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. */ |
40 | int 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 '$': flags |= NOTIFY_STRING; break; |
49 | case 'l': flags |= NOTIFY_LIST; break; |
50 | case 's': flags |= NOTIFY_SET; break; |
51 | case 'h': flags |= NOTIFY_HASH; break; |
52 | case 'z': flags |= NOTIFY_ZSET; break; |
53 | case 'x': flags |= NOTIFY_EXPIRED; break; |
54 | case 'e': flags |= NOTIFY_EVICTED; break; |
55 | case 'K': flags |= NOTIFY_KEYSPACE; break; |
56 | case 'E': flags |= NOTIFY_KEYEVENT; break; |
57 | case 't': flags |= NOTIFY_STREAM; break; |
58 | case 'm': flags |= NOTIFY_KEY_MISS; break; |
59 | case 'd': flags |= NOTIFY_MODULE; break; |
60 | case 'n': flags |= NOTIFY_NEW; break; |
61 | default: return -1; |
62 | } |
63 | } |
64 | return flags; |
65 | } |
66 | |
67 | /* This function does exactly the reverse of the function above: it gets |
68 | * as input an integer with the xored flags and returns a string representing |
69 | * the selected classes. The string returned is an sds string that needs to |
70 | * be released with sdsfree(). */ |
71 | sds keyspaceEventsFlagsToString(int flags) { |
72 | sds res; |
73 | |
74 | res = sdsempty(); |
75 | if ((flags & NOTIFY_ALL) == NOTIFY_ALL) { |
76 | res = sdscatlen(res,"A" ,1); |
77 | } else { |
78 | if (flags & NOTIFY_GENERIC) res = sdscatlen(res,"g" ,1); |
79 | if (flags & NOTIFY_STRING) res = sdscatlen(res,"$" ,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. */ |
104 | void 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 | |