next search path
continue;
}
// File opened, load it
opened = true;
data = resource_loader<T>::load(this, &fs);
fs.close();
break;
}
if (!opened)
{
if (logger)
{
logger->pop_task(EXIT_FAILURE);
}
throw std::runtime_error("resource_manager::load<T>(): Unable to open file \"" + path + "\"");
}
}
catch (const std::exception& e)
{
if (logger)
{
logger->pop_task(EXIT_FAILURE);
}
std::string error = std::string("resource_manager::load<T>(): Failed to load resource \"") + path + std::string("\": \"") + e.what() + std::string("\"");
throw std::runtime_error(error.c_str());
}
// Create a resource handle for the resource data
resource_handle<T>* resource = new resource_handle<T>();
resource->data = data;
resource->reference_count = 1;
// Add resource to the cache
resource_cache[path] = resource;
if (logger)
{
logger->pop_task(EXIT_SUCCESS);
}
return resource->data;
}
template <typename T>
void resource_manager::save(const T* resource, const std::string& path)
{
// Attempt to open file
std::ofstream fs;
fs.open(path.c_str(), std::ios::out | std::ios::binary);
// If unable to open file
if (!fs.is_open() || !fs.good())
{
if (fs.is_open())
{
fs.close();
}
throw std::runtime_error("resource_manager::save<T>(): Unable to open file \"" + path + "\"");
}
try
{
resource_loader<T>::save(this, &fs, resource);
}
catch (const std::exception& e)
{
std::string error = std::string("resource_manager::load<T>(): Failed to save resource \"") + path + std::string("\": \"") + e.what() + std::string("\"");
throw std::runtime_error(error.c_str());
}
}
inline entt::registry& resource_manager::get_archetype_registry()
{
return archetype_registry;
}
#endif // ANTKEEPER_RESOURCE_MANAGER_HPP