1/*
2 * Copyright (c) 2013, Salvatore Sanfilippo <antirez at gmail dot com>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * * Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
10 * * 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 * * Neither the name of Redis nor the names of its contributors may be used
14 * to endorse or promote products derived from this software without
15 * specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#include "server.h"
31
32/* This file implements keyspace events notification via Pub/Sub and
33 * described at https://redis.io/topics/notifications. */
34
35/* Turn a string representing notification classes into an integer
36 * representing notification classes flags xored.
37 *
38 * The function returns -1 if the input contains characters not mapping to
39 * any class. */
40int keyspaceEventsStringToFlags(char *classes) {
41 char *p = classes;
42 int c, flags = 0;
43
44 while((c = *p++) != '\0') {
45 switch(c) {
46 case 'A': flags |= NOTIFY_ALL; break;
47 case 'g': flags |= NOTIFY_GENERIC; break;
48 case '$': flags |= NOTIFY_STRING; break;
49 case 'l': flags |= NOTIFY_LIST; break;
50 case 's': flags |= NOTIFY_SET; break;
51 case 'h': flags |= NOTIFY_HASH; break;
52 case 'z': flags |= NOTIFY_ZSET; break;
53 case 'x': flags |= NOTIFY_EXPIRED; break;
54 case 'e': flags |= NOTIFY_EVICTED; break;
55 case 'K': flags |= NOTIFY_KEYSPACE; break;
56 case 'E': flags |= NOTIFY_KEYEVENT; break;
57 case 't': flags |= NOTIFY_STREAM; break;
58 case 'm': flags |= NOTIFY_KEY_MISS; break;
59 case 'd': flags |= NOTIFY_MODULE; break;
60 case 'n': flags |= NOTIFY_NEW; break;
61 default: return -1;
62 }
63 }
64 return flags;
65}
66
67/* This function does exactly the reverse of the function above: it gets
68 * as input an integer with the xored flags and returns a string representing
69 * the selected classes. The string returned is an sds string that needs to
70 * be released with sdsfree(). */
71sds keyspaceEventsFlagsToString(int flags) {
72 sds res;
73
74 res = sdsempty();
75 if ((flags & NOTIFY_ALL) == NOTIFY_ALL) {
76 res = sdscatlen(res,"A",1);
77 } else {
78 if (flags & NOTIFY_GENERIC) res = sdscatlen(res,"g",1);
79 if (flags & NOTIFY_STRING) res = sdscatlen(res,"$",1);
80 if (flags & NOTIFY_LIST) res = sdscatlen(res,"l",1);
81 if (flags & NOTIFY_SET) res = sdscatlen(res,"s",1);
82 if (flags & NOTIFY_HASH) res = sdscatlen(res,"h",1);
83 if (flags & NOTIFY_ZSET) res = sdscatlen(res,"z",1);
84 if (flags & NOTIFY_EXPIRED) res = sdscatlen(res,"x",1);
85 if (flags & NOTIFY_EVICTED) res = sdscatlen(res,"e",1);
86 if (flags & NOTIFY_STREAM) res = sdscatlen(res,"t",1);
87 if (flags & NOTIFY_MODULE) res = sdscatlen(res,"d",1);
88 if (flags & NOTIFY_NEW) res = sdscatlen(res,"n",1);
89 }
90 if (flags & NOTIFY_KEYSPACE) res = sdscatlen(res,"K",1);
91 if (flags & NOTIFY_KEYEVENT) res = sdscatlen(res,"E",1);
92 if (flags & NOTIFY_KEY_MISS) res = sdscatlen(res,"m",1);
93 return res;
94}
95
96/* The API provided to the rest of the Redis core is a simple function:
97 *
98 * notifyKeyspaceEvent(int type, char *event, robj *key, int dbid);
99 *
100 * 'type' is the notification class we define in `server.h`.
101 * 'event' is a C string representing the event name.
102 * 'key' is a Redis object representing the key name.
103 * 'dbid' is the database ID where the key lives. */
104void notifyKeyspaceEvent(int type, char *event, robj *key, int dbid) {
105 sds chan;
106 robj *chanobj, *eventobj;
107 int len = -1;
108 char buf[24];
109
110 /* If any modules are interested in events, notify the module system now.
111 * This bypasses the notifications configuration, but the module engine
112 * will only call event subscribers if the event type matches the types
113 * they are interested in. */
114 moduleNotifyKeyspaceEvent(type, event, key, dbid);
115
116 /* If notifications for this class of events are off, return ASAP. */
117 if (!(server.notify_keyspace_events & type)) return;
118
119 eventobj = createStringObject(event,strlen(event));
120
121 /* __keyspace@<db>__:<key> <event> notifications. */
122 if (server.notify_keyspace_events & NOTIFY_KEYSPACE) {
123 chan = sdsnewlen("__keyspace@",11);
124 len = ll2string(buf,sizeof(buf),dbid);
125 chan = sdscatlen(chan, buf, len);
126 chan = sdscatlen(chan, "__:", 3);
127 chan = sdscatsds(chan, key->ptr);
128 chanobj = createObject(OBJ_STRING, chan);
129 pubsubPublishMessage(chanobj, eventobj, 0);
130 decrRefCount(chanobj);
131 }
132
133 /* __keyevent@<db>__:<event> <key> notifications. */
134 if (server.notify_keyspace_events & NOTIFY_KEYEVENT) {
135 chan = sdsnewlen("__keyevent@",11);
136 if (len == -1) len = ll2string(buf,sizeof(buf),dbid);
137 chan = sdscatlen(chan, buf, len);
138 chan = sdscatlen(chan, "__:", 3);
139 chan = sdscatsds(chan, eventobj->ptr);
140 chanobj = createObject(OBJ_STRING, chan);
141 pubsubPublishMessage(chanobj, key, 0);
142 decrRefCount(chanobj);
143 }
144 decrRefCount(eventobj);
145}
146