OpenMPI  0.1.1
evrpc-internal.h
1 /*
2  * Copyright (c) 2006-2007 Niels Provos <provos@citi.umich.edu>
3  * Copyright (c) 2007-2010 Niels Provos and Nick Mathewson
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  * notice, this list of conditions and the following disclaimer in the
12  * documentation and/or other materials provided with the distribution.
13  * 3. The name of the author may not be used to endorse or promote products
14  * derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 #ifndef _EVRPC_INTERNAL_H_
28 #define _EVRPC_INTERNAL_H_
29 
30 #include "http-internal.h"
31 
32 struct evrpc;
34 
35 #define EVRPC_URI_PREFIX "/.rpc."
36 
37 struct evrpc_hook {
38  TAILQ_ENTRY(evrpc_hook) next;
39 
40  /* returns EVRPC_TERMINATE; if the rpc should be aborted.
41  * a hook is is allowed to rewrite the evbuffer
42  */
43  int (*process)(void *, struct evhttp_request *,
44  struct evbuffer *, void *);
45  void *process_arg;
46 };
47 
48 TAILQ_HEAD(evrpc_hook_list, evrpc_hook);
49 
50 /*
51  * this is shared between the base and the pool, so that we can reuse
52  * the hook adding functions; we alias both evrpc_pool and evrpc_base
53  * to this common structure.
54  */
55 
56 struct evrpc_hook_ctx;
57 TAILQ_HEAD(evrpc_pause_list, evrpc_hook_ctx);
58 
59 struct _evrpc_hooks {
60  /* hooks for processing outbound and inbound rpcs */
61  struct evrpc_hook_list in_hooks;
62  struct evrpc_hook_list out_hooks;
63 
64  struct evrpc_pause_list pause_requests;
65 };
66 
67 #define input_hooks common.in_hooks
68 #define output_hooks common.out_hooks
69 #define paused_requests common.pause_requests
70 
71 struct evrpc_base {
72  struct _evrpc_hooks common;
73 
74  /* the HTTP server under which we register our RPC calls */
75  struct evhttp* http_server;
76 
77  /* a list of all RPCs registered with us */
78  TAILQ_HEAD(evrpc_list, evrpc) registered_rpcs;
79 };
80 
81 struct evrpc_req_generic;
82 void evrpc_reqstate_free(struct evrpc_req_generic* rpc_state);
83 
84 /* A pool for holding evhttp_connection objects */
85 struct evrpc_pool {
86  struct _evrpc_hooks common;
87 
88  struct event_base *base;
89 
90  struct evconq connections;
91 
92  int timeout;
93 
94  TAILQ_HEAD(evrpc_requestq, evrpc_request_wrapper) (requests);
95 };
96 
98  TAILQ_ENTRY(evrpc_hook_ctx) next;
99 
100  void *ctx;
101  void (*cb)(void *, enum EVRPC_HOOK_RESULT);
102 };
103 
104 struct evrpc_meta {
105  TAILQ_ENTRY(evrpc_meta) next;
106  char *key;
107 
108  void *data;
109  size_t data_size;
110 };
111 
112 TAILQ_HEAD(evrpc_meta_list, evrpc_meta);
113 
115  struct evrpc_meta_list meta_data;
116  struct evhttp_connection *evcon;
117 };
118 
119 /* allows association of meta data with a request */
120 static void evrpc_hook_associate_meta(struct evrpc_hook_meta **pctx,
121  struct evhttp_connection *evcon);
122 
123 /* creates a new meta data store */
124 static struct evrpc_hook_meta *evrpc_hook_meta_new(void);
125 
126 /* frees the meta data associated with a request */
127 static void evrpc_hook_context_free(struct evrpc_hook_meta *ctx);
128 
129 /* the server side of an rpc */
130 
131 /* We alias the RPC specific structs to this voided one */
133  /*
134  * allows association of meta data via hooks - needs to be
135  * synchronized with evrpc_request_wrapper
136  */
137  struct evrpc_hook_meta *hook_meta;
138 
139  /* the unmarshaled request object */
140  void *request;
141 
142  /* the empty reply object that needs to be filled in */
143  void *reply;
144 
145  /*
146  * the static structure for this rpc; that can be used to
147  * automatically unmarshal and marshal the http buffers.
148  */
149  struct evrpc *rpc;
150 
151  /*
152  * the http request structure on which we need to answer.
153  */
154  struct evhttp_request* http_req;
155 
156  /*
157  * Temporary data store for marshaled data
158  */
159  struct evbuffer* rpc_data;
160 };
161 
162 /* the client side of an rpc request */
164  /*
165  * allows association of meta data via hooks - needs to be
166  * synchronized with evrpc_req_generic.
167  */
168  struct evrpc_hook_meta *hook_meta;
169 
170  TAILQ_ENTRY(evrpc_request_wrapper) next;
171 
172  /* pool on which this rpc request is being made */
173  struct evrpc_pool *pool;
174 
175  /* connection on which the request is being sent */
176  struct evhttp_connection *evcon;
177 
178  /* the actual request */
179  struct evhttp_request *req;
180 
181  /* event for implementing request timeouts */
182  struct event ev_timeout;
183 
184  /* the name of the rpc */
185  char *name;
186 
187  /* callback */
188  void (*cb)(struct evrpc_status*, void *request, void *reply, void *arg);
189  void *cb_arg;
190 
191  void *request;
192  void *reply;
193 
194  /* unmarshals the buffer into the proper request structure */
195  void (*request_marshal)(struct evbuffer *, void *);
196 
197  /* removes all stored state in the reply */
198  void (*reply_clear)(void *);
199 
200  /* marshals the reply into a buffer */
201  int (*reply_unmarshal)(void *, struct evbuffer*);
202 };
203 
204 #endif /* _EVRPC_INTERNAL_H_ */
Definition: evrpc-internal.h:59
Structure to represent a single event.
Definition: event_struct.h:87
Definition: evrpc-internal.h:163
Definition: evrpc-internal.h:37
Definition: evrpc-internal.h:71
TAILQ_HEAD(evbuffer_cb_queue, evbuffer_cb_entry) callbacks
A doubly-linked-list of callback functions.
Definition: evbuffer-internal.h:78
Definition: evrpc-internal.h:132
Definition: http-internal.h:62
Definition: evdns.c:185
Definition: evrpc-internal.h:104
provides information about the completed RPC request.
Definition: rpc_struct.h:44
Definition: evrpc-internal.h:114
Definition: evdns.c:158
Definition: http-internal.h:136
Definition: rpc_struct.h:59
Definition: event-internal.h:167
Definition: evrpc-internal.h:97
the request structure that a server receives.
Definition: http_struct.h:57
Definition: evrpc-internal.h:85
EVRPC_HOOK_RESULT
Return value from hook processing functions.
Definition: rpc.h:470