From c81813148b71cd4be686402ef69f628f67dbb8c4 Mon Sep 17 00:00:00 2001 From: Huang Zhw Date: Wed, 30 Nov 2022 17:56:36 +0800 Subject: Add a special notification unlink available only for modules (#9406) Add a new module event `RedisModule_Event_Key`, this event is fired when a key is removed from the keyspace. The event includes an open key that can be used for reading the key before it is removed. Modules can also extract the key-name, and use RM_Open or RM_Call to access key from within that event, but shouldn't modify anything from within this event. The following sub events are available: - `REDISMODULE_SUBEVENT_KEY_DELETED` - `REDISMODULE_SUBEVENT_KEY_EXPIRED` - `REDISMODULE_SUBEVENT_KEY_EVICTED` - `REDISMODULE_SUBEVENT_KEY_OVERWRITE` The data pointer can be casted to a RedisModuleKeyInfo structure with the following fields: ``` RedisModuleKey *key; // Opened Key ``` ### internals * We also add two dict functions: `dictTwoPhaseUnlinkFind` finds an element from the table, also get the plink of the entry. The entry is returned if the element is found. The user should later call `dictTwoPhaseUnlinkFree` with it in order to unlink and release it. Otherwise if the key is not found, NULL is returned. These two functions should be used in pair. `dictTwoPhaseUnlinkFind` pauses rehash and `dictTwoPhaseUnlinkFree` resumes rehash. * We change `dbOverwrite` to `dbReplaceValue` which just replaces the value of the key and doesn't fire any events. The "overwrite" part (which emits events) is just when called from `setKey`, the other places that called dbOverwrite were ones that just update the value in-place (INCR*, SPOP, and dbUnshareStringValue). This should not have any real impact since `moduleNotifyKeyUnlink` and `signalDeletedKeyAsReady` wouldn't have mattered in these cases anyway (i.e. module keys and stream keys didn't have direct calls to dbOverwrite) * since we allow doing RM_OpenKey from withing these callbacks, we temporarily disable lazy expiry. * We also temporarily disable lazy expiry when we are in unlink/unlink2 callback and keyspace notification callback. * Move special definitions to the top of redismodule.h This is needed to resolve compilation errors with RedisModuleKeyInfoV1 that carries a RedisModuleKey member. Co-authored-by: Oran Agra --- src/t_set.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/t_set.c') diff --git a/src/t_set.c b/src/t_set.c index b56b38238..197cabcd9 100644 --- a/src/t_set.c +++ b/src/t_set.c @@ -885,7 +885,7 @@ void spopWithCountCommand(client *c) { setTypeReleaseIterator(si); /* Assign the new set as the key value. */ - dbOverwrite(c->db,c->argv[1],newset); + dbReplaceValue(c->db,c->argv[1],newset); } /* Don't propagate the command itself even if we incremented the -- cgit v1.2.1