/*

 * Copyright (c) 2006-2007 Niels Provos <provos@citi.umich.edu>

 * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. The name of the author may not be used to endorse or promote products

 *    derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#ifndef _EVRPC_INTERNAL_H_

#define _EVRPC_INTERNAL_H_

#include "http-internal.h"

struct evrpc;

struct evrpc_request_wrapper;

#define EVRPC_URI_PREFIX "/.rpc."

struct evrpc_hook {

	TAILQ_ENTRY(evrpc_hook) next;

	/* returns EVRPC_TERMINATE; if the rpc should be aborted.

	 * a hook is is allowed to rewrite the evbuffer

	 */

	int (*process)(void *, struct evhttp_request *,

	    struct evbuffer *, void *);

	void *process_arg;

};

TAILQ_HEAD(evrpc_hook_list, evrpc_hook);

/*

 * this is shared between the base and the pool, so that we can reuse

 * the hook adding functions; we alias both evrpc_pool and evrpc_base

 * to this common structure.

 */

struct evrpc_hook_ctx;

TAILQ_HEAD(evrpc_pause_list, evrpc_hook_ctx);

struct _evrpc_hooks {

	/* hooks for processing outbound and inbound rpcs */

	struct evrpc_hook_list in_hooks;

	struct evrpc_hook_list out_hooks;

	struct evrpc_pause_list pause_requests;

};

#define input_hooks common.in_hooks

#define output_hooks common.out_hooks

#define paused_requests common.pause_requests

struct evrpc_base {

	struct _evrpc_hooks common;

	/* the HTTP server under which we register our RPC calls */

	struct evhttp* http_server;

	/* a list of all RPCs registered with us */

	TAILQ_HEAD(evrpc_list, evrpc) registered_rpcs;

};

struct evrpc_req_generic;

void evrpc_reqstate_free(struct evrpc_req_generic* rpc_state);

/* A pool for holding evhttp_connection objects */

struct evrpc_pool {

	struct _evrpc_hooks common;

	struct event_base *base;

	struct evconq connections;

	int timeout;

	TAILQ_HEAD(evrpc_requestq, evrpc_request_wrapper) (requests);

};

struct evrpc_hook_ctx {

	TAILQ_ENTRY(evrpc_hook_ctx) next;

	void *ctx;

	void (*cb)(void *, enum EVRPC_HOOK_RESULT);

};

struct evrpc_meta {

	TAILQ_ENTRY(evrpc_meta) next;

	char *key;

	void *data;

	size_t data_size;

};

TAILQ_HEAD(evrpc_meta_list, evrpc_meta);

struct evrpc_hook_meta {

	struct evrpc_meta_list meta_data;

	struct evhttp_connection *evcon;

};

/* allows association of meta data with a request */

static void evrpc_hook_associate_meta(struct evrpc_hook_meta **pctx,

    struct evhttp_connection *evcon);

/* creates a new meta data store */

static struct evrpc_hook_meta *evrpc_hook_meta_new(void);

/* frees the meta data associated with a request */

static void evrpc_hook_context_free(struct evrpc_hook_meta *ctx);

/* the server side of an rpc */

/* We alias the RPC specific structs to this voided one */

struct evrpc_req_generic {

	/*

	 * allows association of meta data via hooks - needs to be

	 * synchronized with evrpc_request_wrapper

	 */

	struct evrpc_hook_meta *hook_meta;

	/* the unmarshaled request object */

	void *request;

	/* the empty reply object that needs to be filled in */

	void *reply;

	/*

	 * the static structure for this rpc; that can be used to

	 * automatically unmarshal and marshal the http buffers.

	 */

	struct evrpc *rpc;

	/*

	 * the http request structure on which we need to answer.

	 */

	struct evhttp_request* http_req;

	/*

	 * Temporary data store for marshaled data

	 */

	struct evbuffer* rpc_data;

};

/* the client side of an rpc request */

struct evrpc_request_wrapper {

	/*

	 * allows association of meta data via hooks - needs to be

	 * synchronized with evrpc_req_generic.

	 */

	struct evrpc_hook_meta *hook_meta;

	TAILQ_ENTRY(evrpc_request_wrapper) next;

	/* pool on which this rpc request is being made */

	struct evrpc_pool *pool;

	/* connection on which the request is being sent */

	struct evhttp_connection *evcon;

	/* the actual  request */

	struct evhttp_request *req;

	/* event for implementing request timeouts */

	struct event ev_timeout;

	/* the name of the rpc */

	char *name;

	/* callback */

	void (*cb)(struct evrpc_status*, void *request, void *reply, void *arg);

	void *cb_arg;

	void *request;

	void *reply;

	/* unmarshals the buffer into the proper request structure */

	void (*request_marshal)(struct evbuffer *, void *);

	/* removes all stored state in the reply */

	void (*reply_clear)(void *);

	/* marshals the reply into a buffer */

	int (*reply_unmarshal)(void *, struct evbuffer*);

};

#endif /* _EVRPC_INTERNAL_H_ */