external/bsd/libevent/dist/evrpc-internal.h

   1 /*      $NetBSD: evrpc-internal.h,v 1.1.1.2 2013/04/11 16:43:20 christos Exp $  */
   2 /*
   3  * Copyright (c) 2006-2007 Niels Provos <provos@citi.umich.edu>
   4  * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. The name of the author may not be used to endorse or promote products
  15  *    derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28 #ifndef _EVRPC_INTERNAL_H_
  29 #define _EVRPC_INTERNAL_H_
  30
  31 #include "http-internal.h"
  32
  33 struct evrpc;
  34 struct evrpc_request_wrapper;
  35
  36 #define EVRPC_URI_PREFIX "/.rpc."
  37
  38 struct evrpc_hook {
  39         TAILQ_ENTRY(evrpc_hook) next;
  40
  41         /* returns EVRPC_TERMINATE; if the rpc should be aborted.
  42          * a hook is is allowed to rewrite the evbuffer
  43          */
  44         int (*process)(void *, struct evhttp_request *,
  45             struct evbuffer *, void *);
  46         void *process_arg;
  47 };
  48
  49 TAILQ_HEAD(evrpc_hook_list, evrpc_hook);
  50
  51 /*
  52  * this is shared between the base and the pool, so that we can reuse
  53  * the hook adding functions; we alias both evrpc_pool and evrpc_base
  54  * to this common structure.
  55  */
  56
  57 struct evrpc_hook_ctx;
  58 TAILQ_HEAD(evrpc_pause_list, evrpc_hook_ctx);
  59
  60 struct _evrpc_hooks {
  61         /* hooks for processing outbound and inbound rpcs */
  62         struct evrpc_hook_list in_hooks;
  63         struct evrpc_hook_list out_hooks;
  64
  65         struct evrpc_pause_list pause_requests;
  66 };
  67
  68 #define input_hooks common.in_hooks
  69 #define output_hooks common.out_hooks
  70 #define paused_requests common.pause_requests
  71
  72 struct evrpc_base {
  73         struct _evrpc_hooks common;
  74
  75         /* the HTTP server under which we register our RPC calls */
  76         struct evhttp* http_server;
  77
  78         /* a list of all RPCs registered with us */
  79         TAILQ_HEAD(evrpc_list, evrpc) registered_rpcs;
  80 };
  81
  82 struct evrpc_req_generic;
  83 void evrpc_reqstate_free(struct evrpc_req_generic* rpc_state);
  84
  85 /* A pool for holding evhttp_connection objects */
  86 struct evrpc_pool {
  87         struct _evrpc_hooks common;
  88
  89         struct event_base *base;
  90
  91         struct evconq connections;
  92
  93         int timeout;
  94
  95         TAILQ_HEAD(evrpc_requestq, evrpc_request_wrapper) (requests);
  96 };
  97
  98 struct evrpc_hook_ctx {
  99         TAILQ_ENTRY(evrpc_hook_ctx) next;
 100
 101         void *ctx;
 102         void (*cb)(void *, enum EVRPC_HOOK_RESULT);
 103 };
 104
 105 struct evrpc_meta {
 106         TAILQ_ENTRY(evrpc_meta) next;
 107         char *key;
 108
 109         void *data;
 110         size_t data_size;
 111 };
 112
 113 TAILQ_HEAD(evrpc_meta_list, evrpc_meta);
 114
 115 struct evrpc_hook_meta {
 116         struct evrpc_meta_list meta_data;
 117         struct evhttp_connection *evcon;
 118 };
 119
 120 /* allows association of meta data with a request */
 121 static void evrpc_hook_associate_meta(struct evrpc_hook_meta **pctx,
 122     struct evhttp_connection *evcon);
 123
 124 /* creates a new meta data store */
 125 static struct evrpc_hook_meta *evrpc_hook_meta_new(void);
 126
 127 /* frees the meta data associated with a request */
 128 static void evrpc_hook_context_free(struct evrpc_hook_meta *ctx);
 129
 130 /* the server side of an rpc */
 131
 132 /* We alias the RPC specific structs to this voided one */
 133 struct evrpc_req_generic {
 134         /*
 135          * allows association of meta data via hooks - needs to be
 136          * synchronized with evrpc_request_wrapper
 137          */
 138         struct evrpc_hook_meta *hook_meta;
 139
 140         /* the unmarshaled request object */
 141         void *request;
 142
 143         /* the empty reply object that needs to be filled in */
 144         void *reply;
 145
 146         /*
 147          * the static structure for this rpc; that can be used to
 148          * automatically unmarshal and marshal the http buffers.
 149          */
 150         struct evrpc *rpc;
 151
 152         /*
 153          * the http request structure on which we need to answer.
 154          */
 155         struct evhttp_request* http_req;
 156
 157         /*
 158          * Temporary data store for marshaled data
 159          */
 160         struct evbuffer* rpc_data;
 161 };
 162
 163 /* the client side of an rpc request */
 164 struct evrpc_request_wrapper {
 165         /*
 166          * allows association of meta data via hooks - needs to be
 167          * synchronized with evrpc_req_generic.
 168          */
 169         struct evrpc_hook_meta *hook_meta;
 170
 171         TAILQ_ENTRY(evrpc_request_wrapper) next;
 172
 173         /* pool on which this rpc request is being made */
 174         struct evrpc_pool *pool;
 175
 176         /* connection on which the request is being sent */
 177         struct evhttp_connection *evcon;
 178
 179         /* the actual  request */
 180         struct evhttp_request *req;
 181
 182         /* event for implementing request timeouts */
 183         struct event ev_timeout;
 184
 185         /* the name of the rpc */
 186         char *name;
 187
 188         /* callback */
 189         void (*cb)(struct evrpc_status*, void *request, void *reply, void *arg);
 190         void *cb_arg;
 191
 192         void *request;
 193         void *reply;
 194
 195         /* unmarshals the buffer into the proper request structure */
 196         void (*request_marshal)(struct evbuffer *, void *);
 197
 198         /* removes all stored state in the reply */
 199         void (*reply_clear)(void *);
 200
 201         /* marshals the reply into a buffer */
 202         int (*reply_unmarshal)(void *, struct evbuffer*);
 203 };
 204
 205 #endif /* _EVRPC_INTERNAL_H_ */