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Diffstat (limited to 'src/notify.c')
| -rw-r--r-- | src/notify.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/src/notify.c b/src/notify.c new file mode 100644 index 0000000..2881a48 --- /dev/null +++ b/src/notify.c @@ -0,0 +1,145 @@ +/* + * Copyright (c) 2013, Salvatore Sanfilippo <antirez at gmail dot com> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * * Neither the name of Redis nor the names of its contributors may be used + * to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include "server.h" + +/* This file implements keyspace events notification via Pub/Sub and + * described at https://redis.io/topics/notifications. */ + +/* Turn a string representing notification classes into an integer + * representing notification classes flags xored. + * + * The function returns -1 if the input contains characters not mapping to + * any class. */ +int keyspaceEventsStringToFlags(char *classes) { + char *p = classes; + int c, flags = 0; + + while((c = *p++) != '\0') { + switch(c) { + case 'A': flags |= NOTIFY_ALL; break; + case 'g': flags |= NOTIFY_GENERIC; break; + case '$': flags |= NOTIFY_STRING; break; + case 'l': flags |= NOTIFY_LIST; break; + case 's': flags |= NOTIFY_SET; break; + case 'h': flags |= NOTIFY_HASH; break; + case 'z': flags |= NOTIFY_ZSET; break; + case 'x': flags |= NOTIFY_EXPIRED; break; + case 'e': flags |= NOTIFY_EVICTED; break; + case 'K': flags |= NOTIFY_KEYSPACE; break; + case 'E': flags |= NOTIFY_KEYEVENT; break; + case 't': flags |= NOTIFY_STREAM; break; + case 'm': flags |= NOTIFY_KEY_MISS; break; + case 'd': flags |= NOTIFY_MODULE; break; + case 'n': flags |= NOTIFY_NEW; break; + default: return -1; + } + } + return flags; +} + +/* This function does exactly the reverse of the function above: it gets + * as input an integer with the xored flags and returns a string representing + * the selected classes. The string returned is an sds string that needs to + * be released with sdsfree(). */ +sds keyspaceEventsFlagsToString(int flags) { + sds res; + + res = sdsempty(); + if ((flags & NOTIFY_ALL) == NOTIFY_ALL) { + res = sdscatlen(res,"A",1); + } else { + if (flags & NOTIFY_GENERIC) res = sdscatlen(res,"g",1); + if (flags & NOTIFY_STRING) res = sdscatlen(res,"$",1); + if (flags & NOTIFY_LIST) res = sdscatlen(res,"l",1); + if (flags & NOTIFY_SET) res = sdscatlen(res,"s",1); + if (flags & NOTIFY_HASH) res = sdscatlen(res,"h",1); + if (flags & NOTIFY_ZSET) res = sdscatlen(res,"z",1); + if (flags & NOTIFY_EXPIRED) res = sdscatlen(res,"x",1); + if (flags & NOTIFY_EVICTED) res = sdscatlen(res,"e",1); + if (flags & NOTIFY_STREAM) res = sdscatlen(res,"t",1); + if (flags & NOTIFY_MODULE) res = sdscatlen(res,"d",1); + if (flags & NOTIFY_NEW) res = sdscatlen(res,"n",1); + } + if (flags & NOTIFY_KEYSPACE) res = sdscatlen(res,"K",1); + if (flags & NOTIFY_KEYEVENT) res = sdscatlen(res,"E",1); + if (flags & NOTIFY_KEY_MISS) res = sdscatlen(res,"m",1); + return res; +} + +/* The API provided to the rest of the Redis core is a simple function: + * + * notifyKeyspaceEvent(int type, char *event, robj *key, int dbid); + * + * 'type' is the notification class we define in `server.h`. + * 'event' is a C string representing the event name. + * 'key' is a Redis object representing the key name. + * 'dbid' is the database ID where the key lives. */ +void notifyKeyspaceEvent(int type, char *event, robj *key, int dbid) { + sds chan; + robj *chanobj, *eventobj; + int len = -1; + char buf[24]; + + /* If any modules are interested in events, notify the module system now. + * This bypasses the notifications configuration, but the module engine + * will only call event subscribers if the event type matches the types + * they are interested in. */ + moduleNotifyKeyspaceEvent(type, event, key, dbid); + + /* If notifications for this class of events are off, return ASAP. */ + if (!(server.notify_keyspace_events & type)) return; + + eventobj = createStringObject(event,strlen(event)); + + /* __keyspace@<db>__:<key> <event> notifications. */ + if (server.notify_keyspace_events & NOTIFY_KEYSPACE) { + chan = sdsnewlen("__keyspace@",11); + len = ll2string(buf,sizeof(buf),dbid); + chan = sdscatlen(chan, buf, len); + chan = sdscatlen(chan, "__:", 3); + chan = sdscatsds(chan, key->ptr); + chanobj = createObject(OBJ_STRING, chan); + pubsubPublishMessage(chanobj, eventobj, 0); + decrRefCount(chanobj); + } + + /* __keyevent@<db>__:<event> <key> notifications. */ + if (server.notify_keyspace_events & NOTIFY_KEYEVENT) { + chan = sdsnewlen("__keyevent@",11); + if (len == -1) len = ll2string(buf,sizeof(buf),dbid); + chan = sdscatlen(chan, buf, len); + chan = sdscatlen(chan, "__:", 3); + chan = sdscatsds(chan, eventobj->ptr); + chanobj = createObject(OBJ_STRING, chan); + pubsubPublishMessage(chanobj, key, 0); + decrRefCount(chanobj); + } + decrRefCount(eventobj); +} |