CoolVLViewer/indra/llmessage/llcorehttphandler.h

/**
 * @file llcorehttphandler.h
 * @brief Public-facing declarations for the HttpHandler class
 *
 * $LicenseInfo:firstyear=2012&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2012, Linden Research, Inc.
 *
 * This library 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;
 * version 2.1 of the License only.
 *
 * This library 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 library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#ifndef	_LLCORE_HTTP_HANDLER_H_
#define	_LLCORE_HTTP_HANDLER_H_

#include "llcorehttpcommon.h"

namespace LLCore
{

class HttpResponse;

// HttpHandler defines an interface used by the library to notify library
// callers of significant events, currently request completion. Callers must
// derive or mixin this class then provide an implementation of the @see
// onCompleted method to receive such notifications. An instance may be shared
// by any number of requests and across instances of HttpRequest running in the
// same thread.
//
// Threading: HttpHandler itself is interface and is tread-compatible.
// Most derivations, however, will have different constraints.
//
// Allocation: Not refcounted, may be stack allocated though that is rarely a
// good idea. Queued requests and replies keep a naked pointer to the handler
// and this can result in a dangling pointer if lifetimes aren't managed
// correctly.

// *TODO: public std::enable_shared_from_this<HttpHandler>
class HttpHandler
{
public:
	typedef std::shared_ptr<HttpHandler> ptr_t;
	typedef std::weak_ptr<HttpHandler> wptr_t;

	virtual ~HttpHandler()
	{
	}

	// Method invoked during calls to @see update(). Each invocation represents
	// the completion of some requested operation. Caller can identify the
	// request from the handle and interrogate the response argument for
	// success/failure, data and other information.
	//
	// @param	handle			Identifier of the request generating the
	//							notification.
	// @param	response		Supplies detailed information about the request
	//							including status codes (both programming and
	//							HTTP), HTTP body data and encodings, headers,
	//							etc. The response object is refcounted and the
	//							called code may retain the object by invoking
	//							@see addRef() on it. The library itself drops
	//							all references to object on return and never
	//							touches it again.
	virtual void onCompleted(HttpHandle handle, HttpResponse* response) = 0;

};  // end class HttpHandler

}   // End namespace LLCore

#endif	// _LLCORE_HTTP_HANDLER_H_