text: /*************************************************************************/
  /*  ip.cpp                                                               */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                    http://www.godotengine.org                         */
  /*************************************************************************/
  /* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                 */
  /*                                                                       */
  /* Permission is hereby granted, free of charge, to any person obtaining */
  /* a copy of this software and associated documentation files (the       */
  /* "Software"), to deal in the Software without restriction, including   */
  /* without limitation the rights to use, copy, modify, merge, publish,   */
  /* distribute, sublicense, and/or sell copies of the Software, and to    */
  /* permit persons to whom the Software is furnished to do so, subject to */
  /* the following conditions:                                             */
  /*                                                                       */
  /* The above copyright notice and this permission notice shall be        */
  /* included in all copies or substantial portions of the Software.       */
  /*                                                                       */
  /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
  /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
  /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
  /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
  /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
  /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
  /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
  /*************************************************************************/
  #include "ip.h"
  #include "os/thread.h"
  #include "os/semaphore.h"
  #include "hash_map.h"
  
  
  
  /************* RESOLVER ******************/
  
  
  struct _IP_ResolverPrivate {
  
  	struct QueueItem {
  
  		volatile IP::ResolverStatus status;
  		IP_Address response;
  		String hostname;
  
  		void clear() {
  			status = IP::RESOLVER_STATUS_NONE;
  			response = IP_Address();
  			hostname="";
  		};
  		
  		QueueItem() {
  			clear();
  		};
  	};
  
  	QueueItem queue[IP::RESOLVER_MAX_QUERIES];
  
  	IP::ResolverID find_empty_id() const {
  
  		for(int i=0;i<IP::RESOLVER_MAX_QUERIES;i++) {
  			if (queue[i].status==IP::RESOLVER_STATUS_NONE)
  				return i;
  		}
  		return IP::RESOLVER_INVALID_ID;
  	}
  
  	Semaphore *sem;
  
  	Thread* thread;
  	//Semaphore* semaphore;
  	bool thread_abort;
  
  	void resolve_queues() {
  
  		for(int i=0;i<IP::RESOLVER_MAX_QUERIES;i++) {
  
  			if (queue[i].status!=IP::RESOLVER_STATUS_WAITING)
  				continue;
  			queue[i].response=IP::get_singleton()->resolve_hostname(queue[i].hostname);
  
  			if (queue[i].response.host==0)
  				queue[i].status=IP::RESOLVER_STATUS_ERROR;
  			else
  				queue[i].status=IP::RESOLVER_STATUS_DONE;
  
  		}
  	}
  
  
  	static void _thread_function(void *self) {
  
  		_IP_ResolverPrivate *ipr=(_IP_ResolverPrivate*)self;
  
  		while(!ipr->thread_abort) {
  
  			ipr->sem->wait();
  			GLOBAL_LOCK_FUNCTION;
  			ipr->resolve_queues();
  
  		}
  
  	}
  
  	HashMap<String, IP_Address> cache;
  
  };
  
  
  
  IP_Address IP::resolve_hostname(const String& p_hostname) {
  
  	GLOBAL_LOCK_FUNCTION
  
  	if (resolver->cache.has(p_hostname))
  		return resolver->cache[p_hostname];
  
  	IP_Address res = _resolve_hostname(p_hostname);
  	resolver->cache[p_hostname]=res;
  	return res;
  
  }
  IP::ResolverID IP::resolve_hostname_queue_item(const String& p_hostname) {
  
  	GLOBAL_LOCK_FUNCTION
  
  	ResolverID id = resolver->find_empty_id();
  
  	if (id==RESOLVER_INVALID_ID) {
  		WARN_PRINT("Out of resolver queries");
  		return id;
  	}
  
  	resolver->queue[id].hostname=p_hostname;
  	if (resolver->cache.has(p_hostname)) {
  		resolver->queue[id].response=resolver->cache[p_hostname];
  		resolver->queue[id].status=IP::RESOLVER_STATUS_DONE;
  	} else {
  		resolver->queue[id].response=IP_Address();
  		resolver->queue[id].status=IP::RESOLVER_STATUS_WAITING;
  		if (resolver->thread)
  			resolver->sem->post();
  		else
  			resolver->resolve_queues();
  	}
  
  
  
  
  
  	return id;
  }
  
  IP::ResolverStatus IP::get_resolve_item_status(ResolverID p_id) const {
  
  	ERR_FAIL_INDEX_V(p_id,IP::RESOLVER_MAX_QUERIES,IP::RESOLVER_STATUS_NONE);
  
  	GLOBAL_LOCK_FUNCTION;
  	ERR_FAIL_COND_V(resolver->queue[p_id].status==IP::RESOLVER_STATUS_NONE,IP::RESOLVER_STATUS_NONE);
  
  	return resolver->queue[p_id].status;
  
  }
  IP_Address IP::get_resolve_item_address(ResolverID p_id) const {
  
  	ERR_FAIL_INDEX_V(p_id,IP::RESOLVER_MAX_QUERIES,IP_Address());
  
  	GLOBAL_LOCK_FUNCTION;
  
  	if (resolver->queue[p_id].status!=IP::RESOLVER_STATUS_DONE) {
  		ERR_EXPLAIN("Resolve of '"+resolver->queue[p_id].hostname+"'' didn't complete yet.");
  		ERR_FAIL_COND_V(resolver->queue[p_id].status!=IP::RESOLVER_STATUS_DONE,IP_Address());
  	}
  
  
  	return resolver->queue[p_id].response;
  
  }
  void IP::erase_resolve_item(ResolverID p_id) {
  
  	ERR_FAIL_INDEX(p_id,IP::RESOLVER_MAX_QUERIES);
  
  	GLOBAL_LOCK_FUNCTION;
  
  	resolver->queue[p_id].status=IP::RESOLVER_STATUS_DONE;
  
  }
  
  
  Array IP::_get_local_addresses() const {
  
  	Array addresses;
  	List<IP_Address> ip_addresses;
  	get_local_addresses(&ip_addresses);
  	for(List<IP_Address>::Element *E=ip_addresses.front();E;E=E->next()) {
  		addresses.push_back(E->get());
  	}
  
  	return addresses;
  }
  
  void IP::_bind_methods() {
  
  	ObjectTypeDB::bind_method(_MD("resolve_hostname","host"),&IP::resolve_hostname);
  	ObjectTypeDB::bind_method(_MD("resolve_hostname_queue_item","host"),&IP::resolve_hostname_queue_item);
  	ObjectTypeDB::bind_method(_MD("get_resolve_item_status","id"),&IP::get_resolve_item_status);
  	ObjectTypeDB::bind_method(_MD("get_resolve_item_address","id"),&IP::get_resolve_item_address);
  	ObjectTypeDB::bind_method(_MD("erase_resolve_item","id"),&IP::erase_resolve_item);
  	ObjectTypeDB::bind_method(_MD("get_local_addresses"),&IP::_get_local_addresses);
  
  	BIND_CONSTANT( RESOLVER_STATUS_NONE );
  	BIND_CONSTANT( RESOLVER_STATUS_WAITING );
  	BIND_CONSTANT( RESOLVER_STATUS_DONE );
  	BIND_CONSTANT( RESOLVER_STATUS_ERROR );
  
  	BIND_CONSTANT( RESOLVER_MAX_QUERIES );
  	BIND_CONSTANT( RESOLVER_INVALID_ID );
  
  }
  
  
  IP*IP::singleton=NULL;
  
  IP* IP::get_singleton() {
  
  	return singleton;
  }
  
  
  IP* (*IP::_create)()=NULL;
  
  IP* IP::create() {
  
  	ERR_FAIL_COND_V(singleton,NULL);
  	ERR_FAIL_COND_V(!_create,NULL);
  	return _create();
  }
  
  IP::IP() {
  
  	singleton=this;
  	resolver = memnew( _IP_ResolverPrivate );
  	resolver->sem=NULL;
  
  #ifndef NO_THREADS
  
  	//resolver->sem = Semaphore::create();
  
  	resolver->sem=NULL;
  	if (resolver->sem) {
  		resolver->thread_abort=false;
  
  		resolver->thread = Thread::create( _IP_ResolverPrivate::_thread_function,resolver );
  
  		if (!resolver->thread)
  			memdelete(resolver->sem); //wtf
  	} else {
  		resolver->thread=NULL;
  	}
  #else
  	resolver->sem = NULL;
  	resolver->thread=NULL;
  #endif
  
  
  }
  
  IP::~IP() {
  
  #ifndef NO_THREADS
  	if (resolver->thread) {
  		resolver->thread_abort=true;
  		resolver->sem->post();
  		Thread::wait_to_finish(resolver->thread);
  		memdelete( resolver->thread );
  		memdelete( resolver->sem);
  	}
  	memdelete(resolver);
  
  #endif
  
  }
  