1 /*
2 * Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
3 *
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * * Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 * * 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 * * Neither the name of Redis nor the names of its contributors may be used
15 * to endorse or promote products derived from this software without
16 * specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #ifndef __HIREDIS_LIBEVENT_H__
32 #define __HIREDIS_LIBEVENT_H__
33 #include <event2/event.h>
34 #include "../hiredis.h"
35 #include "../async.h"
36
37 #define REDIS_LIBEVENT_DELETED 0x01
38 #define REDIS_LIBEVENT_ENTERED 0x02
39
40 typedef struct redisLibeventEvents {
41 redisAsyncContext *context;
42 struct event *ev;
43 struct event_base *base;
44 struct timeval tv;
45 short flags;
46 short state;
47 } redisLibeventEvents;
48
redisLibeventDestroy(redisLibeventEvents * e)49 static void redisLibeventDestroy(redisLibeventEvents *e) {
50 hi_free(e);
51 }
52
redisLibeventHandler(int fd,short event,void * arg)53 static void redisLibeventHandler(int fd, short event, void *arg) {
54 ((void)fd);
55 redisLibeventEvents *e = (redisLibeventEvents*)arg;
56 e->state |= REDIS_LIBEVENT_ENTERED;
57
58 #define CHECK_DELETED() if (e->state & REDIS_LIBEVENT_DELETED) {\
59 redisLibeventDestroy(e);\
60 return; \
61 }
62
63 if ((event & EV_TIMEOUT) && (e->state & REDIS_LIBEVENT_DELETED) == 0) {
64 redisAsyncHandleTimeout(e->context);
65 CHECK_DELETED();
66 }
67
68 if ((event & EV_READ) && e->context && (e->state & REDIS_LIBEVENT_DELETED) == 0) {
69 redisAsyncHandleRead(e->context);
70 CHECK_DELETED();
71 }
72
73 if ((event & EV_WRITE) && e->context && (e->state & REDIS_LIBEVENT_DELETED) == 0) {
74 redisAsyncHandleWrite(e->context);
75 CHECK_DELETED();
76 }
77
78 e->state &= ~REDIS_LIBEVENT_ENTERED;
79 #undef CHECK_DELETED
80 }
81
redisLibeventUpdate(void * privdata,short flag,int isRemove)82 static void redisLibeventUpdate(void *privdata, short flag, int isRemove) {
83 redisLibeventEvents *e = (redisLibeventEvents *)privdata;
84 const struct timeval *tv = e->tv.tv_sec || e->tv.tv_usec ? &e->tv : NULL;
85
86 if (isRemove) {
87 if ((e->flags & flag) == 0) {
88 return;
89 } else {
90 e->flags &= ~flag;
91 }
92 } else {
93 if (e->flags & flag) {
94 return;
95 } else {
96 e->flags |= flag;
97 }
98 }
99
100 event_del(e->ev);
101 event_assign(e->ev, e->base, e->context->c.fd, e->flags | EV_PERSIST,
102 redisLibeventHandler, privdata);
103 event_add(e->ev, tv);
104 }
105
redisLibeventAddRead(void * privdata)106 static void redisLibeventAddRead(void *privdata) {
107 redisLibeventUpdate(privdata, EV_READ, 0);
108 }
109
redisLibeventDelRead(void * privdata)110 static void redisLibeventDelRead(void *privdata) {
111 redisLibeventUpdate(privdata, EV_READ, 1);
112 }
113
redisLibeventAddWrite(void * privdata)114 static void redisLibeventAddWrite(void *privdata) {
115 redisLibeventUpdate(privdata, EV_WRITE, 0);
116 }
117
redisLibeventDelWrite(void * privdata)118 static void redisLibeventDelWrite(void *privdata) {
119 redisLibeventUpdate(privdata, EV_WRITE, 1);
120 }
121
redisLibeventCleanup(void * privdata)122 static void redisLibeventCleanup(void *privdata) {
123 redisLibeventEvents *e = (redisLibeventEvents*)privdata;
124 if (!e) {
125 return;
126 }
127 event_del(e->ev);
128 event_free(e->ev);
129 e->ev = NULL;
130
131 if (e->state & REDIS_LIBEVENT_ENTERED) {
132 e->state |= REDIS_LIBEVENT_DELETED;
133 } else {
134 redisLibeventDestroy(e);
135 }
136 }
137
redisLibeventSetTimeout(void * privdata,struct timeval tv)138 static void redisLibeventSetTimeout(void *privdata, struct timeval tv) {
139 redisLibeventEvents *e = (redisLibeventEvents *)privdata;
140 short flags = e->flags;
141 e->flags = 0;
142 e->tv = tv;
143 redisLibeventUpdate(e, flags, 0);
144 }
145
redisLibeventAttach(redisAsyncContext * ac,struct event_base * base)146 static int redisLibeventAttach(redisAsyncContext *ac, struct event_base *base) {
147 redisContext *c = &(ac->c);
148 redisLibeventEvents *e;
149
150 /* Nothing should be attached when something is already attached */
151 if (ac->ev.data != NULL)
152 return REDIS_ERR;
153
154 /* Create container for context and r/w events */
155 e = (redisLibeventEvents*)hi_calloc(1, sizeof(*e));
156 if (e == NULL)
157 return REDIS_ERR;
158
159 e->context = ac;
160
161 /* Register functions to start/stop listening for events */
162 ac->ev.addRead = redisLibeventAddRead;
163 ac->ev.delRead = redisLibeventDelRead;
164 ac->ev.addWrite = redisLibeventAddWrite;
165 ac->ev.delWrite = redisLibeventDelWrite;
166 ac->ev.cleanup = redisLibeventCleanup;
167 ac->ev.scheduleTimer = redisLibeventSetTimeout;
168 ac->ev.data = e;
169
170 /* Initialize and install read/write events */
171 e->ev = event_new(base, c->fd, EV_READ | EV_WRITE, redisLibeventHandler, e);
172 e->base = base;
173 return REDIS_OK;
174 }
175 #endif
176