rpc.h

Go to the documentation of this file.

/*
 * 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 _EVENT2_RPC_H_
#define _EVENT2_RPC_H_

#ifdef __cplusplus
extern "C" {
#endif

#define EVTAG_HAS(msg, member) \
    ((msg)->member##_set == 1)

#ifndef _EVENT2_RPC_COMPAT_H_

#define EVTAG_ASSIGN(msg, member, value) \
    (*(msg)->base->member##_assign)((msg), (value))

#define EVTAG_ASSIGN_WITH_LEN(msg, member, value, len)  \
    (*(msg)->base->member##_assign)((msg), (value), (len))

#define EVTAG_GET(msg, member, pvalue) \
    (*(msg)->base->member##_get)((msg), (pvalue))

#define EVTAG_GET_WITH_LEN(msg, member, pvalue, plen)   \
    (*(msg)->base->member##_get)((msg), (pvalue), (plen))

#endif  /* _EVENT2_RPC_COMPAT_H_ */

#define EVTAG_ARRAY_ADD_VALUE(msg, member, value) \
    (*(msg)->base->member##_add)((msg), (value))

#define EVTAG_ARRAY_ADD(msg, member) \
    (*(msg)->base->member##_add)(msg)

#define EVTAG_ARRAY_GET(msg, member, offset, pvalue)    \
    (*(msg)->base->member##_get)((msg), (offset), (pvalue))

#define EVTAG_ARRAY_LEN(msg, member) ((msg)->member##_length)


struct evbuffer;
struct event_base;
struct evrpc_req_generic;
struct evrpc_request_wrapper;
struct evrpc;

#define EVRPC_STRUCT(rpcname) struct evrpc_req__##rpcname

struct evhttp_request;
struct evrpc_status;
struct evrpc_hook_meta;

#define EVRPC_HEADER(rpcname, reqstruct, rplystruct) \
EVRPC_STRUCT(rpcname) { \
    struct evrpc_hook_meta *hook_meta; \
    struct reqstruct* request; \
    struct rplystruct* reply; \
    struct evrpc* rpc; \
    struct evhttp_request* http_req; \
    struct evbuffer* rpc_data; \
};                                   \
int evrpc_send_request_##rpcname(struct evrpc_pool *, \
    struct reqstruct *, struct rplystruct *, \
    void (*)(struct evrpc_status *, \
    struct reqstruct *, struct rplystruct *, void *cbarg),  \
    void *);

struct evrpc_pool;

struct evrpc_request_wrapper *evrpc_make_request_ctx(
    struct evrpc_pool *pool, void *request, void *reply,
    const char *rpcname,
    void (*req_marshal)(struct evbuffer*, void *),
    void (*rpl_clear)(void *),
    int (*rpl_unmarshal)(void *, struct evbuffer *),
    void (*cb)(struct evrpc_status *, void *, void *, void *),
    void *cbarg);

#define EVRPC_MAKE_CTX(rpcname, reqstruct, rplystruct, \
    pool, request, reply, cb, cbarg)                    \
    evrpc_make_request_ctx(pool, request, reply,            \
        #rpcname,                           \
        (void (*)(struct evbuffer *, void *))reqstruct##_marshal,   \
        (void (*)(void *))rplystruct##_clear,           \
        (int (*)(void *, struct evbuffer *))rplystruct##_unmarshal, \
        (void (*)(struct evrpc_status *, void *, void *, void *))cb, \
        cbarg)

#define EVRPC_GENERATE(rpcname, reqstruct, rplystruct)          \
    int evrpc_send_request_##rpcname(struct evrpc_pool *pool,   \
        struct reqstruct *request, struct rplystruct *reply,    \
        void (*cb)(struct evrpc_status *,               \
        struct reqstruct *, struct rplystruct *, void *cbarg),  \
        void *cbarg) {                      \
    return evrpc_send_request_generic(pool, request, reply, \
        (void (*)(struct evrpc_status *, void *, void *, void *))cb, \
        cbarg,                          \
        #rpcname,                           \
        (void (*)(struct evbuffer *, void *))reqstruct##_marshal,   \
        (void (*)(void *))rplystruct##_clear,           \
        (int (*)(void *, struct evbuffer *))rplystruct##_unmarshal); \
}

#define EVRPC_REQUEST_HTTP(rpc_req) (rpc_req)->http_req

void evrpc_request_done(struct evrpc_req_generic *req);

void *evrpc_get_request(struct evrpc_req_generic *req);
void *evrpc_get_reply(struct evrpc_req_generic *req);

#define EVRPC_REQUEST_DONE(rpc_req) do { \
  struct evrpc_req_generic *_req = (struct evrpc_req_generic *)(rpc_req); \
  evrpc_request_done(_req);                 \
} while (0)


struct evrpc_base;
struct evhttp;

/* functions to start up the rpc system */

struct evrpc_base *evrpc_init(struct evhttp *server);

void evrpc_free(struct evrpc_base *base);

#define EVRPC_REGISTER(base, name, request, reply, callback, cbarg) \
    evrpc_register_generic(base, #name,             \
        (void (*)(struct evrpc_req_generic *, void *))callback, cbarg, \
        (void *(*)(void *))request##_new, NULL,         \
        (void (*)(void *))request##_free,               \
        (int (*)(void *, struct evbuffer *))request##_unmarshal,    \
        (void *(*)(void *))reply##_new, NULL,           \
        (void (*)(void *))reply##_free, \
        (int (*)(void *))reply##_complete, \
        (void (*)(struct evbuffer *, void *))reply##_marshal)

int evrpc_register_rpc(struct evrpc_base *, struct evrpc *,
    void (*)(struct evrpc_req_generic*, void *), void *);

#define EVRPC_UNREGISTER(base, name) evrpc_unregister_rpc((base), #name)

int evrpc_unregister_rpc(struct evrpc_base *base, const char *name);

/*
 * Client-side RPC support
 */

struct evhttp_connection;
struct evrpc_status;

#define EVRPC_MAKE_REQUEST(name, pool, request, reply, cb, cbarg)   \
    evrpc_send_request_##name((pool), (request), (reply), (cb), (cbarg))

int evrpc_make_request(struct evrpc_request_wrapper *ctx);

struct evrpc_pool *evrpc_pool_new(struct event_base *base);
void evrpc_pool_free(struct evrpc_pool *pool);

void evrpc_pool_add_connection(struct evrpc_pool *pool,
    struct evhttp_connection *evcon);

void evrpc_pool_remove_connection(struct evrpc_pool *pool,
    struct evhttp_connection *evcon);

void evrpc_pool_set_timeout(struct evrpc_pool *pool, int timeout_in_secs);

enum EVRPC_HOOK_TYPE {
    EVRPC_INPUT,        
    EVRPC_OUTPUT        
};

#ifndef WIN32

#define INPUT EVRPC_INPUT

#define OUTPUT EVRPC_OUTPUT
#endif

enum EVRPC_HOOK_RESULT {
    EVRPC_TERMINATE = -1,   
    EVRPC_CONTINUE = 0, 
    EVRPC_PAUSE = 1     
};

void *evrpc_add_hook(void *vbase,
    enum EVRPC_HOOK_TYPE hook_type,
    int (*cb)(void *, struct evhttp_request *, struct evbuffer *, void *),
    void *cb_arg);

int evrpc_remove_hook(void *vbase,
    enum EVRPC_HOOK_TYPE hook_type,
    void *handle);

int
evrpc_resume_request(void *vbase, void *ctx, enum EVRPC_HOOK_RESULT res);

void evrpc_hook_add_meta(void *ctx, const char *key,
    const void *data, size_t data_size);

int evrpc_hook_find_meta(void *ctx, const char *key,
    void **data, size_t *data_size);

struct evhttp_connection *evrpc_hook_get_connection(void *ctx);

int evrpc_send_request_generic(struct evrpc_pool *pool,
    void *request, void *reply,
    void (*cb)(struct evrpc_status *, void *, void *, void *),
    void *cb_arg,
    const char *rpcname,
    void (*req_marshal)(struct evbuffer *, void *),
    void (*rpl_clear)(void *),
    int (*rpl_unmarshal)(void *, struct evbuffer *));

int
evrpc_register_generic(struct evrpc_base *base, const char *name,
    void (*callback)(struct evrpc_req_generic *, void *), void *cbarg,
    void *(*req_new)(void *), void *req_new_arg, void (*req_free)(void *),
    int (*req_unmarshal)(void *, struct evbuffer *),
    void *(*rpl_new)(void *), void *rpl_new_arg, void (*rpl_free)(void *),
    int (*rpl_complete)(void *),
    void (*rpl_marshal)(struct evbuffer *, void *));

struct evrpc_pool* evrpc_request_get_pool(struct evrpc_request_wrapper *ctx);
void evrpc_request_set_pool(struct evrpc_request_wrapper *ctx,
    struct evrpc_pool *pool);
void evrpc_request_set_cb(struct evrpc_request_wrapper *ctx,
    void (*cb)(struct evrpc_status*, void *request, void *reply, void *arg),
    void *cb_arg);

#ifdef __cplusplus
}
#endif

#endif /* _EVENT2_RPC_H_ */